Distinctive visual tasks for characterizing mild cognitive impairment and dementia using oculomotor behavior.

Introduction: One's eye movement (in response to visual tasks) provides a unique window into the cognitive processes and higher-order cognitive functions that become adversely affected in cases with cognitive decline, such as those mild cognitive impairment (MCI) and dementia. MCI is a transitional stage between normal aging and dementia. Methods: In the current work, we have focused on identifying visual tasks (such as horizontal and vertical Pro-saccade, Anti-saccade and Memory Guided Fixation tasks) that can differentiate individuals with MCI and dementia from their cognitively unimpaired healthy aging counterparts based on oculomotor Performance indices. In an attempt to identify the optimal combination of visual tasks that can be used to differentiate the participant groups, clustering was performed using the oculomotor Performance indices. Results: Results of our study with a group of 60 cognitively unimpaired healthy aging individuals, a group with 60 individuals with MCI and a group with 60 individuals with dementia indicate that the horizontal and vertical Anti-saccade tasks provided the optimal combination that could differentiate individuals with MCI and dementia from their cognitively unimpaired healthy aging counterparts with clustering accuracy of ∼92% based on the saccade latencies. Also, the saccade latencies during both of these Anti-saccade tasks were found to strongly correlate with the Neuropsychological test scores. Discussion: This suggests that the Anti-saccade tasks can hold promise in clinical practice for professionals working with individuals with MCI and dementia.

Virtual Reality based Gaze-sensitive Aiming Task Platform: Role of Attention Allocation in Task Performance for Individuals with Autism and Typically Developing Individuals.

Individuals with Autism Spectrum Disorder (ASD) often exhibit difficulty in movement preparation and allocating attention towards different Regions of Interest (ROIs) of a visual stimulus. Though research has alluded to differences in movement preparation for aiming tasks between individuals with ASD and typically developing (TD) individuals, there is limited evidence (true for near-aiming tasks) on the contribution of the window (i.e., time duration) of movement preparation (i.e., the planning window preceding movement initiation) on one's aiming performance. However, investigation of the contribution of this planning window on one's performance in far-aiming task remains as majorly unexplored. Again, often one's eye movement leads the initiation of hand movement (for task execution) indicating the importance of monitoring one's eye movement in the planning stage, critical for far-aiming task. Most of the studies (in conventional settings) examining the role of gaze behavior on aiming performance have involved TD individuals and only a few involving individuals with ASD. Here, we have designed Virtual Reality (VR)-based Gaze-sensitive far-aiming (dart throw) task and monitored the looking pattern of participants while they interacted with the task environment. We carried out a study with 40 participants (20 in each of ASD and TD groups) to understand how the participant groups differed in task performance and gaze fixation within the movement planning window. We observed difference in the scan path and last fixation within the movement planning window before triggering the release of the dart with relevance to task performance.