Thought disorder and schizophrenia: Isolating and timing a mental event

Abstract

This study explored the ability of nonparanoid schizophrenic, paranoid schizophrenic, and mixed psychiatric control (manics and schizoaffectives) patients to perform on two types of conceptual, speeded inference (SI) tasks, which differ in type of abstraction process required. The subjects (N = 30) were grouped into high and low levels of thought dysfunction, as measured by the Whitaker Index of Schizophrenic Thinking (WIST). There were no differences among the three clinical groups on the conceptual, SI tasks. Reaction times differed reliably across the two SI tasks. High‐WIST subjects were impaired on SI accuracy. Significant impairment in accuracy was demonstrated by high‐WIST time and error groups on the more complex SI tasks. Information processing deficit was demonstrated in terms of encoding phase and reaction time in problem‐solving of the three diagnostic groups as a function of WIST levels.

A Review of Neuropsychological Differences Between Paranoid and Nonparanoid Schizophrenia Patients

“…Most of the studies measured some form of verbal ability, most often vocabulary, which was tested with several standardized instruments: the Vocabulary subtest from various versions of the WAIS, the Shipley-Hartford Institute of Living Scale Vocabulary subtest (Shipley 1939), and the Mill Hill Vocabulary Test (Raven 1982). Of the investigations specifically examining vocabulary test scores (Russell and Page 1976; Hamlin and Folsom 1977; Neufeld 1977; Asarnow and Mann 1978; Cox and Leventhal 1978; Kay 1979; Magaro and Page 1983; Sengel and Lovallo 1983; Sengel et al 1985; Pishkin and Lovallo 1986; Rosse et al 1991), only two (Hamlin and Folsom 1977; Magaro and Page 1983) reported significant differences, with the paranoid subtype having better vocabulary performance in each case.…”

“…However, the CPZ equivalents may not be useful for some medications (e.g., risperidone and haloperidol decanoate). Most of the studies that specifically examined the effects of medication on dependent variables found no significant medication effects (e.g., Pishkin and Lovallo 1986).…”

“…However, the CPZ equivalents may not be useful for some medications (e.g., risperidone and haloperidol decanoate). Most of the studies that specifically examined the effects of medication on dependent variables found no significant medication effects (e.g., Pishkin and Lovallo 1986). Spohn and Strauss (1989) have suggested that indices such as dose per day or dose per body weight per day are poor indicators of physiological drug levels.…”

“…Studies of information processing, size estimation, subtype differences in cerebral organization, and interhemispheric transfer of information were excluded (e.g., McDowell et al 1975; Asarnow and Mann 1978; Brennan and Hemsley 1984; Lubow et al 1987; Overby et al 1989; Ditchfield and Hemsley 1990; Carter et al 1993). However, if a study included scores from a standard administration of a clinical neuropsychological measure, that portion was included in the review (Asarnow and Mann 1978; Pishkin and Lovallo 1986). When more than one study employed the same sample, only the first was reported (Rund 1983; Rund and Blakar 1986).…”