Global and local biases and biological motion processing in healthy ageing.
43.3044, Monday, 18-May, 8:30 am - 12:30 pm, Banyan Breezeway
Hannah Agnew1, Louise Phillips1, Karin Pilz1; 1University of Aberdeen, School of Psychology
The ability to perceive biological motion has been shown to deteriorate with age and it has been shown previously that older adults rely more on the form than the local motion information when processing point-light walkers (Pilz et al., 2010, Vision Research). Recently, it has been suggested that biological motion processing in ageing is related to a form-based global processing bias (Insch et al., 2012, Psychology and Aging). Here, we investigated the relationship between older adults’ advantage for form information when processing point-light actions and an age-related form-based global processing bias. In a first task, we asked older and younger adults to sequentially match three different point-light actions; normal actions that contained local motion and global form information, scrambled actions that contained primarily local motion information, and random-position actions that contained primarily global form information. In accordance with previous results, we found that both age groups performed best for normal actions, then random-positioned actions and performed worse for scrambled actions. In a second task, we investigated form-based global processing biases using the Navon task. Both age groups exhibited a global processing bias as they displayed faster RT’s for global stimuli in comparison to local stimuli. Interestingly, older adults were found to be more accurate than younger adults in their responses to the Navon stimuli. However, the global processing bias in the Navon task did not correlate with the advantage of form information when processing point-light actions in both age groups. These results indicate that the advantage for form information when processing point-light actions and the form-based global processing bias in the Navon task do not rely on the same underlying processes, and suggest that there is no systematic relationship between the two types of visual task.