Suchergebnisse

AbstractThe visual context in which an object or face resides can provide useful top‐down information for guiding attention orienting, object recognition, and visual search. Although infants have demonstrated sensitivity to covariation in spatial arrays, it is presently unclear whether they can use rapidly acquired contextual knowledge to guide attention during visual search. In this eye‐tracking experiment, 6‐ and 10‐month‐old infants searched for a target face hidden among colorful distracter shapes. Targets appeared in Old or New visual contexts, depending on whether the visual search arrays (defined by the spatial configuration, shape and color of component items in the search display) were repeated or newly generated throughout the experiment. Targets in Old contexts appeared in the same location within the same configuration, such that context covaried with target location. Both 6‐ and 10‐month‐olds successfully distinguished between Old and New contexts, exhibiting faster search times, fewer looks at distracters, and more anticipation of targets when contexts repeated. This initial demonstration of contextual cueing effects in infants indicates that they can use top‐down information to facilitate orienting during memory‐guided visual search.

AbstractThe present study examined the hypothesis that inhibitory visual selection mechanisms play a vital role in memory by limiting distractor interference during item encoding. In Experiment 1a we used a modified spatial cueing task in which 9‐month‐old infants encoded multiple category exemplars in the contexts of an attention orienting mechanism involving suppression (i.e. inhibition of return, IOR) versus one that does not (i.e. facilitation). At test, infants in the IOR condition showed both item‐specific learning and abstraction of broader category information. In contrast, infants in the facilitation condition did not discriminate across novel and familiar test items. Experiment 1b confirmed that the learning observed in the IOR condition was specific to spatial cueing of attention and was not due to timing differences across the IOR and facilitation conditions. In Experiment 2, we replicated the results of Experiment 1, using a within‐subjects design to explicitly examine learning and memory encoding in the context of concurrent suppression. These data show that developing inhibitory selective attention enhances efficacy of memory encoding for subsequent retrieval. Furthermore, these results highlight the importance of considering interactions between developing attention and memory systems.

AbstractPrevious work has shown that infants as young as 8 months of age can use certain features of the environment, such as the shape or color of visual stimuli, as cues to organize simple inputs into hierarchical rule structures, a robust form of reinforcement learning that supports generalization of prior learning to new contexts. However, especially in cluttered naturalistic environments, there are an abundance of potential cues that can be used to structure learning into hierarchical rule structures. It is unclear how infants determine what features constitute a higher‐order context to organize inputs into hierarchical rule structures. Here, we examine whether 9‐month‐old infants are biased to use social stimuli, relative to non‐social stimuli, as a higher‐order context to organize learning of simple visuospatial inputs into hierarchical rule sets. Infants were presented with four face/color‐target location pairings, which could be learned most simply as individual associations. Alternatively, infants could use the faces or colorful backgrounds as a higher‐order context to organize the inputs into simpler color‐location or face‐location rules, respectively. Infants were then given a generalization test designed to probe how they learned the initial pairings. The results indicated that infants appeared to use the faces as a higher‐order context to organize simpler color‐location rules, which then supported generalization of learning to new face contexts. These findings provide new evidence that infants are biased to organize reinforcement learning around social stimuli.

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.

AbstractRule‐guided behavior depends on the ability to strategically update and act on content held in working memory. Proactive and reactive control strategies were contrasted across two experiments using an adapted input/output gating paradigm (Neuron, 81, 2014 and 930). Behavioral accuracies of 3‐, 5‐, and 7‐year‐olds were higher when a contextual cue appeared at the beginning of the task (input gating) rather than at the end (output gating). This finding supports prior work in older children, suggesting that children are better when input gating but rely on the more effortful output gating strategy for goal‐oriented action selection (Cognition, 155, 2016 and 8). A manipulation was added to investigate whether children's use of working memory strategies becomes more flexible when task goals are specified internally rather than externally provided by the experimenter. A shift toward more proactive control was observed when children chose the task goal among two alternatives. Scan path analyses of saccadic eye movement indicated that giving children agency and choice over the task goal resulted in less use of a reactive strategy than when the goal was determined by the experimenter.

AbstractThis study investigates whether infants are sensitive to backward and forward transitional probabilities within temporal and spatial visual streams. Two groups of 8‐month‐old infants were familiarized with an artificial grammar of shapes, comprising backward and forward base pairs (i.e. two shapes linked by strong backward or forward transitional probability) and part‐pairs (i.e. two shapes with weak transitional probabilities in both directions). One group viewed the continuous visual stream as a temporal sequence, while the other group viewed the same stream as a spatial array. Following familiarization, infants looked longer at test trials containing part‐pairs than base pairs, although they had appeared with equal frequency during familiarization. This pattern of looking time was evident for both forward and backward pairs, in both the temporal and spatial conditions. Further, differences in looking time to part‐pairs that were consistent or inconsistent with the predictive direction of the base pairs (forward or backward) indicated that infants were indeed sensitive to direction when presented with temporal sequences, but not when presented with spatial arrays. These results suggest that visual statistical learning is flexible in infancy and depends on the nature of visual input.