Infant temperament and information processing in a visual categorization task.

This study investigates the relation between temperament and information processing in 7-month-old infants. Infant temperament was assessed on multiple dimensions, using mothers' ratings on the Infant Behavior Questionnaire (IBQ). Information processing was measured during a paired-comparison visual categorization task. Infants (N=50) were familiarized with five different pairs of visual stimuli from one category, followed by two test trials, each contrasting a novel familiar-category item with a novel out-of-category item (animals vs. vehicles). Drop-out rate in this task was within a normal range (21%). No differences in temperament were found between completers and non-completers, but high reactivity to novelty and low motor activity were positively correlated with the strength of infants' familiarization response. Group comparisons between infants scoring high and low on these two dimensions of temperament confirmed this general finding: infants high on distress to novelty and low on motor activity showed stronger familiarization responses. Furthermore, infants scoring low on motor activity showed a stronger categorization response than highly active infants. This study provides evidence that performance in a cognitive categorization task and dimensions of infant temperament are systematically related during the second half of the first year of life. Implications for cognitive research with infants of this age-range will be discussed.