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The Faces of Lee Harvey Oswald provides the first comprehensive scholarly analysis of Lee Harvey's Oswald's role in the JFK assassination. Scott P. Johnson objectively examines the various narratives of Lee Harvey Oswald created by researchers and authors over the last fifty years. He finds that at first glance any theory related to Oswald's role appears as convincing as the next, particularly when researchers carefully select information that only advances their preferred theory. In reality, however, Oswald's role in the assassination offers little certainty when one looks at the mystery surr

Children's emotion understanding is crucial for healthy social and academic development. The behaviors influenced by emotion understanding in childhood have received much attention, but less focus has been placed on factors that may predict individual differences in emotion understanding, the principal issue addressed in the current review. A more thorough understanding of the developmental underpinnings of this skill may allow for better prediction of emotion understanding, and for interventions to improve emotion understanding early in development. Here, we present theoretical arguments for the substantial roles of three aspects of children's environments in the development of emotion understanding: family expressiveness, discussions about emotions, and language development, and we discuss how these are interrelated. Ultimately, this may aid in predicting the effects of environmental influences on the development of emotion understanding more broadly and the mechanisms by which they do so.

To explore questions of how human infants begin to perceive partly occluded objects, we devised two connectionist models of perceptual development. The models were endowed with an existing ability to detect several kinds of visual information that have been found important in infants' and adults' perception of object unity (motion, co‐motion, common motion, relatability, parallelism, texture and T‐junctions). They were then presented with stimuli consisting of either one or two objects and an occluding screen. The models' task was to determine whether the object or objects were joined when such a percept was ambiguous, after specified amounts of training with events in which a subset of possible visual information was provided. The model that was trained in an enriched environment achieved superior levels of performance and was able to generalize veridical percepts to a wide range of novel stimuli. Implications for perceptual development in humans, current theories of development and origins of knowledge are discussed.

AbstractFive‐ and 3‐month‐old infants' perception of infant‐directed (ID) faces and the role of speech in perceiving faces were examined. Infants' eye movements were recorded as they viewed a series of two side‐by‐side talking faces, one infant‐directed and one adult‐directed (AD), while listening to ID speech, AD speech, or in silence. Infants showed consistently greater dwell time on ID faces vs. AD faces, and this ID face preference was consistent across all three sound conditions. ID speech resulted in higher looking overall, but it did not increase looking at the ID face per se. Together, these findings demonstrate that infants' preferences for ID speech extend to ID faces.

AbstractWe recently proposed a multi‐channel, image‐filtering model for simulating the development of visual selective attention in young infants (Schlesinger, Amso & Johnson, 2007). The model not only captures the performance of 3‐month‐olds on a visual search task, but also implicates two cortical regions that may play a role in the development of visual selective attention. In the current simulation study, we used the same model to simulate 3‐month‐olds' performance on a second measure, the perceptual unity task. Two parameters in the model – corresponding to areas in the occipital and parietal cortices – were systematically varied while the gaze patterns produced by the model were recorded and subsequently analyzed. Three key findings emerged from the simulation study. First, the model successfully replicated the performance of 3‐month‐olds on the unity perception task. Second, the model also helps to explain the improved performance of 2‐month‐olds when the size of the occluder in the unity perception task is reduced. Third, in contrast to our previous simulation results, variation in only one of the two cortical regions simulated (i.e. recurrent activity in posterior parietal cortex) resulted in a performance pattern that matched 3‐month‐olds. These findings provide additional support for our hypothesis that the development of perceptual completion in early infancy is promoted by progressive improvements in visual selective attention and oculomotor skill.

AbstractWe know that early experience plays a crucial role in the development of face processing, but we know little about how infants learn to distinguish faces from different races, especially for non‐Caucasian populations. Moreover, it is unknown whether differential processing of different race faces observed in typically studied monoracial infants extends to biracial infants as well. Thus, we investigated 3‐month‐old Caucasian, Asian and biracial (Caucasian‐Asian) infants' ability to distinguish Caucasian and Asian faces. Infants completed two within‐subject, infant‐controlled habituation sequences and test trials as an eye tracker recorded looking times and scanning patterns. Examination of individual differences revealed significant positive correlations between own‐race novelty preference and scanning frequency between eye and mouth regions of own‐race habituation stimuli for Caucasian and Asian infants, suggesting that facility in own‐race face discrimination stems from active inspection of internal facial features in these groups. Biracial infants, however, showed the opposite effect: An 'own‐race' novelty preference was associated with reduced scanning between eye and mouth regions of 'own‐race' habituation stimuli, suggesting that biracial infants use a distinct approach to processing frequently encountered faces. Future directions for investigating face processing development in biracial populations are discussed.A video abstract of this article can be viewed at http://youtu.be/a_dDXfFuEfY

AbstractSome cognitive abilities exhibit reliable gender differences, with females outperforming males in specific aspects of verbal ability, and males showing an advantage on certain spatial tasks. Among these cognitive gender differences, differences in mental rotation are the most robust, and appear to be present even in infants. A large body of animal research suggests that gonadal hormones, particularly testosterone, during early development could contribute to this gender difference in mental rotation. Also, substantial evidence supports an influence of socialization on mental rotation performance. The present study investigated the relationship of two types of factors, early postnatal testosterone exposure and parental attitudes about gender, to mental rotation performance in 61 healthy infants (29 males, 32 females). We measured salivary testosterone at two time points: 1–2.5 months of age and 5–6 months of age. Infants' mental rotation performance and parents' attitudes about gender were assessed at 5–6 months of age. As predicted, testosterone concentrations were significantly higher in boys than girls in early infancy (d = 0.54), and boys performed significantly better than girls on mental rotation (d = 0.64). A significant positive correlation between testosterone at age 1–2.5 months and mental rotation was found only in boys (r = 0.50, p = .01). A significant negative correlation between parents' gender‐stereotypical attitudes and mental rotation performance was found only in girls (r = −.57, p = .002). These findings suggest that the early postnatal testosterone surge (also known as "mini‐puberty") may have organizational influences on mental rotation performance in boys, and that parents may influence their daughters' mental rotation abilities beginning very early in life.

Abstract By 7 months of age, infants are able to learn rules based on the abstract relationships between stimuli (

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), but they are better able to do so when exposed to speech than to some other classes of stimuli. In the current experiments we ask whether multimodal stimulus information will aid younger infants in identifying abstract rules. We habituated 5‐month‐olds to simple abstract patterns (ABA or ABB) instantiated in coordinated looming visual shapes and speech sounds (Experiment 1), shapes alone (Experiment 2), and speech sounds accompanied by uninformative but coordinated shapes (Experiment 3). Infants showed evidence of rule learning only in the presence of the informative multimodal cues. We hypothesize that the additional evidence present in these multimodal displays was responsible for the success of younger infants in learning rules, congruent with both a Bayesian account and with the Intersensory Redundancy Hypothesis.

Abstract When viewing an event in which an object moves behind an occluder on part of its trajectory, 4‐month‐old infants perceive the trajectory as continuous only when time or distance out of sight is short. Little is known, however, about the conditions under which young infants perceive trajectories to be discontinuous. In the present studies we focus first on infants' perception of trajectories that change during a period of occlusion. Four‐month‐olds perceive discontinuity in trajectories that change in height or orientation while behind an occluder, and this is true even when a change in direction could be due to an invisible bouncing collision with a surface. Further experiments reveal that infants do not perceive diagonal linear trajectories as continuous across an occlusion unless the occluding and revealing edges are orthogonal to the path of movement. Implications for theories of perceptual and cognitive development are discussed.

This investigation was aimed at validating the feelings of patients with thyroid-associated orbitopathy (TAO), who commonly report psychosocial impairments due to the cosmetic disfigurement caused by the disease. In all, 50 adults, equally divided between two experimental conditions, participated. Adults' visual behavior was recorded with a corneal reflection eye-tracking system as they viewed side-by-side photograph pairings of affected and non-affected individuals' upper facial region. Adults in Experiment 1 viewed photographs of patients before corrective surgery and those in Experiment 2 viewed photographs of patients after corrective surgery. Visual behavior measures of interest included the number of stares and cumulative time spent staring. Adults appear to differentially attend to patients with TAO, staring more often and longer at these individuals, regardless of surgical correction. TAO patients' feeling of self-consciousness and being more concerned about their appearance may be due to differential persistence of fixations (i.e. staring) from their peers.

AbstractStatistical learning is characterized by detection of regularities in one's environment without an awareness or intention to learn, and it may play a critical role in language and social behavior. Accordingly, in this study we investigated the electrophysiological correlates of visual statistical learning in young children with autism spectrum disorder (ASD) using an event‐related potential shape learning paradigm, and we examined the relation between visual statistical learning and cognitive function. Compared to typically developing (TD) controls, the ASD group as a whole showed reduced evidence of learning as defined by N1 (early visual discrimination) and P300 (attention to novelty) components. Upon further analysis, in the ASD group there was a positive correlation between N1 amplitude difference and non‐verbal IQ, and a positive correlation between P300 amplitude difference and adaptive social function. Children with ASD and a high non‐verbal IQ and high adaptive social function demonstrated a distinctive pattern of learning. This is the first study to identify electrophysiological markers of visual statistical learning in children with ASD. Through this work we have demonstrated heterogeneity in statistical learning in ASD that maps onto non‐verbal cognition and adaptive social function.