Narrowing of intersensory speech perception in infancy

From Pons et al.:

The conventional view is that perceptual/cognitive development is an incremental process of acquisition. Several striking findings have revealed, however, that the sensitivity to non-native languages, faces, vocalizations, and music that is present early in life declines as infants acquire experience with native perceptual inputs. In the language domain, the decline in sensitivity is reflected in a process of perceptual narrowing that is thought to play a critical role during the acquisition of a native-language phonological system. Here, we provide evidence that such a decline also occurs in infant response to multisensory speech. We found that infant intersensory response to a non-native phonetic contrast narrows between 6 and 11 months of age, suggesting that the perceptual system becomes increasingly more tuned to key native-language audiovisual correspondences. Our findings lend support to the notion that perceptual narrowing is a domain-general as well as a pan-sensory developmental process.

Racial group membership modulates empathic brain responses.

From Xu et al.:

The pain matrix including the anterior cingulate cortex (ACC) mediates not only first person pain experience but also empathy for others' pain. It remains unknown, however, whether empathic neural responses of the pain matrix are modulated by racial in-group/out-group relationship. Using functional magnetic resonance imaging we demonstrate that, whereas painful stimulations applied to racial in-group faces induced increased activations in the ACC and inferior frontal/insula cortex in both Caucasians and Chinese, the empathic neural response in the ACC decreased significantly when participants viewed faces of other races. Our findings uncover neural mechanisms of an empathic bias toward racial in-group members.


Figure - a, Illustration of Caucasian faces receiving painful and non-painful stimuli. b, Illustration of Chinese faces receiving painful and non-painful stimuli. c, Contrast values of the parameter estimates of signal intensity in the ACC and the frontal cortex that differentiated painful and non-painful stimuli in Caucasians. d, Contrast values of the parameter estimates of signal intensity in the ACC and the frontal cortex that differentiated painful and non-painful stimuli in Chinese. e, Correlation between ACC empathic neural responses to racial in-group and out-group members. X and Y axes respectively indicate ACC empathic responses to racial in-group and racial out-group members indexed in contrast values of painful versus non-painful stimulation. f, Increased activations in the ACC and the frontal/insula cortex shown in whole-brain statistical parametric mapping analyses when participants perceived racial in-group faces. The upper figures show the results from Caucasian subjects and the lower figures show the results from Chinese subjects.

Happiness is just around the corner!

I wish I were taking the same happy pill that Betsy Devine seems to have found... seems a bit Pollyanna to me...

Brain changes caused by encouraging expressions.

Martín-Loeches et al. find that encouraging and discouraging messages elicit a similar long-lasting brain emotional response during a visuospatial task. Further, encouraging expressions are able to alter the customary working pattern of the visual attention system for shape selection in the attended location.

Growing up blind does not change the neural bases of theory of mind.

An interesting piece of work from Bedny et al.

Humans reason about the mental states of others; this capacity is called Theory of Mind (ToM). In typically developing adults, ToM is supported by a consistent group of brain regions: the bilateral temporoparietal junction (TPJ), medial prefrontal cortex (MPFC), precuneus (PC), and anterior temporal sulci (aSTS). How experience and intrinsic biological factors interact to produce this adult functional profile is not known. In the current study we investigate the role of visual experience in the development of the ToM network by studying congenitally blind adults. In experiment 1, participants listened to stories and answered true/false questions about them. The stories were either about mental or physical representations of reality (e.g., photographs). In experiment 2, participants listened to stories about people's beliefs based on seeing or hearing; people's bodily sensations (e.g., hunger); and control stories without people. Participants judged whether each story had positive or negative valance. We find that ToM brain regions of sighted and congenitally blind adults are similarly localized and functionally specific. In congenitally blind adults, reasoning about mental states leads to activity in bilateral TPJ, MPFC, PC, and aSTS. These brain regions responded more to passages about beliefs than passages about nonbelief representations or passages about bodily sensations. Reasoning about mental states that are based on seeing is furthermore similar in congenitally blind and sighted individuals. Despite their different developmental experience, congenitally blind adults have a typical ToM network. We conclude that the development of neural mechanisms for ToM depends on innate factors and on experiences represented at an abstract level, amodally.

Empathetic accuracy

Zaki et al show that the accuracy of attributions made about the mental state of others track with activity in structures within the human mirror neuron system thought to be involved in shared sensorimotor representations, and also with regions implicated in mental state attribution - the superior temporal sulcus and medial prefrontal cortex.

Gender–science stereotypes predict national sex differences in science and math achievement

From Nosek et al:

About 70% of more than half a million Implicit Association Tests completed by citizens of 34 countries revealed expected implicit stereotypes associating science with males more than with females. We discovered that nation-level implicit stereotypes predicted nation-level sex differences in 8th-grade science and mathematics achievement. Self-reported stereotypes did not provide additional predictive validity of the achievement gap. We suggest that implicit stereotypes and sex differences in science participation and performance are mutually reinforcing, contributing to the persistent gender gap in science engagement.

Boiling the frog.

Krugman is right on, as usual. This material on our inability to admit or perceive slow changes is hardly novel (cf. Ornstein and Erlich's "New World, New Mind" from 1989), and one can only hope that marketing efforts like those of Al Gore will bring this glitch in our thinking abilities into more common awareness.

Quiet music to start the week - a Grieg elegy

Grieg Lyric Pieces Op 38 No 6 - Elegy

Caloric restriction enhances longevity in monkeys

It all over the newspapers, but I thought I would pass on the link to work just published by my colleagues at the University of Wisconsin:

Caloric restriction (CR), without malnutrition, delays aging and extends life span in diverse species; however, its effect on resistance to illness and mortality in primates has not been clearly established. We report findings of a 20-year longitudinal adult-onset CR study in rhesus monkeys aimed at filling this critical gap in aging research. In a population of rhesus macaques maintained at the Wisconsin National Primate Research Center, moderate CR lowered the incidence of aging-related deaths. At the time point reported, 50% of control fed animals survived as compared with 80% of the CR animals. Furthermore, CR delayed the onset of age-associated pathologies. Specifically, CR reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy. These data demonstrate that CR slows aging in a primate species.


Figure - Animal appearance in old age. (A and B) Photographs of a typical control animal at 27.6 years of age (about the average life span). (C and D) Photographs of an age-matched animal on caloric restriction.

Face perception - the "Thacher Effect" in monkeys

Our talent for recognizing differences in faces relies on how facial features are configured. But, if the image of a face is flipped, alterations as drastic as inverted mouths and eyes aren't as noticeable — a phenomenon known as the Thatcher effect. Adachi et al. have monitored the length of time rhesus monkeys (Macaca mulatta) look at pictures of monkey faces. Over time, the animals become less interested in all images, but they spend significantly more time looking at the strange, upright altered (Thatcherized) photos than they do looking at the same images upside down. This suggests that perceptual mechanisms for individual recognition have been conserved through primate cognitive evolution.

Doing exactly what you don't want to do.

Dan Wegner has generated an interesting review of a phenomenon that we all know too well. (Wegner is another one of my heroes. He wrote "The Illusion of Conscious Will" - a book that I reference extensively in my "I-Illusion" web lecture and podcast). The subject of the review is the "Imp in your mind" that makes you sometimes blurt out exactly what you are trying to suppress. The theory is that to suppress an insult, for example, the brain must first imagine just that; the very presence of that catastrophic insult, which in turn increases the odds that the brain will spit it out.

In slapstick comedy, the worst thing that could happen usually does: The person with a sore toe manages to stub it, sometimes twice. Such errors also arise in daily life, and research traces the tendency to do precisely the worst thing to ironic processes of mental control. These monitoring processes keep us watchful for errors of thought, speech, and action and enable us to avoid the worst thing in most situations, but they also increase the likelihood of such errors when we attempt to exert control under mental load (stress, time pressure, or distraction). Ironic errors in attention and memory occur with identifiable brain activity and prompt recurrent unwanted thoughts; attraction to forbidden desires; expression of objectionable social prejudices; production of movement errors; and rebounds of negative experiences such as anxiety, pain, and depression. Such ironies can be overcome when effective control strategies are deployed and mental load is minimized.

Mate selection: women not more picky than men?

Sarah Arnquist points to some experiments that question the conventional evolutionary psychology picture that women are pickier than men when choosing a mate. They suggest social conditioning is more important than the usual evolutionary argument that because women have a bigger investment in reproduction — they are the ones who have to endure pregnancy, childbirth and breast-feeding — they need to hedge their bets against selecting a dud to be the father.

Massive technological failure...

Bodanis offers some apocalyptic sentiments.

For a perky start to your day....an Elves' Dance

Grieg Lyric Pieces, Op 12 No 4 Elves' Dance

Feeling the beat....

An open access article from Grahn and Rowe, on premotor and striatal interactions in musicians and nonmusicians during beat perception:

Little is known about the underlying neurobiology of rhythm and beat perception, despite its universal cultural importance. Here we used functional magnetic resonance imaging to study rhythm perception in musicians and nonmusicians. Three conditions varied in the degree to which external reinforcement versus internal generation of the beat was required. The "volume" condition strongly externally marked the beat with volume changes, the "duration" condition marked the beat with weaker accents arising from duration changes, and the "unaccented" condition required the beat to be entirely internally generated. In all conditions, beat rhythms compared with nonbeat control rhythms revealed putamen activity. The presence of a beat was also associated with greater connectivity between the putamen and the supplementary motor area (SMA), the premotor cortex (PMC), and auditory cortex. In contrast, the type of accent within the beat conditions modulated the coupling between premotor and auditory cortex, with greater modulation for musicians than nonmusicians. Importantly, the response of the putamen to beat conditions was not attributable to differences in temporal complexity between the three rhythm conditions. We propose that a cortico-subcortical network including the putamen, SMA, and PMC is engaged for the analysis of temporal sequences and prediction or generation of putative beats, especially under conditions that may require internal generation of the beat. The importance of this system for auditory–motor interaction and development of precisely timed movement is suggested here by its facilitation in musicians.

Neural correlates of our depth of strategic reasoning.

Here is a clip from the introduction to an interesting open access study by Coricellia and Nagel that shows that high-level reasoning and strategic IQ realted to game winning correlates with the neural activity in the medial prefrontal cortex, demonstrating its crucial role in successful mentalizing. The authors use an experimental competitive game, analogous to Keynes's Beauty Contest described below, to characterize the neural systems that mediate different levels of strategic reasoning and mentalizing.

“Professional investment may be likened to those newspaper competitions [Beauty Contest] in which the competitors have to pick out the 6 prettiest faces from a hundred photographs, the prize being awarded to the competitor whose choice most nearly corresponds to the average preferences of the competitors as a whole. It is not a case of choosing those which are really the prettiest, nor even those which average opinion genuinely thinks the prettiest. We have reached the third degree—to anticipating what average opinion expects the average opinion to be. And there are some, I believe, who practise the fourth, fifth, and higher degrees.”

John Maynard Keynes, one of the most influential economists of the 20th century, describes in the above quote different ways of thinking about others in a competitive environment. This can range from low-level reasoning, characterized by self-referential thinking (choosing what you like without considering others' behavior), to higher levels of reasoning, taking into account the thinking of others about others (“third degree”), and so on.

Many features of social and competitive interaction require this kind of reasoning, for example, deciding when to queue for precious theater tickets or when to sell or buy in the stock market before too many others do it. Psychologists and philosophers define this as theory of mind or mentalizing, the ability to think about others' thoughts and mental states to predict their intentions and actions (2–9). Neuroimaging studies have found brain activity related to mentalizing in the medial prefrontal cortex, temporo-parietal junction, superior temporal sulcus, and posterior cingulate cortex. However, little is known about the neural mechanisms underlying the iterated steps of thinking, “what you think the others think about what you think,” and so on. That is, the mechanisms underlying how deeply people think about others, and, particularly, whether deeper mentalizing leads to more successful social outcomes.

Intellectual performance and the efficiency of functional brain networks.

From van den Heuvel et al., an analysis that strongly suggests that our intellectual performance is likely to be related to how efficiently our brain integrates information between multiple brain regions:

Our brain is a complex network in which information is continuously processed and transported between spatially distributed but functionally linked regions. Recent studies have shown that the functional connections of the brain network are organized in a highly efficient small-world manner, indicating a high level of local neighborhood clustering, together with the existence of more long-distance connections that ensure a high level of global communication efficiency within the overall network. Such an efficient network architecture of our functional brain raises the question of a possible association between how efficiently the regions of our brain are functionally connected and our level of intelligence. Examining the overall organization of the brain network using graph analysis, we show a strong negative association between the normalized characteristic path length of the resting-state brain network and intelligence quotient (IQ). This suggests that human intellectual performance is likely to be related to how efficiently our brain integrates information between multiple brain regions. Most pronounced effects between normalized path length and IQ were found in frontal and parietal regions. Our findings indicate a strong positive association between the global efficiency of functional brain networks and intellectual performance.

Most prominent effects between IQ and the level of global connectivity efficiency (as expressed by a shorter node specific normalized path length) were found in the medial prefrontal cortex (yellow box), bilateral inferior parietal cortex (red box depicts effect in right hemisphere), and precuneus/posterior cingulate regions (orange box) of the functional brain network. Shown are correlation coefficient values of those voxels that had a significant negative association between IQ and normalized path length for T = 0.45 (linear regression, p less than 0.05 uncorrected for multiple comparisons, df = 18, corrected for age).

The synchronization of brains

A relevant follow up to the recent posts on Metzinger's book, which discussed the synchronization of our 'ego tunnels': Bharucha suggests that understanding of how brains synchronize — or fail to do so — will be a game-changing scientific development.

Calming aperitif for a Tuesday morning - a Grieg Arietta

This is the first item in Grieg's Lyrical Pieces series, the Arietta Op. 12 No. 1. I'm thinking I might record a series of these short pieces, each of which has a distinctive emotional tone, to punctuate the regular blog posts....