INFORMATION PROCESSING CORRELATES OF MEMORY SPAN: AN INDIVIDUAL DIFFERENCES APPROACH
RHOADES, HOWARD MORGRIDGE
Doctor of Philosophy
Three processes, item identification speed, susceptibility to proactive interference, and memory for order, identified for their potential as sources of memory span differences, were the subjects of the present investigation. A fourth variable, item memory, was included as the experimental complement of order memory (Healy, 1974). Performance on each of these four variables and memory span was obtained for 90 college-aged subjects. Moderate to high reliability was evidenced for each of the tasks. Memory span correlated significantly with each source of differences examined. Additionally, using a multiple regression analysis, each variable was shown to contribute significant, independent variance in the joint prediction of memory span. Subjects' scores on the four predictor variables were used in a cluster analysis which identified four subsets of individuals. An ANOVA determined that the four groups differed in their mean memory span scores. The differences among these groups were examined using a multiple discriminant analysis. The groups were found to differ along three dimensions. Evidence from these analyses indicates that an individual's memory span is the result of complex processes involving, at least, components of item identification speed, susceptibility to proactive interference, order, and item memory. Finally, individuals' performance levels across these tasks were not uniform, indicating possible differential contributions of these processes.