Genetic and environmental relationships between head circumference growth in the first year of life and sociocognitive development in the second year: a longitudinal twin study

Although growth in head circumference (HC) during infancy is known to predict later childhood outcomes, the mechanisms underlying this association with later sociocognitive abilities remain undetermined. Thus, using a sample of 241 pairs of normally developing Japanese twins, this study investigated the underpinnings of the association between HC growth (difference between HC at birth and at 10 months) and sociocognitive abilities at 19 months as measured by 10 items from the M-CHAT. Phenotypic correlations between HC at birth and sociocognitive abilities and between HC growth and sociocognitive abilities were marginal and not significant. However, multivariate genetic analyses using Cholesky decomposition revealed that genetic influences on HC growth and those on sociocognitive abilities were negatively associated. On the other hand, shared and nonshared environmental influences on HC growth were positively associated with influences on sociocognitive abilities. Genetic and environmental influences on HC at birth were not significantly associated with influences on sociocognitive abilities. These results help to clarify the role of brain growth during infancy in the subsequent development of sociocognitive abilities and highlight the importance of examining the different roles of genetic and environmental influences in studies of these areas.     

Sequential learning and rule abstraction in Bengalese finches

The Bengalese finch (Lonchura striata var. domestica) is a species of songbird. Males sing courtship songs with complex note-to-note transition rules, while females discriminate these songs when choosing their mate. The present study uses serial reaction time (RT) to examine the characteristics of the Bengalese finches’ sequential behaviours beyond song production. The birds were trained to produce the sequence with an “A–B–A” structure. After the RT to each key position was determined to be stable, we tested the acquisition of the trained sequential response by presenting novel and random three-term sequences (random test). We also examined whether they could abstract the embedded rule in the trained sequence and apply it to the novel test sequence (abstract test). Additionally, we examined rule abstraction through example training by increasing the number of examples in baseline training from 1 to 5. When considered as (gender) groups, training with 5 examples resulted in no statistically significant differences in the abstract tests, while statistically significant differences were observed in the random tests, suggesting that the male birds learned the trained sequences and transferred the abstract structure they had learned during the training trials. Individual data indicated that males, as opposed to females, were likely to learn the motor pattern of the sequence. The results are consistent with observations that males learn to produce songs with complex sequential rules, whereas females do not.     

Effect of an observer's presence on facial behavior during dyadic communication

In everyday life, people communicate not only with another person but also in front of other people. How do people behave during communication when observed by others? Effects of an observer (presence vs absence) and interpersonal relationship (friends vs strangers vs alone) on facial behavior were examined. Participants viewed film clips that elicited positive affect (film presentation) and discussed their impressions about the clips (conversation). Participants rated their subjective emotions and social motives. Durations of smiles, gazes, and utterances of each participant were coded. The presence of an observer did not affect facial behavior during the film presentation, but did affect gazes during conversation. Whereas the presence of an observer seemed to facilitate affiliation in pairs of strangers, communication between friends was exclusive and not affected by an observer.     

Does simile comprehension differ from metaphor comprehension? A functional MRI study

Since Aristotle, people have believed that metaphors and similes express the same type of figurative meaning, despite the fact that they are expressed with different sentence patterns. In contrast, recent psycholinguistic models have suggested that metaphors and similes may promote different comprehension processes. In this study, we investigated the neural substrates involved in the comprehension of metaphor and simile using functional magnetic resonance imaging (fMRI) to evaluate whether simile comprehension differs from metaphor comprehension or not. In the metaphor and simile sentence conditions, higher activation was seen in the left inferior frontal gyrus. This result suggests that the activation in both metaphor and simile conditions indicates similar patterns in the left frontal region. The results also suggest that similes elicit higher levels of activation in the medial frontal region which might be related to inference processes, whereas metaphors elicit more right-sided prefrontal activation which might be related to figurative language comprehension.     

Sounds exaggerate visual shape

While perceiving speech, people see mouth shapes that are systematically associated with sounds. In particular, a vertically stretched mouth produces a /woo/ sound, whereas a horizontally stretched mouth produces a /wee/ sound. We demonstrate that hearing these speech sounds alters how we see aspect ratio, a basic visual feature that contributes to perception of 3D space, objects and faces. Hearing a /woo/ sound increases the apparent vertical elongation of a shape, whereas hearing a /wee/ sound increases the apparent horizontal elongation. We further demonstrate that these sounds influence aspect ratio coding. Viewing and adapting to a tall (or flat) shape makes a subsequently presented symmetric shape appear flat (or tall). These aspect ratio aftereffects are enhanced when associated speech sounds are presented during the adaptation period, suggesting that the sounds influence visual population coding of aspect ratio. Taken together, these results extend previous demonstrations that visual information constrains auditory perception by showing the converse - speech sounds influence visual perception of a basic geometric feature.     

A unique role of endogenous visual-spatial attention in rapid processing of multiple targets

Visual spatial attention can be exogenously captured by a salient stimulus or can be endogenously allocated by voluntary effort. Whether these two attention modes serve distinctive functions is debated, but for processing of single targets the literature suggests superiority of exogenous attention (it is faster acting and serves more functions). We report that endogenous attention uniquely contributes to processing of multiple targets. For speeded visual discrimination, response times are faster for multiple redundant targets than for single targets because of probability summation and/or signal integration. This redundancy gain was unaffected when attention was exogenously diverted from the targets but was completely eliminated when attention was endogenously diverted. This was not a result of weaker manipulation of exogenous attention because our exogenous and endogenous cues similarly affected overall response times. Thus, whereas exogenous attention is superior for processing single targets, endogenous attention plays a unique role in allocating resources crucial for rapid concurrent processing of multiple targets.     

Audition dominates vision in duration perception irrespective of salience,attention, and temporal discriminability

Whereas the visual modality tends to dominate over the auditory modality in bimodal spatial perception, the auditory modality tends to dominate over the visual modality in bimodal temporal perception. Recent results suggest that the visual modality dominates bimodal spatial perception because spatial discriminability is typically greater for the visual than for the auditory modality; accordingly, visual dominance is eliminated or reversed when visual-spatial discriminability is reduced by degrading visual stimuli to be equivalent or inferior to auditory spatial discriminability. Thus, for spatial perception, the modality that provides greater discriminability dominates. Here, we ask whether auditory dominance in duration perception is similarly explained by factors that influence the relative quality of auditory and visual signals. In contrast to the spatial results, the auditory modality dominated over the visual modality in bimodal duration perception even when the auditory signal was clearly weaker, when the auditory signal was ignored (i.e., the visual signal was selectively attended), and when the temporal discriminability was equivalent for the auditory and visual signals. Thus, unlike spatial perception, where the modality carrying more discriminable signals dominates, duration perception seems to be mandatorily linked to auditory processing under most circumstances.     

History of Psychological Testing from the Perspective of Test Developers in Japan1

In this study, the history of psychological testing in Japan is described using the oral history method. Seven test developers discussed the development of Japanese versions of the Wechsler Intelligence Scale, Binet-Simon Intelligence Scale, and Kaufman Assessment Battery for Children. Three conclusions were identified. First, the motivation for developing the tests shifted from one of personal aspiration to a wider responsibility of specialists' desiring to make social contributions. Second, the test developers shifted from working in small, familiar, collaborative groups to working in groups of specialists conducting well-organized projects. Third, the development of tests has variously been led by researchers, publishers, researcher-and-publisher collaborations, or institutes. In addition, this study identifies contemporary challenges for developing psychological tests, specifically due to insufficient numbers of participants and test developers.     

Is the genetic structure of human personality universal? A cross-cultural twin study from North America, Europe, and Asia

This study examined whether universality of the 5-factor model (FFM) of personality operationalized by the Revised NEO Personality Inventory is due to genetic influences that are invariant across diverse nations. Factor analyses were conducted on matrices of phenotypic, genetic, and environmental correlations estimated in a sample of 1,209 monozygotic and 701 dizygotic twin pairs from Canada, Germany, and Japan. Five genetic and environmental factors were extracted for each sample. High congruence coefficients were observed when phenotypic, genetic, and environmental factors were compared in each sample as well as when each factor was compared across samples. These results suggest that the FFM has a solid biological basis and may represent a common heritage of the human species.     

Enhanced memory for the wolf in sheep’s clothing:: Facial trustworthiness modulates face-trait associative memory

Our decision about whether to trust and cooperate with someone is influenced by the individual’s facial appearance despite its limited predictive power. Thus, remembering trustworthy-looking cheaters is more important than remembering untrustworthy-looking cheaters because we are more likely to trust and cooperate with the former, resulting in a higher risk of unreciprocated cooperation. The present study investigated whether our mind adaptively copes with this problem by enhancing memory for trustworthy-looking cheaters. Participants played a debt game, wherein they learned to discriminate among good, neutral, and bad lenders, who respectively charged no, moderate, and high interest on the debt. Each lender had either a trustworthy- or untrustworthy-looking face. A subsequent memory test revealed that participants remembered the bad traits of trustworthy-looking lenders more accurately than those of untrustworthy-looking lenders. The results demonstrate enhanced memory for trustworthy-looking cheaters, or wolves in sheep’s clothing, implying that humans are equipped with protective mechanisms against disguised, unfaithful signs of trustworthiness.