Neural Correlates of Spatial Bias in Healthy Cognitive Ageing

Harvey, M. , Maerker, G., Learmonth, G. and Thut, G. (2019) Neural Correlates of Spatial Bias in Healthy Cognitive Ageing. Scottish Vision Group Meeting, Isle of Skye, Scotland, 05-07 Apr 2019.

Abstract

Young adults tend to overestimate the 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, for some spatial tasks, healthy older adults have been shown to lose this leftward bias, yet at present little is known as to whether these behavioural shifts reflect hemispheric changes. Here we present two experiments: firstly we aimed to identify a 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 only the landmark task (in which participants are instructed to indicate which side of a pre-transected centrally presented line is shorter/longer) showing significant age related bias shifts. 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 aging processes or an early indication of neurodegeneration.

• Item Type: Conference or Workshop Item
• Additional Information: Abstract published in i-Perception 10(S1):17, https://doi.org/10.1177/2041669519854233
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Thut, Professor Gregor and Learmonth, Dr Gemma and Harvey, Professor Monika and Maerker, Ms Gesine
• Authors: Harvey, M., Maerker, G., Learmonth, G., and Thut, G.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience; College of Science and Engineering > School of Psychology