Poster Session A, Saturday, March 23, 1:30 pm - 3:30 pm, Pacific Concourse
Spatial Attention in Healthy Cognitive Ageing
Monika Harvey1, Gesine Maerker1, Gemma Learmonth1,2, Gregor Thut1,2; 1School of Psychology, University of Glasgow, UK, 2Institute of Neuroscience & Psychology, University of Glasgow, UK
Young adults tend to overestimate the number, size and luminance of objects located in the left side of space(“pseudoneglect”), a spatial bias deemed to be caused by a right hemisphere dominance for visuospatial attention. Intriguingly, healthy older adults have been shown to lose this leftward bias, yet at present little is known as to whether these behavioural shifts are reflected in hemispheric changes. Here we present two experiments: firstly we aimed to identify an ideal spatial task teasing out age related spatial bias changes. Secondly, we wanted to investigate potential hemispheric alterations with EEG. In the first experiment we found that for a single given task, both young and older participants showed consistent spatial biases across different testing days. However, different tasks generated different biases, with the landmark task (in which participants are instructed to indicate which side of a pre-transected centrally presented line is shorter/longer) best at potentially teasing ageing biases apart. In the second experiment, we compared young and older adults on this task whilst recording event-related potentials (ERPs). Full-scalp cluster mass permutation tests identified a larger right parieto-occipital response for long compared to short landmark stimuli in young adults, an effect not present in the older group. To conclude we report task and stimulus-driven reduction of right hemispheric control over spatial attention in older adults. Future studies will need to determine whether these hemispheric changes can be mapped for other spatial tasks and methodologies, and whether they represent normal ageing processes or an early indication of neurodegeneration.
Topic Area: ATTENTION: Spatial