Human cognitive neuroscience seminar

Speaker: Dr Andreea Stamate

Title: Sampled testing delays forgetting of unsampled items in both younger and older adults

Abstract: Selective retrieval of specific items enhances their subsequent recall at the expense of non-retrieved items. In contrast, a few recent findings demonstrate that retrieval of subparts of material, can enhance later recall of the non-retrieved subparts. It is still unknown whether this positive effect emerges in older populations. We present two experiments using sampled testing on two types of material to investigate whether selective retrieval enhances performance in both young and older adults. Additionally, we examined whether older adults present with faster forgetting compared to younger individuals when assessed over a long delay. We used a novel design which contrasts the performance of the groups in conditions with and without retrieval practice.

In both experiments, younger and older adults learned material to a criterion of 70% correct recall. Half were tested after one day, one week and one month, with cues for different sections of each passage tested on each occasion. The other half were tested only one month later. Experiment 1 used integrated material (four short stories). Experiment 2 used material with a disrupted narrative (16 sentences).

Both age groups showed significant forgetting over one month. However, groups tested repeatedly showed less forgetting (irrespective of age or material). When retested only at one-month, older adults showed more forgetting than younger, suggesting age-associated accelerated rate of forgetting. The use of disrupted narratives did not affect forgetting. We propose that the beneficial effect of selective retrieval depends on implicit priming of existing representations.