The Effect of Local Element Density on Processing of Visual Hierarchical Patterns: An Infant ERP Study

Previous research with infants, children, and adults has shown that global, or configural, information is processed before local, or featural, information in high density visual hierarchical patterns (Freeseman, Colombo, & Coldren, 1993; Ghim & Eimas, 1988; Kimchi, 1988; Navon, 1981; Navon, 1977). The current study used event-related potential to determine if a well documented bias toward global processing in infancy can be disrupted when the number and density of local elements is reduced through increasing the distance between elements. Infant responses were compared between high and low density conditions to global and local novel patterns and to familiar patterns. A significant interaction was found between stimulus type and stimulus density in the Late Slow Wave component. The findings are consistent with previous research which shows that infants process high density visual patterns at the global level, and also indicate that infants fail to effectively process either global or local information in low density hierarchical patterns

Neural correlates of individuation and categorization of other-species faces in infancy

The goal of this study was to investigate 9-month-old infants' ability to individuate and categorize other-species faces at the subordinate level. We were also interested in examining the effects of initial exposure conditions on infant categorization and individuation processes. Infants were either familiarized with a single monkey face in an individuation procedure or familiarized with multiple exemplars of monkey faces from the same species in a categorization procedure. Event-related potentials were recorded while the infants were presented: familiar faces, novel faces from the familiar species, or novel faces from a novel species. The categorization group categorized monkey faces by species at the subordinate level, whereas the individuation group did not discriminate monkey faces at the individual or subordinate level. These findings indicate initial exposure to multiple exemplars facilitates infant processing of other-species faces, and infants are efficient at subordinate-level categorization at 9 months of age