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

  title={Spatio-temporal luminance contrast sensitivity and visual backward masking in schizophrenia},
  author={Walter L. Slaghuis},
  journal={Experimental Brain Research},
  • 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… 

No Evidence for Prolonged Visible Persistence in Patients with Schizophrenia

Together with the preserved ability of patients, to detect temporal asynchronies in permanently presented stimuli, the results indicate a more specific deficit in temporal processing of schizophrenic patients.

Psychophysical assessment of magno- and parvocellular function in schizophrenia

No evidence for an early magnocellular deficit could be detected as the thresholds of all schizophrenic observers were higher both in the steady paradigm and in the pulse paradigm, suggesting that mag nocellular dysfunction, if present in schizophrenia, must concern more integrated processes, possibly at levels at which parvocellular and magNocellular paths interact.

When doors of perception open: visual contrast sensitivity in never-medicated, first-episode schizophrenia.

Results indicate the heightened sensitivity of magnocellular pathways in unmedicated first-episode schizophrenia, which may contribute to anomalous perceptual experiences and sensory overloading.

Altered Velocity Processing in Schizophrenia during Pursuit Eye Tracking

Altered correlation of target velocity and neural activation in the cortical network supporting SPEM implies impaired transformation of the visual motion signal into an adequate motor command in patients.

Low Spatial Frequency Bias in Schizophrenia is Not Face Specific: When the Integration of Coarse and Fine Information Fails

The LSF preference found in schizophrenia confirms the previous study conducted with faces, and shows that this LSF bias generalizes to other categories of objects.

Magnocellular contributions to impaired motion processing in schizophrenia

Schizophrenia and visual backward masking: a general deficit of target enhancement

High density electrophysiological recordings (EEG) show that indeed neural activity is strongly reduced in schizophrenic patients which is attributed to the lack of vernier enhancement, supported by findings relating visual masking to genetic deviants of the nicotinic α7 receptor (CHRNA7).



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.