Neurological Soft Signs in Psychometrically Identified Schizotypy

Abstract

Patients with schizophrenia often exhibit structural brain abnormalities, as well as neurological soft signs, consistent with its conceptualization as a neurodevelopmental disorder. Neurological soft signs are mild, presumably nonlocalizing, neurological impairments that are inferred from performance deficits in domains such as sensory integration, motor coordination, and motor sequencing. The vulnerability for schizophrenia is presumed to be expressed across a broad continuum of impairment referred to as schizotypy. It is hypothesized that nondisordered people along the schizotypy continuum should exhibit elevated rates of neurological soft signs. The present study examined the relation of psychometrically identified positive and negative schizotypy with neurological soft signs using the Neurological Evaluation Scale (NES) in a nonclinically ascertained sample of young adults (n = 177). As hypothesized, negative, but not positive, schizotypy was related to increased neurological soft signs in tasks that assessed fine and gross motor coordination, motor sequencing, eye movement abnormalities, and memory recall. However, positive schizotypy was associated with increased neurological soft signs in tasks related to sensory integration dysfunction. In general, the positive x negative schizotypy interaction term was unrelated to individual neurological soft sign tasks. The findings support: a) the theory that the vulnerability for schizophrenia is expressed across a broad continuum of subclinical and clinical impairment referred to as schizotypy; b) the multidimensional structure of schizotypy; and c) the notion that schizotypy is an appropriate construct for understanding the etiology and development of schizophrenia-spectrum disorders. NEUROLOGICAL SOFT SIGNS IN PSYCHOMETRICALLY IDENTIFIEDSCHIZOTYPY by

Psychotic-like symptoms and positive schizotypy are associated with mixed and ambiguous handedness in an adolescent community sample

“…Nevertheless, other indicators of neurodevelopmental impairment, such as developmental instability have stronger associations with negative schizotypy (Rosa et al, 2000, Barrantes-Vidal et al, 2003and Kaczorowski et al, 2009. Prenatal indicators of developmental disturbances occurring in a narrow prenatal time window, such as dermatoglyphic anomalies, might relate to negative schizotypy, resembling the pattern found in schizophrenia (Rosa et al, 2000), whereas later functional lateralization, reflected by handedness, might be more related to positive schizotypy.…”

Psychometric Properties of the Wisconsin Schizotypy Scales in an Undergraduate Sample: Classical Test Theory, Item Response Theory, and Differential Item Functioning

“…Confirmatory factor analyses have provided evidence for the scales' structural validity, particularly the division of the scales into broader positive and negative symptom dimensions (Kwapil et al 2008). Evidence for score validity isn't easily summarized, given the extensive use of the scales over the past several decades, but the WSS have been widely used in cross-sectional and longitudinal studies with psychotic patients and psychosis-prone subjects (e.g., Barrantes-Vidal et al 2009Kaczorowski et al 2009). In longitudinal research, nonpsychotic people with markedly elevated scores on these scales show psychological and physiological deficits similar to those seen in schizophrenia patients and are at heightened risk for developing schizophrenia-spectrum disorders (e.g., Chapman et al 1994;Gooding et al 2005Gooding et al , 2007Kwapil 1998).…”

Inferring about individual drug and schizotypy effects on cognitive functioning in polydrug using mephedrone users before and after clubbing

“…Yet, in the latter case, individuals with elevated schizotypy are also likely to be subject to relative enhanced polydrug use, without this drug consumption being accounted for. We found 14 studies investigating the link between schizotypy and cognitive flexibility, verbal memory and verbal fluency; seven of them did not report on drug use (Lenzenweger and Korfine, ; Park et al ., ; Giraldez et al ., ; Dinn et al ., ; Tsakanikos and Claridge, ; Burch et al ., ; Laws et al ., ), and the others varied in their drug control criteria (Poreh et al ., ; Suhr, ; Daneluzzo et al ., ; Matheson and Langdon, ; Kaczorowski et al ., ; Kim et al ., ; Koychev et al ., ). It is thus possible that substance use (e.g.…”

“…In more detail, cognitive impairments that are common in patients with psychosis are also found along the psychosis dimension, although less severe, such as in individuals with a schizotypal personality disorder [see Reichenberg and Harvey, , for overview] and individuals from the general population scoring relatively high on self‐report schizotypy questionnaires (Poreh et al ., ; Laurent et al ., ; Vollema and Postma, ; Burch et al ., ; Krabbendam et al ., ). Most important to the present study, cognitive functions relying on the frontal lobes such as cognitive flexibility (Voglmaier et al ., ; Diforio et al ., ; Laurent et al ., ; Blanchard et al ., ), working memory (Park and McTigue, ; Voglmaier et al ., ; Kopp et al ., ; Voglmaier et al ., ), verbal memory (Burch et al ., ; Kaczorowski et al ., ) and verbal fluency (Laurent et al ., ; Tsakanikos and Claridge, ) seem attenuated along the psychosis spectrum including schizotypy (see also Reichenberg and Harvey, , for overview).…”