Date of Award

5-2009

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Neuroscience and Behavior

First Advisor

Berthier, Neil E.

Second Advisor

Davidson, Matthew C.

Third Advisor

Keen, Rachel E.

Keywords

Psychobiology, Developmental psychology, Cognitive psychology

Subject Categories

Cognitive Psychology | Developmental Psychology | Neuroscience and Neurobiology

Abstract

Previous research using violation-of-expectation paradigms suggests that very young infants have a good understanding of unobserved physical events. Yet toddlers appear to lack this knowledge when confronted with the door task, a visuospatial reasoning task which parallels ones used in the habituation/looking time studies. Many studies have been conducted in an effort to determine why toddlers perform poorly on the door task yet the answer remains unclear. The current study used a correlational approach to investigate door task performance from both psychological (executive function), and neuroscience (prefrontal cortex) perspectives. Children between the ages of 2 ½ - 3 years were tested on the standard door task as well as four other tasks. Three of the tasks were believed to activate prefrontal cortex: the three boxes-stationary, a spatial working memory task; the three boxes-scrambled, a non-spatial working memory task; and the three pegs task, an inhibitory control task. The fourth task was a recognition memory task which had been previously linked to the medial temporal lobe. Only a single task, the three pegs task, was found to correlate with door task performance (r = .510, p<.01). Even with age, sex, and performance on the other tasks controlled for, this correlation remained significant (r = .459, p<.05). Furthermore, in a logistic regression the three pegs task was found to be the only significant predictor of door task performance (z=2.87, p<.01). An examination of the errors children made on the door task revealed that over half (58%) could be classified as inhibitory control errors (children returned to the previously rewarded location or repeatedly searched a favorite door). Taken together these data suggest a possible relationship between inhibitory control ability and successful completion of the door task.