Details

Autor(en) / Beteiligte

• Kenney, Joanne P. M.
• Ward, Christina
• Gallen, Dervla
• Roche, Richard A. P.
• Dockree, Paul
• Hohensen, Nicola
• Cassidy, Clare
• Keane, Michael A.
• Hogan, Michael J.

Titel

Self‐initiated learning reveals memory performance and electrophysiological differences between younger, older and older adults with relative memory impairment

Ist Teil von

• The European journal of neuroscience, 2019-12, Vol.50 (11), p.3855-3872

Ort / Verlag

France: Wiley Subscription Services, Inc

Erscheinungsjahr

2019

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Older adults display difficulties in encoding and retrieval of information, resulting in poorer memory. This may be due to an inability of older adults to engage elaborative encoding strategies during learning. This study examined behavioural and electrophysiological effects of explicit cues to self‐initiate learning during encoding and subsequent recognition of words in younger adults (YA), older control adults (OA) and older adults with relative memory impairment (OD). The task was a variation of the old/new paradigm, some study items were preceded by a cue to learn the word (L) while others by a do not learn cue (X). Behaviourally, YA outperformed OA and OD on the recognition task, with no significant difference between OA and OD. Event‐related potentials at encoding revealed enhanced early visual processing (70–140 ms) for L‐ versus X‐words in young and old. Only YA exhibited a greater late posterior positivity (LPP; 200–500 ms) for all words during encoding perhaps reflecting superior encoding strategy. During recognition, only YA differentiated L‐ versus X‐words with enhanced frontal P200 (150–250 ms) suggesting impaired early word selection for retrieval in older groups; however, OD had enhanced P200 activity compared to OA during L‐word retrieval. The LPP (250–500 ms) was reduced in amplitude for L‐words compared to both X‐ and new words. However, YA showed greater LPP amplitude for all words compared to OA. For older groups, we observed reduced left parietal hemispheric asymmetry apparent in YA during encoding and recognition, especially for OD. Findings are interpreted in the light of models of compensation and dedifferentiation associated with age‐related changes in memory function. Older adults display difficulties in encoding and retrieval of information, resulting in poorer memory. During a variation of the old/new paradigm consisting of words to learn and words to not learn, young adults outperform older adults on behavioural performance. In terms of electrophysiological activity, we find that older adults display reduced left parietal hemispheric asymmetry apparent in young adults during encoding and recognition phases. Patterns of compensatory or dedifferentiation associated with age‐related changes in memory function include enhanced parietal and frontal activity during recognition for older adults with relative memory impairment.