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Three experiments investigated the perception of collisions involving bouncing balls by 7‐ and 10‐month‐old infants and adults. In previous research, 10‐month‐old infants perceived the causality of launching collisions (events in which one object moves along a smooth horizontal trajectory toward a second object, apparently launching it into motion) in relatively simple event contexts. In more complex event contexts, infants failed to discriminate among the events or respond to changes in individual features. Experiments 1 and 2 of the present investigation revealed that 7‐ and 10‐month‐old infants attended to spatial and temporal contiguity, but not causality, in collisions involving the movement of bouncing balls. In Experiment 3, both spatiotemporal contiguity and general knowledge about movement trajectories influenced adults' judgments of causality for these collisions. The present results add to a growing understanding of infants' event perception as constructive and a function, in part, of the complexity of the event context.

AbstractTwo experiments examined the hypothesis that developing visual attentional mechanisms influence infants' Visual Short‐Term Memory (VSTM) in the context of multiple items. Five‐ and 10‐month‐old infants (N = 76) received a change detection task in which arrays of three differently colored squares appeared and disappeared. On each trial one square changed color and one square was cued; sometimes the cued item was the changing item, and sometimes the changing item was not the cued item. Ten‐month‐old infants exhibited enhanced memory for the cued item when the cue was a spatial pre‐cue (Experiment 1) and 5‐month‐old infants exhibited enhanced memory for the cued item when the cue was relative motion (Experiment 2). These results demonstrate for the first time that infants younger than 6 months can encode information in VSTM about individual items in multiple‐object arrays, and that attention‐directing cues influence both perceptual and VSTM encoding of stimuli in infants as in adults.

Abstract Two experiments demonstrate that 14‐ to 18‐month‐old toddlers can adaptively change how they categorize a set of objects within a single session, and that this ability is related to vocabulary size. In both experiments, toddlers were presented with a sequential touching task with objects that could be categorized either according to some perceptually salient dimension corresponding to a taxonomic distinction (e.g. animals vs. vehicles) or to some less obvious dimension (e.g. rigid vs. deformable). In each experiment, children with larger productive vocabularies responded to both dimensions, showing evidence of sensitivity to each way of categorizing the items. Children with smaller productive vocabularies attended only to the taxonomically related categorical grouping. These experiments confirm that toddlers can adaptively shift the basis of their categorization and highlight the dynamic interaction between the child and the current task in early categorization.

AbstractLittle is known about the development of higher‐level areas of visual cortex during infancy, and even less is known about how the development of visually guided behavior is related to the different levels of the cortical processing hierarchy. As a first step toward filling these gaps, we used representational similarity analysis (RSA) to assess links between gaze patterns and a neural network model that captures key properties of the ventral visual processing stream. We recorded the eye movements of 4‐ to 12‐month‐old infants (N = 54) as they viewed photographs of scenes. For each infant, we calculated the similarity of the gaze patterns for each pair of photographs. We also analyzed the images using a convolutional neural network model in which the successive layers correspond approximately to the sequence of areas along the ventral stream. For each layer of the network, we calculated the similarity of the activation patterns for each pair of photographs, which was then compared with the infant gaze data. We found that the network layers corresponding to lower‐level areas of visual cortex accounted for gaze patterns better in younger infants than in older infants, whereas the network layers corresponding to higher‐level areas of visual cortex accounted for gaze patterns better in older infants than in younger infants. Thus, between 4 and 12 months, gaze becomes increasingly controlled by more abstract, higher‐level representations. These results also demonstrate the feasibility of using RSA to link infant gaze behavior to neural network models. A video abstract of this article can be viewed at https://youtu.be/K5mF2Rw98Is

AbstractMeasures of attention and memory were evaluated in 6‐ to 9‐month‐old infants from two diverse contexts. One sample consisted of African infants residing in rural Malawi (N = 228, 118 girls, 110 boys). The other sample consisted of racially diverse infants residing in suburban California (N = 48, 24 girls, 24 boys). Infants were tested in an eye‐tracking version of the visual paired comparison procedure and were shown racially familiar faces. The eye tracking data were parsed into individual looks, revealing that both groups of infants showed significant memory performance. However, how a look was operationally defined impacted some—but not other—measures of infant VPC performance.Research Highlights
In both the US and Malawi, 6‐ to 9‐month‐old infants showed evidence of memory for faces they had previously viewed during a familiarization period.
Infant age was associated with peak look duration and memory performance in both contexts.
Different operational definitions of a look yielded consistent findings for peak look duration and novelty preference scores—but not shift rate.
Operationalization of look‐defined measures is an important consideration for studies of infants in different cultural contexts.