Brain activation in young and older adults during implicit and explicit retrieval

摘要: Positron emission tomography was used to study regional cerebral blood flow (H215O method) in groups of young and older adults during implicit explicit retrieval, following a procedure devised by Squire et al. (1992). At study, subjects were exposed four lists words. Following list presentation, presented with three-letter word stems under conditions: (1) silent viewing, (2) completion that could not form words from the list, instruction provide first came mind (baseline), (3) stems, half which (priming), (4) use as cues for recall (memory). The behavioral data indicated an agerelated deficit cued reduced priming. Both age showed similar decrease right posterior cortex priming relative baseline. During recall, bilateral increases observed prefrontal anterior cingulate gyrus both groups. selective activity left cerebellum Wernicke's area, whereas activation perirhinal region medial-temporal recall. results suggest simiiar biological basis groups: neural required process particular stimulus subsequent encounter compared previous one. In addition, importance regions conscious retrieval substantiated extended late adulthood. Finally, agedifferential activations discussed prominent concepts current literature on cognitive aging (e.g., speed processing, self-initiated operations, cross-modal recoding).