Neuropsychological contributions to theories of part/whole organization.

Recent evidence from neuropsychology has proven useful in defining neural and cognitive subsystems involved in certain cognitive processes such as spatial attention (Posner, Walker, Friedrich, & Rafal, 1984) and imagery (Farah, 1988; Kosslyn, 1986). In this article we discuss neuropsychological evidence that suggests a modular system is responsible for the organization of parts and wholes by the visual system. We review both normal and neuropsychological evidence that suggest that hierarchical organization of objects within objects involves the coordination of at least four separate subsystems, one that emphasizes the global properties of a figure (association with right posterior superior temporal-parietal regions), one that emphasizes the local properties of a figure (associated with left posterior superior temporal-parietal regions), one that controls the distribution of attentional resources to these subsystems (associated with right or left lateral parietal lobe), and one that interconnects global and local properties and relies on the integrity of posterior temporal-temporal pathways.