Abstract:
Cancellation tests (marking multiple target images across a display) have been clinically used primarily to assess unilateral spatial neglect in stroke patients. More recently, the organization of cancellation (i.e., the spatial pattern of target-marking over time) has been assessed using affordable technologies to track both exploratory eye and hand movements. These methods have indicated that brain illness patients are more disorganized than neurologically healthy individuals, suggesting a potential new biomarker of post-stroke disability. Organization is important to living independently, and brain illnesses impact cognitive abilities such as search organization. However, aphasic patients have largely been excluded from such research because their impaired speech comprehension was assumed to prevent testing. We have found, however, that demonstrating the test to aphasic patients, using minimal instruction, allowed testing. Therefore, we conducted this preliminary proof of principle study to compare aphasic and non-aphasic stroke patients and controls on search organization. Participants were divided into three groups of three participants each: group one including aphasic patients, group two including non-aphasic patients, and group three including neurologically healthy controls. Four parallel Star Cancellation test patterns were presented to each participant, each containing 56 small stars (“targets”) scattered amongst other symbols (“distractors”). Participants were shown to circle targets on a computer tablet with a stylus pen, using custom software to track pen movements. Preliminary results indicate that the methods were feasible and suggest that patients displayed more disorganized hand movements than healthy controls. Future directions for this study will determine whether eye movements are directly coupled with concurrent hand movements on cancellation in relation to participant status (patient vs control) and whether these measures of organization and hand-eye coordination may predict functional recovery in acute inpatient rehabilitation.