SEQUENTIAL AND COORDINATIVE PROCESSING DYNAMICS IN FIGURAL TRANSFORMATIONS ACROSS THE LIFE-SPAN

This work tests the proposition that two distinct factors involved in life span cognitive development are mental speed and coordination effi ciency. Dynamics of information processing in a figural transformation task were assessed via time-accuracy functions for children (mean age = 9.5 years), young adults (mean age = 23.7 years), and old adults (m ean age = 73.7 years). Corresponding to the two proposed factors, spee d and coordination, both sequential and coordinative aspects of comple xity were varied. Sequential complexity was manipulated through the nu mber of objects to be checked for transformations; coordinative comple xity was manipulated through the number of transformations to be consi dered simultaneously. Individual time-accuracy operating characteristi cs were adequately described by exponential functions for all age and complexity levels. Complexity-specific effects confirmed the general e xpectation of a particularly large age sensitivity of coordinative fun ctions. Proportional adult age effects in the processing time paramete r were larger for coordinatively complex than for sequentially complex conditions. For the contrast between children and young adults this w as the case only for high coordinative complexity. Results are interpr eted in terms of (a) dissociable developmental changes in speed of pro cessing and working memory functioning across the life span and (b) di fferential effects of coordinative demands in children and old adults.