Multisensory constraints on awareness

Given that multiple senses are often stimulated at the same time, perceptual awareness is most likely to take place in multisensory situations. However, theories of awareness are based on studies and models established for a single sense (mostly vision). Here, we consider the methodological and theoretical challenges raised by taking a multisensory perspective on perceptual awareness. First, we consider how well tasks designed to study unisensory awareness perform when used in multisensory settings, stressing that studies using binocular rivalry, bistable figure perception, continuous flash suppression, the attentional blink, repetition blindness and backward masking can demonstrate multisensory influences on unisensory awareness, but fall short of tackling multisensory awareness directly. Studies interested in the latter phenomenon rely on a method of subjective contrast and can, at best, delineate conditions under which individuals report experiencing a multisensory object or two unisensory objects. As there is not a perfect match between these conditions and those in which multisensory integration and binding occur, the link between awareness and binding advocated for visual information processing needs to be revised for multisensory cases. These challenges point at the need to question the very idea of multisensory awareness.

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Use of backward masking test for the study of visual information processing in healthy subjects and schizophrenic patients

Human Physiology ◽

10.1134/s036211971605011x ◽

2016 ◽

Vol 42 (5) ◽

pp. 492-498

Author(s):

V. V. Myamlin ◽

A. V. Kirenskaya ◽

V. Y. Novototsky-Vlasov

Keyword(s):

Information Processing ◽

Visual Information ◽

Healthy Subjects ◽

Visual Information Processing ◽

Backward Masking ◽

Schizophrenic Patients

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Development of Information Processing in Normal and Disabled Readers

Perceptual and Motor Skills ◽

10.2466/pms.1978.46.3c.1047 ◽

1978 ◽

Vol 46 (3_suppl) ◽

pp. 1047-1054 ◽

Cited By ~ 41

Author(s):

William Lovegrove ◽

Christina Brown

Keyword(s):

Information Processing ◽

Visual Information ◽

Reading Ability ◽

Short Term Memory ◽

Backward Masking ◽

Disabled Children ◽

Specific Reading ◽

The Difference ◽

Disabled Readers ◽

Reading Disabled

8- and 11-yr.-old reading-disabled children were compared in two experiments with controls matched on intelligence and age. Exp. I measured duration of visual information store by means of a separation threshold technique. Exp. II determined the rate of transfer from visual information store to short-term memory using a backward masking technique. Results from Exp. I showed that at each age specific reading-disabled children had significantly longer durations of visual information store than controls. The difference between the reading ability groups decreased with increasing age. Exp. II demonstrated that rate of transfer of information was significantly slower for specific reading-disabled children than for controls at both age levels. In contrast to Exp. I, this difference increased with increasing age. The results are considered in terms of their possible relevance to developmental lag theories. The evidence indicates that the development of visual information processing in reading-disabled children is similar to that in controls but occurs at a slower rate.

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Dysfunction of Magnocellular/dorsal Processing Stream in Schizophrenia

Current Psychiatry Research and Reviews ◽

10.2174/1573400515666190119163522 ◽

2019 ◽

Vol 15 (1) ◽

pp. 26-36

Author(s):

Sergio Chieffi

Keyword(s):

Information Processing ◽

Visual Processing ◽

Visual Information ◽

Visual Information Processing ◽

Contour Detection ◽

Backward Masking ◽

Dorsal Pathway ◽

Processing Stream ◽

Early Processing ◽

Processing Of Visual Information

Background: Patients with schizophrenia show not only cognitive, but also perceptual deficits. Perceptual deficits may affect different sensory modalities. Among these, the impairment of visual information processing is of particular relevance as demonstrated by the high incidence of visual disturbances. In recent years, the study of neurophysiological mechanisms that underlie visuo-perceptual, -spatial and -motor disorders in schizophrenia has increasingly attracted the interest of researchers. Objective: The study aims to review the existent literature on magnocellular/dorsal (occipitoparietal) visual processing stream impairment in schizophrenia. The impairment of relatively early stages of visual information processing was examined using experimental paradigms such as backward masking, contrast sensitivity, contour detection, and perceptual closure. The deficits of late processing stages were detected by examining visuo-spatial and -motor abilities. Results: Neurophysiological and behavioral studies support the existence of deficits in the processing of visual information along the magnocellular/dorsal pathway. These deficits appear to affect both early and late stages of visual information processing. Conclusion: The existence of disturbances in the early processing of visual information along the magnocellular/dorsal pathway is strongly supported by neurophysiological and behavioral observations. Early magnocellular dysfunction may provide a substrate for late dorsal processing impairment as well as higher-level cognition deficits.

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Backward Masking Performance in Schizophrenic Patients and their Healthy Relatives

European Psychiatry ◽

10.1016/s0924-9338(09)71357-4 ◽

2009 ◽

Vol 24 (S1) ◽

pp. 1-1

Author(s):

E. Chkonia ◽

M. Roynishvili ◽

A. Kezeli ◽

M.H. Herzog ◽

A. Brand

Keyword(s):

Information Processing ◽

Visual Information ◽

Control Group ◽

Backward Masking ◽

Level Information ◽

Schizophrenic Patients ◽

Healthy Control ◽

Information Processing Deficits ◽

The One ◽

Visual Backward Masking

Over the past years, studies of unaffected first-degree relatives of schizophrenic patients have reported cognitive deficits in the domains of executive functions, memory, and attention. However, these deficits may rely on lower level information processing deficits. Here, we investigated visual information processing with a visual backward masking task. A vernier target was followed by a grating mask. Observers had to indicate the offset direction of the vernier. We determined the SOA between the vernier and the grating onset for schizophrenic patients, their healthy first order relatives, and a healthy control group. Schizophrenic patients needed SOAs about three times longer than healthy controls to reach a predefined criterion level. Backward masking performance of unaffected relatives was significantly better than the one of patients but significantly worse than performance of controls. This result adds further evidence that low level deficits as determined by visual backward masking are endophenotypes of schizophrenia.

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