Spatio-temporal luminance contrast sensitivity and visual backward masking in schizophrenia

@article{Slaghuis2004SpatiotemporalLC,
  title={Spatio-temporal luminance contrast sensitivity and visual backward masking in schizophrenia},
  author={Walter L. Slaghuis},
  journal={Experimental Brain Research},
  year={2004},
  volume={156},
  pages={196-211}
}
  • W. Slaghuis
  • Published 30 January 2004
  • Psychology
  • Experimental Brain Research
The aim of two experiments was to investigate the relationship between spatio-temporal contrast sensitivity and visual backward masking in normal observers and in subgroups with positive or negative symptoms in schizophrenia. Experiment 1 measured contrast sensitivity for stationary and counterphase-modulated sinusoidal gratings at four spatial (0.5, 2.0, 4.0, 8.0 cycles/degree) and four temporal frequencies (0, 4.0, 8.0, 16.0 Hz). The results showed that there were no differences in spatio… 

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References

SHOWING 1-10 OF 127 REFERENCES

Luminance flicker sensitivity in positive- and negative-symptom schizophrenia

It was concluded that the significant reductions in flicker sensitivity at medium and high temporal frequencies in the negative-symptom group provided evidence for an impairment in magnocellular channels.

Spatial frequency masking in positive- and negative-symptom schizophrenia.

The role of transient and sustained channels in masking was investigated in groups with positive and negative symptoms in schizophrenia and in a control group, providing evidence for distinguishable differences in visual masking.

Visual processing deficits in acute and chronic schizophrenics.

Repeated measures analyses of variance revealed that schizophrenics do not conform to the typical relationship between iconic persistence and spatial frequency of the grating and have longer iconic persistence than normals on all spatial frequencies.

Visual processing deficits in acute and chronic schizophrenics.

: Psychophysical techniques have been used to assess the duration that brief visual stimuli remain in visual memory. At the earliest "iconic" stage the duration depends on several parameters, one of

Visual backward-masking deficits in schizophrenia: relationship to visual pathway function and symptomatology

Visual masking as a probe for abnormal gamma range activity in schizophrenia

Dysfunction of early-stage visual processing in schizophrenia.

A dysfunction of lower-level visual pathways, which was more prominent for magnocellular than parvocellular biased stimuli, is suggested, which could contribute to higher- level visual cognitive deficits in schizophrenia.

Backward masking in schizophrenia and mania. II. Specifying the visual channels.

Schizophrenic deficits within masking paradigms may involve abnormalities in transient, as opposed to sustained, visual channels, and masking performance deficits were found in manic patients.
...