Backward masking as a measure of slow processing in schizophrenia spectrum disorders.

Abstract

Three groups of hospitalized adolescents (schizophrenics, schizotypal personalities, and borderline personality adolescent adjustment reactions) with 10 subjects in each group were compared for their ability to identify masked and unmasked stimuli. Results revealed that the schizophrenic group required longer minimum exposure durations for criterion identification of unmasked stimuli than the other two groups (p < .01). Under conditions of visual backward masking, however, schizotypal personalities as well as schizophrenics showed a relative deficit. Results supported Heston's notion that schizophrenia spectrum disorders may be different degrees of expression of the same underlying defect. Previous results with visual backward masking in adults were also extended to adolescents. The findings were consistent with a slow information processing hypothesis for schizophrenia spectrum disorders. Theoretical implications of this hypothesis are discussed.

New perspectives on schizotypal personality disorder

“…Backward masking performance has also differentiated patients with SPD from controls in some studies [8,9] but not others [6].…”

Revisiting the Backward Masking Deficit in Schizophrenia: Individual Differences in Performance and Modeling With Transcranial Magnetic Stimulation

“…The slower rising masking function in patients may have been the result of a comparative slowness in processing, in which the target information was not successfully transferred from the sensory register to higher centers before the mask icon arrived (Saccuzzo and Schubert 1981). As the complexity of the visual system has been uncovered over the past few decades, it has become clear that modeling human information processing in terms of serial stages is inadequate.…”

“…However, poor general performance in a small subset of patients could also have explained those results. Saccuzzo and Schubert (1981) entertained the possibility of low motivation in patients resulting in flat masking functions, but rejected it based on considerations of the group means. However, means may have varied due to a group of outliers.…”

Visual Perception and Working Memory in Schizotypal Personality Disorder

“…In contrast, the sustained channel of the visual system involved in the perception of form or object properties appears less affected by the disorder (1)(2)(3)(4)(5). Backwardmasking deficits in schizophrenia have sometimes been interpreted to be indicative of transient channel abnormalities, although processing speed and short-term memory disturbances may also contribute to these deficits (9)(10)(11)(12)(13)(14). These visual deficits are consistent with positron emission tomography and functional magnetic resonance imaging studies reporting hyperactivation of the visual cortex in response to photic stimulation in schizophrenia (15,16) and neuropathological evidence of increased neuronal density in the occipital area 17 (17).…”