Effects of trifluoperazine, chlorpromazine, and haloperidol upon temporal information processing by schizophrenic patients.

Healthy controls, unmedicated, actively symptomatic schizophrenics, and similar patients undergoing treatment with either trifluoperazine, chlorpromazine, or haloperidol were studied with tests of temporal discrimination and measures of transmitted information shown previously to be sensitive to various kinds of brain dysfunction, including haloperidol effects in a nonpsychotic population. Variations in psychophysical method, cognitive load, discrimination complexity, and sense-mode conditions permitted representative sampling of the temporal processing. Untreated, actively psychotic patients showed no impairment of temporal processing while all three antipsychotic medications were associated with significant deficit; trifluoperazine and haloperidol produced the most deficit, with chlorpromazine in the middle between the higher potency drugs on the one hand and unmedicated patients and healthy controls on the other.

Temporal information processing by alcoholics.

In time-discrimination tests using visual and auditory stimuli, more information was transmitted by social drinkers than by alcoholics, and cognitively unimpaired alcoholics transmitted more information than did cognitively impaired alcoholics.

The effects of haloperidol upon temporal information processing by patients with Tourette's syndrome.

Tourette's syndrome patients treated successfully with haloperidol, untreated patients, and healthy controls were studied with tests of temporal discrimination and measures of transmitted information shown previously to be sensitive to brain dysfunction. Untreated patients showed no impairment of temporal processing while those treated with haloperidol showed significant deficit in amount of transmitted information comparable to prior studies of brain syndromes.

Signal pulse-rate and judged duration.

Therories which construct perception of time from content of input predict monotonic functions of rate-judged duration of stimuli, and do not account for intersensory differences. Two experiments required Ss to compare directly the durations of paird lights or sounds pulsed at various rates to produce discriminable beats and flickers (6.0, 10.0, 14.0 Hz), and steady signals. Pulsed lights, not sounds, were judged longer than steady, and this visual effect was identical for all flicker rates. Faster pulsled sounds and lights were judged longer than slower ones for all frequency combinations except for 10.0 to 14.0-Hz comparisons with vision. No monotonic function of ratejudged durations of pulses was obtained; the effect was all-or-none. Although pulse rate did affect judged duration, neither simple functions nor symmetry across senses was found.

Temporal information processing and psychopathology.

Prior studies showed impaired temporal discrimination by schizophrenic and neurologic patients reflected in decreased information transmission. This report describes a study of 8 more carefully diagnosed schizophrenic patients, separating those with neurologic signs. Using temporal discrimination tasks involving two psychophysical methods, 8 schizophrenic patients with no organic signs did not differ from 17 nonpsychotic, nonorganic patients; and organic group (n = 5) transmitted less information than the other patient samples. It is suggested that prior results were a product of casual diagnosis that ignored organic factors; reduced efficiency of temporal processing is associated predominantly with neurologic impairment.

Temporal information processing by young and senior adults and patients with senile dementia.

Temporal discrimination by healthy young and senior adults and patients with senile dementia was studied using the measure of transmitted information and two psychophysical methods (single-stimulus-ranking and pair-comparison). The patients with senile dementia showed very severe impairment on both methods and performed much less efficiently than the healthy adults of the same age; thus the former revealed a deficit in both memory and discrimination. The healthy seniors showed less alteration of temporal judgment with significant loss only with the single-stimulus method, which reflects memory deficit alone. Temporal cognition is very sensitive to changes in brain function.