Monday, May 22, 2017

The Science of Consciousness

In 1994 I went to the first of what has become an annual gathering, sponsored by the Center for Consciousness Studies of the University of Arizona, of researchers, mystics, and random wackos, all interested in understanding the scientific basis of consciousness. In attending the first few of these conferences I made connections with others in the field, like Daniel Dennett, that motivated me to develop the course notes from a new offering I put together the University of Wisconsin "The Biology of Mind" into a book with the same title. This year's meeting in La Jolla, CA., has the usual mixture of hard science and far-out speculation. Just looking at the titles of the main talks is an interesting read, and I paste in those here:

Plenary Program 

Can Machines Be Conscious?
Sir Roger Penrose, Oxford, 'How can Consciousness Arise within the Laws of Physics?'
Joscha Bach, Harvard, 'Consciousness as a Memory of Coordinating Attention: The Conductor Model of Consciousness'
Hartmut Neven, Google , Quantum AI, 'Possible Roles of Quantum Effects and Subjective Experience in Artificial Intelligence' 

Language and Consciousness
Noam Chomsky, MIT, 'Language and Unconscious Mental Acts' 
Thomas Bever, U Arizona, 'Three Aspects of (Un)conscious Processing in Language and its Normal Use'
Michael J Spivey, UC Merced, 'Language, Consciousness and Embodied Cognition' 

Biophysics 1 - Memory, Spin and Anesthesia
Matthew Fisher, UC Santa Barbara, 'Are We Quantum Computers, or Merely Clever Robots?' 
Travis Craddock, Nova Southeastern U, 'A Unitary Mechanism of Anesthesia?: Altering Collective Oscillations in Microtubules' 

Non-Invasive Brain Stimulation 
Marom Bikson, CCNY/CUNY, 'Non-Invasive Brain Stimulation Devices to Change Thought and Behavior' 
John Allen, Arizona, 'Transcranial Ultrasound, Mood, and Resting State Network Connectivity' 
Marvin Berman, VieLight, 'Integrating Noninvasive Photobiomodulation and Neuromodulation' 
Michael Rohan, Harvard, 'The Effects of Low Field Magnetic Stimulation on Mood and Brain Function' 

Physics, Cosmology and Consciousness
Ivette Fuentes, U Nottingham, 'Gravity in the Quantum Lab' 
Brian Keating, UCSD, 'Conscious Cosmos' 
​James Tagg, Cengine, Penrose Institute, 'Are Human Beings Computers?' 

Music and the Brain
Elaine Chew, Queen Mary University London, 'Mind over Music Perception'
Scott Makeig, UCSD, 'Mind Over Consciousness?'  

Neuroscience and Consciousness 1
Stephen Grossberg, Boston U, 'The Varieties of Brain Resonances and the Conscious Experiences They Support' 
Georg Northoff, U Ottawa, 'Temporo-Spatial Theory of Consciousness' 
Friday, June 9, 2017

Neuroscience and Consciousness 2 - Anomalies
Daniel P. Sheehan, U San Diego, 'It's About Time: Experiments in Consciousness and Retrocausation' 
Peter Fenwick, UC London, 'A Meditation Teacher Who Can 'Transmit' Subjective Light/Energy'​
Lakhmir S. Chawla, George Washington U, 'End-of-Life Brain Activity' 

Biophysics 2 - Memristors in the Brain?
Leon Chua, UCSF, 'Brains are Made of Memristors' 
Jack A. Tuszynski, U Alberta, 'Microtubules as Subcellular Memristors'   

Neuroscience and Consciousness 3
Gentry Patrick, UCSD, 'Destruction as a Means of Remodeling: The Many Roles of Ubiquitin at the Synapse' 
VS Ramachandran, UCSD, 'Embodied Brains and Disembodied Minds' 
Charles F. Stevens, Salk Institute, UCSD, 'The Evolutionary Brain Mechanisms That Underlie Consciousness' 
Saturday, June 10, 2017

Vibrations, Resonance and Consciousness
Anirban Bandyopadhyay, NIMS, Tsukuba, 'Vibrational Frequencies of Biomaterials are the Key to Integration of Information' 
Jiapei Dai, South Central University, China, 'Biophotonic Activities and Transmission in Relation to Consciousness' 
Erik Viirre, UCSD, 'Auditory Vibrations and Frequencies: Sounds in Your Head'   

Eastern Philosophy
Xu Yingjin, Fudan University, China, 'Contemporary Theories of Consciousness and Nishida's notion of 'Basho'' 
Deepak Chopra, Chopra Foundation, 'Mind, Body, and Universe as Human Constructs'  

Origin and Evolution of Life and Consciousness
Bruce Damer, UC Santa Cruz, 'The Origin of Life and Consciousness' 
Alysson R. Muotri, UCSD, 'Cerebral Organoids for Neurodevelopmental and Evolutionary Studie's 
Stuart Hameroff, U Arizona, 'The 'Quantum Pleasure Principle' - Did Life Evolve to Feel Good?'  



Friday, May 19, 2017

Our brains have an innate knowledge of tools.

From Striem-Amit et al.:

Significance
To what extent is brain organization driven by innate genetic constraints, and how dependent is it on individual experience during early development? We show that an area of the visual system that processes both hands and tools can develop without sensorimotor experience in manipulating tools with one’s hands. People born without hands show typical hand–tool conjoined activity, in a region connected to the action network. Taken with findings from studies with people born blind, who also show intact hand and tool specialization in the visual system, these findings suggest that no specific sensory or motor experience is crucial for domain-specific organization of visual cortex. Instead, the results suggest that functional brain organization is largely innately determined.
Abstract
The visual occipito-temporal cortex is composed of several distinct regions specialized in the identification of different object kinds such as tools and bodies. Its organization appears to reflect not only the visual characteristics of the inputs but also the behavior that can be achieved with them. For example, there are spatially overlapping responses for viewing hands and tools, which is likely due to their common role in object-directed actions. How dependent is occipito-temporal cortex organization on object manipulation and motor experience? To investigate this question, we studied five individuals born without hands (individuals with upper limb dysplasia), who use tools with their feet. Using fMRI, we found the typical selective hand–tool overlap (HTO) not only in typically developed control participants but also in four of the five dysplasics. Functional connectivity of the HTO in the dysplasics also showed a largely similar pattern as in the controls. The preservation of functional organization in the dysplasics suggests that occipito-temporal cortex specialization is driven largely by inherited connectivity constraints that do not require sensorimotor experience. These findings complement discoveries of intact functional organization of the occipito-temporal cortex in people born blind, supporting an organization largely independent of any one specific sensory or motor experience.

Thursday, May 18, 2017

The invisibility cloak illusion - You're too focused on what you're focused on.

Boothy does a summary of her work with Clark and Bargh. Some slightly edited clips:
That coffee stain on your shirt, those mismatched earrings you absent-mindedly selected this morning...people do not notice those things as much as you think...In a classic study from the 1990s, for example, participants put on a shirt emblazoned with the face of the singer Barry Manilow and then walked into a room full of people... It turned out that the number of people who actually noticed noticed was half the number they had thought.
...here’s the bad news. Most of the time, when you’re minding your own business and feeling relatively inconspicuous, you’re being watched much more than you realize...In one experiment, we asked two strangers participating in our study to arrive in our lab at the same time. They were seated in a waiting room and told that the experimenter was running a little behind schedule...Unbeknown to the participants, the study had begun the moment they walked into the waiting room. The real reason they were made to wait was to give them an opportunity to watch — and to feel observed or unobserved by — each other.
Once the participants were in their private rooms, one of them was asked to write down anything he or she noticed or thought about the other person, and then to report on a numerical scale how much he or she had observed the other person. The other participant was asked to write down anything he or she believed the other person had noticed or thought about him or her, and then to estimate how much the other person had observed him or her, using the same scale...Although people surreptitiously noticed all kinds of details about each other — clothing, personality, mood — we found that people were convinced that the other person wasn’t watching them much, if at all.
So other people notice our coffee stains less than we think, but they watch us in general more than we think. The problem, in both cases, is that we project the focus of our attention onto others...In short, we pay too much attention to what we’re paying attention to.

Wednesday, May 17, 2017

Increasing honesty in humans with noninvasive brain stimulation

MarĂ©chal et al. show that a bit of electricity applied to your right prefrontal cortex makes you half as likely to be dishonest.  Hmmm..... I wonder if we could get a battery and a few small wires into the "Make America Great Again" baseball cap that Trump wears?

Significance
Honesty affects almost every aspect of social and economic life. We conducted experiments in which participants could earn considerable amounts of money by cheating on a die-rolling task. Cheating was substantial but decreased by more than one-half during transcranial direct current stimulation over the right dorsolateral prefrontal cortex. This stimulation-induced increase in honesty was functionally specific: It did not affect other types of behavioral control related to self-interest, risk-taking, and impulsivity. Moreover, cheating was only reduced when it benefited the participants themselves rather than another person. Thus, the human brain implements specialized processes that enable us to remain honest when faced with opportunities to cheat for personal material gain. Importantly, these processes can be strengthened by external interventions.
Abstract
Honesty plays a key role in social and economic interactions and is crucial for societal functioning. However, breaches of honesty are pervasive and cause significant societal and economic problems that can affect entire nations. Despite its importance, remarkably little is known about the neurobiological mechanisms supporting honest behavior. We demonstrate that honesty can be increased in humans with transcranial direct current stimulation (tDCS) over the right dorsolateral prefrontal cortex. Participants (n = 145) completed a die-rolling task where they could misreport their outcomes to increase their earnings, thereby pitting honest behavior against personal financial gain. Cheating was substantial in a control condition but decreased dramatically when neural excitability was enhanced with tDCS. This increase in honesty could not be explained by changes in material self-interest or moral beliefs and was dissociated from participants’ impulsivity, willingness to take risks, and mood. A follow-up experiment (n = 156) showed that tDCS only reduced cheating when dishonest behavior benefited the participants themselves rather than another person, suggesting that the stimulated neural process specifically resolves conflicts between honesty and material self-interest. Our results demonstrate that honesty can be strengthened by noninvasive interventions and concur with theories proposing that the human brain has evolved mechanisms dedicated to control complex social behaviors.

Tuesday, May 16, 2017

The fading American dream in a nutshell...

From Chetty et al.:
We estimated rates of “absolute income mobility”—the fraction of children who earn more than their parents—by combining data from U.S. Census and Current Population Survey cross sections with panel data from de-identified tax records. We found that rates of absolute mobility have fallen from approximately 90% for children born in 1940 to 50% for children born in the 1980s. Increasing Gross Domestic Product (GDP) growth rates alone cannot restore absolute mobility to the rates experienced by children born in the 1940s. However, distributing current GDP growth more equally across income groups as in the 1940 birth cohort would reverse more than 70% of the decline in mobility. These results imply that reviving the “American dream” of high rates of absolute mobility would require economic growth that is shared more broadly across the income distribution.

Monday, May 15, 2017

Our spatial memory is driven by perceived animacy of simple shapes.

Chin points to work of van Buren and Scholl who use “wolfpack” animations of dart shapes whose points track the movement of a disc (the prey) to show that these are more readily remembered than identical animations in which the dart points are oriented away from or perpendicular to the prey. Perceiving such moving shapes as animate reinforces visual memory and has possibly been important in human evolution. The abstract of the article:
Even simple geometric shapes are seen as animate and goal-directed when they move in certain ways. Previous research has revealed a great deal about the cues that elicit such percepts, but much less about the consequences for other aspects of perception and cognition. Here we explored whether simple shapes that are perceived as animate and goal-directed are prioritized in memory. We investigated this by asking whether subjects better remember the locations of displays that are seen as animate vs. inanimate, controlling for lower-level factors. We exploited the ‘Wolfpack effect’: moving darts (or discs with ‘eyes’) that stay oriented toward a particular target are seen to be actively pursuing that target, even when they actually move randomly. (In contrast, shapes that stay oriented perpendicular to a target are correctly perceived to be drifting randomly.) Subjects played a ‘matching game’ – clicking on pairs of panels to reveal animations with moving shapes. Across four experiments, the locations of Wolfpack animations (compared to control animations equated on lower-level visual factors) were better remembered, in terms of more efficient matching. Thus perceiving animacy influences subsequent visual memory, perhaps due to the adaptive significance of such stimuli.

Friday, May 12, 2017

Semantics and the science of fear - the amygdala doesn't 'cause' fear.

Here are some core clips from an article in which Joseph Ledoux updates an idea he proposed several decades ago:
…that objectively measurable behavioral and physiological responses elicited by emotional stimuli were controlled nonconsciously by subcortical circuits, such as those involving the amygdala, while the conscious emotional experience was the result of cortical (mostly prefrontal) circuits that contribute to working memory and related higher cognitive functions. Building on a distinction emerging in the study of memory, I referred to these as implicit (nonconscious) and explicit (conscious) fear circuits
He has come to realize:
...that the implicit–explicit distinction had less traction in the case of emotions than in memory. The vernacular meaning of emotion words is simply too strong. When we hear the word ‘fear’, the default interpretation is the conscious experience of being in danger, and this meaning dominates. For example, although I consistently emphasized that the amygdala circuits operate nonconsciously, I was often described in both lay and scientific contexts as having shown how feelings of fear emerge from the amygdala. Even researchers working in the objective tradition sometimes appear confused about what they mean by fear; papers in the field commonly refer to ‘frightened rats’ that ‘freeze in fear’. A naĂ¯ve reader naturally thinks of frightened rats as feeling ‘fear’. As noted above, using mental state terms to describe the function of brain circuits infects the circuit with surplus meaning (psychological properties of the mental state) and confusion invariably results.
Recently, I have … abandoned the implicit–explicit fear approach in favor of a conception that restricts the use of mental state terms to conscious mental states. I now only use ‘fear’ to refer to the experience of fear. It is common these days to argue that folk psychological ideas will be replaced with more accurate scientific constructs as the field matures. Indeed, for nonsubjective brain functions, subjective state labels should be eliminated. This is what I had in mind when I proposed calling the amygdala circuit a defensive survival circuit instead of a fear circuit (see Figure). However, the language of folk psychology describes conscious experiences, such as fear, just fine.



Figure - The Two-Circuit View of Threat Processing and the Experience of Fear. (A) In the two-circuit model, threats are processed in parallel by subcortical and cortical circuits. A subcortical defensive survival circuit centered on the amygdala initiates defensive behaviors in response to threats, while a cortical (mostly prefrontal) cognitive circuit underlying working memory gives rise to the conscious experience of fear. In many situations, survival circuit activity also contributes, albeit indirectly, to fearful feelings. (B) Conscious feelings of fear are proposed to emerge in the cortical circuit as a result of information integration in working memory, including information about sensory and various memory representations, as well as information from survival and arousal circuit activity within the brain, and feedback from body responses.
Psychology is different from other sciences, and has hurdles that they lack. Atoms do not study atoms, but minds study mental states and behaviors. When we engage in psychological research, we must take care to account for the prominent role of subjective experiences in our lives, while also being careful not to attribute subjective causes to behaviors controlled nonconsciously. Conflation of behavioral control circuits with subjective states by indiscriminate use of subjective state terms for both behavioral control circuits and conscious experiences is not a problem restricted to fear. It is present in many areas, including motivation, reward, pain, perception, and memory, to name a few obvious ones. Fear researchers, by addressing this issue, might well set an example that also paves the way for crisper conceptions in other areas of research.




Thursday, May 11, 2017

What we perceive depends on how much it costs us.

Interesting work from Hagura et al. showing that our perceptual decisions are biased by the action costs that are associated with our subsequent decisions is summarized by de Lange and Fritsche:
Perceptual decision-making is not solely determined by the characteristics of the sensory stimulus, but is influenced by several factors such as expectation, reward, and previous history , which may all facilitate perceptual decision-making under uncertainty. A factor that has been mostly neglected in laboratory settings is that, in everyday life, making perceptual decisions between several options entails actions which can differ dramatically in their associated motor cost. For instance, imagine standing in front of an apple tree and searching for the reddest-looking apple to pick. Naturally, picking apples higher up in the tree requires more physical effort than picking low-hanging apples. Therefore, your decision about whether to pick a high- or low-hanging apple has consequences for the subsequently accruing motor costs. Does this difference in expected motor costs influence your perceptual decision about the color of the apples? That is, do you judge the low-hanging fruit as more red? We know that motor costs can bias the choice behavior in perceptual decision-making tasks to maximize the expected utility of the choice, but it is unclear whether motor costs can affect the perceptual decision itself.
Hagura et al. shed light on this question. They asked participants to indicate the direction of motion (leftward or rightward) of a cloud of moving dots, by moving one of two robotic manipulanda with their left or right hand, respectively. Unknown to the participants, the resistance for moving one of the manipulanda was gradually increased, while the other remained unchanged. In line with a previous study, Hagura et al. found that participants subsequently showed a tendency to avoid decisions for the motion direction that was associated with the energetically more-costly motor response. Crucially, after the induction of asymmetric motor response costs for manual responses, participants showed a similar bias when indicating their decisions vocally. This transfer of the bias onto decisions reported with a different effector – for which motor response costs were not manipulated – suggests that the repeated exposure to motor response costs associated with a particular decision can bias future perceptual decisions themselves. Thus, the manual-to-vocal transfer effect provides first evidence that motor costs are not necessarily integrated with perceptual decisions at the motor output stage, but that recent experience of motor costs can change how sensory input is transformed into a perceptual decision.
The current results suggest that motor costs can bias perceptual decisions before they are transformed into an effector-specific response. However, the exact stage along the visual processing stream at which this bias occurs is unclear. Motor costs could target an early stage of visual processing, biasing the sensory representation of visual input, or occur at a later stage, targeting a general, effector-unspecific decision stage. Using a drift-diffusion model approach, the authors found that their data were best explained by a model in which the motor costs change the decision bound that is used to make the decision, rather than the evidence accumulation process itself. This suggests that motor costs target a later decision layer, rather than the sensory representation, and distinguishes it from other processes such as attentional biases which affect the accumulation rate of sensory evidence. An intriguing outstanding question, related to this issue, is whether motor costs can alter the appearance of visual stimuli

Wednesday, May 10, 2017

Has Trump stolen philosophy’s critical tools?

Casey Williams does an intriguing piece in the NYTimes “The Stone” section on topics in philosophy. I’m sure he is not crediting Trump with any awareness of Foucault, Derrida, deconstruction, etc., but here are a few chunks, the whole piece is worth reading:
Trump’s playbook should be familiar to any student of critical theory and philosophy. It often feels like Trump has stolen our ideas and weaponized them.
For decades, critical social scientists and humanists have chipped away at the idea of truth. We’ve deconstructed facts, insisted that knowledge is situated and denied the existence of objectivity. The bedrock claim of critical philosophy, going back to Kant, is simple: We can never have certain knowledge about the world in its entirety. Claiming to know the truth is therefore a kind of assertion of power.
These ideas animate the work of influential thinkers like Nietzsche, Foucault and Derrida, and they’ve become axiomatic for many scholars in literary studies, cultural anthropology and sociology. From these premises, philosophers and theorists have derived a number of related insights. One is that facts are socially constructed. People who produce facts — scientists, reporters, witnesses — do so from a particular social position (maybe they’re white, male and live in America) that influences how they perceive, interpret and judge the world. They rely on non-neutral methods (microscopes, cameras, eyeballs) and use non-neutral symbols (words, numbers, images) to communicate facts to people who receive, interpret and deploy them from their own social positions.
Call it what you want: relativism, constructivism, deconstruction, postmodernism, critique. The idea is the same: Truth is not found, but made, and making truth means exercising power.
The reductive version is simpler and easier to abuse: Fact is fiction, and anything goes. It’s this version of critical social theory that the populist right has seized on and that Trump has made into a powerful weapon.
Some liberals have argued that the best way to combat conservative mendacity is to insist on the existence of truth and the reliability of hard facts. But blind faith in objectivity and factual truth alone has not proven to be a promising way forward...Even if we felt comfortable asserting the existence of something like “truth,” there’s no going back to the days when Americans agreed on matters of fact — when debates about policy were guided by a commitment to truth and reason. Indeed, critique shows us that it’s doubtful that those days, like Trump’s “great” America, ever existed.
For this very reason, these strategies remain useful, however much something like them may be misused, and however carelessly some critical theorists and philosophers have deployed them. Even in a “post-truth era,” a critical attitude allows us to question dominant systems of thought, whether they derive authority from an appearance of neutrality, objectivity or inevitability or from a more Trumpian appeal to alternative facts that dispense with empirical evidence. In a world where lawmakers still appeal to common sense to promote regressive policies, critique remains an important tool for anyone seeking to move past the status quo.
This is because critical ways of thinking demand that we approach knowledge with attention and humility and recognize that, while facts might be created, not all facts are created equal.
While Trump appeals more often to emotions than to facts — or even to common sense — critique can help those who oppose him question the Trumpian version of reality. We can ask not whether a statement is true or false, but how and why it was made and what effects it produces when people feel it to be true. Paying attention to how knowledge is created and used can help us hold leaders like Trump accountable for what they say.
And if we question all ideas — not just the ones we dislike — perhaps our critiques can also reveal new ways of thinking and suggest political possibilities undreamed of by either Trump or his centrist opponents.

Tuesday, May 09, 2017

Details of our brain's upstairs-downstairs emotion regulation.

Morawetz et al. (open source) offer a study probing how our brain's prefrontal upstairs modulates the up-regulation or down-regulation of our emotional reactivity downstairs, in the amygdala:
The ability to voluntarily regulate our emotional response to threatening and highly arousing stimuli by using cognitive reappraisal strategies is essential for our mental and physical well-being. This might be achieved by prefrontal brain regions (e.g. inferior frontal gyrus, IFG) down-regulating activity in the amygdala. It is unknown, to which degree effective connectivity within the emotion-regulation network is linked to individual differences in reappraisal skills. Using psychophysiological interaction analyses of functional magnetic resonance imaging data, we examined changes in inter-regional connectivity between the amygdala and IFG with other brain regions during reappraisal of emotional responses and used emotion regulation success as an explicit regressor. During down-regulation of emotion, reappraisal success correlated with effective connectivity between IFG with dorsolateral, dorsomedial and ventromedial prefrontal cortex (PFC). During up-regulation of emotion, effective coupling between IFG with anterior cingulate cortex, dorsomedial and ventromedial PFC as well as the amygdala correlated with reappraisal success. Activity in the amygdala covaried with activity in lateral and medial prefrontal regions during the up-regulation of emotion and correlated with reappraisal success. These results suggest that successful reappraisal is linked to changes in effective connectivity between two systems, prefrontal cognitive control regions and regions crucially involved in emotional evaluation.

Monday, May 08, 2017

Brain correlates of third person perspective improving interactions with criticism.

Interesting work (open source) from Leitner et al.:
Previous research suggests that people show increased self-referential processing when they provide criticism to others, and that this self-referential processing can have negative effects on interpersonal perceptions and behavior. The current research hypothesized that adopting a self-distanced perspective (i.e. thinking about a situation from a non-first person point of view), as compared with a typical self-immersed perspective (i.e. thinking about a situation from a first-person point of view), would reduce self-referential processing during the provision of criticism, and in turn improve interpersonal perceptions and behavior. We tested this hypothesis in an interracial context since research suggests that self-referential processing plays a role in damaging interracial relations. White participants prepared for mentorship from a self-immersed or self-distanced perspective. They then conveyed negative and positive evaluations to a Black mentee while electroencephalogram (EEG) was recorded. Source analysis revealed that priming a self-distanced (vs self-immersed) perspective predicted decreased activity in regions linked to self-referential processing (medial prefrontal cortex; MPFC) when providing negative evaluations. This decreased MPFC activity during negative evaluations, in turn, predicted verbal feedback that was perceived to be more positive, warm and helpful. Results suggest that self-distancing can improve interpersonal perceptions and behavior by decreasing self-referential processing during the provision of criticism.

Friday, May 05, 2017

Histone variants promote vulnerability to depressive behaviors

Lepack et al. find that a particular histone protein variant in the nucleus accumbens contributes to stress susceptibility in mice (histones are highly alkaline proteins found in eukaryotic cell nuclei that package and order the DNA into structural units called nucleosomes.) The work suggests that compounds that block its action might be sought as potential therapies for human stress and depressive disorders.

Significance
Human major depressive disorder is a chronic remitting syndrome that affects millions of individuals worldwide; however, the molecular mechanisms mediating this syndrome remain elusive. Here, using a unique combination of epigenome-wide and behavioral analyses, we demonstrate a role for histone variant dynamics in the nucleus accumbens (NAc)—a critical brain center of reward and mood—contributing to stress susceptibility in mice. These studies, which also demonstrate that molecular blockade of aberrant dynamics in the NAc promotes resilience to chronic stress, promise to aid in the identification of novel molecular targets (i.e., downstream genes displaying altered expression as the result of stress-induced histone dynamics) that may be exploited in the development of more effective pharmacotherapeutics.
Abstract
Human major depressive disorder (MDD), along with related mood disorders, is among the world’s greatest public health concerns; however, its pathophysiology remains poorly understood. Persistent changes in gene expression are known to promote physiological aberrations implicated in MDD. More recently, histone mechanisms affecting cell type- and regional-specific chromatin structures have also been shown to contribute to transcriptional programs related to depressive behaviors, as well as responses to antidepressants. Although much emphasis has been placed in recent years on roles for histone posttranslational modifications and chromatin-remodeling events in the etiology of MDD, it has become increasingly clear that replication-independent histone variants (e.g., H3.3), which differ in primary amino acid sequence from their canonical counterparts, similarly play critical roles in the regulation of activity-dependent neuronal transcription, synaptic connectivity, and behavioral plasticity. Here, we demonstrate a role for increased H3.3 dynamics in the nucleus accumbens (NAc)—a key limbic brain reward region—in the regulation of aberrant social stress-mediated gene expression and the precipitation of depressive-like behaviors in mice. We find that molecular blockade of these dynamics promotes resilience to chronic social stress and results in a partial renormalization of stress-associated transcriptional patterns in the NAc. In sum, our findings establish H3.3 dynamics as a critical, and previously undocumented, regulator of mood and suggest that future therapies aimed at modulating striatal histone dynamics may potentiate beneficial behavioral adaptations to negative emotional stimuli.

Thursday, May 04, 2017

Watching the brain think about friends.

Work from Wlodarski and Dunbar (open source) produces imaging data suggesting that maintaining friendships may be more cognitively exacting than maintaining kin relationships. The graphics of imaging showing differences in kin versus friend processing are very nice. Their introduction offers background on the cognitive underpinnings for managing different types of relationships having varying degrees of closeness. Their abstract:
The aim of this study was to examine differences in the neural processing of social information about kin and friends at different levels of closeness and social network level. Twenty-five female participants engaged in a cognitive social task involving different individuals in their social network while undergoing functional magnetic resonance imaging scanning to detect BOLD (Blood Oxygen Level Dependent) signals changes. Greater levels of activation occurred in several regions of the brain previously associated with social cognition when thinking about friends than when thinking about kin, including the posterior cingulate cortex (PCC) and the ventral medial prefrontal cortex (vMPFC). Linear parametric analyses across network layers further showed that, when it came to thinking about friends, activation increased in the vMPFC, lingual gyrus, and sensorimotor cortex as individuals thought about friends at closer layers of the network. These findings suggest that maintaining friendships may be more cognitively exacting than maintaining kin relationships.

Wednesday, May 03, 2017

From learning to instinct

I pass on a few chunks from the Science Perspective article by Robinson and Barron:
An animal mind is not born as an empty canvas: Bottlenose dolphins know how to swim and honey bees know how to dance without ever having learned these skills. Little is known about how animals acquire the instincts that enable such innate behavior. Instincts are widely held to be ancestral to learned behavior. Some have been elegantly analyzed at the cellular and molecular levels, but general principles do not exist. Based on recent research, we argue instead that instincts evolve from learning and are therefore served by the same general principles that explain learning.
Tierney first proposed in 1986 that instincts can evolve from behavioral plasticity, but the hypothesis was not widely accepted, perhaps because there was no known mechanism. Now there is a mechanism, namely epigenetics. DNA methylation, histone modifications, and noncoding RNAs all exert profound effects on gene expression without changing DNA sequence. These mechanisms are critical for orchestrating nervous system development and enabling learning-related neural plasticity.
For example, when a mouse has experienced fear of something, changes in DNA methylation and chromatin structure in neurons of the hippocampus help stabilize long-term changes in neural circuits. These changes help the mouse to remember what has been learned and support the establishment of new behavioral responses. Epigenetic mechanisms that support instinct by operating on developmental time scales also support learning by operating on physiological time scales. Evolutionary changes in epigenetic mechanisms may sculpt a learned behavior into an instinct by decreasing its dependence on external stimuli in favor of an internally regulated program of neural development (see the figure).

There is evidence for such epigenetically driven evolutionary changes in behavior. For example, differences in innate aggression levels between races of honey bees can be attributed to evolutionary changes in brain gene expression that also control the onset of aggressive behavior when threatened. These kinds of changes can also explain more contemporary developments, including new innate aspects of mating and foraging behavior in house finches associated with their North American invasion 75 years ago, and new innate changes in the frequency and structure of song communication in populations of several bird species now living in urban environments. We propose that these new instincts have emerged through evolutionary genetic changes that acted on initially plastic behavioral responses.

Tuesday, May 02, 2017

The Nature Fix

Suttie points to a recent book from Florence Williams, also reviewed by Jason Mark, that I would like to be able to slow down enough to actually read, rather than just doing a slightly amplified tweet. 

From Suttie:
...researchers in Finland found that even short walks in an urban park or wild forest were significantly more beneficial to stress relief than walks in an urban setting. And researchers at Stanford found that walks in a natural setting led to better moods, improved performance on memory tasks, and decreased rumination when compared to urban walks.
Similarly, having nature nearby seems to benefit our health. Researchers in England analyzed data from 40 million people and found that residents who lived in a neighborhood with nearby open, undeveloped land tended to develop fewer diseases and were less likely to die before age 65. Most significantly, this finding was not related to income levels, suggesting that green spaces may buffer against poverty-related stress. And nature experiences have been used to treat mental disorders, like PTSD and drug addiction, with some level of success.
From Mark:
Two centuries ago, the Romantics trumpeted the virtues of nature as the antidote to the viciousness of industrialization. In 1984, the biologist Edward O. Wilson put a scientific spin on the idea with his book “Biophilia,” which posited that humans possess an innate love of nature.
Wilson’s argument was persuasive, yet it was mostly an aspiration dressed up as a hypothesis. In the generation since, scientists have sought to confirm the biophilia hypothesis — and they’re starting to get results. As little as 15 minutes in the woods has been shown to reduce test subjects’ levels of cortisol, the stress hormone. Increase nature exposure to 45 minutes, and most individuals experience improvements in cognitive performance. There are society-scale benefits as well. Researchers in England have shown that access to green spaces reduces income-related mental health disparities.
It’s all very encouraging, but how exactly does nature have such an effect on people? To answer that question, Williams shadows researchers on three continents who are working on the frontiers of nature neuroscience.
Maybe it’s the forest smells that turn us on; aerosols present in evergreen forests act as mild sedatives while also stimulating respiration. Perhaps it’s the soundscape, since water and, especially, birdsong have been proven to improve mood and alertness. Nature’s benefits might be due to something as simple as the fact that natural landscapes are, literally, easy on the eyes. Many of nature’s patterns — raindrops hitting a pool of water or the arrangement of leaves — are organized as fractals, and the human retina moves in a fractal pattern while taking in a view. Such congruence creates alpha waves in the brains — the neural resonance of relaxation.
In this context, I want to mention again Wallace Nicholl's book on our connection to water, "Blue Mind." He recently asked me to attend a conference he organized on this subject, and I was sorry that I was not free to do this.

Monday, May 01, 2017

Brain stimulation enhances memory.

Important work from Ezzyat et al., a potential approach to ameliorating memory loss in dementia:

Highlights
•Intracranial brain stimulation has variable effects on episodic memory performance 
•Stimulation increased memory performance when delivered in poor encoding states 
•Recall-related brain activity increased after stimulation of poor encoding states 
•Neural activity linked to contextual memory predicted encoding state modulation
Summary
People often forget information because they fail to effectively encode it. Here, we test the hypothesis that targeted electrical stimulation can modulate neural encoding states and subsequent memory outcomes. Using recordings from neurosurgical epilepsy patients with intracranially implanted electrodes, we trained multivariate classifiers to discriminate spectral activity during learning that predicted remembering from forgetting, then decoded neural activity in later sessions in which we applied stimulation during learning. Stimulation increased encoding-state estimates and recall if delivered when the classifier indicated low encoding efficiency but had the reverse effect if stimulation was delivered when the classifier indicated high encoding efficiency. Higher encoding-state estimates from stimulation were associated with greater evidence of neural activity linked to contextual memory encoding. In identifying the conditions under which stimulation modulates memory, the data suggest strategies for therapeutically treating memory dysfunction.

Friday, April 28, 2017

Brain-heart dialogue shows how racism hijacks perception

Tsakiris does a nice summary of his work that shows a biological basis for why you’re more than twice as likely as a white person to be unarmed if you’re killed in an encounter with the police. Here is the core text:
At my lab at Royal Holloway, University of London, we decided to test whether the cardiac cycle made a difference to the expression of racial prejudice. The heart is constantly informing the brain about the body’s overall level of ‘arousal’, the extent to which it is attuned to what is happening around it. On a heartbeat, sensors known as ‘arterial baroreceptors’ pick up pressure changes in the heart wall, and fire off a message to the brain; between heartbeats, they are quiescent. Such visceral information is initially encoded in the brainstem, before reaching the parts implicated in emotional and motivational behaviour. The brain, in turn, responds by trying to help the organism stabilise itself. If it receives signals of a raised heart-rate, the brain will generate predictions about the potential causes, and consider what the organism should do to bring itself down from this heightened state. This ongoing heart-brain dialogue, then, forms the basis of how the brain represents the body to itself, and creates awareness of the external environment.
In our experiment, we used what’s known as the ‘first-person shooter’s task’, which simulates the snap judgments police officers make. Participants see a white or black man holding a gun or phone, and have to decide whether to shoot depending on the perceived level of threat. In prior studies, participants were significantly more likely to shoot an unarmed black individual than a white one.
But we timed the stimuli to occur either between or on a heartbeat. Remarkably, the majority of misidentifications occurred when black individuals appeared at the same time as a heartbeat. Here, the number of false positives in which phones were perceived as weapons rose by 10 per cent compared with the average. In a different version of the test, we used what’s known as the ‘weapons identification task’, where participants see a white or black face, followed by an image of a gun or tool, and must classify the object as quickly as possible. When the innocuous items were presented following a black face, and on a heartbeat, errors rose by 20 per cent.
Yet in both instances, when the judgment happened between heartbeats, we observed no differences in people’s accuracy, irrespective of whether they were responding to white or black faces. It seems that the combination of the firing of signals from the heart to the brain, along with the presentation of a stereotypical threat, increased the chances that even something benign will be perceived as dangerous.
It’s surprising to think of racial bias as not just a state or habit of mind, nor even a widespread cultural norm, but as a process that’s also part of the ebbs and flows of the body’s physiology. The heart-brain dialogue plays a crucial role in regulating blood pressure and heart rate, as well as motivating and supporting adaptive behaviour in response to external events. So, in fight-or-flight responses, changes in cardiovascular function prepare the organism for subsequent action. But while the brain might be predictive, those predictions can be inaccurate. What our findings illustrate is the extent to which racial and possibly other stereotypes are hijacking bodily mechanisms that have evolved to deal with actual threats.
The psychologist Lisa Barrett Feldman at Northeastern University in Boston coined the term ‘affective realism’ to describe how the brain perceives the world through the body. On the one hand, this is a reason for optimism: if we can better understand the neurological mechanisms behind racial bias, then perhaps we’ll be in a better position to correct it. But there is a grim side to the analysis, too. The structures of oppression that shape who we are also shape our bodies, and perhaps our most fundamental perceptions. Maybe we do not ‘misread’ the phone as a gun; we might we actually see a gun, rather than a phone. Racism might not be something that societies can simply overcome with fresh narratives and progressive political messages. It might require a more radical form of physiological retraining, to bring our embodied realities into line with our stated beliefs.

Thursday, April 27, 2017

Underestimating the value of being in another person's shoes.

I pass on a bit of the introduction from Zhou et al., and then their abstract:
A lot of leaders are coming here, to sit down and visit. I think it’s important for them to look me in the eye. Many of these leaders have the same kind of inherent ability that I’ve got, I think, and that is they can read people. We can read. I can read fear. I can read confidence. I can read resolve. And so can they—and they want to see it. —George W. Bush (quoted in Fineman & Brant, 2001, p. 27)
You never really understand a person until you consider things from his point of view. . . . Until you climb into his skin and walk around in it. —Atticus Finch to his daughter, Scout, in Harper Lee’s To Kill a Mockingbird (Lee, 1960/1988, pp. 85–87)
Bush and Lee offer very different strategies for solving a frequent challenge in social life: accurately understanding the mind of another person. Bush suggested reading another person by watching body language, facial expressions, and other behavioral cues to infer that person’s feelings and mental states. Lee suggested being another person by actually putting oneself in that person’s situation and using one’s own experience to simulate his or her experience. These two strategies also broadly describe the two most intensely studied mechanisms for mental-state inference in the scientific literature, theorization (i.e., theory theory) and simulation (i.e., self-projection or surrogation).
In the experiments reported here, we asked some participants (experiencers) to watch 50 emotionally evocative pictures and to report how they felt about each one. Separate groups of participants (predictors) predicted the experiencers’ feelings. We assessed the presumed versus actual effectiveness of the theorization and simulation strategies by allowing some predictors to see experiencers’ facial expressions (theorization) and allowing other predictors to see the same pictures the experiencers saw (simulation). This paradigm provided a comprehensive test of our hypotheses by allowing us to measure confidence, accuracy, and preferences for the two strategies.
Here is the abstract:
People use at least two strategies to solve the challenge of understanding another person’s mind: inferring that person’s perspective by reading his or her behavior (theorization) and getting that person’s perspective by experiencing his or her situation (simulation). The five experiments reported here demonstrate a strong tendency for people to underestimate the value of simulation. Predictors estimated a stranger’s emotional reactions toward 50 pictures. They could either infer the stranger’s perspective by reading his or her facial expressions or simulate the stranger’s perspective by watching the pictures he or she viewed. Predictors were substantially more accurate when they got perspective through simulation, but overestimated the accuracy they had achieved by inferring perspective. Predictors’ miscalibrated confidence stemmed from overestimating the information revealed through facial expressions and underestimating the similarity in people’s reactions to a given situation. People seem to underappreciate a useful strategy for understanding the minds of others, even after they gain firsthand experience with both strategies.

Wednesday, April 26, 2017

MindBlog is moving to Austin. Texas

A personal note...the picture is of a crane moving my Steinway B out of our second floor condo in Fort Lauderdale. It's been a good run. I started the snowbird gig between Madison,Wisconsin (where I still maintain my university office) and Fort Lauderdale in 2005. MindBlog began in February of 2006. Over the past twelve years I've done ~9 piano concerts, a number of lectures on aging and the brain, and started a contemporary topics and ideas discussion group. The move to Austin Texas is occasioned by my desire to be closer to my son, and my 3 and 5 year old grandsons. Until recently they lived in the modest family house I grew up in. He has been professionally successful (check out praxisis.com), and has now moved into a larger house in an almost magical old downtown Austin neighborhood with 300+ year old live oak trees in the yards. It's front living room is large enough to accommodate the Steinway B, and I will play and practice there, hoping the grandsons might be influenced by what they hear. My husband Len and I will move into the smaller family house. I'm attempting to maintain a steady stream of MindBlog posts during this transition.



Tuesday, April 25, 2017

Reading what the mind thinks from how the eye sees.

Expressive eye widening (as in fear) and eye narrowing (as in disgust) are associated with opposing optical consequences and serve opposing perceptual functions. Lee and Anderson suggest that the opposing effects of eye widening and narrowing on the expresser’s visual perception have been socially co-opted to denote opposing mental states of sensitivity and discrimination, respectively, such that opposing complex mental states may originate from this simple perceptual opposition. Their abstract:
Human eyes convey a remarkable variety of complex social and emotional information. However, it is unknown which physical eye features convey mental states and how that came about. In the current experiments, we tested the hypothesis that the receiver’s perception of mental states is grounded in expressive eye appearance that serves an optical function for the sender. Specifically, opposing features of eye widening versus eye narrowing that regulate sensitivity versus discrimination not only conveyed their associated basic emotions (e.g., fear vs. disgust, respectively) but also conveyed opposing clusters of complex mental states that communicate sensitivity versus discrimination (e.g., awe vs. suspicion). This sensitivity-discrimination dimension accounted for the majority of variance in perceived mental states (61.7%). Further, these eye features remained diagnostic of these complex mental states even in the context of competing information from the lower face. These results demonstrate that how humans read complex mental states may be derived from a basic optical principle of how people see.

Monday, April 24, 2017

Brooks on "The crisis of Western Civilization"

A brief screed by David Brooks, worth a read, notes the decline of a progressive Western civilization narrative that “that people, at least in Europe and North America, used for most of the past few centuries to explain their place in the world and in time” , and he laments that “the basic fabric of civic self-government seems to be eroding following the loss of faith in democratic ideals.”
This Western civ narrative came with certain values — about the importance of reasoned discourse, the importance of property rights, the need for a public square that was religiously informed but not theocratically dominated. It set a standard for what great statesmanship looked like. It gave diverse people a sense of shared mission and a common vocabulary, set a framework within which political argument could happen and most important provided a set of common goals.
Mr. Brooks, card carrying conservative that he is, fails to make the point that these values were exercised mainly by white males and came as a package with sexism and racism. This is why:
Starting decades ago, many people, especially in the universities, lost faith in the Western civilization narrative. They stopped teaching it, and the great cultural transmission belt broke. Now many students, if they encounter it, are taught that Western civilization is a history of oppression.
The rise of illiberalism has unfortunately thrown out the baby with the bathwater, so that
More and more governments, including the Trump administration, begin to look like premodern mafia states, run by family-based commercial clans. Meanwhile, institutionalized, party-based authoritarian regimes, like in China or Russia, are turning into premodern cults of personality/Maximum Leader regimes, which are far more unstable and dangerous.
...there has been the collapse of the center. For decades, center-left and center-right parties clustered around similar versions of democratic capitalism that Western civilization seemed to point to. But many of those centrist parties, like the British and Dutch Labour Parties, are in near collapse. Fringe parties rise...there has been the collapse of liberal values at home. On American campuses, fragile thugs who call themselves students shout down and abuse speakers on a weekly basis...the share of young Americans who say it is absolutely important to live in a democratic country has dropped from 91 percent in the 1930s to 57 percent today.
These days, the whole idea of Western civ is assumed to be reactionary and oppressive. All I can say is, if you think that was reactionary and oppressive, wait until you get a load of the world that comes after it.

Friday, April 21, 2017

A.I. better at predicting heart attacks, learns implicit racial and gender bias.

Lohr notes a study that suggest we need to develop and "A.I. index" analogous to the Consumer Price Index, to track the pace and spread of artificial intelligence technology. Two recent striking finding in this field:

 Weng et al. show that AI is better at predicting heart attacks from routine clinical data on risk factors than human doctors are. Hutson notes that the best The best of the four A.I. algorithms tried — neural networks — correctly predicted 7.6% more events than the American College of Cardiology/American Heart Association (ACC/AHA) method (based on eight risk factors—including age, cholesterol level, and blood pressure, that physicians effectively add up), and it raised 1.6% fewer false alarms.

Caliskan et al. show that machines can learn word associations from written texts and that these associations mirror those learned by humans, as measured by the Implicit Association Test (IAT). In large bodies of English-language text, they decipher content corresponding to human attitudes (likes and dislikes) and stereotypes. In addition to revealing a new comprehension skill for machines, the work raises the specter that this machine ability may become an instrument of unintended discrimination based on gender, race, age, or ethnicity. Their abstract:
Machine learning is a means to derive artificial intelligence by discovering patterns in existing data. Here, we show that applying machine learning to ordinary human language results in human-like semantic biases. We replicated a spectrum of known biases, as measured by the Implicit Association Test, using a widely used, purely statistical machine-learning model trained on a standard corpus of text from the World Wide Web. Our results indicate that text corpora contain recoverable and accurate imprints of our historic biases, whether morally neutral as toward insects or flowers, problematic as toward race or gender, or even simply veridical, reflecting the status quo distribution of gender with respect to careers or first names. Our methods hold promise for identifying and addressing sources of bias in culture, including technology.

Thursday, April 20, 2017

Study suggests social media are not contributing to political polarization.

Bromwich does an interesting piece on increasing political polarization in the US. The number of the 435 house districts in the country competitive for both parties has decreased from 90 to 72 over the past four years. It has been commonly assumed that internet social media are a major culprit driving polarization, because they make it easier for people to remain in their own tribal bubbles. The problem with this model is that the increase in political polarization has been seven times higher among older Americans (who are least likely to use the internet) than among adults under 40 (see Boxell et al.). An explanatory factor has to make sense equally across demographics.

Wednesday, April 19, 2017

How to feel good - and how feeling good can be bad for you.

In case you feel like another click,  I pass on these two self-helpy feel-good or happiness bits, in the common list form ...

First, a bit from Scelfo noting a Martin Seligman recipe for well being:

1. Identifying signature strengths;
2. Finding the good;
3. Practicing gratitude;
4. Responding constructively.

And second, Five way feeling good can be bad for you:

1. When you’re working on critical reasoning tasks.
2. When you want to judge people fairly and accurately.
3. When you might get taken advantage of.
4. When there’s temptation to cheat.
5. When you’re empathizing with suffering.

Tuesday, April 18, 2017

Scratching is contagious.

The precis from Science Magazine, followed by the abstract:
Observing someone else scratching themselves can make you want to do so. This contagious itching has been observed in monkeys and humans, but what about rodents? Yu et al. found that mice do imitate scratching when they observe it in other mice. The authors identified a brain area called the suprachiasmatic nucleus as a key circuit for mediating contagious itch. Gastrin-releasing peptide and its receptor in the suprachiasmatic nucleus were necessary and sufficient to transmit this contagious behavior.
Abstract
Socially contagious itch is ubiquitous in human society, but whether it exists in rodents is unclear. Using a behavioral paradigm that does not entail prior training or reward, we found that mice scratched after observing a conspecific scratching. Molecular mapping showed increased neuronal activity in the suprachiasmatic nucleus (SCN) of the hypothalamus of mice that displayed contagious scratching. Ablation of gastrin-releasing peptide receptor (GRPR) or GRPR neurons in the SCN abolished contagious scratching behavior, which was recapitulated by chemogenetic inhibition of SCN GRP neurons. Activation of SCN GRP/GRPR neurons evoked scratching behavior. These data demonstrate that GRP-GRPR signaling is necessary and sufficient for transmitting contagious itch information in the SCN. The findings may have implications for our understanding of neural circuits that control socially contagious behaviors.

Monday, April 17, 2017

Is "The Stack" the way to understand everything?

When the Apple II computer arrived in 1977, I eagerly took its BASIC language tutorials and began writing simple programs to work with my laboratory’s data. When Apple Pascal, based on the UCSD Pascal system, arrived in 1979 I plunged in and wrote a number of data analysis programs. Pascal is a structured programming language, and I soon found myself structuring my mental life around its metaphors. Thus Herrman’s recent article on “the stack” has a particular resonance with me. Some clips:
…the explanatory metaphors of a given era incorporate the devices and the spectacles of the day…technology that Greeks and Romans developed for pumping water, for instance, underpinned their theories of the four humors and the pneumatic soul. Later, during the Enlightenment, clockwork mechanisms left their imprint on materialist arguments that man was only a sophisticated machine. And as of 1990, it was concepts from computing that explained us to ourselves..
We don’t just talk intuitively about the ways in which people are “programmed” — we talk about our emotional “bandwidth” and look for clever ways to “hack” our daily routines. These metaphors have developed right alongside the technology from which they’re derived…Now we’ve arrived at a tempting concept that promises to contain all of this: the stack. These days, corporate managers talk about their solution stacks and idealize “full stack” companies; athletes share their recovery stacks and muscle-building stacks; devotees of so-called smart drugs obsessively modify their brain-enhancement stacks to address a seemingly infinite range of flaws and desires.
“Stack,” in technological terms, can mean a few different things, but the most relevant usage grew from the start-up world: A stack is a collection of different pieces of software that are being used together to accomplish a task.
An individual application’s stack might include the programming languages used to build it, the services used to connect it to other apps or the service that hosts it online; a “full stack” developer would be someone proficient at working with each layer of that system, from bottom to top. The stack isn’t just a handy concept for visualizing how technology works. For many companies, the organizing logic of the software stack becomes inseparable from the logic of the business itself. The system that powers Snapchat, for instance, sits on top of App Engine, a service owned by Google; to the extent that Snapchat even exists as a service, it is as a stack of different elements. …A healthy stack, or a clever one, is tantamount (the thinking goes) to a well-structured company…On StackShare, Airbnb lists over 50 services in its stack, including items as fundamental as the Ruby programming language and as complex and familiar as Google Docs.
Other attempts to elaborate on the stack have been more rigorous and comprehensive, less personal and more global. In a 2016 book, “The Stack: On Software and Sovereignty,” the professor and design theorist Benjamin Bratton sets out to, in his words, propose a “specific model for the design of political geography tuned to this era of planetary-scale computation,” by drawing on the “multilayered structure of software, hardware and network ‘stacks’ that arrange different technologies vertically within a modular, interdependent order.” In other words, Bratton sees the world around us as one big emerging technological stack. In his telling, the six-layer stack we inhabit is complex, fluid and vertigo-inducing: Earth, Cloud, City, Address, Interface and User. It is also, he suggests, extremely powerful, with the potential to undermine and replace our current conceptions of, among other things, the sovereign state — ushering us into a world blown apart and reassembled by software. This might sound extreme, but such is the intoxicating logic of the stack.
As theory, the stack remains mostly a speculative exercise: What if we imagined the whole world as software? And as a popular term, it risks becoming an empty buzzword, used to refer to any collection, pile or system of different things. (What’s your dental care stack? Your spiritual stack?) But if tech start-ups continue to broaden their ambitions and challenge new industries — if, as the venture-capital firm Andreessen-Horowitz likes to say, “software is eating the world” — then the logic of the stack can’t be trailing far behind, ready to remake more and more of our economy and our culture in its image. It will also, of course, be subject to the warning with which Daugman ended his 1990 essay. “We should remember,” he wrote, “that the enthusiastically embraced metaphors of each ‘new era’ can become, like their predecessors, as much the prison house of thought as they first appeared to represent its liberation.”

Friday, April 14, 2017

Anterior temporal lobe and the representation of knowledge about people

Anzellotti frames work by Wang et al.:
Patients with semantic dementia (SD), a neurodegenerative disease affecting the anterior temporal lobes (ATL), present with striking cognitive deficits: they can have difficulties naming objects and familiar people from both pictures and descriptions. Furthermore, SD patients make semantic errors (e.g., naming “horse” a picture of a zebra), suggesting that their impairment affects object knowledge rather than lexical retrieval. Because SD can affect object categories as disparate as artifacts, animals, and people, as well as multiple input modalities, it has been hypothesized that ATL is a semantic hub that integrates information across multiple modality-specific brain regions into multimodal representations. With a series of converging experiments using multiple analysis techniques, Wang et al. test the proposal that ATL is a semantic hub in the case of person knowledge, investigating whether ATL: (i) encodes multimodal representations of identity, and (ii) mediates the retrieval of knowledge about people from representations of perceptual cues.
The Wang et al. Significance and Abstract statements:

Significance
Knowledge about other people is critical for group survival and may have unique cognitive processing demands. Here, we investigate how person knowledge is represented, organized, and retrieved in the brain. We show that the anterior temporal lobe (ATL) stores abstract person identity representation that is commonly embedded in multiple sources (e.g. face, name, scene, and personal object). We also found the ATL serves as a “neural switchboard,” coordinating with a network of other brain regions in a rapid and need-specific way to retrieve different aspects of biographical information (e.g., occupation and personality traits). Our findings endorse the ATL as a central hub for representing and retrieving person knowledge.
Abstract
Social behavior is often shaped by the rich storehouse of biographical information that we hold for other people. In our daily life, we rapidly and flexibly retrieve a host of biographical details about individuals in our social network, which often guide our decisions as we navigate complex social interactions. Even abstract traits associated with an individual, such as their political affiliation, can cue a rich cascade of person-specific knowledge. Here, we asked whether the anterior temporal lobe (ATL) serves as a hub for a distributed neural circuit that represents person knowledge. Fifty participants across two studies learned biographical information about fictitious people in a 2-d training paradigm. On day 3, they retrieved this biographical information while undergoing an fMRI scan. A series of multivariate and connectivity analyses suggest that the ATL stores abstract person identity representations. Moreover, this region coordinates interactions with a distributed network to support the flexible retrieval of person attributes. Together, our results suggest that the ATL is a central hub for representing and retrieving person knowledge.

Thursday, April 13, 2017

Lying is a feature, not a bug, of Trump’s presidency.

PolitiFact rates half of Trump’s disputed public statements to be completely false. Adam Smith points out that Trump is telling…
“blue” lies—a psychologist’s term for falsehoods, told on behalf of a group, that can actually strengthen the bonds among the members of that group…blue lies fall in between generous “white” lies and selfish “black” ones.
…lying is a feature, not a bug, of Trump’s campaign and presidency. It serves to bind his supporters together and strengthen his political base—even as it infuriates and confuses most everyone else. In the process, he is revealing some complicated truths about the psychology of our very social species.
…while black lies drive people apart and white lies draw them together, blue lies do both: They help bring some people together by deceiving those in another group. For instance, if a student lies to a teacher so her entire class can avoid punishment, her standing with classmates might actually increase.
A variety of research highlights...
...a difficult truth about our species: We are intensely social creatures, but we’re prone to divide ourselves into competitive groups, largely for the purpose of allocating resources. People can be “prosocial”—compassionate, empathic, generous, honest—in their groups, and aggressively antisocial toward outside groups. When we divide people into groups, we open the door to competition, dehumanization, violence—and socially sanctioned deceit.
If we see Trump’s lies not as failures of character but rather as weapons of war, then we can come to understand why his supporters might see him as an effective leader. To them, Trump isn’t Hitler (or Darth Vader, or Voldemort), as some liberals claim—he’s President Roosevelt, who repeatedly lied to the public and the world on the path to victory in World War II.
...partisanship for many Americans today takes the form of a visceral, even subconscious, attachment to a party group...Democrats and Republicans have become not merely political parties but tribes, whose affiliations shape the language, dress, hairstyles, purchasing decisions, friendships, and even love lives of their members.
...when the truth threatens our identity, that truth gets dismissed. For millions and millions of Americans, climate change is a hoax, Hillary Clinton ran a sex ring out of a pizza parlor, and immigrants cause crime. Whether they truly believe those falsehoods or not is debatable—and possibly irrelevant. The research to date suggests that they see those lies as useful weapons in a tribal us-against-them competition that pits the “real America” against those who would destroy it.
Perhaps the above clips will motivate you read Smith's entire article, which goes on to discuss how anger fuels lying, and suggests some approaches to defying blue lies.

Wednesday, April 12, 2017

How exercise calms anxiety.

Another mouse story, as in the previous post, hopefully applicable to us humans. Gretchen Reynolds points to work of Gould and colleagues at Princeton showing that in the hippocampus of mice that have been in a running regime not only are new excitatory neurons and synapses generated, but also inhibitory neurons are more likely to become activated to dampen the excitatory neurons, in response to stress. This was a long term running response, because running mice were blocked from exercise for a day before stress testing in a cold bath that showed them to be less reactive to the cold than sedentary mice.
Physical exercise is known to reduce anxiety. The ventral hippocampus has been linked to anxiety regulation but the effects of running on this subregion of the hippocampus have been incompletely explored. Here, we investigated the effects of cold water stress on the hippocampus of sedentary and runner mice and found that while stress increases expression of the protein products of the immediate early genes c-fos and arc in new and mature granule neurons in sedentary mice, it has no such effect in runners. We further showed that running enhances local inhibitory mechanisms in the hippocampus, including increases in stress-induced activation of hippocampal interneurons, expression of vesicular GABA transporter (vGAT), and extracellular GABA release during cold water swim stress. Finally, blocking GABAA receptors in the ventral hippocampus, but not the dorsal hippocampus, with the antagonist bicuculline, reverses the anxiolytic effect of running. Together, these results suggest that running improves anxiety regulation by engaging local inhibitory mechanisms in the ventral hippocampus.

Tuesday, April 11, 2017

The calming effect of breathing.

Sheikhbahaei1 and Smith do a Perspective article in Science on the work of Yackle et al. in the same issue. The first bit of their perspective, followed by the Yackle et al. abstract:
Breathing is one of the perpetual rhythms of life that is often taken for granted, its apparent simplicity belying the complex neural machinery involved. This behavior is more complicated than just producing inspiration, as breathing is integrated with many other motor functions such as vocalization, orofacial motor behaviors, emotional expression (laughing and crying), and locomotion. In addition, cognition can strongly influence breathing. Conscious breathing during yoga, meditation, or psychotherapy can modulate emotion, arousal state, or stress. Therefore, understanding the links between breathing behavior, brain arousal state, and higher-order brain activity is of great interest...Yackle et al. identify an apparently specialized, molecularly identifiable, small subset of ∼350 neurons in the mouse brain that forms a circuit for transmitting information about respiratory activity to other central nervous system neurons, specifically with a group of noradrenergic neurons in the locus coeruleus (LC) in the brainstem, that influences arousal state. This finding provides new insight into how the motor act of breathing can influence higher-order brain functions.
The Yackle et al. abstract:
Slow, controlled breathing has been used for centuries to promote mental calming, and it is used clinically to suppress excessive arousal such as panic attacks. However, the physiological and neural basis of the relationship between breathing and higher-order brain activity is unknown. We found a neuronal subpopulation in the mouse preBötzinger complex (preBötC), the primary breathing rhythm generator, which regulates the balance between calm and arousal behaviors. Conditional, bilateral genetic ablation of the ~175 Cdh9/Dbx1 double-positive preBötC neurons in adult mice left breathing intact but increased calm behaviors and decreased time in aroused states. These neurons project to, synapse on, and positively regulate noradrenergic neurons in the locus coeruleus, a brain center implicated in attention, arousal, and panic that projects throughout the brain.

Monday, April 10, 2017

Brain correlates of information virality

Scholz et al. show that activity in brain areas associated with value, self and social cognition correlates with internet sharing of articles, reflecting how people express themselves in positive ways to strengthen their social bonds.

Significance
Why do humans share information with others? Large-scale sharing is one of the most prominent social phenomena of the 21st century, with roots in the oldest forms of communication. We argue that expectations of self-related and social consequences of sharing are integrated into a domain-general value signal, representing the value of information sharing, which translates into population-level virality. We analyzed brain responses to New York Times articles in two separate groups of people to predict objectively logged sharing of those same articles around the world (virality). Converging evidence from the two studies supports a unifying, parsimonious neurocognitive framework of mechanisms underlying health news virality; these results may help advance theory, improve predictive models, and inform new approaches to effective intervention.
Abstract
Information sharing is an integral part of human interaction that serves to build social relationships and affects attitudes and behaviors in individuals and large groups. We present a unifying neurocognitive framework of mechanisms underlying information sharing at scale (virality). We argue that expectations regarding self-related and social consequences of sharing (e.g., in the form of potential for self-enhancement or social approval) are integrated into a domain-general value signal that encodes the value of sharing a piece of information. This value signal translates into population-level virality. In two studies (n = 41 and 39 participants), we tested these hypotheses using functional neuroimaging. Neural activity in response to 80 New York Times articles was observed in theory-driven regions of interest associated with value, self, and social cognitions. This activity then was linked to objectively logged population-level data encompassing n = 117,611 internet shares of the articles. In both studies, activity in neural regions associated with self-related and social cognition was indirectly related to population-level sharing through increased neural activation in the brain's value system. Neural activity further predicted population-level outcomes over and above the variance explained by article characteristics and commonly used self-report measures of sharing intentions. This parsimonious framework may help advance theory, improve predictive models, and inform new approaches to effective intervention. More broadly, these data shed light on the core functions of sharing—to express ourselves in positive ways and to strengthen our social bonds.

Friday, April 07, 2017

Three sources of cancer - the importance of “bad luck”

Tomasetti and Vogelstein raised a storm by claiming several years ago that 65% of the risk of certain cancers is not due to inheritance or environmental factors, but rather to mutations linked to stem cell division in the cancerous tissues examined. Now they have provided further evidence that this is not specific to the United States. Here is a summary of, and the abstract from, their more recent paper:

Cancer and the unavoidable R factor
Most textbooks attribute cancer-causing mutations to two major sources: inherited and environmental factors. A recent study highlighted the prominent role in cancer of replicative (R) mutations that arise from a third source: unavoidable errors associated with DNA replication. Tomasetti et al. developed a method for determining the proportions of cancer-causing mutations that result from inherited, environmental, and replicative factors. They found that a substantial fraction of cancer driver gene mutations are indeed due to replicative factors. The results are consistent with epidemiological estimates of the fraction of preventable cancers.
Abstract
Cancers are caused by mutations that may be inherited, induced by environmental factors, or result from DNA replication errors (R). We studied the relationship between the number of normal stem cell divisions and the risk of 17 cancer types in 69 countries throughout the world. The data revealed a strong correlation (median = 0.80) between cancer incidence and normal stem cell divisions in all countries, regardless of their environment. The major role of R mutations in cancer etiology was supported by an independent approach, based solely on cancer genome sequencing and epidemiological data, which suggested that R mutations are responsible for two-thirds of the mutations in human cancers. All of these results are consistent with epidemiological estimates of the fraction of cancers that can be prevented by changes in the environment. Moreover, they accentuate the importance of early detection and intervention to reduce deaths from the many cancers arising from unavoidable R mutations.

Thursday, April 06, 2017

How "you" makes meaning.

Orvell et al. do some experiments on our use of the generic “you” rather than the first-person pronoun “I.”
“You” is one of the most common words in the English language. Although it typically refers to the person addressed (“How are you?”), “you” is also used to make timeless statements about people in general (“You win some, you lose some.”). Here, we demonstrate that this ubiquitous but understudied linguistic device, known as “generic-you,” has important implications for how people derive meaning from experience. Across six experiments, we found that generic-you is used to express norms in both ordinary and emotional contexts and that producing generic-you when reflecting on negative experiences allows people to “normalize” their experience by extending it beyond the self. In this way, a simple linguistic device serves a powerful meaning-making function.

Wednesday, April 05, 2017

Religiosity and social support

I found this article by Eleanor Power to be an interesting read. Here is her abstract:.
In recent years, scientists based in a variety of disciplines have attempted to explain the evolutionary origins of religious belief and practice1. Although they have focused on different aspects of the religious system, they consistently highlight the strong association between religiosity and prosocial behaviour (acts that benefit others). This association has been central to the argument that religious prosociality played an important role in the sociocultural florescence of our species. But empirical work evaluating the link between religion and prosociality has been somewhat mixed. Here, I use detailed, ethnographically informed data chronicling the religious practice and social support networks of the residents of two villages in South India to evaluate whether those who evince greater religiosity are more likely to undertake acts that benefit others. Exponential random graph models reveal that individuals who worship regularly and carry out greater and costlier public religious acts are more likely to provide others with support of all types. Those individuals are themselves better able to call on support, having a greater likelihood of reciprocal relationships. These results suggest that religious practice is taken as a signal of trustworthiness, generosity and prosociality, leading village residents to establish supportive, often reciprocal relationships with such individuals.

Tuesday, April 04, 2017

Wiser than than the crowd.

In a summary in Nature Human Behavior, Kousta points to work by Prelec et al. The summary:
The notion that the average judgment of a large group is more accurate than that of any individual, including experts, is widely accepted and influential. This ‘wisdom of the crowd’ principle, however, has serious limitations, as it is biased against the latest knowledge that is not widely shared.
Dražen Prelec and colleagues propose an alternative principle — the ‘surprisingly popular’ principle — that requires people to answer a question and also predict how others will answer it. By selecting the answer that is more popular than people predict, the surprisingly popular algorithm outperforms the wisdom of crowds. To understand why it works, think of a scenario where the correct answer is mostly known by experts. While those who do not know the correct answer will incorrectly predict that their answer will be the most popular, those who know the correct answer — the experts — also know it is not widely known and hence will predict that the incorrect answer will prevail. The authors formalize and test the surprisingly popular principle in a series of studies that demonstrate that it yields more accurate answers than an algorithm relying on the ‘democratic vote’.
Polling people for their views as well as their predictions of the views of others offers a powerful tool for allowing expert knowledge to win out when popular views are incorrect.

Monday, April 03, 2017

Several takes on extending our lives.

In spite of the fact that I am unsympathetic to efforts to extend our lifespan, I want to pass on several recent articles on the effort. Tad Friend does an excellent article on Silicon Valley money supporting a variety of different efforts to let us attain eternal life,  Baar et al. find that an anti-aging protein that causes the apoptosis (death) of senescent cells reverses symptoms of aging,  Li et al. show that NAD+ directly regulates protein-protein interactions which may protect against cancer, radiation, and aging; and Rich Handy points to several pieces of research, one by Baar et al. on a peptide that restores fitness, hair density, and renal function in fast and naturally aged mice.

Friday, March 31, 2017

Preverbal foundations of human fairness

I want to point to two articles in the second issue of Nature Human Behavior. One is a review by McAuliffe et al.:
New behavioural and neuroscientific evidence on the development of fairness behaviours demonstrates that the signatures of human fairness can be traced into childhood. Children make sacrifices for fairness (1) when they have less than others, (2) when others have been unfair and (3) when they have more than others. The latter two responses mark a critical departure from what is observed in other species because they enable fairness to be upheld even when doing so goes against self-interest. This new work can be fruitfully combined with insights from cognitive neuroscience to understand the mechanisms of developmental change.
And the second is interesting work on preverbal infants from Kanakogi et al.:
Protective interventions by a third party on the behalf of others are generally admired, and as such are associated with our notions of morality, justice and heroism. Indeed, stories involving such third-party interventions have pervaded popular culture throughout recorded human history, in myths, books and movies. The current developmental picture is that we begin to engage in this type of intervention by preschool age. For instance, 3-year-old children intervene in harmful interactions to protect victims from bullies, and furthermore, not only punish wrongdoers but also give priority to helping the victim. It remains unknown, however, when we begin to affirm such interventions performed by others. Here we reveal these developmental origins in 6- and 10-month old infants (N = 132). After watching aggressive interactions involving a third-party agent who either interfered or did not, 6-month-old infants preferred the former. Subsequent experiments confirmed the psychological processes underlying such choices: 6-month-olds regarded the interfering agent to be protecting the victim from the aggressor, but only older infants affirmed such an intervention after considering the intentions of the interfering agent. These findings shed light upon the developmental trajectory of perceiving, understanding and performing protective third-party interventions, suggesting that our admiration for and emphasis upon such acts — so prevalent in thousands of stories across human cultures — is rooted within the preverbal infant’s mind.