The role of perceptual similarity of the task environments in children's perseverative responding

Motor constraints on infant search: The impact of reaching around a barrier on search performance

This study investigated the impact of perceptual-motor context on a classic paradigm used to assess cognitive-spatial reasoning. Specifically, this project explored the effect on search behavior of reaching around a barrier versus not reaching around a barrier during the A portion in the B phase of the well-known A-not-B task. In examining 8- and 16-month-old infants, this study found that both age groups demonstrated poorer performance on A trials when needing to reach around a barrier than when there was no barrier present. More interestingly, for the younger infants, needing to reach around a barrier on A trials led to better performance on B trials relative to infants who did not reach around a barrier. Older infants, however, showed no difference in B trial performance. These results demonstrate that inducing constraints on reaching (e.g., reaching around a barrier) has a significant impact on search behavior, a finding that theoretically fits with a literature demonstrating a fundamental role in behavior of perceptual and motor influences in A-not-B behavior.

To Cue or Not to Cue: Toddlers' Use of Beacons and Associative Cues in Object-displacement Tasks

Two experiments examined 24- and 30-month-olds' use of different forms of landmark information in an object-displacement task involving a car rolling down a ramp whose trajectory was occluded by a screen containing doors. A pompom attached to the car, visible through a transparent window running across the screen, served as a cue for the car's location and functioned either as a beacon cue, directly guiding search to a given location, or an associative cue, indirectly marking target location. Interestingly, one way in which the cue information was modified from a beacon to an associative cue was in terms of the structure of the search apparatus, and not necessarily the cue information itself. Consistent with previous literature, 24-month-olds' search was significantly influenced by the shift from beacon to associative cue information, whereas 30-month-olds, although affected by the shift from one to the other, were less affected by this variation. These findings suggest that the cue drives attention to specific locations in space, with search behavior being more accurate when the cue directly marks the hiding location (i.e., beacon) than when the cue indirectly marks it (i.e., associative cue).

The role of stimulus novelty on children's inflexible dimensional switching

Children's ability to flexibly shift attention between different representational schemes was investigated using the dimensional change card sorting task. Across three experiments (N = 56 three-year-olds and N = 40 four-year-olds in ; N = 14 three-year-olds in ; and N = 14 three-year-olds in ) the role of perceptual information on children's cognitive flexibility was investigated by manipulating different aspects of the task materials between pre- and postswitch phases. Better performance was observed when either task-relevant (the color or shape of the images on the cards) or task-irrelevant information (the background color or shape of the actual cards) was changed, with this improvement occurring when the changes were salient enough to induce a stimulus novelty effect.