Closing-In Behavior and Motor Distractibility in Persons with Brain Injury.

This study investigates closing-in behavior (CIB), a phenomenon observed in graphic copying tasks when responses encroach upon or overlap the model. The behavior is most common amongst individuals with dementia and amongst pre-school children. We explored the relationship between CIB and the 'distractor effect' in reaching, whereby salient visual stimuli can influence the spatial trajectory of the reach. A group of individuals with overlap-CIB (n = 9), without CIB (n = 9) and healthy controls (HC; n = 6) underwent a task-irrelevant and a task-relevant distractors and the deviation of the movement trajectory towards the distractor location was measured in both tasks. Individuals with graphic CIB showed more distractor-directed veering during reaching than did individuals without CIB or HC, provided that the distractor was relevant for the reaching task. These results strengthen the relationship between CIB and the distractor effect and reinforce the hypothesis that CIB represents a disinhibited tendency to act towards the focus of attention.