Pomiechowska, B. & Gliga, T.
Center for Brain and Cognitive Development, Birkbeck College, University of London
Infants show knowledge of some words at 6 months of age (Bergelson & Swingley, 2012) and are able to detect semantic mismatch at 9 months of age (Parise & Csbira, 2012). Verbal labels help infants to categorize objects (Waxman & Braun, 2005; Balaban & Waxman, 1997) and modulate how the objects associated with them are processed (Gliga et al., 2010). The aim of the current study was to explore whether verbal labels affect how object representations are maintained in memory. We recorded scalp EEG of 12 month old infants presented with an occlusion paradigm in which they saw objects being revealed, occluded and then either replaced by another object belonging to the same object kind (within-category change) or an object from a different object kind (across-category change) or revealed as they were before occlusion (no change). We tested two groups of infants: first group saw objects with familiar labels (label group), second group saw objects with unfamiliar labels (no label group). By measuring event-related potentials in response to object reappearance after the occlusion, we demonstrated that the knowledge of verbal labels influenced object recognition. Infants in label group detected across-category changes, but not within-category changes, suggesting that they used the label and not the surface feature information to store the object in memory. Infants in no-label group detected both across-category and within-category changes, suggesting that they used the featural information to maintain the object representation across the occlusion. These results suggest that vocabulary acquisition modulates how the infant brain stores and maintains object representations.