Abstract
Mild Cognitive Impairment (MCI) refers to a progressive cognitive decline that can lead to Alzheimer Disease. Recent literature on MCI stressed the importance of looking at eye-movement responses as a key marker for cognitive decline. In the present study, we investigated the role that attentional responses play on the maintenance and access of visual information held in working memory.14 participants with MCI and 16 age-matched controls performed a change detection task on 120 photographs of naturalistic scenes (60 experimental/change trials, 60 fillers/no change trials), while being eye-tracked. We manipulated high-level semantic changes on a critical object in each scene under three experimental conditions: Congruency (it became another object), Location (it moved to another location) or Both (it changed and moved). We analyzed the detection accuracy and the distance of the closest fixation from the center of the critical object. MCI participants performed significantly worse than the control group. Both groups were better at remembering the change when the critical object changed Location, or when Both features changed, than when the change involved Congruency, a condition which proved particularly challenging for the people with MCI. Considering eye-movements, we found that the closer the participant's eye fixation was to the critical object, the more likely the change would be detected. Crucially, healthy controls were able to foveate closer to the center of the object in correct trials compared to people with MCI, particularly in the Congruency condition. This indicates that MCI patients had more difficulties attending at purely semantic changes, and consequently, failed to recognize them more often than healthy controls. These preliminary results suggest that attentional responses and high-level processing of semantic information are good proxies to the formation of and access to visual memories, and can be revealing about healthy and pathological ageing.
Meeting abstract presented at VSS 2018