Biological Motion and Attention in Healthy Ageing

Biological motion perception is the ability of the visual system to perceive complex human movement patterns. Previous studies have shown a direct link between attentional abilities and performance on biological motion tasks, both of which have been shown to deteriorate with age. However, it is not known whether there is a direct link between age-related deficits in biological motion processing and attention. Here, we investigated whether age-related decline in biological motion perception is mediated by impaired attentional abilities. In a first task, we assessed biological motion performance, and asked 27 younger (M = 23 years) and 22 older adults (M = 68 years) to indicate the facing direction of point-light actions. In a second task, we assessed selective visual attention using a conjunctive visual search. Finally, in a third task, we combined both and assessed attentional demands related to biological motion perception similar to (Cavanagh, Labianca & Thornton, 2001, Cognition, 80, 47-60), in that younger and older adults had to indicate the presence of the target point-light walker among a varied number of distracters. Interestingly, younger adults displayed steeper search slopes than older adults on the conjunctive visual search, but the age groups did not differ in their performance on the biomotion search task. Correlations between the search tasks were only found for younger adults suggesting that older adults use different search strategies on each task.