Longitudinal and cross-sectional comparisons of young children's cognitive ERPs and behavior in a picture-matching task: preliminary findings.
Event-related brain potentials (ERPs) were recorded from 19 children (6-8 years old at initial testing) performing cognitive tasks in two longitudinal testing sessions administered one year apart. The task used was a modification, using pictorial stimuli, of Posner's (1978) letter-matching experiments. In separate blocks of trials, subjects had to decide whether two sequentially-presented slides were physically identical, shared the same name, or came from the same semantic category. Subjects indicated their choice via a same-different delayed response following the second slide. Behavioral data showed large effects of longitudinal Age reflecting increases in accuracy from Run 1 to Run 2. These effects were corroborated by analyses of cross-sectional Age, suggesting that the performance changes reflected cognitive growth, rather than practice effects. In a similar fashion, both N400 and P700 (classical 'P300') showed reductions in peak latency that appeared to be true age changes, since these latencies shortened as a function of Run of testing as well as cross-sectional Age, and there were no Run by Age interactions. Small sample sizes as well as methodological shortcomings of the current design limit the conclusions that can be drawn from these data. Nevertheless, this study demonstrates the feasibility and usefulness of a cross-sectional/short-term longitudinal design and provides information on the extent and direction of behavioral and ERP changes that can be observed over this limited age range.
Friedman
D
D
New York State Psychiatric Institute, NY 10032.
Putnam
L
L
Sutton
S
S
D002648:Child; D002652:Child Behavior / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D004192:Discrimination, Psychological; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D005556:Form Perception; D006801:Humans; D007361:Intelligence Tests; D008137:Longitudinal Studies; D008297:Male