Immediate perceptual response to intersensory discrepancy.

Abstract

The present article critically reviews the literature on the intersensory bias that results when the information available to different sensory modalities is caused to be discrepant. The characteristics for which discrepant sensory information has been provided include spatial location, shape, size/length, and orientation. Stimulus variables that affect the magnitude of intersensory bias are (a) structural factors, such as amount of discrepancy, active versus passive placement of the limb, and timing of the stimulus information, and (b) cognitive factors, such as subjects' awareness of the intersensory discrepancy, their assumption of the unitariness of the event being perceived, and the "compellingness" of the stimulus situation. Response variables that affect intersensory bias are the type and timing of the response required of the subjects. The evidence on developmental trends and individual differences in the susceptibility to intersensory bias is both sparse and conflicting. Also unclear is the relationship between intersensory bias and adaptation to perceptual rearrangement. None of the various theories-modality precision, directed attention, and modality appropriateness-accounts for all of the intersensory discrepancy results. Consequently, a new model is proposed, based on the supposition that intersensory bias is a result of an attempt by the perceptual system to maintain a perceptual experience consonant with a unitary event.Adult human perception is, for the most part, fully developed, very accurate, and served by a multiplicity of redundant cues. As a consequence, much of our current understanding of perceptual processes has come about when these processes have, for one reason or another, malfunctioned. Color blindness and congenital cataracts are examples of perceptual failures that have revealed a great deal about certain aspects of normal vision. Since such naturally occurring events are relatively rare, however, it has become a common procedure to deliberately interfere with the perception of otherwise normal human observers. The study of illusions is the best

Causality and cross-modal integration.

“…This finding is at odds with the consensus view that in temporal tasks, auditory influence on vision is strong Shams, Kamitani, & Shimojo, 2002), whereas visual influence on audition is either weak (Welch, DuttonHurt, & Warren, 1986; J. T. Walker & Scott, 1981;Welch & Warren, 1980) or nonexistent (Shipley, 1964). The perception of event duration (which concerns us here) is no exception (J. T. Walker & Scott, 1981;.…”

Multisensory Integration of Low-level Information in Autism Spectrum Disorder: Measuring Susceptibility to the Flash-Beep Illusion

“…The modality appropriateness hypothesis states that the sensory modality that is most relevant to the completion of a particular task will influence the perception of the other modalities (Welch and Warren 1980). Vision has "higher spatial resolution" so it will dominate and alter the perception of sound on spatial tasks, but sound, which has a "higher temporal resolution", will alter the perception of other sensory modalities on tasks that are more temporal in nature (Welch and Warren 1980).…”

“…Vision has "higher spatial resolution" so it will dominate and alter the perception of sound on spatial tasks, but sound, which has a "higher temporal resolution", will alter the perception of other sensory modalities on tasks that are more temporal in nature (Welch and Warren 1980). However, more recent work suggests that a reliability-based framework of sensory integration may be more appropriate in describing auditory-visual multisensory effects (Alais and Burr 2004).…”

Embodiment, ownership and disownership

“…I suggest that the answer can be found in the literature on multimodal integration, which also comes in degrees. In particular, Welch and Warren (1980) propose that integration between various sensory inputs requires what they call the 'assumption of unity', that is, the assumption that the inputs carry information about the same object. Furthermore, they claim that the extent of the integration depends on the reliability of the assumption.…”