Showing posts with label emotion. Show all posts
Showing posts with label emotion. Show all posts

Monday, November 30, 2020

Emotions do not have distinctive brain and body ‘fingerprints’

This post, following an introduction in last Friday’s post, is a series of clips and paraphrases from Ch. 1 of Lisa Feldman Barrett’s book “How Emotions are Made: The Secret Life of the Brain.”, roughly a 10-fold condensation of the material. And, here is the next installment on Chapters 2 and 3, "Emotions are constructed, and are not universal"
According to the classical view of emotion, our faces hold the key to assessing emotions objectively and accurately (Darwin, Tomkins, Izard, Ekman)..As it turns out in study after study, facial muscle movements do not reliably indicate when someone is angry, sad, or fearful; they don’t form predictable fingerprints for each emotion…An emotion like “Fear” does not have a single expression but a diverse population of facial movements that vary from one situation to the next…Likewise, happiness, sadness, anger, and every other emotion you know is a diverse category, with widely varying facial movements.
With respect to emotions and the autonomic nervous system (controlling heart rate, blood pressure, skin conductance, etc.) .. None of four significant meta-analyses, the largest of which covered more than 220 physiology studies and nearly 22,000 test subjects, found consistent and specific emotion fingerprints in the body. .. On different occasions, in different contexts, in different studies, within the same individual and across different individuals, the same emotion category involves different bodily responses. Any emotion category has tremendous variety, and variation, not uniformity, is the norm. This requires population thinking. A category such as anger can only be described as a collection of instances with no distinctive fingerprint at their core. There is far more variation than the classical view of emotion predicts or can explain. The category can be described at the group level only in abstract, statistical terms.
If not in facial expressions or autonomic nervous system changes, can fingerprints of emotions such as fear be found in the brain? Brain lesion studies undermine the idea that the amygdala contains the circuit for fear. They point instead to the idea that the brain must have multiple ways of creating fear, and therefore the emotion category “Fear” cannot be necessarily localized to a specific region. Results for other emotion categories have been similarly variable. Brain regions like the amygdala are routinely important to emotion, but they are neither necessary nor sufficient for emotion. Many combinations of neurons can produce the same emotional category - this degeneracy is a humbling reality check.
The brain contains core systems that participate in creating a wide variety of mental states. A single core system can play a role in thinking, remembering, decision-making, seeing, hearing, and experiencing and perceiving diverse emotions. A core system is “one to many”: a single brain area or network contributes to many different mental states. The classical view of emotion, in contrast, considers particular brain areas to have dedicated psychological functions, that is, they are “one to one.” Core systems are therefore the antithesis of neural fingerprints. Most neurons are multipurpose, playing more than one part, much as flour and eggs in your kitchen can participate in many recipes.
A meta-analysis covering every usable published neuroimaging study on anger, disgust, happiness, fear, and sadness, (nearly 100 published studies involving nearly 1,300 test subjects across almost 20 years) found that no brain region contained the fingerprint for any single emotion. Fingerprints are also absent if you consider multiple connected regions at once (a brain network), or stimulate individual neurons with electricity. The same results hold in experiments with other animals that allegedly have emotion circuits, such as monkeys and rats. Emotions arise from firing neurons, but no neurons are exclusively dedicated to emotion. These findings are the final, definitive nail in the coffin for localizing emotions to individual parts of the brain.
Brain circuitry operates by the many-to-one principle of degeneracy: instances of a single emotion category, such as fear, are handled by different brain patterns at different times and in different people. Conversely, the same neurons can participate in creating different mental states (one-to-many). …variation is the norm. Emotion fingerprints are a myth. If we want to truly understand emotions, we must start taking that variation seriously. We must consider that an emotion word, like “anger,” does not refer to a specific response with a unique physical fingerprint but to a group of highly variable instances that are tied to specific situations. What we colloquially call emotions, such as anger, fear, and happiness, are better thought of as emotion categories, because each is a collection of diverse instances. .. instances of “Anger” vary in their physical manifestations (facial movements, heart rate, hormones, vocal acoustics, neural activity, and so on), and this variation might is related to their environment or context.

Friday, November 27, 2020

A unified view of reasons and emotions.

As indicated in my Nov. 18 post, I have been taking a mini-sabbitical from grinding out daily MindBlog posts to sort out my understanding of what emotions are. The catalyst for this pause has been my careful reading of Lisa Feldman Barrett’s book “How Emotions are Made: The Secret Life of the Brain.” I have dutifully abstracted text clips (and dived into some primary reference sources) to line up core points in each chapter. I will proceed, as I have with books by Metzinger, Harari, Pinker, Sapolsky, Graziano, Gilbert and others, to do a series of posts on the chapters. I have decided to cut to the chase, and present the bottom lines I agree with urging you to read the book to find the sometimes massive amounts of evidence presented. Barretts’ presentation is a bit more folksy, rambling, and disorganized that suits my taste, but her style does make the material more friendly and palatable to a general readership. 

What we are now seeing is a new view of what emotions are, fueled by data from improving brain imaging techniques that started to appear in the 1990’s. Here is my paraphrase and editing of Barrett’s introduction:

The classical view of ancient Greek philosophers up through prominent modern thinkers is that we have many evolved universal emotion circuits in our brains (for fear, sadness, rage, etc), each with a distinctive fingerprint, brute reflexes often at war with our rationality. Embedded in our social institutions and legal systems is the assumption that emotions are part of our inherent animal nature, needing control by rational thoughts.
In fact they are not universal, varying from culture to culture, with a century of effort failing to reveal a consistent, physical fingerprint for even a single emotion (for example in facial expressions, heart rate, blood pressure, or brain activity patterns).
The classical view of emotion remains compelling, despite evidence against it, because it’s intuitive. It provides reassuring answers to deep questions like where we come from, evolutionarily speaking, whether we are responsible for our actions when we get emotional.
Barrett’s ‘theory of constructed emotion’ takes the data to show that
…emotions are not built in, but made from more basic parts. They are not triggered but emerge as you create them from a combination of the physical properties of your body and a flexible brain that wires itself to whatever physical and cultural environment it develops in. Emotions are real in same sense that money is real - a product of human agreement.

A core distinction is between: 

-essentialism, which posits evolved hard wired modules of behavior such as a universal set of basic emotions signaled by stereotypes brain, facial and visceral changes, or a layered triune brain generating evolutionarily older and newer behaviors. 

versus 

-constructionism, which describes virtually all behaviors as being instances of construction transiently executed on the fly to deal with affect (feelings) registered along axes of valence (pleasant/unpleasant) and intensity (calm vs. arousal) using a basic toolkit of evolved brain hubs. (An analogy would be the many kinds of bakery products that can be made from the same simple set of ingredients such as flour, water, eggs, fat, etc,). 

The ultimate referent is suggested to be interoceptive sensing of allostatic (achieving stability) well being. The interoceptive sensory cortex of the brain’s insula appears to be central to generating our feelings (affect) of comfort/discomfort, pleasant/unpleasant, calm/arousal - the valence and degrees of arousal that inform actions such as the four F’s (fighting, fleeing, feeding, and fornicating), our emotions, and our feelings - all in the service of maintaining general well being. 

 *******

Subsequent posts will deal with material in chapters 1-13 of Barrett’s book. Here is the next installment, on Ch. 1.

Wednesday, November 18, 2020

We have been wrong about what emotions are - MindBlog is taking a study mini-sabbitical

I have been doing a careful reading of Barrett's book "How Emotions are Made: The Secret Life of the Brain" - hence the decreased frequency of MindBlog posts. Much of the material in the book references research that MindBlog has dutifully reported, showing that our brains are prediction machines working with statistical probabilities, how what we see is what we expect to see, etc. But MindBlog has been seriously remiss in not pointing out the conflicts with, and continuing to use, concepts and categories that we now know to be flawed, such as the triune brain model, emotional categories and facial expressions that are erroneously claimed to be universal across cultures, etc. When I have finished my reading and abstracting of Barrett's book, I hope to pass on a synopsis of the main points, trying to be cautious about the new constructionist models replacing older essential assumptions about evolutionarily hard wired circuits dedicated to specific emotional categories. I want to be sure I'm not tossing out the baby with the bathwater, as far as our older essentialist explanations are concerned. Anyway, as this post's title indicates, I'm diverting time away from the scanning of journals' tables of contents that I use to find interesting material to post. 

Here is the first installment in the series of posts on Barrett's book.  

Friday, October 30, 2020

MindBlog's 5,000th post - The milliseconds of a choice - Watching your mind when it matters.

This was going to be a post on oxytocin research...but I looked at the Blogger counter to see that it will be the 5,000th post done since the start of MindBlog in 2006.  Wow, that's a lot of words.  I've decided to note the occasion by repeating for the second time a post on material I find very fascinating. Here is the 2017 repeat of a 2014 post:

I'm finding, with increasing frequency, that an article about health or psychology in the New York Times that I find interesting has an attached note that it was first published several years earlier. While working on yesterday's MindBlog post I came across a 2014 post I wrote that I think makes some important points about our self-regulation that are worth repeating. So, I'm going to copy what the Times is doing and repeat it today. I'm tempted to edit it, but won't, beyond mentioning that I would considerably tone down my positive reference to brain training games (that I no longer indulge in). Here is the 2014 post:

This is actually a post about mindfulness, in reaction to Dan Hurley's article describing how contemporary applications of the ancient tradition of mindfulness meditation are being engaged in many more contexts than the initial emphasis on chilling out in the 1970s, and being employed for very practical purses such as mental resilience in a war zone. It seems like to me that we are approaching a well defined technology of brain control whose brain basis is understood in some detail. I've done numerous posts on behavioral and brain correlates of mindfulness meditation (enter 'meditation' or 'mindfulness' in MindBlog's search box in the left column). For example, only four weeks of a mindfulness meditation regime emphasizing relaxation of different body parts correlates with increases in white matter (nerve tract) efficiency. Improvements in cognitive performance, working memory, etc. have been claimed. A special issue of The journal Social Cognitive and Affective Neuroscience discusses issues in the research.

Full time mindfulness might be a bad idea, suppressing the mind wandering that facilitates bursts of creative insight. (During my vision research career, my most original ideas popped up when I was spacing out, once when I was riding a bike along a lakeshore path.) Many physicists and writers reports their best ideas happen when they are disengaged. It also appears that mindfulness may inhibit implicit learning in which habits and skill are acquired without conscious awareness.

Obviously knowing whether we are in an attentional or mind wandering (default, narrative) modes is useful (see here, and here), and this is where the title of this posts comes in. To note and distinguish our mind state is most effectively accomplished with a particular style of alertness or awareness that is functioning very soon (less than 200 milliseconds) after a new thought or sensory perception appears to us. This is a moment of fragility that offers a narrow time window of choice over whether our new brain activity will be either enhanced or diminished in favor of a more desired activity. This is precisely what is happening in mindfulness meditation that instructs a central focus of some sort (breathing, body relaxation, or whatever) to which one returns as soon as one notes that any other thoughts or distractions have popped into awareness. The ability to rapidly notice and attend to thoughts and emotions of these short time scales is enhanced by brain training regimes of the sort offered by BrainHq of positscience.com and others. I have found the exercises on this site, originated by Michael Merznich, to be the most useful.  It offers summaries of changes in brain speed, attention, memory, intelligence, navigation, etc. that result from performing the exercises - changes that can persist for years.

A book title that has been popping into my head for at least the last 15 years is "The 200 Millisecond Manager." (a riff on the title the popular book of the early 1980's by Blanchard and Johnson, "The One Minute Manager.") The gist of the argument would be that given in the "Guide" section of some 2005 writing, and actually in Chapter 12 of my book, Figure 12-7.

It might make the strident assertion that the most important thing that matters in regulating our thoughts, feelings, and actions is their first 100-200 msec in the brain, which is when the levers and pulleys are actually doing their thing. It would be a nuts and bolts approach to altering - or at least inhibiting - self limiting behaviors. It would suggest that a central trick is to avoid taking on on the ‘enormity of it all,’ and instead use a variety of techniques to get our awareness down to the normally invisible 100-200 msec time interval in which our actions are being programmed. Here we are talking mechanics during the time period is when all the limbic and other routines that result from life script, self image, temperament, etc., actually can start-up. The suggestion is that you can short circuit some of this process if you bring awareness to the level of observing the moments during which a reaction or behavior is becoming resident, and can sometimes say “I don’t think so, I think I'll do something else instead.”

"The 200 msec Manager" has gone through the ‘this could be a book’ cycle several times, the actual execution  bogging down as I actually got into description of the underlying science and techniques for expanding awareness. Also, I note the enormous number of books out there on meditation, relaxation, etc. that are all really addressing the same core processes in different ways.

Thursday, October 22, 2020

Compassion research

I want to point to a recent "Making Sense" podcast titled "The power of compassion" in which Sam Harris interviews James R. Doty, a Stanford neurosurgeon who is director of the Center for Compassion and Altruism Research and Education at Stanford University School of Medicine. Doty is an inventor, entrepreneur and philanthropist who has given support to a number of charitable organizations, is on the Board of Directors of a number of non-profit foundations, is chairman of the Dalai Lama Foundation, vice-chair of the Charter for Compassion International, and is on the International Advisory Board of the Council for the Parliament of the World’s Religions. He also writes for The Huffington Post. 

I found a brief tour of the website of the Center for Compassion and Altruism Research and Education to be most instructive. It points to numerous sources of compassion research and training. Doty's website points to his book "Into the Magic Shop," which is discussed in the podcast.

Friday, October 16, 2020

Want to feel better? Make a fake smile by holding a pencil in your teeth.

Neat work by Marmolejo-Ramos et al in Experimental Psychology, Research subjects who forced their facial muscles to replicate the movement of a smile by holding a pen between their teeth altered their perception to see the world in a more positive way, and to have a lower threshold for the perception of happy expression in facial stimuli. This correlated with changes in activity of the amygdala, an emotion regulation center in the brain. I pass on their abstract (motivated readers can obtain the whole article by emailing me):
In this experiment, we replicated the effect of muscle engagement on perception such that the recognition of another’s facial expressions was biased by the observer’s facial muscular activity (Blaesi & Wilson, 2010). We extended this replication to show that such a modulatory effect is also observed for the recognition of dynamic bodily expressions. Via a multilab and within-subjects approach, we investigated the emotion recognition of point-light biological walkers, along with that of morphed face stimuli, while subjects were or were not holding a pen in their teeth. Under the “pen-in-the-teeth” condition, participants tended to lower their threshold of perception of happy expressions in facial stimuli compared to the “no-pen” condition, thus replicating the experiment by Blaesi and Wilson (2010). A similar effect was found for the biological motion stimuli such that participants lowered their threshold to perceive happy walkers in the pen-in-the-teeth condition compared to the no-pen condition. This pattern of results was also found in a second experiment in which the no-pen condition was replaced by a situation in which participants held a pen in their lips (“pen-in-lips” condition). These results suggested that facial muscular activity alters the recognition of not only facial expressions but also bodily expressions.

Thursday, October 01, 2020

Acetaminophen increases risk taking

From Keaveney et al.:
Acetaminophen (Tylenol), an analgesic and antipyretic available over-the-counter and used in over 600 medicines, is one of the most consumed drugs in the USA. Recent research has suggested that acetaminophen’s effects extend to the blunting of negative as well as positive affect. Because affect is a determinant of risk perception and risk taking, we tested the hypothesis that acute acetaminophen consumption (1000 mg) could influence these important judgments and decisions. In three double-blind, placebo-controlled studies, healthy young adults completed a laboratory measure of risk taking (Balloon Analog Risk Task) and in Studies 1 and 2 completed self-report measures of risk perception. Across all studies (total n = 545), acetaminophen increased risk-taking behavior. On the more affectively stimulating risk perception measure used in Study 2, acetaminophen reduced self-reported perceived risk and this reduction statistically mediated increased risk-taking behavior. These results indicate that acetaminophen can increase risk taking, which may be due to reductions in risk perceptions, particularly those that are highly affect laden.

Monday, September 21, 2020

Brain circuits signaling the absence of emotion in body language

Sokolov et al. show that modulation of the reciprocal effective connectivity between the amygdala and insula during processing of neutral and emotional body language predicts people’s ability to recognize neutral body language, suggesting that their interplay may be important not only for the processing of emotions but also, for inferring the absence of emotional content in body language. Their abstract:
Adaptive social behavior and mental well-being depend on not only recognizing emotional expressions but also, inferring the absence of emotion. While the neurobiology underwriting the perception of emotions is well studied, the mechanisms for detecting a lack of emotional content in social signals remain largely unknown. Here, using cutting-edge analyses of effective brain connectivity, we uncover the brain networks differentiating neutral and emotional body language. The data indicate greater activation of the right amygdala and midline cerebellar vermis to nonemotional as opposed to emotional body language. Most important, the effective connectivity between the amygdala and insula predicts people’s ability to recognize the absence of emotion. These conclusions extend substantially current concepts of emotion perception by suggesting engagement of limbic effective connectivity in recognizing the lack of emotion in body language reading. Furthermore, the outcome may advance the understanding of overly emotional interpretation of social signals in depression or schizophrenia by providing the missing link between body language reading and limbic pathways. The study thus opens an avenue for multidisciplinary research on social cognition and the underlying cerebrocerebellar networks, ranging from animal models to patients with neuropsychiatric conditions.

Thursday, August 13, 2020

Placebos without deception reduce self-report and neural measures of emotional distress

Interesting work from Guevarra et al. (open source):
Several recent studies suggest that placebos administered without deception (i.e., non-deceptive placebos) can help people manage a variety of highly distressing clinical disorders and nonclinical impairments. However, whether non-deceptive placebos represent genuine psychobiological effects is unknown. Here we address this issue by demonstrating across two experiments that during a highly arousing negative picture viewing task, non-deceptive placebos reduce both a self-report and neural measure of emotional distress, the late positive potential. These results show that non-deceptive placebo effects are not merely a product of response bias. Additionally, they provide insight into the neural time course of non-deceptive placebo effects on emotional distress and the psychological mechanisms that explain how they function.
Here is a description from their text of the EEG signals measured:
The LPP is an electroencephalogram (EEG) derived event-related brain potential (ERP) response that measures millisecond changes in the neural activity involved in emotional processing. The early-time window of the LPP (400–1000 ms) indexes attention allocation34; the sustained time window (1000–6000 ms) indexes conscious appraisals and meaning-making mechanisms involved in emotion processing34,35 and is consistently downregulated by cognitive emotion regulation strategies. Consistent with its role in immediate attentional orienting responses to emotional stimuli and later appraisal processes, neural sources of the LPP include both the amygdala and dorsolateral prefrontal cortex41. Thus, the LPP is ideally suited to help examine the neural mechanisms and time course of non-deceptive placebo effects on emotional distress.
And, conditions presented to participants:
In both experiments, we randomly assigned participants to either a non-deceptive placebo group or a control group. Participants in the non-deceptive placebo group read about placebo effects and were then asked to inhale a nasal spray consisting of saline solution. They were told that the nasal spray was a placebo that contained no active ingredients, but would help reduce their negative emotional reactions to viewing distressing images if they believed it would. Participants in the control group read about the neural processes underlying the experience of pain and were also asked to inhale the same saline solution spray; however, they were told that the purpose of the nasal spray was to improve the clarity of the physiological readings we were recording in the study. The articles were matched for narrative structure, emotional content, and length

Tuesday, July 07, 2020

Brain correlates of the muting of our emotions as we age.

 (This is a re-post of the MindBlog post of Oct. 1, 2008, as relevant today as then.)

My boyfriend in the early 19980’s was a pharmacy graduate student whose t-shirt read “Drugs are my life.” If I were to wear such a t-shirt now it would read “Hormones and neurotransmitters are my life.” I increasingly feel that all this verbal stuff we do - chattering in person or in the electronic ether, writing blogs, etc. - is a superficial veneer, noise on top of what is really running the show, which is the waxing and waning of hormones and neurotransmitters directed by an “it”, a martian inside us utterly running its own show. These compounds regulate our assertiveness versus passivity , our trust versus mistrust, our anxiety versus calm, our pleasure during antipication and reward. (They function, respectively, in neural systems that use testosterone, oxytocin, adrenaline, and dopamine.). The swings in these systems become less dramatic as we 'mellow' with aging.

Dreher et al. have published an interesting bit of work that deals specifically with the muting of the intensity of the pleasures we feel during anticipation and reward, in their article on “Age-related changes in midbrain dopaminergic regulation of the human reward system.” Their data show what is going on as we experience less excitement at opening a present when we are 60 than when we are 10 years old. There are changes in the brain's production of dopamine, which plays a central role in our reward system, as well as in which parts of the brain respond to it, and by how much they respond. (a recent brief article on dopamine and the reward system of the brain is here.) Here is their abstract, followed by a figure from the paper.
The dopamine system, which plays a crucial role in reward processing, is particularly vulnerable to aging. Significant losses over a normal lifespan have been reported for dopamine receptors and transporters, but very little is known about the neurofunctional consequences of this age-related dopaminergic decline. In animals, a substantial body of data indicates that dopamine activity in the midbrain is tightly associated with reward processing. In humans, although indirect evidence from pharmacological and clinical studies also supports such an association, there has been no direct demonstration of a link between midbrain dopamine and reward-related neural response. Moreover, there are no in vivo data for alterations in this relationship in older humans. Here, by using 6-[18F]FluoroDOPA (FDOPA) positron emission tomography (PET) and event-related 3T functional magnetic resonance imaging (fMRI) in the same subjects, we directly demonstrate a link between midbrain dopamine synthesis and reward-related prefrontal activity in humans, show that healthy aging induces functional alterations in the reward system, and identify an age-related change in the direction of the relationship (from a positive to a negative correlation) between midbrain dopamine synthesis and prefrontal activity. These results indicate an age-dependent dopaminergic tuning mechanism for cortical reward processing and provide system-level information about alteration of a key neural circuit in healthy aging. Taken together, our findings provide an important characterization of the interactions between midbrain dopamine function and the reward system in healthy young humans and older subjects, and identify the changes in this regulatory circuit that accompany aging.


Legend (click on figure to enlarge). Statistical t maps of the within-groups effects in the different phases of the reward paradigm. (A) (Left) Main effect of anticipating reward in young subjects during the delay period, showing activation in the left intraparietal cortex, ventral striatum, caudate nucleus, and anterior cingulate cortex. (Right) Main effect of anticipating reward in older subjects during the delay period, showing activation in the left intraparietal cortex only. The glass brain and the coronal slice indicate that no ventral striatum activity was observed in older subjects. (B) (Left) Main effect of reward receipt in young subjects at the time of the rewarded outcome showing activation in a large bilateral prefronto-parietal network. (Right) Main effect of reward receipt in older subjects at the time of the rewarded outcome showing bilateral prefronto-parietal activation.

Friday, July 03, 2020

Which way are you wagging your tail?

Blakeslee writes a review (PDF here) of work by Vallortigara et al (PDF here) on emotional asymmetric tail wagging by dogs that is a further reflection of lateralized functions of the brain. Some edited clips from her article:
In most animals, including birds, fish and frogs, the left brain specializes in behaviors involving what the scientists call approach and energy enrichment. In humans, that means the left brain is associated with positive feelings, like love, a sense of attachment, a feeling of safety and calm. It is also associated with physiological markers, like a slow heart rate.

At a fundamental level, the right brain specializes in behaviors involving withdrawal and energy expenditure. In humans, these behaviors, like fleeing, are associated with feelings like fear and depression. Physiological signals include a rapid heart rate and the shutdown of the digestive system.

Because the left brain controls the right side of the body and the right brain controls the left side of the body, such asymmetries are usually manifest in opposite sides of the body. Thus many birds seek food with their right eye (left brain/nourishment) and watch for predators with their left eye (right brain/danger).

In humans, the muscles on the right side of the face tend to reflect happiness (left brain) whereas muscles on the left side of the face reflect unhappiness (right brain).

Dog tails are interesting...because they are in the midline of the dog’s body, neither left nor right. So do they show emotional asymmetry, or not?

Vallortigara et al show that when dogs were attracted to something, including a benign, approachable cat, their tails wagged right, and when they were fearful, their tails went left. It suggests that the muscles in the right side of the tail reflect positive emotions while the muscles in the left side express negative ones.

Brain asymmetry for approach and withdrawal seems to be an ancient trait..Thus it must confer some sort of survival advantage on organisms.

Animals that can do two important things at the same time, like eat and watch for predators, might be better off. And animals with two brain hemispheres could avoid duplication of function, making maximal use of neural tissue.

The asymmetry may also arise from how major nerves in the body connect up to the brain... Nerves that carry information from the skin, heart, liver, lungs and other internal organs are inherently asymmetrical, he said. Thus information from the body that prompts an animal to slow down, eat, relax and restore itself is biased toward the left brain. Information from the body that tells an animal to run, fight, breathe faster and look out for danger is biased toward the right brain.
(This is a re-posting of the MindBlog post of 4/27/2007, material as interesting and fresh today as it was then.)

Friday, May 29, 2020

Brain connectivity fingerprinting of complex human personality traits - another tool for the surveillance state?

A group of researchers in the Department of Radiology, Anhui Medical University, Hefei, China, find that resting-state functional connectivity patterns of whole-brain large-scale networks can effectively and reliably predict complex human personality traits, including agreeableness, openness, conscientiousness and neuroticism, at the individual level. Fascinating work, but one wonders whether this might become yet another tool that might be used by a government to assess its citizens? :
Neuroimaging studies have linked inter-individual variability in the brain to individualized personality traits. However, only one or several aspects of personality have been effectively predicted based on brain imaging features. The objective of this study was to construct a reliable prediction model of personality in a large sample by using connectome-based predictive modeling (CPM), a recently developed machine learning approach. High-quality resting-state functional magnetic resonance imaging data of 810 healthy young participants from the Human Connectome Project dataset were used to construct large-scale brain networks. Personality traits of the five-factor model (FFM) were assessed by the NEO Five Factor Inventory. We found that CPM successfully and reliably predicted all the FFM personality factors (agreeableness, openness, conscientiousness and neuroticism) other than extraversion in novel individuals. At the neural level, we found that the personality-associated functional networks mainly included brain regions within default mode, frontoparietal executive control, visual and cerebellar systems. Although different feature selection thresholds and parcellation strategies did not significantly influence the prediction results, some findings lost significance after controlling for confounds including age, gender, intelligence and head motion. Our finding of robust personality prediction from an individual’s unique functional connectome may help advance the translation of ‘brain connectivity fingerprinting’ into real-world personality psychological settings.

Tuesday, April 28, 2020

Non-invasive DIY brain stimulators are a bad idea.

I must admit that I've been sorely tempted to have a try with one of the transcranial magnetic or direct current stimulators, easily ordered from web vendors, whose use is claimed to enhance your smarts or chill you out. A meta-analysis by Smits et al. casts cold water on the prospects of these working as advertised.
Excessive emotional responses to stressful events can detrimentally affect psychological functioning and mental health. Recent studies have provided evidence that non-invasive brain stimulation (NBS) targeting the prefrontal cortex (PFC) can affect the regulation of stress-related emotional responses. However, the reliability and effect sizes have not been systematically analyzed. In the present study, we reviewed and meta-analyzed the effects of repetitive transcranial magnetic (rTMS) and transcranial direct current stimulation (tDCS) over the PFC on acute emotional stress reactivity in healthy individuals. Forty sham-controlled single-session rTMS and tDCS studies were included. Separate random effects models were performed to estimate the mean effect sizes of emotional reactivity. Twelve rTMS studies together showed no evidence that rTMS over the PFC influenced emotional reactivity. Twenty-six anodal tDCS studies yielded a weak beneficial effect on stress-related emotional reactivity (Hedges’ g = −0.16, CI95% = [−0.33, 0.00]). These findings suggest that a single session of NBS is insufficient to induce reliable, clinically significant effects but also provide preliminary evidence that specific NBS methods can affect emotional reactivity. This may motivate further research into augmenting the efficacy of NBS protocols on stress-related processes.

Monday, April 20, 2020

Older adults proactively downregulate anticipated negative affect.

Interesting work from Corbett et al. (open source):
Previous studies have only investigated age-related differences in emotional processing and encoding in response to, not in anticipation of, emotional stimuli. In the current study, we investigated age-related differences in the impact of emotional anticipation on affective responses and episodic memory for emotional images. Young and older adults were scanned while encoding negative and neutral images preceded by cues that were either valid or invalid predictors of image valence. Participants were asked to rate the emotional intensity of the images and to complete a recognition task. Using multivariate behavioral partial least squares (PLS) analysis, we found that greater anticipatory recruitment of the amygdala, ventromedial prefrontal cortex (vmPFC), and hippocampus in older adults predicted reduced memory for negative than neutral images and the opposite for young adults. Seed PLS analysis further showed that following negative cues older adults, but not young adults, exhibited greater activation of vmPFC, reduced activation of amygdala, and worse memory for negative compared with neutral images. To the best of our knowledge, this is the first study to provide evidence that the “positivity effect” seen in older adults’ memory performance may be related to the spontaneous emotional suppression of negative affect in anticipation of, not just in response to, negative stimuli.

Wednesday, January 01, 2020

Increased emotional reactivity in men with high hair testosterone concentrations.

As I was scanning the table of contents of the latest issue of the journal "Social Cognitive and Affective Neuroscience" the article whose abstract I pass on below jumped out at me. (This is because I feel more emotional and sexual when my androgen levels reach their highest point in a monthly cycle, with lower points in the cycle correlating with lower motivation and anhedonia.) From Klein et al.:
Testosterone has been linked to alterations in the activity of emotion neurocircuitry including amygdala, orbitofrontal cortex (OFC) and insula and diminished functional amygdala/prefrontal coupling. Such associations have only ever been studied using acute measures of testosterone, thus little is known about respective relationships with long-term testosterone secretion. Here, we examine associations between hair testosterone concentration (HTC), an index of long-term cumulative testosterone levels and neural reactivity during an emotional passive viewing task using functional magnetic resonance imaging (fMRI). Forty-six men viewed negative, positive and neutral pictures in the MRI. HTCs were assessed from 2 cm hair segments. The emotional paradigm elicited neural activation in the amygdala, insula and OFC. HTCs were associated with increased reactivity to negative pictures in the insula and increased reactivity to positive pictures in the OFC. We show an association of long-term testosterone levels with increased emotional reactivity in the brain. These results suggest a heightened emotional vigilance in individuals with high trait testosterone levels.

Wednesday, September 04, 2019

Training wisdom - the Illeist (third person) method.

I think my most sane moments are those when I experience myself as watching, in third-person mode, rather than “being” Deric, the immersed actor. Science journalist David Robson does an essay on this perspective in Aeon, “Why speaking to yourself in the third person makes you wiser,” noting that this ancient rhetorical method, used by Julius Caesar and termed ‘illeism’ in 1809 by the poet Coleridge (latin ille meaning ‘he, that’) can clear the emotional fog of simple rumination, shifting perspective to see past biases. Robson notes the work of Igor Grossmann at the University of Waterloo in Canada, whose aim is:
...to build a strong experimental footing for the study of wisdom, which had long been considered too nebulous for scientific enquiry. In one of his earlier experiments, he established that it’s possible to measure wise reasoning and that, as with IQ, people’s scores matter. He did this by asking participants to discuss out-loud a personal or political dilemma, which he then scored on various elements of thinking long-considered crucial to wisdom, including: intellectual humility; taking the perspective of others; recognising uncertainty; and having the capacity to search for a compromise. Grossmann found that these wise-reasoning scores were far better than intelligence tests at predicting emotional wellbeing, and relationship satisfaction – supporting the idea that wisdom, as defined by these qualities, constitutes a unique construct that determines how we navigate life challenges.
The abstract from Grossmann et al.:
We tested the utility of illeism – a practice of referring to oneself in the third person – for the trainability of wisdom-related characteristics in everyday life: i) wise reasoning (intellectual humility, open-mindedness in ways a situation may unfold, perspective-taking, attempts to integrate different viewpoints) and ii) accuracy in emotional forecasts toward close others. In a month-long field experiment, people adopted either the third-person training or first-person control perspective when describing their most significant daily experiences. Assessment of spontaneous wise reasoning before and after the intervention revealed substantial growth in the training (vs. control) condition. At the end of the intervention, people forecasted their feelings toward a close other in challenging situations. A month later, these forecasted feelings were compared against their experienced feelings. Participants in the training (vs. control) condition showed greater alignment of forecasts and experiences, largely due to changes in their emotional experiences. The present research demonstrates a path to evidence-based training of wisdom-related processes via the practice of illeism.
Robson finds this work particularly fascinating,
...considering the fact that illeism is often considered to be infantile. Just think of Elmo in the children’s TV show Sesame Street, or the intensely irritating Jimmy in the sitcom Seinfeld – hardly models of sophisticated thinking. Alternatively, it can be taken to be the sign of a narcissistic personality – the very opposite of personal wisdom. After all, Coleridge believed that it was a ruse to cover up one’s own egotism: just think of the US president’s critics who point out that Donald Trump often refers to himself in the third person. Clearly, politicians might use illeism for purely rhetorical purposes but, when applied to genuine reflection, it appears to be a powerful tool for wiser reasoning.
For an example of third person usage reflecting not wisdom, but a narcissistic personality, look no further than our current president, Donald Trump, as noted in this Washington Post piece by Rieger.

Wednesday, August 28, 2019

Interindividual variability - rather than universality - in facial-emotion perception.

Brooks et al. do experiments suggesting that the representational structure of emotion expressions in visual face-processing regions may be shaped by idiosyncratic conceptual understanding of emotion categories:

Significance
Classic theories of emotion hold that emotion categories (e.g., Anger and Sadness) each have corresponding facial expressions that can be universally recognized. Alternative approaches emphasize that a perceiver’s unique conceptual knowledge (e.g., memories, associations, and expectations) about emotions can substantially interact with processing of facial cues, leading to interindividual variability—rather than universality—in facial-emotion perception. We find that each individual’s conceptual structure significantly predicts the brain’s representational structure, over and above the influence of facial features. Conceptual structure also predicts multiple behavioral patterns of emotion perception, including cross-cultural differences in patterns of emotion categorizations. These findings suggest that emotion perception, and the brain’s representations of face categories, can be flexibly influenced by conceptual understanding of emotions.
Abstract
Humans reliably categorize configurations of facial actions into specific emotion categories, leading some to argue that this process is invariant between individuals and cultures. However, growing behavioral evidence suggests that factors such as emotion-concept knowledge may shape the way emotions are visually perceived, leading to variability—rather than universality—in facial-emotion perception. Understanding variability in emotion perception is only emerging, and the neural basis of any impact from the structure of emotion-concept knowledge remains unknown. In a neuroimaging study, we used a representational similarity analysis (RSA) approach to measure the correspondence between the conceptual, perceptual, and neural representational structures of the six emotion categories Anger, Disgust, Fear, Happiness, Sadness, and Surprise. We found that subjects exhibited individual differences in their conceptual structure of emotions, which predicted their own unique perceptual structure. When viewing faces, the representational structure of multivoxel patterns in the right fusiform gyrus was significantly predicted by a subject’s unique conceptual structure, even when controlling for potential physical similarity in the faces themselves. Finally, cross-cultural differences in emotion perception were also observed, which could be explained by individual differences in conceptual structure. Our results suggest that the representational structure of emotion expressions in visual face-processing regions may be shaped by idiosyncratic conceptual understanding of emotion categories.

Friday, April 12, 2019

Tracking emotions of unseen persons by their context.

Martinez does a commentary on work by Chen and Whitney (open source) in the same issue of PNAS.  Here is a clip from that commentary:
Face perception is a fundamental component of our cognitive system and, arguably, a core ability that allowed humans to create the large, advanced societies of today. When we look at someone else’s face, we recognize who they are, whether they are female or male, attractive or unattractive, and happy or sad; that is, their affective state. Correctly interpreting these signals is essential for a functional, cooperative society. For example, when looking at the faces in Fig. 1, most people identify a female expressing sadness on the left and an angry male on the right. But while identity and other attributes are recognized quite accurately, affect is not. To see this, look at the images in Fig. 2A and B. What expressions would you now say these two individuals express? Most of us classify them as expressing excitement or euphoria; that is, positive emotions. What is behind this radical change in our interpretation of these images? Context. Our interpretation of a facial configuration is dependent on the context in which the facial expression is situated. In an ambitious new study in PNAS, Chen and Whitney show that people make reasonably good predictions of people’s affect when only the contextual information is known; that is, when the face is not observable (Fig. 2C). This inference is shown to be accurate, even when the whole body of the person is masked (Fig. 2D), thus preventing an inference based on body pose. Context, therefore, is not only necessary for a correct interpretation of how others feel but, in some instances, it is sufficient. This surprising result will provide renewed interest in the value that context plays in our interpretation of how others feel.
Fig. 1. When asked to identify the emotions shown in these images, most people agree that the left image expresses sadness, while the right image is a clear display of anger. If asked whether these expressions communicate positive or negative valence, most people agree that both correspond to a negative expression. The problem with these assessments is that context is not observable, which may lead to incorrect interpretations. Images courtesy of (Left) Imgflip and (Right) Getty Images/Michael Steele.

Fig. 2. Adding context to the facial expressions previously seen in Fig. 1 radically changes our interpretation of the emotion being experienced by a person. (A and B) In these two images, most observers agree that the people shown are experiencing a joyful event (i.e., positive valence). (C and D) When the face and body are blurred out, inference of valence and arousal is still possible. Images courtesy of (Upper Left, Lower Left, and Lower Right) Imgflip and (Upper Right) Getty Images/Michael Steele.


Here is the Chen and Whitney abstract:
Emotion recognition is an essential human ability critical for social functioning. It is widely assumed that identifying facial expression is the key to this, and models of emotion recognition have mainly focused on facial and bodily features in static, unnatural conditions. We developed a method called affective tracking to reveal and quantify the enormous contribution of visual context to affect (valence and arousal) perception. When characters’ faces and bodies were masked in silent videos, viewers inferred the affect of the invisible characters successfully and in high agreement based solely on visual context. We further show that the context is not only sufficient but also necessary to accurately perceive human affect over time, as it provides a substantial and unique contribution beyond the information available from face and body. Our method (which we have made publicly available) reveals that emotion recognition is, at its heart, an issue of context as much as it is about faces.

Thursday, March 21, 2019

Knowing your own heart - distinguishing interoceptive accuracy and awareness

Garfinkel et al. categorize three different aspects of the internal bodily sensing (interoception) that informs our interactions with the external world, focusing on heartbeats - whose frequency and intensity vary with the degree of our emotional arousal (calm, anticipating, fearful, excited, etc.).

Highlights
• Interoception refers to the signalling and perception of internal bodily sensations.
• We validate a three dimensional construct of interoception.
• This comprises: interoceptive accuracy, sensibility and awareness (metacognition).
• These interoceptive dimensions represent dissociable interoceptive processes.
• Interoceptive accuracy serves as the core (central) construct.
Abstract
Interoception refers to the sensing of internal bodily changes. Interoception interacts with cognition and emotion, making measurement of individual differences in interoceptive ability broadly relevant to neuropsychology. However, inconsistency in how interoception is defined and quantified led to a three-dimensional model. Here, we provide empirical support for dissociation between dimensions of: (1) interoceptive accuracy (performance on objective behavioural tests of heartbeat detection), (2) interoceptive sensibility (self-evaluated assessment of subjective interoception, gauged using interviews/questionnaires) and (3) interoceptive awareness (metacognitive awareness of interoceptive accuracy, e.g. confidence-accuracy correspondence). In a normative sample (N = 80), all three dimensions were distinct and dissociable. Interoceptive accuracy was only partly predicted by interoceptive awareness and interoceptive sensibility. Significant correspondence between dimensions emerged only within the sub-group of individuals with greatest interoceptive accuracy. These findings set the context for defining how the relative balance of accuracy, sensibility and awareness dimensions explain cognitive, emotional and clinical associations of interoceptive ability.

Wednesday, March 20, 2019

Lethal mass partisanship

I think everyone should read this lucid piece by Thomas Edsall, which describes the emerging consensus on the stark biological and evolved psychological roots of the contempt. moral disgust, and aggression that individual members of right and left wing political groups are now directing toward members of the opposing camp, playing out a primitive tribal in-group/out-group dynamic that has ancient evolutionary roots in primate and other social animal behaviors. We seem to be tearing down the fragile political and legal structures, erected by framers of the US constitution, that allowed this country to at least briefly transcend the warring tribes scenario that has prevailed through most of human history.

Some clips of points that I found fascinating:
As partisan hostility deepens, there is one group that might ordinarily be expected to help pull the electorate out of this morass — the most knowledgeable and sophisticated voters... In “Understanding Partisan Cue Receptivity,” Bert N. Bakker and Yphtach Lelkes...find...the most active voters — those notably “high in cognitive resources” — are the most willing to accept policy positions endorsed by their party, and they are doing so not out of principle, but to affirm their identity as a Democrat or Republican. They are expressing “the desire to reach conclusions that are consistent with a valued identity.”
Ironically, reflective citizens, who are sometimes seen as ideal citizens, might be the subset of strong partisan identifiers most likely to fall in line with the party. Since higher levels of cognitive resources and partisan social identity are associated with higher levels of political activism, the effect may be self-reinforcing, wherein political elites polarize the strongly identified and cognitively reflective, who then elect more polarized elites. The democratic dilemma may not be whether low information citizens can learn what they need to know, but whether high information citizens can set aside their partisan predispositions.
And, some quotes from Steven Pinker:
Certainly there is a tribal flavor to political polarization. Men’s testosterone rises or falls on election night, depending on whether their side wins, just as it does on Super Bowl Sunday...the coalitions clustering at the poles are not tribes in the classical anthropological sense. Today’s left- and right-wingers for the most part aren’t inventing myths of shared blood and common ancestry, or binding together in ritual ordeals, or blending in appearance with a common uniform...I think we’re seeing a somewhat different psychological phenomenon: dynamically sorting ourselves into coalitions defined by moralistic condemnation of designated enemies.
From John Hibbing, a political scientist at the University of Nebraska,
...the central political issues of the day revolve around in-group versus out-group, the definition of the in-group, and the unity and security of the in-group...the problem today is that there are so few cross-cutting cleavages. There is only one cleavage and it is the most evolutionarily primal cleavage of them all...people became tribal because the fundamental substantive issues today are about tribe. We are a group-based species.
From Cosmides and Tooby at UC Santa Barbara,
The set of evolved programs that enable and drive warfare and politics strongly overlap with the set of evolved programs that drive human morality. The mapping of these evolved programs and their embedded circuit logic is only in its infancy, and we have only sketched out some of the known or predicted features of our coalitional and moral psychologies. However, progress in this enterprise holds out the possibility of gradually throwing light on some of the darkest areas of human life...everybody benefits from participating in groups of alliances and factions on different scales, and people also benefit by fractionating solidarity in such a way that those on the far side of the boundary seem undesirable, worth spurning, contemptible, deplorable.
And, the most sobering note from NYU psychologist Jonathan Haidt:
I am expecting that America’s political dysfunction and anger will worsen, and will continue to worsen even after Donald Trump leaves the White House....The reasons for my pessimism are that 1) social media gets ever more effective at drowning us in outrage; 2) overall trust in institutions continues to decline, which makes it seem ever more urgent that “our” side take total control; 3) the younger generations have not seen effective political institutions or norms during their lives, and also seem less adept at handling political disagreements; and 4) the norms of campus regarding call-out culture seem to be spreading quickly into business and many other institutions.