Naturalistic action production following right hemisphere stroke

An unselected group of right hemisphere, semi-acute stroke patients (n = 30 ) was run on a laboratory test of naturalistic action production and was fo und to commit errors of action at a higher rate than what was previously re ported for recovering head injury patients [Schwartz et al., Naturalistic a ction impairment in closed head injury. Neuropsychology, 1997, 8, 59-72]. T here were strong similarities in how these two patient groups responded to variations in task demands and in the pattern of errors they produced. Hemi spatial biases were evident in the errors of right hemisphere patients with neglect but not those without neglect; and neglect patients also many erro rs that were unrelated to the spatial layout. We argue that a non-specific resource limitation - which might translate as reduced arousal or effort - is central to the breakdown of naturalistic action production after brain d amage, and right hemisphere patients are especially vulnerable to this reso urce limitation and its behavioral consequences. (C) 1998 Elsevier Science Ltd. All rights reserved.