SELECTIVE ATTENTION IN A REACHING TASK - EFFECT OF NORMAL AGING AND ALZHEIMERS-DISEASE

This study examined the ability of young adults, older adults, and old er adults suffering from Alzheimer's disease (AD) to perform a selecti ve reaching task. Normal aging did not increase interference caused by distracters. In contrast, patients with AD showed massively increased effects of distracter interference. AD patients showed a high probabi lity of making responses to distracter items. The proportion of these incorrect responses was related to the inability to use inhibitory pro cesses, which increased with the severity of AD. Responses to distract ers occurred despite the fact that patients could discriminate targets and distracters and knew that their responses to distracters were in error. These data suggest that AD patients are impaired in their abili ty to inhibit incorrect responses.