The Threatening Scent of Fertile Women

I've finally had time to check out the abundant links to background articles in John Tierney's Feb. 21 article in the NYTimes. I had not realized that there was such firm evidence that men can unconsciously detect, via changes in womens' cues and behavior and perhaps via pheromones, when women are at the ovulation stage of their menstrual cycle.

...recent studies have found large changes in cues and behavior when a woman is at this stage of peak fertility. Lap dancers get much higher tips (unless they’re taking birth-control pills that suppress ovulation, in which case their tips remain lower). The pitch of a woman’s voice rises. Men rate her body odor as more attractive and respond with higher levels of testosterone.

I would recommend reading the whole article, which describes experiments supporting rather elaborate evolutionary psychology theories about maintaining breeding relationships while also enhancing genetic diversity, such as:

...the “good genes” evolutionary explanation for adultery: a quick fling with a good-looking guy can produce a child with better genes, who will therefore have a better chance of passing along the mother’s genes. But this sort of infidelity is risky if the woman’s unsexy long-term partner finds out and leaves her alone to raise the child. So it makes sense for her to limit her risks by being unfaithful only at those times she’s fertile....By that same evolutionary logic, it makes sense for her partner to be most worried when she’s fertile.

Hugs follow a 3-second rule.

A fascinating bit from ScienceNow points to work by Emese Nagy:

How long does a hug lasts? The quick answer is about 3 seconds, according to Nagy's study of the post-competition embraces of Olympic athletes. The long answer is more profound. A hug lasts about as much time as many other human actions and neurological processes, which supports a hypothesis that we go through life perceiving the present in a series of 3-second windows...Crosscultural studies dating back to 1911 have shown that people tend to operate in 3-second bursts. Goodbye waves, musical phrases, and infants' bouts of babbling and gesturing all last about 3 seconds. Many basic physiological events, such as relaxed breathing and certain nervous system functions do, too. And several other species of mammals and birds follow the general rule in their body-movement patterns. A 1994 study of giraffes, okapis, roe deer, raccoons, pandas, and kangaroos living in zoos, for example, found that although the duration of the animals' every move, from chewing to defecating, varied considerably, the average was...3 seconds...The results reinforce an idea current among some psychologists that intervals of about 3 seconds are basic temporal units of life that define our perception of the present moment...the "feeling of nowness" tends to last 3 seconds.

Hope over experience - the persistence of optimism

Many studies have shown that people are excessively optimistic about marriage, work, sports, health, and life expectancy. Maasey et al. have asked: does such optimism persists as people acquire feedback from real-world experiences? And, second, is optimism actually caused by desire or hope? These are important question, for many of life’s most consequential decisions (e.g., about health, investments, or relationships) feature both strong preferences and the chance to revise beliefs in light of new information (e.g., medical exams, balance statements, or a second date). They asked National Football League (NFL) fans to predict game outcomes before each week of the 17-week NFL season. Studying football predictions offered four important benefits:

First, the 17-week season provided participants with quick, frequent, and unambiguous feedback over a significant (and nonarbitrary) duration of time, and thus it provided an ideal context for evaluating the effect of experience on optimism. Second, NFL fans’ preferences for their favorite teams are strong and often held with a degree of intensity unlikely to be generated by incentives offered in the laboratory. Third, a number of alternative explanations for the effects of desirability, such as those implicating team strength and familiarity, can be controlled methodologically and statistically. Finally, unlike predictions in other emotionally important domains, football predictions offer the benefit of objective benchmarks—both ex ante and ex post—against which the accuracy of predictions can be evaluated.

Their results:

We found that people are optimistic in their predictions—they judge preferred outcomes to be more likely than nonpreferred outcomes. We extended this observation in two important ways. First, we showed that optimism persists despite extensive experience—football fans are as optimistic after 4 months of feedback as they are after 4 weeks of feedback. Second, we found that desirability fueled this optimistic bias. Using four distinct tests, and a wide variety of control variables, we found that optimistic predictions were robust and uniquely related to the desirability of the outcome.

Happy people live longer.

It's a common assumption that happier people live longer, but the convincing data on this has not been easy to come by. Studies have offered widely different and competing findings - some finding no causation or reverse causation, others suggesting that unidentified, unobserved factors influence both happiness and longevity and health. Frey points to work by Diener and Chan showing that many kinds of studies, using different methods, conclude that happiness has a positive causal effect on longevity and physiological health. One of the studies noted by their survey is a meta-analysis based on 24 studies that estimates that happy people live 14% longer than persons who report that they are unhappy. In a survey of people living in industrial countries, happier people enjoy an increased longevity of between 7.5 and 10 years. Happier people are also less likely to commit suicide, and they are less often the victims of accidents...In longitudinal studies individuals are followed over many years, to identify whether the happier ones live longer. In the famous "nun study" researchers asked young women about their subjective happiness level before they entered a monastery. Those who perceived themselves to be happier died at a median age of 93.5 years. Those who considered themselves to be less happy died at a median age of 86.6 years.

Conscious attention influences unconscious cognition.

This work by Martens et al. demonstrates that our conscious attention to one task area (such as noting geometric shapes) can sensitize unconscious processes in that area such as subliminal priming (facilitatory effects elicited by masked stimuli that are not consciously perceived.) This shows that unconscious processing is crucially dependent on top-down attention, and contrasts with the classical view that unconscious cognition is characterized by the lack of top-down influences.

Are unconscious processes susceptible to attentional influences? In two subliminal priming experiments, we investigated whether task sets differentially modulate the sensitivity of unconscious processing pathways. We developed a novel procedure for masked semantic priming of words (Experiment 1) and masked visuomotor priming of geometrical shapes (Experiment 2). Before presentation of the masked prime, participants performed an induction task in which they attended to either semantic or perceptual object features designed to activate a semantic or perceptual task set, respectively. Behavioral and electrophysiological effects showed that the induction tasks differentially modulated subliminal priming: Semantic priming, which involves access to conceptual meaning, was found after the semantic induction task but not after the perceptual induction task. Visuomotor priming was observed after the perceptual induction task but not after the semantic induction task. These results demonstrate that unconscious cognition is influenced by attentional control. Unconscious processes in perceptual and semantic processing streams are coordinated congruently with higher-level action goals.

Go easy on yourself...

Being a self critical person who rarely gets off his own case,  I was considerably softened by a Sarah Parker-Pope article in this morning's Science section of the NYTimes on:

...a burgeoning new area of psychological research called self-compassion — how kindly people view themselves...The research suggests that giving ourselves a break and accepting our imperfections may be the first step toward better health. People who score high on tests of self-compassion have less depression and anxiety, and tend to be happier and more optimistic. Preliminary data suggest that self-compassion can even influence how much we eat and may help some people lose weight.

The article contains links to several original research papers.

Sharing the spoils develops early in humans.

From Tomasello and collaborators:

Egalitarian behavior is considered to be a species-typical component of human cooperation. Human adults tend to share resources equally, even if they have the opportunity to keep a larger portion for themselves. Recent experiments have suggested that this tendency emerges fairly late in human ontogeny, not before 6 or 7 years of age. Here we show that 3-year-old children share mostly equally with a peer after they have worked together actively to obtain rewards in a collaboration task, even when those rewards could easily be monopolized. These findings contrast with previous findings from a similar experiment with chimpanzees, who tended to monopolize resources whenever they could. The potentially species-unique tendency of humans to share equally emerges early in ontogeny, perhaps originating in collaborative interactions among peers.

Politics in Madison, WI

I spend the spring, summer, and fall months in Madison, WI., writing this blog from my university office there, and so have been closely following the theatrical union busting efforts of the new Republican majority.  With all the agonizing over long term debt incurred by the states, I thought this graphic from yesterday's NY Times Magazine, from an article on New Jersey governor Christie, was revealing (click on figure to enlarge): 

Improving your cognitive toolkit - V

Continuation of my abstracting of a few of the answers to the annual question at edge.org, "What scientific concept would improve everybody's cognitive toolkit?":

Daniel Dennett - Look for the Cycles

A good rule of thumb...when confronting the apparent magic of the world of life and mind is: look for the cycles that are doing all the hard work....it turns out that all the "magic" of cognition depends, just as life itself does, on cycles within cycles of recurrent, re-entrant, reflexive information-transformation processes from the biochemical scale within the neuron to the whole brain sleep cycle, waves of cerebral activity and recovery revealed by EEGs. Computer programmers have been exploring the space of possible computations for less than a century, but their harvest of invention and discovery so far includes millions of loops within loops within loops. The secret ingredient of improvement is always the same: practice, practice, practice.

Andy Clark - We are engines of prediction

The basic idea is simple, the brain is basically an engine of prediction. To perceive the world is to successfully predict our own sensory states. The brain uses stored knowledge about the structure of the world and the probabilities of one state or event following another to generate a prediction of what the current state is likely to be, given the previous one and this body of knowledge. Mismatches between the prediction and the received signal generate error signals that nuance the prediction or (in more extreme cases) drive learning and plasticity.

Some Implications:

First, the notion of good ('veridical') sensory contact with the world becomes a matter of applying the right expectations to the incoming signal...Second, the time course of perception becomes critical. Predictive coding models suggest that what emerges first is the general gist (including the general affective feel) of the scene, with the details becoming progressively filled in as the brain uses that larger context — time and task allowing — to generate finer and finer predictions of detail...Third, the line between perception and cognition becomes blurred. What we perceive (or think we perceive) is heavily determined by what we know, and what we know (or think we know) is constantly conditioned on what we perceive (or think we perceive)...Fourth, if we now consider that prediction errors can be suppressed not just by changing predictions but by changing the things predicted, we have a simple and powerful explanation for behavior and the way we manipulate and sample our environment. In this view, action is there to make predictions come true.

A potpuorri of almost-posts

As I scan journals' tables of contents and abstracts of articles looking for potential MindBlog posts, I accumulate a list of post candidates. Most never make it into a post, yet are very interesting chunks. My list now is 30 pages long, and I though I would begin to dispel that list by selecting a few to pass as a list of links, hoping that a few readers might find an item useful to them.

Writing about testing worries boosts exam performance.

Memory formation without the hippocampus.

Temporary suppression of fear memories during adolescence.

Solving the cocktail party problem.

Your Brain on Improv....to be creative, you have to have this weird dissociation in your frontal lobe. One area turns on, and a big area shuts off, so that you're not inhibited, so that you're willing to make mistakes, so that you're not constantly shutting down all of these new generative impulses.

Control your spotlight.

Retracted Autism Study.

Past adversity strengthens.

Courage.

Your brain on technology.

Krugman - The New Voodo.

Oliver Sachs - Change your brain.

How stress damages or enhances different aspects of our vision

Richie Davidson, Alex Schackman and colleagues report a fascinating study that demonstrates that stress (painful, but not harmful, random electric shocks delivered to informed consent study participants) makes us more sensitive to our external surroundings as a way of learning where or what a threat may be, but interferes with our ability to do more complex thinking:

Stress can fundamentally alter neural responses to incoming information. Recent research suggests that stress and anxiety shift the balance of attention away from a task-directed mode, governed by prefrontal cortex, to a sensory-vigilance mode, governed by the amygdala and other threat-sensitive regions. A key untested prediction of this framework is that stress exerts dissociable effects on different stages of information processing. This study exploited the temporal resolution afforded by event-related potentials to disentangle the impact of stress on vigilance, indexed by early perceptual activity, from its impact on task-directed cognition, indexed by later postperceptual activity in humans. Results indicated that threat of shock amplified stress, measured using retrospective ratings and concurrent facial electromyography. Stress also double-dissociated early sensory-specific processing from later task-directed processing of emotionally neutral stimuli: stress amplified N1 (184–236 ms) and attenuated P3 (316–488 ms) activity. This demonstrates that stress can have strikingly different consequences at different processing stages. Consistent with recent suggestions, stress amplified earlier extrastriate activity in a manner consistent with vigilance for threat (N1), but disrupted later activity associated with the evaluation of task-relevant information (P3). These results provide a novel basis for understanding how stress can modulate information processing in everyday life and stress-sensitive disorders.

Uncertainty increases romantic attraction

Another interesting bit of work from Daniel Gilbert and collaborators:

This research qualifies a social psychological truism: that people like others who like them (the reciprocity principle). College women viewed the Facebook profiles of four male students who had previously seen their profiles. They were told that the men (a) liked them a lot, (b) liked them only an average amount, or (c) liked them either a lot or an average amount (uncertain condition). Comparison of the first two conditions yielded results consistent with the reciprocity principle. Participants were more attracted to men who liked them a lot than to men who liked them an average amount. Results for the uncertain condition, however, were consistent with research on the pleasures of uncertainty. Participants in the uncertain condition were most attracted to the men—even more attracted than were participants who were told that the men liked them a lot. Uncertain participants reported thinking about the men the most, and this increased their attraction toward the men.

Strategies for remembering.

Two recent articles offer different perspectives on retaining information. The interesting NYTimes magazine article by world class memory athlete Joshua Foer describes an ancient memory training tradition that flourished in ancient Greece before the invention of printing.  Brain imaging of  memory athletes who have engaged this training (who are of ordinary intelligence in virtually all other respects) shows more activation of brain areas known to be involved in spatial memory during memory tasks. The training derives from discoveries of Simonides of Ceos in the fifth century B.C.,

...who reasoned that just about anything could be imprinted upon our memories, and kept in good order, simply by constructing a building in the imagination and filling it with imagery of what needed to be recalled. This imagined edifice could then be walked through at any time in the future. Such a building would later come to be called a memory palace...a short Latin rhetoric textbook called “Rhetorica ad Herennium,” written sometime between 86 and 82 B.C. It is the only comprehensive discussion of the memory techniques attributed to Simonides to have survived into the Middle Ages. The techniques described in this book were widely practiced in the ancient and medieval worlds. Memory training was considered a centerpiece of classical education in the language arts, on par with grammar, logic and rhetoric...What distinguishes a great mnemonist...is the ability to create lavish images on the fly, to paint in the mind a scene so unlike any other it cannot be forgotten. And to do it quickly. Many competitive mnemonists argue that their skills are less a feat of memory than of creativity.

Both ancient and more recent memory enhancement techniques focus on the processing that occurs when we encode knowledge. A recent fairly simple experiment by Karpicke and Blunt suggests the effectiveness of another strategy that emphasizes practice.  From their introduction:

It is beyond question that activities that promote effective encoding, known as elaborative study tasks, are important for learning. However, research in cognitive science has challenged the assumption that retrieval is neutral and uninfluential in the learning process. Not only does retrieval produce learning, but a retrieval event may actually represent a more powerful learning activity than an encoding event. This research suggests a conceptualization of mind and learning that is different from one in which encoding places knowledge in memory and retrieval simply accesses that stored knowledge. Because each act of retrieval changes memory, the act of reconstructing knowledge must be considered essential to the process of learning.

Their abstract:

Educators rely heavily on learning activities that encourage elaborative studying, whereas activities that require students to practice retrieving and reconstructing knowledge are used less frequently. Here, we show that practicing retrieval produces greater gains in meaningful learning than elaborative studying with concept mapping. The advantage of retrieval practice generalized across texts identical to those commonly found in science education. The advantage of retrieval practice was observed with test questions that assessed comprehension and required students to make inferences. The advantage of retrieval practice occurred even when the criterial test involved creating concept maps. Our findings support the theory that retrieval practice enhances learning by retrieval-specific mechanisms rather than by elaborative study processes. Retrieval practice is an effective tool to promote conceptual learning about science.

Improving your cognitive toolkit - IV

Continuation of my abstracting of a few of the answers to the annual question at edge.org, "What scientific concept would improve everybody's cognitive toolkit?":

Charles Seife - Random events in the aggregate behave predictably.

Randomness is daunting; it sets limits where even the most sophisticated theories can not go, shielding elements of nature from even our most determined inquiries. Nevertheless, to say that something is random is not equivalent to saying that we can't understand it. Far from it...Randomness follows its own set of rules — rules that make the behavior of a random process understandable and predictable...These rules state that even though a single random event might be completely unpredictable, a collection of independent random events is extremely predictable — and the larger the number of events, the more predictable they become. The law of large numbers is a mathematical theorem that dictates that repeated, independent random events converge with pinpoint accuracy upon a predictable average behavior. Another powerful mathematical tool, the central limit theorem, tells you exactly how far off that average a given collection of events is likely to be. With these tools, no matter how chaotic, how strange a random behavior might be in the short run, we can turn that behavior into stable, accurate predictions in the long run.

The rules of randomness are so powerful that they have given physics some of its most sacrosanct and immutable laws. Though the atoms in a box full of gas are moving at random, their collective behavior is described by a simple set of deterministic equations. Even the laws of thermodynamics derive their power from the predictability of large numbers of random events; they are indisputable only because the rules of randomness are so absolute...Paradoxically, the unpredictable behavior of random events has given us the predictions that we are most confident in.

Emanuel Derman - Distrust Pragmamorphism

Anthropomorphism means attributing the characteristics of human beings to inanimate things or animals...I have invented the word pragmamorphism as a short-hand extension for the attribution of the properties of inanimate things to human beings...One of the meanings of the Greek word pragma is a material object...It's pragmamorphic to equate material correlates with human psychological states, to equate PET scans with emotion. It's also pragmamorphic to ignore human qualities you cannot measure.

We have discovered useful metrics for material objects -- length, temperature, pressure, volume, kinetic energy, etc. Pragmamorphism is a good word for the attempt to assign such one-dimensional thing-metrics to the mental qualities of humans...IQ, a length scale for intelligence, is a result of pragmamorphism. Intelligence is more diffuse than linear...The utility function in economics is similar. It's clear that people have preferences. But is it clear that there is a function that describes their preferences?

Nicholas Carr - Respect your cognitive load

...our brains can hold only about seven pieces of information simultaneously. Even that figure may be too high. Some brain researchers now believe that working memory has a maximum capacity of just three or four elements...The amount of information entering our consciousness at any instant is referred to as our cognitive load. When our cognitive load exceeds the capacity of our working memory, our intellectual abilities take a hit. Information zips into and out of our mind so quickly that we never gain a good mental grip on it...The information vanishes before we've had an opportunity to transfer it into our long-term memory and weave it into knowledge. We remember less, and our ability to think critically and conceptually weakens. An overloaded working memory also tends to increase our distractedness.

...it's important to remember that, when it comes to the way your brain works, information overload is not just a metaphor; it's a physical state. When you're engaged in a particularly important or complicated intellectual task, or when you simply want to savor an experience or a conversation, it's best to turn the information faucet down to a trickle.

Empire at the End of Decadence

Since MindBlog seems to be doing a political weekend, I'm thinking I should, after yesterday's pointer to George Lakoff, also note the excellent summary by Charles Blow in Friday's NYTimes on the eroding American Empire. Here is the graphic (you should be able to read the small print if you click on the image.)

What conversatives really want.

A great essay from George Lakoff on the real significance of what is going on back in my Madison Wisconsin home.

A Sunday School Hymn - Evolution Made Us All

From The Laughing Squid site, a spoof of a sunday school hymn:


Evolution Made Us All from Ben Hillman on Vimeo.

Suppressing emotions correlates with larger prefrontal cortical area

I'm a "keep calm and carry on" kind of guy, always suppressing my emotional reactivity in charged situations (which is probably why my colleagues said I was a good university department chair back when...). Kühn et al suggest that this might mean that the grey matter (nerve cell) volume of my dorsomedial (top, toward the middle) prefrontal cortex is a bit larger than that of those exploding around me:

There is a growing appreciation that individuals differ systematically in their use of particular emotion regulation strategies. Our aim was to examine the structural correlates of the habitual use of expressive suppression of emotions. Based on our previous research on the voluntary suppression of actions we expected this response-focused emotion regulation strategy to be associated with increased grey matter volume in the dorsomedial prefrontal cortex (dmPFC). On high-resolution MRI scans of 42 college-aged healthy adults we computed optimized voxel-based-morphometry (VBM) to explore the correlation between grey matter volume and inter-individual differences in the tendency to suppress the expression of emotions assessed by means of the Emotion Regulation Questionnaire (Gross & John, 2003). We found a positive correlation between the habitual use of expressive suppression as an emotion regulation strategy and grey matter volume in the dmPFC. No other brain area showed a significant positive or negative correlation with the Emotion Regulation Questionnaire scores. The association between the suppression of expression of emotions and volume in the dmPFC supports the behavioural stability and biological foundation of the concept of this particular emotion regulation strategy within an age-homogenous sample of adults.

Placebo in 3 minutes

This sent by a loyal blog reader, pulled from this Australian site:

Blue-enriched light keeps us alert...

I think I've mentioned before that I used to put natural spectrum florescent lights (with more blue wavelengths) in my research laboratory, because I found it promoted my relaxation and alertness, and my graduate students and post-docs reported the same effect. Chellappa et al. offer yet another study that documents this effect, and relates it to suppression of melatonin levels by blue wavelengths. The observations can be made by simply comparing commercially available compact fluorescent lamps that provide correlated lamp colour temperature in kelvin (K), that indicate the relative proportion of warm versus cool colours in a light source. The authors found that 2-hour exposure to light in the evening with compact fluorescent light at 6500K (blue shifted) will attenuate the expression of endogenous melatonin levels, and also promote an augmentation of subjective and objective alertness levels when compared with lights at 2500K and at 3000K (more yellow). The light with more blue wavelengths has the overall effect of enhancing alertness and performance in cognitive tasks specifically associated with sustained attention.