Grieg Lyric Pieces Op 38 No 6 - Elegy
Monday, July 13, 2009
Caloric restriction enhances longevity in monkeys
It all over the newspapers, but I thought I would pass on the link to work just published by my colleagues at the University of Wisconsin:
Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species.
Figure - Animal appearance in old age. (A and B) Photographs of a typical control animal at 27.6 years of age (about the average life span). (C and D) Photographs of an age-matched animal on caloric restriction.
Face perception - the "Thacher Effect" in monkeys
Our talent for recognizing differences in faces relies on how facial features are configured. But, if the image of a face is flipped, alterations as drastic as inverted mouths and eyes aren't as noticeable — a phenomenon known as the Thatcher effect. Adachi et al. have monitored the length of time rhesus monkeys (Macaca mulatta) look at pictures of monkey faces. Over time, the animals become less interested in all images, but they spend significantly more time looking at the strange, upright altered (Thatcherized) photos than they do looking at the same images upside down. This suggests that perceptual mechanisms for individual recognition have been conserved through primate cognitive evolution.
Friday, July 10, 2009
Doing exactly what you don't want to do.
Dan Wegner has generated an interesting review of a phenomenon that we all know too well. (Wegner is another one of my heroes. He wrote "The Illusion of Conscious Will" - a book that I reference extensively in my "I-Illusion" web lecture and podcast). The subject of the review is the "Imp in your mind" that makes you sometimes blurt out exactly what you are trying to suppress. The theory is that to suppress an insult, for example, the brain must first imagine just that; the very presence of that catastrophic insult, which in turn increases the odds that the brain will spit it out.
In slapstick comedy, the worst thing that could happen usually does: The person with a sore toe manages to stub it, sometimes twice. Such errors also arise in daily life, and research traces the tendency to do precisely the worst thing to ironic processes of mental control. These monitoring processes keep us watchful for errors of thought, speech, and action and enable us to avoid the worst thing in most situations, but they also increase the likelihood of such errors when we attempt to exert control under mental load (stress, time pressure, or distraction). Ironic errors in attention and memory occur with identifiable brain activity and prompt recurrent unwanted thoughts; attraction to forbidden desires; expression of objectionable social prejudices; production of movement errors; and rebounds of negative experiences such as anxiety, pain, and depression. Such ironies can be overcome when effective control strategies are deployed and mental load is minimized.
Mate selection: women not more picky than men?
Sarah Arnquist points to some experiments that question the conventional evolutionary psychology picture that women are pickier than men when choosing a mate. They suggest social conditioning is more important than the usual evolutionary argument that because women have a bigger investment in reproduction — they are the ones who have to endure pregnancy, childbirth and breast-feeding — they need to hedge their bets against selecting a dud to be the father.
Thursday, July 09, 2009
Feeling the beat....
An open access article from Grahn and Rowe, on premotor and striatal interactions in musicians and nonmusicians during beat perception:
Little is known about the underlying neurobiology of rhythm and beat perception, despite its universal cultural importance. Here we used functional magnetic resonance imaging to study rhythm perception in musicians and nonmusicians. Three conditions varied in the degree to which external reinforcement versus internal generation of the beat was required. The "volume" condition strongly externally marked the beat with volume changes, the "duration" condition marked the beat with weaker accents arising from duration changes, and the "unaccented" condition required the beat to be entirely internally generated. In all conditions, beat rhythms compared with nonbeat control rhythms revealed putamen activity. The presence of a beat was also associated with greater connectivity between the putamen and the supplementary motor area (SMA), the premotor cortex (PMC), and auditory cortex. In contrast, the type of accent within the beat conditions modulated the coupling between premotor and auditory cortex, with greater modulation for musicians than nonmusicians. Importantly, the response of the putamen to beat conditions was not attributable to differences in temporal complexity between the three rhythm conditions. We propose that a cortico-subcortical network including the putamen, SMA, and PMC is engaged for the analysis of temporal sequences and prediction or generation of putative beats, especially under conditions that may require internal generation of the beat. The importance of this system for auditory–motor interaction and development of precisely timed movement is suggested here by its facilitation in musicians.
Neural correlates of our depth of strategic reasoning.
Here is a clip from the introduction to an interesting open access study by Coricellia and Nagel that shows that high-level reasoning and strategic IQ realted to game winning correlates with the neural activity in the medial prefrontal cortex, demonstrating its crucial role in successful mentalizing. The authors use an experimental competitive game, analogous to Keynes's Beauty Contest described below, to characterize the neural systems that mediate different levels of strategic reasoning and mentalizing.
“Professional investment may be likened to those newspaper competitions [Beauty Contest] in which the competitors have to pick out the 6 prettiest faces from a hundred photographs, the prize being awarded to the competitor whose choice most nearly corresponds to the average preferences of the competitors as a whole. It is not a case of choosing those which are really the prettiest, nor even those which average opinion genuinely thinks the prettiest. We have reached the third degree—to anticipating what average opinion expects the average opinion to be. And there are some, I believe, who practise the fourth, fifth, and higher degrees.”
John Maynard Keynes, one of the most influential economists of the 20th century, describes in the above quote different ways of thinking about others in a competitive environment. This can range from low-level reasoning, characterized by self-referential thinking (choosing what you like without considering others' behavior), to higher levels of reasoning, taking into account the thinking of others about others (“third degree”), and so on.
Many features of social and competitive interaction require this kind of reasoning, for example, deciding when to queue for precious theater tickets or when to sell or buy in the stock market before too many others do it. Psychologists and philosophers define this as theory of mind or mentalizing, the ability to think about others' thoughts and mental states to predict their intentions and actions (2–9). Neuroimaging studies have found brain activity related to mentalizing in the medial prefrontal cortex, temporo-parietal junction, superior temporal sulcus, and posterior cingulate cortex. However, little is known about the neural mechanisms underlying the iterated steps of thinking, “what you think the others think about what you think,” and so on. That is, the mechanisms underlying how deeply people think about others, and, particularly, whether deeper mentalizing leads to more successful social outcomes.
Wednesday, July 08, 2009
Intellectual performance and the efficiency of functional brain networks.
From van den Heuvel et al., an analysis that strongly suggests that our intellectual performance is likely to be related to how efficiently our brain integrates information between multiple brain regions:
Our brain is a complex network in which information is continuously processed and transported between spatially distributed but functionally linked regions. Recent studies have shown that the functional connections of the brain network are organized in a highly efficient small-world manner, indicating a high level of local neighborhood clustering, together with the existence of more long-distance connections that ensure a high level of global communication efficiency within the overall network. Such an efficient network architecture of our functional brain raises the question of a possible association between how efficiently the regions of our brain are functionally connected and our level of intelligence. Examining the overall organization of the brain network using graph analysis, we show a strong negative association between the normalized characteristic path lengthof the resting-state brain network and intelligence quotient (IQ). This suggests that human intellectual performance is likely to be related to how efficiently our brain integrates information between multiple brain regions. Most pronounced effects between normalized path length and IQ were found in frontal and parietal regions. Our findings indicate a strong positive association between the global efficiency of functional brain networks and intellectual performance.
Most prominent effects between IQ and the level of global connectivity efficiency (as expressed by a shorter node specific normalized path length) were found in the medial prefrontal cortex (yellow box), bilateral inferior parietal cortex (red box depicts effect in right hemisphere), and precuneus/posterior cingulate regions (orange box) of the functional brain network. Shown are correlation coefficient values of those voxels that had a significant negative association between IQ and normalized path length for T = 0.45 (linear regression, p less than 0.05 uncorrected for multiple comparisons, df = 18, corrected for age).
The synchronization of brains
A relevant follow up to the recent posts on Metzinger's book, which discussed the synchronization of our 'ego tunnels': Bharucha suggests that understanding of how brains synchronize — or fail to do so — will be a game-changing scientific development.
Tuesday, July 07, 2009
Calming aperitif for a Tuesday morning - a Grieg Arietta
This is the first item in Grieg's Lyrical Pieces series, the Arietta Op. 12 No. 1. I'm thinking I might record a series of these short pieces, each of which has a distinctive emotional tone, to punctuate the regular blog posts....
The computation of social behavior
I point out this article by Behrens et al. on the quest to compute social behavior, mainly to pass on their nice summary graphic, preceded by their abstract. They review the recent application of formal behavioral models in the area of social cognitive neuroscience, and the challenge of identifying which behaviors are causes, which are effects, and which are epiphenomena.
Neuroscientists are beginning to advance explanations of social behavior in terms of underlying brain mechanisms. Two distinct networks of brain regions have come to the fore. The first involves brain regions that are concerned with learning about reward and reinforcement. These same reward-related brain areas also mediate preferences that are social in nature even when no direct reward is expected. The second network focuses on regions active when a person must make estimates of another person’s intentions. However, it has been difficult to determine the precise roles of individual brain regions within these networks or how activities in the two networks relate to one another. Some recent studies of reward-guided behavior have described brain activity in terms of formal mathematical models; these models can be extended to describe mechanisms that underlie complex social exchange. Such a mathematical formalism defines explicit mechanistic hypotheses about internal computations underlying regional brain activity, provides a framework in which to relate different types of activity and understand their contributions to behavior, and prescribes strategies for performing experiments under strong control.
Fig. 1 (A) The functional neuroanatomy of social behavior. Primary colors denote brain regions activated by reward and valuation, frequently identified in studies of social interaction within the frame of reference of the subject’s own actions: anterior cingulate cortex sulcus (ACCs), ventromedial prefrontal cortex (VMPFC), amygdala, and ventral striatum (VStr). Pastels denote brain regions activated by considering the intentions of another individual: anterior cingulate cortex gyrus (ACCg), dorsomedial prefrontal cortex (DMPFC), temporoparietal junction (TPJ), and superior temporal sulcus (STS). (B) Schematic of an approach that combines mathematical models of behavior with neural recordings. The model contains parameters that represent specific computations underlying behavior. As the subject/model undergoes different experiences, these parameters will fluctuate. The fluctuation in these parameters is used to find neural correlates of the specific underlying computations. Separately, the same parameter fluctuations come together to predict changes in behavior.
Stumbling blocks on the path of righteousness
I've been meaning to pass on this brief piece by Benedict Carey on studies of the "holier-than-thou effect."
The age of reputation
Gloria Origgi suggests that the internet is ushering in a new 'reputation age', in which the reputation of an item — that is how others value and rate the item — will be the only way we have to extract information about it.
"Internet addiction disorder" in China
An American Psychiatric Association panel is now weighing whether to include Internet addiction in the fifth edition of the field's practices bible, the Diagnostic and Statistical Manual of Mental Disorders, planned for release in 2012. In China, the official view appears to be that Internet addiction is a genuine disorder, but attitudes are shifting about how aggressively it should be treated. Stone describes mild to extreme (military camp) remedies.
Monday, July 06, 2009
Metzinger: A new kind of ethics.
Metzinger's "The Ego Tunnel" - Chapter 9 - A new kind of ethics
In principle, we can design our own Ego Tunnels by tinkering with the hardware responsible for the relevant information-processing: Phenotechnology. (I do not extract at this point a fairly extended section on drugs and altered states of consciousness), which ends with: we must decide which of these altered states can be integrated into our culture and which are to be avoided at all cost.
What is a good state of consciousness?
Metzinger’s intuition is that it should satisfy at least three conditions. It should minimize suffering, in humans and other beings capable of suffering; it should possess an epistemic potential (have component of insight and expanding knowledge; and, should have consequences that increase the probability of future valuable types of experience.
The ego tunnel evolved as a biological system of representation and information processing that is part of a social network of communicating ego tunnels...now embedded in a global data cloud characterized by rapid growth, increasing speed, and an autonomous dynamic of its own....it has begun to reconfigure our brains..perhaps body perception will change as we learn to control multiple avatars in multiple virtual realities, embedding our conscious self into entirely new kinds of sensorimotor loops... we will understand what our social life has been all along - an interaction between images, a highly mediated process in which mental model of persons begin to causally influence one another... communication viewed as estimating and controlling dynamical internal models in other people’s brains.
For those of us intensively working with it, the Internet has already become a part of our self-model. We use it for external memory storage, as a cognitive prosthesis, and for emotional autoregulation...We are learning to multitask, our attention span is becoming shorter, and many of our social relationships are taking on a strangely disembodied character... The integration of hundreds of millions of human brains (and the Ego Tunnels those brains create) into ever new medial environments has already begun to change the structure of conscious experience itself. Where this will lead is unforeseeable.
The new media are also consciousness technologies, and we should ask ourselves again what a good state of consciousness would be.
The ability to attend to our environment, to our own feelings, and to those of others is a naturally evolved feature of the human brain. Attention is a finite commodity, and it is absolutely essential to living a good life. We need attention in order to truly listen to others - and even to ourselves. We need attention to truly enjoy sensory pleasures, as well as for efficient learning. We need it in order to be truly present during sex or to be in love or when we are simply contemplating nature. Our brains can generate only a limited amount of this precious resource every day.
Today, the advertisement and entertainment industries are attacking the very foundations of our capacity for experience, drawing us into the vast and confusing media jungle. They are trying to rob us of as much of our scarce resource as possible, and they are doing so in every more persistent and intelligent ways. Of course, they are increasingly making use of the new insights in the human mind offered by cognitive and brain science to achieve their goals ("neuromarketing" is one of the ugly new buzzwords). We can see the probable result in the epidemic of attention-deficit disorder in children and young adults, in midlife burnout, in rising levels of anxiety in large parts of the population. If I am right that consciousness is the space of attentional agency, and if (as discussed in chapter 4) it is also true that the experience of controlling and sustaining your focus of attention is one of the deeper layers of phenomenal selfhood, then we are currently witnessing not only an organized attack on the space of consciousness per se, but a mild form of depersonalization. New medial environments many create a new form of waking consciousness that resembles weakly subjective states - a mixture of dreaming, dementia, intoxication, and infantilization.
Metzinger suggests we counter the attacks on our reserves of attention by introducing classes in meditation in our high schools, by making the young aware of our limited capacity for attention, and the need to learn techniques to sustain it and enhance mindfulness. ]
Riding the tiger: A new cultural context
On normative issues, there is no such thing as expert knowledge.. we must all do this together. Prospects for open and free democratic discussion on global scale are dim. Authoritarian societies growing more rapidly than democratic ones. To protect open societies from irrationalism and fundamentalism, we might try to create a ‘consciousness culture” in which people are free to explore their own minds and design their own conscious reality models, unless the interests of others are directly threatened. How can we increase the autonomy of the individual and protect it from the increasing possibilities of manipulation. If we demystify consciousness, do we automatically lose our sense of human solidarity at the same time?
The interplay of virtual-reality technology, new psychoactive substances, ancient psychological techniques such as meditation, and future neurotechnology will introduce us to a universe of self-exploration barely imaginable today.
Through the naturalistic turn in the image of mind, do we lose our “dignity?” Dignity can be seen in the refusal to humiliate oneself by simply looking the other way or escaping to some metaphysical Disneyland, sliding back into various forms of irrationalism and fundamentalism. We could face the historical transition in our image of ourselves creatively and with a will to clarity.
In principle, we can design our own Ego Tunnels by tinkering with the hardware responsible for the relevant information-processing: Phenotechnology. (I do not extract at this point a fairly extended section on drugs and altered states of consciousness), which ends with: we must decide which of these altered states can be integrated into our culture and which are to be avoided at all cost.
What is a good state of consciousness?
Metzinger’s intuition is that it should satisfy at least three conditions. It should minimize suffering, in humans and other beings capable of suffering; it should possess an epistemic potential (have component of insight and expanding knowledge; and, should have consequences that increase the probability of future valuable types of experience.
The ego tunnel evolved as a biological system of representation and information processing that is part of a social network of communicating ego tunnels...now embedded in a global data cloud characterized by rapid growth, increasing speed, and an autonomous dynamic of its own....it has begun to reconfigure our brains..perhaps body perception will change as we learn to control multiple avatars in multiple virtual realities, embedding our conscious self into entirely new kinds of sensorimotor loops... we will understand what our social life has been all along - an interaction between images, a highly mediated process in which mental model of persons begin to causally influence one another... communication viewed as estimating and controlling dynamical internal models in other people’s brains.
For those of us intensively working with it, the Internet has already become a part of our self-model. We use it for external memory storage, as a cognitive prosthesis, and for emotional autoregulation...We are learning to multitask, our attention span is becoming shorter, and many of our social relationships are taking on a strangely disembodied character... The integration of hundreds of millions of human brains (and the Ego Tunnels those brains create) into ever new medial environments has already begun to change the structure of conscious experience itself. Where this will lead is unforeseeable.
The new media are also consciousness technologies, and we should ask ourselves again what a good state of consciousness would be.
The ability to attend to our environment, to our own feelings, and to those of others is a naturally evolved feature of the human brain. Attention is a finite commodity, and it is absolutely essential to living a good life. We need attention in order to truly listen to others - and even to ourselves. We need attention to truly enjoy sensory pleasures, as well as for efficient learning. We need it in order to be truly present during sex or to be in love or when we are simply contemplating nature. Our brains can generate only a limited amount of this precious resource every day.
Today, the advertisement and entertainment industries are attacking the very foundations of our capacity for experience, drawing us into the vast and confusing media jungle. They are trying to rob us of as much of our scarce resource as possible, and they are doing so in every more persistent and intelligent ways. Of course, they are increasingly making use of the new insights in the human mind offered by cognitive and brain science to achieve their goals ("neuromarketing" is one of the ugly new buzzwords). We can see the probable result in the epidemic of attention-deficit disorder in children and young adults, in midlife burnout, in rising levels of anxiety in large parts of the population. If I am right that consciousness is the space of attentional agency, and if (as discussed in chapter 4) it is also true that the experience of controlling and sustaining your focus of attention is one of the deeper layers of phenomenal selfhood, then we are currently witnessing not only an organized attack on the space of consciousness per se, but a mild form of depersonalization. New medial environments many create a new form of waking consciousness that resembles weakly subjective states - a mixture of dreaming, dementia, intoxication, and infantilization.
Metzinger suggests we counter the attacks on our reserves of attention by introducing classes in meditation in our high schools, by making the young aware of our limited capacity for attention, and the need to learn techniques to sustain it and enhance mindfulness. ]
Riding the tiger: A new cultural context
On normative issues, there is no such thing as expert knowledge.. we must all do this together. Prospects for open and free democratic discussion on global scale are dim. Authoritarian societies growing more rapidly than democratic ones. To protect open societies from irrationalism and fundamentalism, we might try to create a ‘consciousness culture” in which people are free to explore their own minds and design their own conscious reality models, unless the interests of others are directly threatened. How can we increase the autonomy of the individual and protect it from the increasing possibilities of manipulation. If we demystify consciousness, do we automatically lose our sense of human solidarity at the same time?
The interplay of virtual-reality technology, new psychoactive substances, ancient psychological techniques such as meditation, and future neurotechnology will introduce us to a universe of self-exploration barely imaginable today.
Through the naturalistic turn in the image of mind, do we lose our “dignity?” Dignity can be seen in the refusal to humiliate oneself by simply looking the other way or escaping to some metaphysical Disneyland, sliding back into various forms of irrationalism and fundamentalism. We could face the historical transition in our image of ourselves creatively and with a will to clarity.
Old age: always older than you are...
Arnquist notes a recent Pew Research Center study that interviewed 3,000 adults, age 18 and older:
The survey found not just a gap between actual age and the age people say they feel, but also that the gap between reality and perception increases with age. Most adults over age 50 feel at least 10 years younger than their actual age, the survey found. One-third of those between 65 and 74 said they felt 10 to 19 years younger, and one-sixth of people 75 and older said they felt 20 years younger.
On average, survey respondents said old age begins at 68. But few people over 65 agreed; they said old age begins at 75...Respondents under 30 said 60 marks the beginning of old age...Younger people tend to think growing old will be worse than the elderly report...Older adults said they had experienced the negative aspects of aging — including illness, loneliness and financial difficulty — far less often than younger people anticipated. But older participants also said they found less time for family and leisure activities than younger adults expected they would when they reach old age.
Meditation increases brain's gray matter?
Passing this on, but I can't find any published work online. UPDATE: an alert reader just sent a comment, below, with the relevant reference (Neuroimage. 2009 Apr 15;45(3):672-8). PDF is here.
The "acts of kindness" iPhone app
A group of University of Michigan students has created an iPhone app, called DoGood, that challenges users to do a different good deed each day, and reports the total number of users who have done this...
Subscribe to:
Posts (Atom)