MENTAL REPRESENTATIONS FOR VISUAL SEQUENCES - INCREASED SPEED OF CENTRAL PROCESSING FROM 22 TO 32 MONTHS

Measures of infant attention, particularly speed of processing, correl ate with later intelligence, implying that they are tapping central pr ocessing ability. Yet, little is known about changes in speed of proce ssing beyond the first year of life and before the child reaches schoo l age. To assess changes in processing speed in the second to third ye ar of life, two sequential visual events were shown to 22-, 27- and 32 -month-old children. Twelve children were examined at each age using a Standard-Transformation-Return paradigm designed to address a number of limitations of attentional measures. Two coders scored attentional and affective behavioral responses while beat-by-beat heart rate was m easured. Response clusters, rather than single responses, and first re cognition reactions, rather than measures of habituation, were examine d. Response clusters, implying mental representations (a central proce ssing phenomenon), occurred following fewer trials of exposure for old er children, indicating that speed of processing increases with age. L onger latencies to first clusters during the transformation relative t o the standard phase imply proactive inhibition that also declines wit h age.