Background Lapses in attention are a debilitating feature of Dementia with Lewy Bodies (DLB). Caffeine is the most widely consumed stimulant worldwide however its potential to ameliorate attention impairment in healthy ageing and neurodegenerative disease is unknown. In this study we explore whether caffeine will improve performance attention in older participants without cognitive disorder and those with DLB.

Methods 30 healthy elderly participants and 6 people affected by DLB performed a blinded, placebo-controlled, cross-over study using a battery of cognitive tasks including simple and choice reaction time, attentional blink, Stroop, digit span and walking while talking tasks. Participants initially abstained from caffeine for 7 days before cognitive testing on day 8 with a caffeinated (100 mg) or de-caffeinated drink 1 hour prior to testing. On day 9 the alternative drink was received.

Results Data from healthy elderly participants demonstrates caffeine reduces digit span (p=0.027) and delays the attentional blink (p=0.01), but in contrast improves choice reaction time (p=0.03) and Stroop task performance (p=0.042), with no clear effects yet in DLB group.

Discussion In healthy older people, caffeine can boost performance on simple and complex attentional tasks and alter the temporal dynamics of attention but at a cost to working memory.