Division of attention: age differences on a visually presented memory task.

Young and old adults were compared in their efficiency of remembering concurrently presented . series ofletters and digits in three separate experiments. Instructions and payoffs to vary attenI tional emphasis across the two types of material in different conditions allowed the examination I ofattention-operating characteristics in the two age groups. Strategy-independent measures deI rived from these attention-operating characteristics revealed that older adults exhibited greater I performance deficits than young adults when dividing their attention between the two tasks, even though dual-task difficulty was individually adjusted for each subject. It was concluded that either the total amount of attention available for distribution or the efficiency of its allocation decreased with age even though the ability to vary one's attention between concurrent tasks in response to instructions and payoffs remained intact.