Attention to semantic and spatial information in aging and Alzheimer's disease

Résumé 0

"In two experiments we explored the patterns of attention to semantic andspatial information in younger adults, older adults, and patients withAlzheimer’s disease (AD). In the first experiment, a semantic priming taskmeasured age- and AD-related changes in attentional sensitivity to semanticinformation. In the second experiment, the semantic priming task wasmodified to additionally serve as a spatial inhibition of return (IOR) task.The combined semantic and spatial task measured (a) age- and AD-relatedchanges in sensitivity to spatial cues as well as to semantic primes, and (b)interactions between the networks that subserve attention to semantic andspatial information. The results of both experiments revealed groupdifferences in the utilization of semantic primes as a function of primevalidity, suggesting that both older adults and AD patients were less likelythan younger adults to generate controlled attention-dependent expectanciesfor semantically related information. Spatial IOR effects in Experiment 2were evident in the performance of all three groups, but were of reducedmagnitude in AD patients. Younger adults’ performance reflected interactionsbetween semantic priming and spatial cuing effects. These findings areconsistent with conclusions that (a) selectivity via semantic primes and viaspatial cues reflect separate attentional mechanisms, and (b) semantic andspatial aspects of attention are mediated by different but closelyinterconnected neural networks."