Research report Action-based distractor effects on the manual response times of chimpanzees during discrimination tasks

AbstractTwo chimpanzees performed visual search and simple discrimination tasks in which manual pointing to the target stimulus wasrequired. To clarify the action-based interference effects of the distractors, response time data were analyzed on the basis of therelationship among the positions of the target, distractors, and hand. In both tasks, clear action-based interference effects were observed.Firstly, distractors along the path of the manual response to the target caused greater interference (the response-path effect). Secondly,when distractors were located ipsilateral to the responding hand, response times were longer (the ipsilateral effect). These results areconsistent with previous studies on selective reaching in humans, and they suggest that manual responses in chimpanzees are controlledby action-centered attention as is the case for humans. 2002 Elsevier Science B.V. All rights reserved. Theme: Motor systems and sensorimotor integrationTopic: Control of posture and movementKeywords: Discrimination task; Chimpanzee; Distractor effect