Graphic neglect - More than the sum of the parts

Patients who seem to "ignore" objects or people on one side of space have b een described in the medical literature for well over a century. The term " visuospatial neglect" is now used to describe the cluster of behaviors wher eby patients after unilateral cerebral lesions (most frequently of right pa rietal cortex) fail to attend or explore (predominantly) the side of space contralateral to the lesion. Although the condition comprises a complex dis ruption of space-related behaviors, the prevailing view was that the differ ent symptoms could be accommodated in terms of damage to one of three diffe rent cognitive mechanisms mediating attention (e.g., K, M, Heilman and E, V alenstein, Ann, Neurol, 5: 166-170, 1979), intention (R. T, Watson, E, Vale nstein, and K, Heilman, Ann, Neurol, 3: 505-508, 1978), and/or representati on (E. Bisiach, Q. J. Exp. Psychol, 46: 435-461, 1993). The general consens us favors an attentional deficit but the notion of attention has always pro ved conceptually slippery and difficult to operationalize (P, W, Halligan a nd J, C, Marshall, Cogn, Neuropsychol, 11: 167-206, 1994a), In this paper, we consider how drawing performance after right brain damage in patients wi th "visual neglect" reveals the involvement and interplay of several cognit ive deficits, including aspects of mental representation and Spatial awaren ess. (C) 2001 Academic Press.