Using Fixation Related Potentials to Explore the Difference Between Cancellations and Re-cancellations During Visual Search
Purpose - De cits in spatial working memory (SWM) are thought to aggravate the symptoms of neglect. This study investigates brain activity during a visual search task, a task which depends on SWM, in order to better understand the role of SWM during such tasks. Design - Using EEG, four healthy subjects were recorded while performing a visual search task in which target stimuli had to be found in between distractor stimuli. An eye-tracker was used to determine which stimulus the subject was xating on. Findings - Cancellations could be distinguished from re-cancellations well above chance for one out of four participants (59%). Two others performed slightly above chance (53%) and for one participant performance was at chance level. Possible limitations - It seems that a distinction between cancellations and re-cancellations based on EEG data can be made but improvements to the task paradigm are needed to gather more and higher quality FRPs in order to get a better overall performance. Improvements to the current paradigm were suggested and implemented. Originality/value - Very little is known about the cognitive de cits underlying spatial neglect syndrome. This study attempts to increase our understanding by looking at the brain activity of healthy subjects during a task that neglect patients typically do not perform well on. This study can provide novel insights into what happens during the processing of targets in healthy subjects. As such it can provide data for future studies on neglect patients to compare to.
Faculteit der Sociale Wetenschappen