When the stored representation of the meaning of a stimulus is accessed through the processing of a sensory input it is maintained in an activated state for a certain amount of time that allows for further processing. This semantic activation is generally accompanied by conscious identification, which can be demonstrated by the ability of a person to perform discriminations on the basis of the meaning of the stimulus. The idea that a sensory input can give rise to semantic activation without (...) concomitant conscious identification was the central thesis of the controversial research in subliminal perception. Recently, new claims for the existence of such phenomena have arisen from studies in dichotic listening, parafoveal vision, and visual pattern masking. Because of the fundamental role played by these types of experiments in cognitive psychology, the new assertions have raised widespread interest. (shrink)

Integrates data from various research areas concerned with the effects of unconscious perception and the preconscious antecedents of subjective experience. Discusses the possible nature and origin of preconscious processes, the evidence for unconscious perception, and the effects of unperceived stimuli on perception, verbal behavior, and memory. Examines the theory that cognitive processes evolved for the gratification of need.