From the Bach Collegium Munchen....

The emotional resonance of this magnificent high church music pierces right through my materialistic rationalist armor. The setting of this performance reminds me of my week in Munich this summer, and visits to several of its Baroque churches.

How our brains keep multiple things in mind.

Siegel et al. have made a fundamental advance in revealing how the brain manages to keep multiple things in mind in our working (short term) memory system. A review by Vogel and Fukada in the same issue of PNAS gives a nice description of the context and nature of the experiments:

...brain oscillations are thought to provide a vehicle for coordinating and sharing information within a given cortical region as well as a means of communicating signals between different brain areas. Oscillations can occur across a number of different frequency bands, ranging from very slow cycles (4–7 Hz, theta band) to very fast cycles (25–100 Hz, gamma band). In the context of working memory, oscillations in the gamma band have been proposed to play a fundamental role in linking up the various attributes of the memoranda (e.g., position, shape, color, etc.) across numerous individual neurons into a unified working memory representation. However, if working memories are all represented in the same gamma oscillation, how do we manage to keep from blurring all of the active memories together? One solution that has been proposed in a number of computational models has been to keep the memories separated by positioning each one in a different phase within the oscillation. That is, individual memories can be kept segregated, so long as they are “out of phase” with one another in the oscillation.

...the study by Siegel et al. appears to provide the first demonstration of such a phase-coding scheme in the brain for working memory. To do this, they recorded the local field potential over the prefrontal cortex while monkeys performed a sequential short-term memory task. In this task, monkeys are shown two pictures, one at a time, that they had to remember. After a short delay, memory was tested by presenting three pictures simultaneously; two of which were the pictures they had seen earlier in the trial, and one was a novel picture. To perform correctly, the monkey responded by initially looking at the first picture in the original sequence, then looking at the second picture, but not the novel picture. This task requires them to actively remember both of the pictures from the sequence and the order of presentation. By examining the gamma oscillation over prefrontal cortex during the blank delay period while these memories were being maintained in mind, Siegel et al. found that the two remembered objects were represented in distinct phase orientations of the oscillation depending on the order of presentation. That is, the first object of the sequence was preferentially coded in one phase orientation, and the second object was always in a separate phase orientation. Thus, they found direct evidence that the brain kept these two active memories separated by keeping them out of phase.

From Siegal et al's abstract:

We recorded neuronal activity from the prefrontal cortices of monkeys remembering two visual objects over a brief interval. We found that during this memory interval prefrontal population activity was rhythmically synchronized at frequencies around 32 and 3 Hz and that spikes carried the most information about the memorized objects at specific phases. Further, according to their order of presentation, optimal encoding of the first presented object was significantly earlier in the 32 Hz cycle than that for the second object. Our results suggest that oscillatory neuronal synchronization mediates a phase-dependent coding of memorized objects in the prefrontal cortex. Encoding at distinct phases may play a role for disambiguating information about multiple objects in short-term memory.

One more light show...

Amazing Grace Techno - Computer Controlled Christmas Lights from Richard Holdman on Vimeo.

The "protocol society"

In a recent Op-Ed piece Brooks makes some points about the new economy:

In the 19th and 20th centuries we made stuff: corn and steel and trucks. Now, we make protocols: sets of instructions. A software program is a protocol for organizing information. A new drug is a protocol for organizing chemicals. Wal-Mart produces protocols for moving and marketing consumer goods. Even when you are buying a car, you are mostly paying for the knowledge embedded in its design, not the metal and glass...Physical stuff is subject to the laws of scarcity: you can use up your timber. But it’s hard to use up a good idea. Prices for material goods tend toward equilibrium, depending on supply and demand. Equilibrium doesn’t really apply to the market for new ideas.

A protocol economy tends toward inequality because some societies and subcultures have norms, attitudes and customs that increase the velocity of new recipes while other subcultures retard it. Some nations are blessed with self-reliant families, social trust and fairly enforced regulations, while others are cursed by distrust, corruption and fatalistic attitudes about the future. It is very hard to transfer the protocols of one culture onto those of another...When the economy was about stuff, economics resembled physics. When it’s about ideas, economics comes to resemble psychology.

For the season...

Can't let the holiday pass without a light show:

'Tis the season to be generous'...but watch the testosterone

A nice nugget from Zak et al:

How do human beings decide when to be selfish or selfless? In this study, we gave testosterone to 25 men to establish its impact on prosocial behaviors in a double-blind within-subjects design. We also confirmed participants' testosterone levels before and after treatment through blood draws. Using the Ultimatum Game from behavioral economics, we find that men with artificially raised T, compared to themselves on placebo, were 27% less generous towards strangers with money they controlled. This effect scales with a man's level of total-, free-, and dihydro-testosterone (DHT). Men in the lowest decile of DHT were 560% more generous than men in the highest decile of DHT. We also found that men with elevated testosterone were more likely to use their own money punish those who were ungenerous toward them. Our results continue to hold after controlling for altruism. We conclude that elevated testosterone causes men to behave antisocially.

More on the psychology of Liberals and Conservatives

Michael Shermer does an interesting column on this topic in the December Scientific American. It focuses mainly on the work of Jonathan Haidt, who explains liberal and conservative stereotypes in terms of his Moral Foundations Theory...

Haidt proposes that the foundations of our sense of right and wrong rest within “ ve innate and universally available psychological systems” that might be summarized as follows:
1. Harm/care: Evolved mammalian attachment systems mean we can feel the pain of others, giving rise to the virtues of kindness, gentleness and nurturance.
2. Fairness/reciprocity: Evolved reciprocal altruism generates a sense of justice.
3. Ingroup/loyalty: Evolved in-group tribalism leads to patriotism.
4. Authority/respect: Evolved hierarchical social structures translate to respect for authority and tradition.
5. Purity/sanctity: Evolved emotion of disgust related to disease and contamination underlies our sense of bodily purity.

Over the years Haidt and his University of Virginia colleague Jesse Graham have surveyed the moral opinions of more than 110,000 people from dozens of countries and have found this consistent difference: self-reported liberals are high on 1 and 2 (harm/ care and fairness/reciprocity) but are low on 3, 4 and 5 (ingroup/loyalty, authority/respect and purity/sanctity), whereas selfreported conservatives are roughly equal on all five dimensions, although they place slightly less emphasis on 1 and 2 than liberals do. (Take the survey yourself.)

Clever octopus, using tools.

No sooner do I get back from a restaurant in which I had a marvelous octopus ceviche, than I come across this video. 

The origins of tidyness.

Turns out that ~800,000 year old Neanderthal dwellings excavated in Israel show signs of separate "activity areas" such as hearths, stone-tool knapping areas, food preparation areas, sleeping areas, etc. (added note: this morning's NYTimes has an article on the work)

Editor's choice at the Journal of Behavioral and Brain Science

Back in the dark ages I had an article in a special issue of Behavioral and Brain Science (in an issue devoted to publishing the papers given at a meeting on vision - "Controversies in Neuroscience III: Signal Transduction in the Retina and Brain"). They put me on the mailing list of reviewers, which is how I can occasionally pass on interesting papers that are appearing in the journal.   A recent email offered a list of articles what the editors found most interesting.  I've enjoyed reading several of them.   Here is that list, with links:

Consciousness, accessibility, and the mesh between psychology and neuroscience -  Ned Block

The myth of language universals: Language diversity and its importance for cognitive science -  Nicholas Evans and Stephen C. Levinson

Understanding and sharing intentions: The origins of cultural cognition (a PDF download) - Michael Tomasello, Malinda Carpenter, Josep Call, Tanya Behne, and Henrike Moll

Consciousness without a cerebral cortex: A challenge for neuroscience and medicine Bjorn Merker

Resolving the paradox of common, harmful, heritable mental disorders: Which evolutionary genetic models work best?  - Matthew C. Keller and Geoffrey Miller

Précis of the book: "Principles of Brain Evolution" - Georg F. Striedter

Cruelty's rewards: The gratification of perpetrators and spectators  - Victor Nell

How to lie more skillfully

Just apply transcranial direct current stimulation (tDCS) to your anterior prefrontal cortex (aPFC). From Karim et al:

Recent neuroimaging studies have indicated a predominant role of the anterior prefrontal cortex (aPFC) in deception and moral cognition, yet the functional contribution of the aPFC to deceptive behavior remains unknown. We hypothesized that modulating the excitability of the aPFC by transcranial direct current stimulation (tDCS) could reveal its functional contribution in generating deceitful responses. Forty-four healthy volunteers participated in a thief role-play in which they were supposed to steal money and then to attend an interrogation with the Guilty Knowledge Test. During the interrogation, participants received cathodal, anodal, or sham tDCS. Remarkably, inhibition of the aPFC by cathodal tDCS did not lead to an impairment of deceptive behavior but rather to a significant improvement. This effect manifested in faster reaction times in telling lies, but not in telling the truth, a decrease in sympathetic skin-conductance response and feelings of guilt while deceiving the interrogator and a significantly higher lying quotient reflecting skillful lying. Increasing the excitability of the aPFC by anodal tDCS did not affect deceptive behavior, confirming the specificity of the stimulation polarity. These findings give causal support to recent correlative data obtained by functional magnetic resonance imaging studies indicating a pivotal role of the aPFC in deception.

Neuromarketing nonsense

A blog reader pointed out to me this nice popular press debunking, by Sally Satel (interestingly, a resident scholar at the American Enterprise Institute), of the headset marketed by EmSense to gauge consumer reactions to advertising and products. The company website is notably lacking in documentation of any studies supporting their claims.  Here are clips from Satel's piece:

Neuromarketers are becoming the next generation of Mad Men. They are working for companies like Google, Frito-Lay and Disney. But instead of directly asking consumers whether they like a product, neuromarketers are asking their brains....Using electroencephalography (EEG)--a technology typically used by neurologists to diagnose seizures--marketers measure brain wave activity in response to advertisements and products. Electrodes placed on the subject's scalp collect the data. The consumer herself doesn't say a thing.

And that's the point. In the new world of neuromarketing, it is the more immediate, unedited emotional brain-level reaction to a product or ad that presumably indicates what the consumer really wants, even if she doesn't really know it. The rational and deliberate responses elicited in focus groups are considered unreliable....No wonder EmSense, a San Francisco-based market research company, succeeded in raising $9 million in capital last month....EmSense tests products with a band-like EEG device called the Emband that goes across the consumer's forehead. As she shops, the four sensors contained in the Emband collect data that, according to the company Web site, "open a window into the mind of the consumer."

Brain activation detected through the band's sensors is believed to signal the consumer's emotional engagement with a product. Engagement, in turn, is essential to sustaining interest and in enhancing memorability, important for developing brand loyalty. Yet the practical dimensions of neuromarketing are far from well-established.

First, how well does EEG detect emotion? It can gauge alertness, yes, but the more subtle kinds of mental states that relate to purchasing decisions--such as attraction, disgust, nostalgia or aspirational fantasy--are not accessible via brain wave analysis....Second, the notion of a discrete "buy button in the brain," as marketers call the holy grail of marketing, is deeply naive. Response to the shape, smell and color of a product is the culmination of complex processes that engage many areas of the brain...there is nothing close to a direct path between brain activation and actual consumer behavior.

Third, and most important, we still don't know whether any measure of neural activity predicts actual market performance or sales better than existing methods. Right now the data that are trumpeted by neuromarketers as revelatory have not been published in peer-reviewed journals. Nor has testing occurred under real-world circumstances in which consumers juggle their pocketbooks, the foreseeable reaction from spouse (you bought what?!?), other purchases they have recently made and even their mood at the time they go shopping.

Companies don't sell to brains; they sell to people. And human actions are determined by an array of motives and impulses that come into play once the subject removes the EEG apparatus from her head....Until the EEG marketing paradigm can prove itself to independent scientists, consumer actions will always speak louder than brain activation. Nonetheless, the allure of neuromarketing is obvious: Traditional focus groups seem too fuzzy and subjective; brain technology is objective, measurable and scientific...Having raised an impressive $9 million, the least one can safely say about EmSense is that it surely knows how to market itself. But whether EmSense, or other neuromarketers for that matter, can deliver on their high-tech promises remains to be seen.

Transiently blocking our concern for our good reputation

A fascinating open access piece by Knoch et al shows that brief disruption of our right lateral prefrontal cortex with low-frequency repetitive transcranial magnetic stimulation diminishes our ability to build a favorable reputation (by increasing our tendency to defect in a game of trust), even though ability to recognize both the fairness standards necessary for acquiring a good reputation and its future benefits are intact. This may help explain why reputation formation remains less prominent in most other species with less developed prefrontal cortices.

Reputation formation pervades human social life. In fact, many people go to great lengths to acquire a good reputation, even though building a good reputation is costly in many cases. Little is known about the neural underpinnings of this important social mechanism, however. In the present study, we show that disruption of the right, but not the left, lateral prefrontal cortex (PFC) with low-frequency repetitive transcranial magnetic stimulation (rTMS) diminishes subjects' ability to build a favorable reputation. This effect occurs even though subjects' ability to behave altruistically in the absence of reputation incentives remains intact, and even though they are still able to recognize both the fairness standards necessary for acquiring and the future benefits of a good reputation. Thus, subjects with a disrupted right lateral PFC no longer seem to be able to resist the temptation to defect, even though they know that this has detrimental effects on their future reputation. This suggests an important dissociation between the knowledge about one's own best interests and the ability to act accordingly in social contexts. These results link findings on the neural underpinnings of self-control and temptation with the study of human social behavior, and they may help explain why reputation formation remains less prominent in most other species with less developed prefrontal cortices.

Eldest children are less cooperative, trusting, and reciprocating

In a brief review titled "Why your older brother didn't share" ScienceNow points to interesting work by Courtiol et al. Their abstract:

Explaining the behavioural variations observed between individuals is an important step for understanding the evolution of human cooperation and personality traits. Birth order is a potentially important variable that implies physical and cognitive differences between siblings and differential access to parental resources during childhood. These differences have been shown to influence several personality characteristics in adulthood. We tested the hypothesis that birth order can shape adult cooperative behaviours towards nonkin. An anonymous investment game was played by 510 unrelated students. The results of the game show that firstborns were less trustful and reciprocated less than others. No significant differences in trust or reciprocity were found among laterborn and only children based on birth order. Firstborn status was a better predictor of cooperativeness than age, sex, income or religion. These results constitute some of the first experimental evidence that birth order differences established within the family can persist in adult behaviour among nonkin. We discuss the implications of this finding for the evolution of human cooperation.

Spoken language and symbolic gestures processed by same brain areas

Xu et al perform MRI measurements that suggest that anterior and posterior perisylvian areas identified since the mid-19th century as the core of the brain's language system (including Broca's and Wernicke's area) may in fact function as a modality-independent semiotic system that plays a broader role in human communication, linking meaning with symbols whether these are words, gestures, images, sounds, or objects.

Symbolic gestures, such as pantomimes that signify actions (e.g., threading a needle) or emblems that facilitate social transactions (e.g., finger to lips indicating “be quiet”), play an important role in human communication. They are autonomous, can fully take the place of words, and function as complete utterances in their own right. The relationship between these gestures and spoken language remains unclear. We used functional MRI to investigate whether these two forms of communication are processed by the same system in the human brain. Responses to symbolic gestures, to their spoken glosses (expressing the gestures' meaning in English), and to visually and acoustically matched control stimuli were compared in a randomized block design....esults support a model in which bilateral modality-specific areas in superior and inferior temporal cortices extract salient features from vocal-auditory and gestural-visual stimuli respectively. However, both classes of stimuli activate a common, left-lateralized network of inferior frontal and posterior temporal regions in which symbolic gestures and spoken words may be mapped onto common, corresponding conceptual representations. We suggest that these anterior and posterior perisylvian areas, identified since the mid-19th century as the core of the brain's language system, are not in fact committed to language processing, but may function as a modality-independent semiotic system that plays a broader role in human communication, linking meaning with symbols whether these are words, gestures, images, sounds, or objects.

Figure - Common areas of activation for processing symbolic gestures and spoken language minus their respective baselines, identified using a random effects conjunction analysis. The resultant t map is rendered on a single subject T1 image: 3D surface rendering above, axial slices with associated z axis coordinates, below.

When seeing outweighs feeling.

Anders et al. make an interesting observation on patients who are blind in part of their visual field due to damage of a portion of the visual cortex. They still register negative feelings and somatic changes when a threatening stimulus is presented to their blind area, presumably due to sub-cortical pathways. However, when the visual stimulus is visible and receives full cortical processing, the patients’ phenomenal experience of affect does not closely reflect somatic changes. This decoupling of phenomenal affective experience and somatic changes is associated with an increase of activity in the left ventrolateral prefrontal cortex and a decrease of affect-related somatosensory activity. Here is their abstract:

Affective neuroscience has been strongly influenced by the view that a ‘feeling’ is the perception of somatic changes and has consequently often neglected the neural mechanisms that underlie the integration of somatic and other information in affective experience. Here, we investigate affective processing by means of functional magnetic resonance imaging in nine cortically blind patients. In these patients, unilateral postgeniculate lesions prevent primary cortical visual processing in part of the visual field which, as a result, becomes subjectively blind. Residual subcortical processing of visual information, however, is assumed to occur in the entire visual field. As we have reported earlier, these patients show significant startle reflex potentiation when a threat-related visual stimulus is shown in their blind visual field. Critically, this was associated with an increase of brain activity in somatosensory-related areas, and an increase in experienced negative affect. Here, we investigated the patients’ response when the visual stimulus was shown in the sighted visual field, that is, when it was visible and cortically processed. Despite the fact that startle reflex potentiation was similar in the blind and sighted visual field, patients reported significantly less negative affect during stimulation of the sighted visual field. In other words, when the visual stimulus was visible and received full cortical processing, the patients’ phenomenal experience of affect did not closely reflect somatic changes. This decoupling of phenomenal affective experience and somatic changes was associated with an increase of activity in the left ventrolateral prefrontal cortex and a decrease of affect-related somatosensory activity. Moreover, patients who showed stronger left ventrolateral prefrontal cortex activity tended to show a stronger decrease of affect-related somatosensory activity. Our findings show that similar affective somatic changes can be associated with different phenomenal experiences of affect, depending on the depth of cortical processing. They are in line with a model in which the left ventrolateral prefrontal cortex is a relay station that integrates information about subcortically triggered somatic responses and information resulting from in-depth cortical stimulus processing. Tentatively, we suggest that the observed decoupling of somatic responses and experienced affect, and the reduction of negative phenomenal experience, can be explained by a left ventrolateral prefrontal cortex-mediated inhibition of affect-related somatosensory activity.

A biological rationale for musical scales

An interesting article from Gill and Purves on musical scales, and how humans use only a few of the enormous number of possible tone combinations to create music. I found the illustrations to be fascinating and very educational:

Scales are collections of tones that divide octaves into specific intervals used to create music. Since humans can distinguish about 240 different pitches over an octave in the mid-range of hearing, in principle a very large number of tone combinations could have been used for this purpose. Nonetheless, compositions in Western classical, folk and popular music as well as in many other musical traditions are based on a relatively small number of scales that typically comprise only five to seven tones. Why humans employ only a few of the enormous number of possible tone combinations to create music is not known. Here we show that the component intervals of the most widely used scales throughout history and across cultures are those with the greatest overall spectral similarity to a harmonic series. These findings suggest that humans prefer tone combinations that reflect the spectral characteristics of conspecific vocalizations. The analysis also highlights the spectral similarity among the scales used by different cultures.

Rapid amygdala activation by fearful objects in our peripheral vision

Bayle et al. use Magnetoencephalography (MEG) to show that fearful objects presented to our peripheral field of vision while we are consciously looking at a central object cause rapid (80 msec) activation of the amygdala. If the fearful stimulus is presented to our central field of view and processed by the classical occipito-temporal visual pathway, it takes between 140 and 190 ms to register. Some clips:

In ecological situations, threatening stimuli often come out from the peripheral vision. Such aggressive messages must trigger rapid attention to the periphery to allow a fast and adapted motor reaction... Fearful and neutral faces were briefly presented in the central or peripheral visual field, and were followed by target faces stimuli. An event-related beamformer source analysis model was applied in three time windows following the first face presentations: 80 to 130 ms, 140 to 190 ms, and 210 to 260 ms. The frontal lobe and the right internal temporal lobe part, including the amygdala, reacted as soon as 80 ms of latency to fear occurring in the peripheral vision. For central presentation, fearful faces evoked the classical neuronal activity along the occipito-temporal visual pathway between 140 and 190 ms...Thus, the high spatio-temporal resolution of MEG allowed disclosing a fast response of a network involving medial temporal and frontal structures in the processing of fear related stimuli occurring unconsciously in the peripheral visual field.

A related study is offered by Sabatinelli et al., who examine the timing of emotional discrimination in the amygdala and ventral visual cortex.

Sequence of presentation influences our choice between alternatives.

FromMantonakis et al.:

When several choice options are sampled one at a time in a sequence and a single choice of the best option is made at the end of the sequence, which location in the sequence is chosen most often? We report a large-scale experiment that assessed tasting preferences in choice sets of two, three, four, or five wines. We found a large primacy effect—the first wine had a large advantage in the end-of-sequence choice. We also found that participants who were knowledgeable about wines showed a recency effect in the longer sequences.

The model they propose to explain their findings is interesting:

We propose that two biases operated within that sequential competitive evaluation process. First, a first-is-best bias accounts for the consistent primacy effect. Second, a bias in favor of each new wine among high-knowledge participants accounts for the recency effect, and for an interesting reason: Compared with the low-knowledge participants, the high-knowledge participants were more persistent in looking for a better wine later in the sequence—a plausible result of greater expertise. Thus, high-knowledge participants were likelier to make a comparison between their current favorite and the new wine when each new wine was sampled. Thus, there was a substantial chance that each new wine would beat the current favorite, and this habit produced the pronounced recency effect in longer sequences, especially for high-knowledge participants. For example, suppose that each new wine has a .30 chance of beating the current favorite, and the current favorite remains the preferred choice with a .70 probability. Note that these values are consistent with the size of the observed primacy effects (e.g., the first wine was chosen with approximately .70 probability in the two-option sets) and with the recency effects for the high-knowledge participants (the last wine was chosen with approximately .30 probability in the four-option and five-option sets).

We account for the lack of recency effects among the low-knowledge participants by proposing that they followed the pair-wise competitive-evaluation strategy less vigorously than the high-knowledge participants, eliminating the potential recency advantage. We speculate that the low-knowledge participants were more likely to be overwhelmed by the cognitive demands of the pair-wise competitive strategy as memory load and interference increased across the sampling trials.

The pair-wise model provides an almost perfect fit to the data if we add one more assumption about the comparison process. Thus far, we have assumed that all current favorites have a .70-versus-.30 advantage in all pair-wise comparisons. But if we suppose that the current-favorite advantage increases for later favorites (e.g., if the third option wins its pair-wise competition, its advantage increases to .75 vs. .25; if the fourth wins, its advantage is .80 vs. .20), then the model fits the data almost perfectly. This pair-wise-competition process model is impressive; its one failing is that it predicts a small recency effect for the three-option set for high-knowledge participants.

Experiencing our causality warps our sense of time.

Buehner et al. make the interesting observation that two events we know to be causally related are experienced as closer in time than similar unrelated events.  Thus, expectation warps our sense of time. :

According to widely held views in cognitive science harking back to David Hume, causality cannot be perceived directly, but instead is inferred from patterns of sensory experience, and the quality of these inferences is determined by perceivable quantities such as contingency and contiguity. We report results that suggest a reversal of Hume's conjecture: People's sense of time is warped by the experience of causality. In a stimulus-anticipation task, participants' response behavior reflected a shortened experience of time in the case of target stimuli participants themselves had generated, relative to equidistant, equally predictable stimuli they had not caused. These findings suggest that causality in the mind leads to temporal binding of cause and effect, and extend and generalize beyond earlier claims of intentional binding between action and outcome.