Impaired Visual Perceptual Categorization in Right Brain-Damaged Patients: Failure To Replicate

Abstract

The association of both Perceptual Categorization (PC) and Semantic Categorization (SC) with sensory performance was investigated. 28 RBD, 27 LBD and 21 non-brain-damaged subjects were tested with the PC and SC tasks described by Warrington and Taylor (1978) and with 6 sensory tasks. PC was related to sensory performance in RBD but not in LBD patients. SC was only marginally associated with sensory ability in both lesion groups. RBD and LBD patients differed significantly at neither PC nor at SC. Thus the dissociation between PC and SC, described by Warrington and Taylor (1978) was not replicated. Moreover, PC and SC were significantly correlated in both RBD and LBD patients. This suggests that the serial organization of PC and SC is questionable. It is concluded that the associations we obtained between SC, PC and sensory performance are likely to be functional. The contribution of a cognitive factor (“abstraction”) to PC and SC is discussed.