title: Covariation between two-flash threshold and skin conductance level in first-breakdown schizophrenics: relationships in drug-free patients and effects of treatment.
abstract: Earlier research suggested that, compared with other individuals, schizophrenics show a different form of covariation between electrodermal level and perceptual discrimination, as indexed by the two-flash threshold. However, dispute has arisen as to whether previous contradictory results obtained on patient samples can be explained by a conventional inverted-U function or whether the relationship takes on an entirely different form, i.e., a U function. The latter alternative was confirmed here in a study of first-breakdown drug-free schizophrenics, tested on 3 consecutive days after hospital admission and before treatment began. However, the U function was evident only in the larger of two subgroups of schizophrenics, identified as patients whose treatment was delayed longer after admission, who were clinically less emotionally responsive and who, in basic personality, were more introverted. When the patients were subsequently tested during treatment, no systematic relationship between two-flash threshold and skin conductance could be discerned. The latter presumably reflected the fact that, during this phase of the experiment, there were marked and complex changes in the individual measures, the effects of treatment on which were briefly examined.
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001143:Arousal / Q000187:drug effects*; D004193:Discrimination Learning / Q000187:drug effects*; D005260:Female; D005712:Galvanic Skin Response / Q000187:drug effects; D006801:Humans; D008297:Male; D010640:Phenothiazines; D010775:Photic Stimulation; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D014796:Visual Perception / Q000187:drug effects*
chemical_list: D014150:Antipsychotic Agents; D010640:Phenothiazines