Abstract
During the first year of life, learning that an individual-level label corresponds to an object or face increased visual differentiation of within-group exemplars (Scott & Monesson, 2009; Scott, 2011). The present study sought to follow-up these results and determine whether individual-level training differentially impacted infants' attention-related visual strategies and neural responses. Here, six-month-old infants were trained for three months with storybooks containing novel objects labeled either with category-level or individual-level names. Before and after training infants' visual fixation location and duration toward serially presented objects was assessed with an eye-tracker. This was followed by an examination of infants' event-related potentials (ERPs) during an oddball task. Total dwell time to the top and bottom half of untrained exemplars within the trained group were examined before and after training and across groups. Analyses suggest that infants fixated the untrained images longer at 9 months compared to at 6 months, F(1, 20) = 5.82, p < .05. This main effect was qualified by an interaction between age and group, F(1, 20) = 4.82, p < .05 which was driven by a significant increase in looking from 6 to 9 months for the individual-level group but not the category-level group, p < .05. ERP analyses revealed a greater Nc amplitude in response to infrequent versus frequent objects, F(1,40) = 5.80, p = .02, which was qualified by a 3-way interaction. The 3-way interaction, F(1,40) = 4.51, p = .04, was driven by a larger Nc amplitude to infrequent relative to frequent objects, but only for the 9-month-old infants trained with individual-level labels (p= .003). No amplitude differences were found after category-level training. Our findings extend past training work by demonstrating that infants use labels to shape the specificity of their perceptual representations and that individual-level labels differentially increases attention relative to category-level labels.
Meeting abstract presented at VSS 2016