Backward masking as a measure of attention in schizophrenia.

Abstract

Backward-masking functions for two schizophrenic groups were compared with the masking functions for two control groups (college students and nonschizophrenic psychiatric patients). Masking functions were obtained for both singleletter and eight-letter visual displays. The procedure involved a forced-choice letter recognition method analogous to signal detection methodology. Both schizophrenic groups produced longer masking functions, under all conditions, than the two control groups whose functions were highly similar. Consistent with "attention" theories of schizophrenia, results indicated that some deficit occurs in schizophrenia at a very early stage of information processing in the visual system.1 This paper is based on a doctoral dissertation by the first author under the direction of the second and third authors. The authors are indebted to the Veteran's Administration Hospital in Cleveland, Ohio, for allowing the use of its patients for subjects.2 Requests for reprints should be sent to Dennis

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

“…In some of the earliest studies of backward masking, it was also found that schizophrenia patients did not reach unmasked performance levels (e.g., Saccuzzo et al 1974). Braff and Saccuzzo (1985) attributed this poor performance to floor and ceiling effects.…”

“…The presence of masking deficits over a broad range of ISIs (short [Green et al 1994a[Green et al , 1994b and long [Saccuzzo et al 1974[Saccuzzo et al , 1996) may be due to heterogeneity amongst patients, differences in testing paradigms or deficits involving multiple stages of visual processing (Green et al 1997;Michaels and Turvey 1979). Alternatively, the lack of temporal specificity may be due to more general attentional or motivational factors in schizophrenia patients.…”

Early-Stage Visual Processing Deficits in Schizophrenia

“…Perceptual deficits have become increasingly well documented in the visual system in schizophrenia [9-17,18•,19-21] and may contribute to higher level cognitive impairments and community outcome [12,[22][23][24]. An early report by Saccuzzo et al [25] of visual backward masking dysfunction in schizophrenia was particularly important not only because it indicated deficits in the earliest components of visual information processing [16,26,27], but also because it suggested dysfunction of a particular visual pathway -the psychophysically defined transient visual pathway [27][28][29][30].…”

The schizophrenia spectrum: A study of the relationship among the Rorschach, MMPI, and visual backward masking

“…Saccuzzo, Hirt, and Spencer (1974), for example, found that schizophrenics required about twice as long as normal and patient controls to evade the effects of the mask. This result, which has subsequently been replicated in other investigations, has been interpreted in terms of abnormally slow processing in schizophrenic individuals Brody, Saccuzzo, & Braff, 1980;Saccuzzo, Braff, & Sprock, 1982a;Saccuzzo & Miller, 1977).…”