Chapter 10 - DISORDERS OF PERCEPTUAL PROCESSING

Abstract

The discipline of human neuropsychology is a new branch of the bio-behavioral sciences that contributed to the burgeoning field of cognitive psychology by demonstrating relationships between regional brain systems and higher mental functions. This chapter discusses the experimental and clinical observations that have focused on disorders of perceptual processing. Perception is a principal factor in virtually every aspect of human activity. Investigations in the neurosciences during the past quarter century have brought about a radical revision of the concept of perception. The neuropsychological studies of this important area have also contributed significantly to the contemporary psychologist's understanding of human information processing systems. The major sources of data that have shown how injury affects perceptual processing in the human brain come from the neuropsychological studies of local brain lesions. The chapter describes the major disorders of perceptual processing as discrete symptom complexes. Certain disorders occur fairly frequently, while others are rare and seldom occur as the only predominant sequelae of brain damage. Certain disorders, such as finger agnosia, occur most often in a context with other related disturbances such as spatial agnosia. Other disorders, including many of the visual agnosias, may occur most often after recovery from sensory defects. It is the task of the science of neuropsychology to determine whether each of these disorders represents a true clinical entity, a part of an interrelated set of symptoms known as a syndrome, or a problem that can be best understood as representing a part of a clinical picture of progressive intellectual deterioration.