Pattern recognition research is an important part of cognitive psychology, as well as of such other disciplines, as neurobiology, computer science, and communications engineering. From the information-processing point of view, how people recognize patterns is one of the more interesting and researchable aspects of the larger question of how they perceive and interact with their environment. Given the physiological evidence that perception involves successive transformations of input information, information-processing models have been readily applied to pattern recognition problems. Within the information-processing approach, pattern recognition requires the matching of incoming information with information stored in permanent memory. Pattern recognition theorists often argue by analogy from the visual system to the auditory system, because of some evident similarities between the two and because the visual system is better understood. The contributions of psycholinguistic theories and theories of pattern recognition to the understanding of complex behaviours such as reading will continue to be substantial.