Visual short-term memory, response delay, and age

Recall and recognition memory performance of 12 young (M = 19 yr.) and 12 older (M = 72 yr.) females was studied in relation to response delay (5, 25, and 125 sec.) and stimulus complexity (6.1 and 13.7 bits of information). The subjects were matched on verbal IQ, visual acuity, and educational levels. Stimuli were abstract, black and white, 4 X 4 square matrices. Age-related decrements in memory performance were associated with stimulus complexity but not with response delay. Older subjects also reported experiencing encoding difficulties during the registration phase. The results were discussed with reference to the locus of age-related decrements in visual short-term memory.