Biomedical subjects

E F Rabinowicz

Publications and source records attributed to E F Rabinowicz.

4 recordsLinked to original sources

PubMed2001

Impaired sensory processing as a basis for object-recognition deficits in schizophrenia.

OBJECTIVE: Individuals are able to recognize common objects even when portions of them are obscured from view, reflecting the operation of neural perceptual closure processes. This study evaluates the integrity of object recognition and perceptual closure as a function of sensory and cognitive manipulations. METHOD: Object recognition was examined in 26 subjects with schizophrenia and 23 nonpsychiatric comparison subjects of similar age with a presentation of fragmented pictures by means of the ascending method of limits. The effects of prior exposure to subsets of stimuli and of word prompting were examined in separate testing phases. Demographic and clinical characteristics were evaluated as covariates. RESULTS: Although they had impairments in perceptual closure, schizophrenic patients showed improvement in performance equivalent to that of nonpatient comparison subjects with prior exposure to the pictures (i.e., repetition priming) and with presentation of valid word prompts. A significant correlation was found between impaired performance and the severity of negative symptoms. CONCLUSIONS: The results support models of widespread dysfunction in information processing in patients with schizophrenia involving both sensory and cognitive regions. Perceptual closure is significantly impaired in schizophrenic patients; however, this deficit in sensory precision is dissociated from the effects of higher-order repetition priming and word prompting. Furthermore, this work suggests that deficits in perceptual closure may contribute to the muted world experience of patients with the persistent negative symptoms of schizophrenia.

Adult↗

PubMed2000

Auditory sensory dysfunction in schizophrenia: imprecision or distractibility?

BACKGROUND: Schizophrenia is associated with large effect-size deficits in auditory sensory processing, as reflected in impaired delayed-tone matching performance. The deficit may reflect either impaired sensory precision, which would be indicative of neural dysfunction within auditory sensory (temporal) regions, or of increased distractibility, which would be indicative of impaired prefrontal function. The present study evaluates susceptibility of schizophrenic subjects to same-modality distraction to determine whether patients fit a "bitemporal" or "prefrontal" model of sensory dysfunction. METHODS: Tone-matching ability was evaluated in 15 first-episode patients, 18 outpatients with chronic illness, and 21 patients in long-term residential care, relative to 32 nonpsychiatric controls of a similar age. A staircase procedure determined individual thresholds for attaining criterion level correct performance. RESULTS: Tone-matching thresholds in the absence of distractors were significantly elevated in patients in long-term residential care relative to all other groups (P<.001). The effect size (d) of the difference relative to controls was extremely large (SD, 1.95). Schizophrenic patients, even those with elevated tone-matching thresholds, showed no increased susceptibility to auditory distraction (P =.42). Deficits in tone-matching performance in subjects with chronic illness could not be attributed to medication status or level of symptoms. CONCLUSIONS: These findings suggest that sensory processing dysfunction in schizophrenia is particularly severe in a subgroup of patients who can be considered poor-outcome based on their need for long-term residential treatment. Furthermore, the absence of increased auditory distractibility argues against prefrontal dysfunction as an origin for auditory sensory imprecision in schizophrenia. Arch Gen Psychiatry. 2000;57:1149-1155.

Acoustic Stimulation↗

PubMed1998

Evaluation of problem solving and communication skills of persons with schizophrenia.

Although much research has shown positive outcomes of teaching problem solving and communication skills to persons with schizophrenia, the amount of research on the assessment of these two sets of skills has been modest. The current study demonstrates an effective model for their assessment and includes a previously neglected procedure to determine if subjects attended to the skill prompts. It replicates and expands prior findings on problem solving and communication skills. Results indicated that persons with schizophrenia were generally deficit in problem solving skills. Persons without schizophrenia seemed to use more behavioral information when deciding if a problem existed and they were better able to differentiate between appropriate and inappropriate solutions to problems. Persons with schizophrenia were found to be deficit in communication skills that facilitate interaction and showed a style that subordinated their wants to those of others.

Adult↗

PubMed1996

Dot Enumeration Perceptual Organization Task (DEPOT): evidence for a short-term visual memory deficit in schizophrenia.

The Dot Enumeration Perceptual Organization Task (DEPOT) evaluates the validity of 2 specific competing cognitive models of early input dysfunction in schizophrenic individuals: a primary Stage 1, sensory store, perceptual organization deficit vs. a Stage 2, short-term visual memory (STVM) deficit. DEPOT was also designed to assess the hypothesis that schizophrenic individuals tend to perform poorly on all cognitive tasks. In DEPOT both number and form judgments are made about the same dot patterns. A response delay manipulation assesses the persistence and operation of STVM. The study included 41 psychotic inpatients (8 with acute and 16 with chronic schizophrenia and 7 with bipolar and 10 with nonbipolar affective disorder) and 38 controls (22 college students and 16 hospital personnel). Although the pattern of results was consistent with neither the Stage 1 deficit nor the general deficit hypotheses, a Stage 2, STVM deficit hypothesis could account parsimoniously for the data.

Adult↗