Electrophysiological correlates of cognitive inhibition in college students with schizotypal traits

Objective: We investigated cognitive inhibition in non-clinical individuals with schizotypal traits using event-related potentials. Methods: College students with psychometrically defined schizotypal traits (n = 16) and normal controls (n = 15) participated. The computerized Stroop task with three types of stimuli, i.e., congruent, incongruent, and neutral words, was used to measure cognitive inhibition. Results: The schizotypal-trait group committed significantly more errors in response to incongruent words than did the control group. The control group showed frontal negativity (FN) of significantly greater amplitude in response to incongruent than to congruent and neutral stimuli, whereas the schizotypal-trait group showed no significant difference in FN amplitude between incongruent and congruent/neutral stimuli at 300 - 400 ms poststimulus. A source localization analysis conducted in different waveforms for incongruent minus congruent conditions at 300-400 ms poststimulus showed reduced activation in the left cingulate cortex and in the middle/medial prefrontal cortex in the schizotypal-trait group compared with the control group. The two groups did not differ in the sustained potential amplitudes observed at 550-650 ms after stimulus-onset at parietal sites. Conclusions: These results suggest that individuals with schizotypal traits have difficulties in conflict detection and cognitive inhibition, possibly mediated by the cingulate cortex and prefrontal cortex.

Behavioral inhibition in female college students with schizotypal traits: An event-related potential study

This study investigated behavioral inhibition in female college students with psychometrically defined schizotypal traits using a Go/NoGo task and event-related potentials (ERPs). The schizotypal-trait (n = 15) and normal control (n = 15) groups were selected based on scores of the Schizotypal Personality Questionnaire (SPQ). The Go/NoGo task consisted of Go (requires response) and NoGo (requires no response) conditions. In terms of response time and accuracy rate for the Go/NoGo task, the two groups did not differ significantly. In terms of ERPs, the control group showed greater N2 amplitudes in response to NoGo (NoGo-N2) than to Go stimuli (Go-N2), whereas the schizotypal-trait group showed no significant difference in NoGo-N2 and Go-N2 amplitudes. In addition, the schizotypal-trait group showed reduced NoGo-N2 amplitudes at the frontal site compared to controls, and an association between SPQ scores and NoGo-N2 amplitudes measured at the frontal site. The two groups did not differ in P3 amplitudes. Since the N2 reflects the detection of response conflict and behavioral inhibition, the present results indicate that nonclinical individuals with schizotypal traits have difficulties in detecting response conflict and behavioral inhibition.

Three-Factor structure of self-report schizotypal traits in a French nonclinical sample

Evidence suggests that the structure of psychosis-proneness in the general population may involve three distinct related dimensions. Therefore we conducted a study, using a wider range of measures, to explore the factorial structure of schizotypy assessed by a mixed self-report Schizotypal Traits Questionnaire (mSTQ) in young French healthy individuals. Raine’s Schizotypal Personality Questionnaire [SPQ] and four of the Chapman’s scales [Magical Ideation Scale-MIS;Perceptual Aberration Scale-PAS;Revised Physical Anhedonia Scale-PhA and Revised Social Anhedonia Scale-SA] were combined to form a mSTQ which was administered to 232 French undergraduate students aged from 18 to 25 years old. A Principal Component Analysis [PCA] was carried out on scores for each scale to examine the factorial structure of schizotypal traits in this sample. PCA evidenced a three-factor model of schizotypy in the sample as a whole and even in the lower score sub-sample. The three factors were “positive or cognitive-perceptual”, “negative or social-interpersonal” and “disorganization” latent. Schizotypy, as assessed by these scales, is a multidimensional construct composed by at least three dimensions in this nonclinical sample. This factorial structure is similar to those of schizophrenia symptoms which raise the hypothesis of a continuum from normality to schizophrenia via schizotypal

Scientists Identify Different Developmental Trajectories for Individuals with Schizotypal Traits

Schizotypy,defined as the personality organization underlying schizophrenia and other related mental disorders,is a critical construct for a broad range of scientific disciplines.Because schizotypy can be psychometrically identified in the general population,investigating schizotypy may provide a unique