The effects of divided attention during encoding and retrieval on amnesic patients' memory performance

This study examined the effect of divided attention during encoding or retrieval on primary (recall) or secondary (button-pressing) task performance by amnesic patients and control subjects. Experiment 1 demonstrated that control subjects' recall was affected by divided attention during encoding but not during retrieval, while the amnesic patients' recall remained at the same low level for all conditions. Both groups showed a reduction in rate of button-pressing during encoding relative to their baseline levels and a further reduction during the retrieval interval. In Experiment 2, five learning trials, instead of just one, were presented. This acted to increase all subjects' recall and also had the effect of producing superior recall following free encoding relative to encoding during divided attention for the amnesic patients as well as for the control subjects. Button-pressing performance during the encoding interval increased to baseline for both groups during the five presentation trials, but there was no increase in the rate of button-pressing during the retrieval interval. Amnesic patients' normal attention to the primary task during encoding and retrieval was felt to have several implications for future neuroimaging tasks with these patients.