Stimulus-driven control in visual neglect: the role of awareness

A person’s field of vision, or visual field, includes an enormous amount of information. By means of attention and eye movements, people are able to select certain objects and location from any point in the visual field. Selection may be stimulus-driven (the properties of the object attract a person’s attention involuntarily, such as a flashing light) or goal-driven (the observer purposely turns their attention to an object). People with damage to the right parietal or parieto-temporal lobes of the brain—commonly brought on by stroke, vascular, demyelinating or infectious diseases—suffer from visual neglect, limiting their ability to select information from the visual field. They often fail to notice items in the visual field opposite to the damaged area of their brain. Interestingly, research has suggested that visual neglect in these people is a function of goal-driven selection, and that stimulus-driven selection function may remain intact. Wieske van Zoest’s research is investigating the role of stimulus-driven control in patients with visual neglect. While participants—patients and healthy controls alike—may not be aware of stimulus-driven influences in selection, direct measures (such as eye movement recording) allow for investigation of the contribution of stimulus-driven control. The proposed work may have significant practical relevance for patients, allowing them to process information if it is presented in such a way that it draws attention automatically in a stimulus-driven fashion.