Effects of aging on hippocampal and anterior temporal activations during successful retrieval of memory for face-name associations.

Memory for face-name associations is an important type of memory in our daily lives, and often deteriorates in older adults. Although difficulty retrieving face-name associations is often apparent in the elderly, there is little neuroscientific evidence of age-related decline in this memory. The current fMRI study investigated differences in brain activations between healthy young and older adults during the successful retrieval of people's names (N) and job titles (J) associated with faces. During encoding, participants viewed unfamiliar faces, each paired with a job title and name. During retrieval, each learned face was presented with two job titles or two names, and participants were required to choose the correct job title or name. Retrieval success activity (RSA) was identified by comparing retrieval-phase activity for hits versus misses in N and J, and the RSAs in each task were compared between young and older adults. The study yielded three main findings. First, the hippocampus showed significant RSA in both tasks of N and J, and the activity was greater for young compared to older subjects. Second, the left anterior temporal lobe (ATL) showed greater RSA in N than in J, but there was no age difference in the activity in this region. Third, functional connectivity between hippocampal and ATL activities in both retrieval tasks was higher for young than for older adults. Taken together, age-related differences in hippocampal activities and hippocampus-ATL connectivity could contribute to age-related decline in relational memory and to complaints of poor retrieval of people's names by older adults.