Spatial representation by young infants: Categorization of spatial relations or sensitivity to a crossing primitive?

Evidence for mental subdivision of space by infants: 3- to 4-month-olds spontaneously bisect a small-scale area into left and right categories

“…1 display comparable experimental sequences designed to investigate formation of the category representation "diamond right of vertical midline" with a second group of infants. This experimental design matches with that of Quinn's (2004a) investigation of infant representation of left versus right categories, except that in the earlier study, infants could represent the depicted shape (i.e., the diamond) in relation to an externally available referent (i.e., vertical bar), whereas in the present study, the vertical bar was not present.…”

“…Although within-category discrimination ability for exemplars of leftright relations was reported in Quinn (2004a), encoding of location of the exemplars in the earlier study could have been facilitated by the presence of the external bar. It therefore becomes important to demonstrate within-category discrimination for the exemplars used in the present study.…”

“…Stimuli Stimuli were adapted from those used by Quinn (2004a). Each was created by arranging a black diamond onto a 17.7 cm × 17.7 cm white posterboard card.…”

“…For example, 3-to 4-month-olds who have been presented with stimuli in which a target shape (e.g., a dot or diamond) appears in discriminably different positions above or below a referent shape (i.e., a horizontal bar) will generalize looking time responsiveness to a stimulus in which the target shape has moved to a novel location in the familiarized relation, but will display preferential responsiveness to a stimulus in which the target shape has moved to a location depicting the contrasting relation (e.g., Quinn, 1994;Quinn, Cummins, Kase, Martin, & Weissman, 1996). Likewise, infants of the same age who have been presented with stimuli depicting the target shape in distinct locations to the left or right of a vertical referent bar will generalize responsiveness to a stimulus depicting the shape in a novel location on the same side of the bar, but will display preferential responsiveness to a stimulus depicting the shape on the opposite side of the bar (Quinn, 2004a; see also Gava, Valenza, & Turati, 2009, for corroborating evidence in newborns). Importantly, infant performance in these studies could not have been based on distance information, because the shape on the opposite side of the bar was positioned the same distance away from the familiar shape locations as the shape in the novel location on the same side of the bar.…”

“…Importantly, infant performance in these studies could not have been based on distance information, because the shape on the opposite side of the bar was positioned the same distance away from the familiar shape locations as the shape in the novel location on the same side of the bar. In addition, the infants were not simply encoding the arbitrary crossing of a shape from one to the other side of the bar, because when the bar was diagonal and the changeover from familiar to novel category involved a shape changing location from, for example, below-left to above-right of the bar, the infants did not respond differentially (Quinn, 2004a). Taken together, the results suggest that young infants can represent at least some spatial relations as categories (i.e., above, below, left, right).…”