Walking perception by walking observers

People frequently analyze the actions of other people for the purpose of action coordination. To understand whether such self-relative action perception differs from other-relative action perception, the authors had observers either compare their own walking speed with that of a point-light walker or compare the walking speeds of 2 point-light walkers. In Experiment 1, observers walked, bicycled, or stood while performing a gait-speed discrimination task. Walking observers demonstrated the poorest sensitivity to walking speed, suggesting that perception and performance of the same action alters visual-motion processes. Experiments 2-6 demonstrated that the processes used during self-relative and other-relative action perception differ significantly in their dependence on observers' previous motor experience, current motor effort, and potential for action coordination. These results suggest that the visual analysis of human motion during traditional laboratory studies can differ substantially from the visual analysis of human movement under more realistic conditions.     

Communicative skills in relation to gender, birth order, childcare and socioeconomic status in 18-month-old children

Variation in communicative skills, defined as gestures, vocabulary comprehension and vocabulary production, was examined as a function of gender, birth order, childcare and socioeconomic status (SES) in 1,019 18-month-old children. The children were recruited at their regular check-up at a number of randomly selected Child Health Care centers in a Swedish county. The participation rate was 88%. The children were assessed by their mothers using a short version of the Swedish Early Communicative Development Inventories. The results demonstrate significant effects of gender and birth order on vocabulary comprehension and vocabulary production. Girls scored higher than boys and first-born children scored higher than later-born children. Type of childcare (family care, care at home and day-care centers) interacted with gender and birth order on vocabulary production and indicated that family care is not as advantageous as care at home or at day-care centers. SES had no effect on children's communicative skills at this age.     

Sleep-wake state tradeoffs, impulsivity and life history theory

Evolutionary ecological theory predicts that sleep-wake state tradeoffs may be related to local environmental conditions and should therefore correlate to alterations in behavioral life history strategies. It was predicted that firefighters who slept more and reported better quality sleep on average would exhibit lower impulsivity inclinations related to slower life history trajectories. UPPS impulsivity scores and self-reported sleep averages were analyzed and indicated a negative association between sleep variables and urgency and a positive association with premeditation. Perseverance, and in some cases premeditation, however, disclosed an unpredicted marginally significant positive association between increased and emergency nighttime waking-related sleep deprivation. Sensation seeking was not associated with sleep variables, but was strongly associated with number of biological children. This research contributes to understanding the implications of human sleep across ecological and behavioral contexts and implies further research is necessary for constructing evolutionarily oriented measures of impulsivity inclination and its meaning in the context of life history strategies.     

Gaze behavior predicts memory bias for angry facial expressions in stable dysphoria

Interpersonal theories suggest that depressed individuals are sensitive to signs of interpersonal rejection, such as angry facial expressions. The present study examined memory bias for happy, sad, angry, and neutral facial expressions in stably dysphoric and stably nondysphoric young adults. Participants' gaze behavior (i.e., fixation duration, number of fixations, and distance between fixations) while viewing these facial expressions was also assessed. Using signal detection analyses, the dysphoric group had better accuracy on a surprise recognition task for angry faces than the nondysphoric group. Further, mediation analyses indicated that greater breadth of attentional focus (i.e., distance between fixations) accounted for enhanced recall of angry faces among the dysphoric group. There were no differences between dysphoria groups in gaze behavior or memory for sad, happy, or neutral facial expressions. Findings from this study identify a specific cognitive mechanism (i.e., breadth of attentional focus) that accounts for biased recall of angry facial expressions in dysphoria. This work also highlights the potential for integrating cognitive and interpersonal theories of depression.     

When babies watch television: Attention-getting,attention-holding,and the implications for learning from video material

The recent increase in the availability of infant-directed video material (e.g., Baby Einstein) and the corresponding increase in the amount of time that infants and toddlers spend viewing them have prompted concern among parents and professionals that these media might impede aspects of cognitive and social development. In contrast, supporters and producers of these media contend that, as has been shown with preschool children, age-appropriate videos with carefully selected educational content can provide an opportunity to support and enhance early learning. The scientific evidence for these opposing views is reviewed, evaluated, and interpreted in a developmental framework.     

Bilingual advantage,bidialectal advantage or neither? Comparing performance across three tests of executive function in middle childhood

When bilinguals speak, both fluent language systems become activated in parallel and exert an influence on speech production. As a consequence of maintaining separation between the two linguistic systems, bilinguals are purported to develop enhanced executive control functioning. Like bilinguals, individuals who speak two dialects must also maintain separation between two linguistic systems, albeit to a lesser degree. Across three tests of executive function, we compared bilingual and bidialectal children's performance to that of a monolingual control group. No evidence for a bidialectal advantage was found. However, in line with a growing number of recent partial and failed replications, we observed a significant bilingual advantage only in one measure in one task. This calls the robustness of the bilingual advantage into question. A comprehensive review of studies investigating advantages of inhibitory control and cognitive flexibility in bilingual children reveals that the bilingual advantage is likely to be both task and sample specific, and the interaction between these factors makes qualification of the effect challenging. These findings highlight the importance of tracking the impact of dual linguistic systems across the lifespan using tasks calibrated for difficulty across different ages.     

Shape, color and the other-race effect in the infant brain

The 'other-race' effect describes the phenomenon in which faces are difficult to distinguish from one another if they belong to an ethnic or racial group to which the observer has had little exposure. Adult observers typically display multiple forms of recognition error for other-race faces, and infants exhibit behavioral evidence of a developing other-race effect at about 9 months of age. The neural correlates of the adult other-race effect have been identified using ERPs and fMRI, but the effects of racial category on infants' neural response to face stimuli have to date not been described. We examine two distinct components of the infant ERP response to human faces and demonstrate through the use of computer-generated 'hybrid' faces that the observed other-race effect is not the result of low-level sensitivity to 3D shape and color differences between the stimuli. Rather, differential processing depends critically on the joint encoding of race-specific features.     

A social‐contextual understanding of concordance and discordance between maternal prenatal representations of the infant and infant–mother attachment

This prospective study examined the relationship between maternal prenatal representations of the infant and later infant–mother attachment, including contextual factors related to concordance and discordance among dyads over time. Participants were 173 pregnant women between the ages of 18 and 40 who were interviewed during their last trimester of pregnancy and 2 and 13 months after birth. Maternal representations were assessed by the Working Model of the Child Interview during pregnancy (WMCI; C.H. Zeanah, D. Benoit, L. Hirshberg, M.L. Barton, & C. Regan, 1994), and infant–mother attachment was assessed through the Strange Situation procedure (M.D.S. Ainsworth, M. Blehar, E. Waters, & S. Wall, 1978) when infants were 13 months old. There was substantial discordance between maternal and infant classifications, although a significant concordance rate was found when classifications were collapsed into balanced/secure and nonbalanced/insecure groups based on prenatal representations and postnatal infant attachment groups (60%; χ² = 6.90, p < .01; κ .20). As expected, discordance between maternal representations and infant–mother attachment was meaningfully related to contextual risk factors, maternal depression, and infant behaviors.