Lateralisation of language and emotion in schizotypal personality: Evidence from dichotic listening

Striking disturbances have been reported in language and emotional prosody processing by patients diagnosed with schizophrenia. In view of this and of research suggesting that schizotypal personality traits can also be expressed sub-clinically, the present study aimed to discover whether similar disturbances would be reflected in cognitive laterality patterns when symptoms of schizotypy are present yet at a non-clinical level. A dichotic listening task was used to examine the sensitivity and speed with which 132 right-handed participants (85 females and 47 males, mean age = 32.44, SD = 12.29) detected both words and emotional prosody, all of whom also completed the Schizotypal Personality Questionnaire. Findings indicated that both high (n = 64) and low (n = 68) schizotypy groups demonstrated the typical right ear advantage for the detection of words and left ear advantage for the detection of emotional prosody. Individuals with higher schizotypal personality scores also demonstrated poorer sensitivity in detecting emotional prosody. These results reveal that within the healthy population, higher levels of schizotypy are not associated with the atypical lateralisation of language and emotion. Nevertheless, the existence of these symptoms does signal the presence of shared characteristics with the clinical sphere, namely poorer emotion recognition performance.     

Sense of agency over thought: external misattribution of thought in a memory task and proneness to auditory hallucination

Previous studies have suggested that auditory hallucination is closely related to thought insertion. In this study, we investigated the relationship between the external misattribution of thought and auditory hallucination-like experiences. We used the AHES-17, which measures auditory hallucination-like experiences in normal, healthy people, and the Deese–Roediger–McDermott paradigm, in which false alarms of critical lure are regarded as spontaneous external misattribution of thought. We found that critical lures elicited increased the number of false alarms as AHES-17 scores increased and that scores of AHES-17 predicted the rate of false memory of critical lures. Furthermore, we revealed that the relationship between AHES-17 scores and the rates of false alarms to critical lures was strictly linear. Therefore, it might be said that individual differences in auditory hallucination-like experiences are highly related to the external misattribution of thought. We discussed these results from the perspective of the sense of agency over thought.     

Correlations between psychometric schizotypy,scan path length,fixations on the eyes and face recognition

Psychometric schizotypy in the general population correlates negatively with face recognition accuracy, potentially due to deficits in inhibition, social withdrawal, or eye-movement abnormalities. We report an eye-tracking face recognition study in which participants were required to match one of two faces (target and distractor) to a cue face presented immediately before. All faces could be presented with or without paraphernalia (e.g., hats, glasses, facial hair). Results showed that paraphernalia distracted participants, and that the most distracting condition was when the cue and the distractor face had paraphernalia but the target face did not, while there was no correlation between distractibility and participants’ scores on the Schizotypal Personality Questionnaire (SPQ). Schizotypy was negatively correlated with proportion of time fixating on the eyes and positively correlated with not fixating on a feature. It was negatively correlated with scan path length and this variable correlated with face recognition accuracy. These results are interpreted as schizotypal traits being associated with a restricted scan path leading to face recognition deficits.     

Clinical functioning and cutoff of eccentricity dimension with psychiatric patients and non-patients

ObjectivesThis study investigated the Eccentricity scale's clinical functioning from the Dimensional Clinical Personality Inventory 2 (IDCP-2). Additionally, we sought to establish a cutoff for a screening scenario to be taken as the first indicator of Eccentricity characteristics’ possible clinically relevant functioning.MethodIn total, 2167 adults, aged from 18 to 90 years (M = 28.98, SD = 11.12), being 1244 women (63%), and the majority of undergraduate students (67.9%). Total sample was comprised into five groups, namely, outpatients diagnosed with both schizotypal and schizoid PDs (n = 3), outpatients diagnosed with schizotypal PD (n = 5), outpatients diagnosed with schizoid PD (n = 2), outpatients diagnosed with other PDs and clinical disorders (n = 172), and a general population-based sample (n = 1985). Not all participants answered all the items from IDCP-2; therefore, we used the equating procedure.ResultsThe groups were statistically different in ANOVA. For the −0.40 cutoff in the theta metric scale, equivalent to a total score of 38, the area under the curve was equal to 0.85, reaching 90% of sensitivity and 87.4% of specificity.ConclusionsFindings provide clinical data on the Eccentricity scale, supporting its professional use in a clinical setting; specifically, we suggested a clinical cutoff to the scale, helping the professional address typical characteristics from schizoid schizotypal functioning.     

Me, myself, and lie: The role of self-awareness in deception

Deception has been studied extensively but still little is known about individual differences in deception ability. We investigated the relationship between self-awareness and deception ability. We enlisted novice actors to portray varying levels of deception. Forty-two undergraduates viewed the videotaped portrayals and rated the actors’ believability. Actors with high private self-awareness were more effective deceivers, suggesting that high self-monitors are more effective at deceiving. Self-awareness may lead to knowledge of another’s mental state (i.e., Theory of Mind), which may improve an individual’s deception ability.     

Schizotypal personality traits and atypical lateralization in motor and language functions

Atypical cerebral lateralization in motor and language functions in regard to schizotypal personality traits in healthy populations, as well as among schizophrenic patients, has attracted attention because these traits may represent a risk factor for schizophrenia. Although the relationship between handedness and schizotypal personality has been widely examined, few studies have adopted an experimental approach. This study consisted of three experiments focusing on motor and language functional lateralization in regard to schizotypal personality in the absence of mental illness: line-drawing, finger tapping, and a semantic go/no-go task. The results suggested that positive schizotypal personality might be related to functional non-lateralization in regard to at least some functions (e.g., spatial motor control and semantic processing in the present study). Subjects with high schizotypal personality traits performed equally with their right and left-hands in the line-drawing task and they reacted equally with their right and left-hands in a semantic go/no-go task involving semantic auditory stimuli presented in both ears. However, those low in schizotypal personality traits showed typical lateralization in response to these tasks. We discuss the implications of these findings for schizotypal atypical lateralization.     

Sex differences in the Schizotypal Personality Questionnaire Brief among Japanese employees and undergraduates: A cross-sectional study

Schizotypal personality may be seen as an indicator predisposition to schizophrenia and psychosis proneness. Schizotypal personality traits behave differently depending on a person’s age and sex, but few studies have examined the causal relationship between age-related sex differences and schizotypal personality traits. The aim of the present study was to examine the relationship between the schizotypal personality and sex in different age groups. In our study, we used the Schizotypal Personality Questionnaire Brief (SPQ-B). Participants were 371 college students (107 men) with an age range from 18 to 25 years, and 322 working people (156 men) with an age range of 22–67 years. The results showed that the young adult males in the college student group had tendencies to score higher than females in the same group on the SPQ-B total score and its two subscale scores (the cognitive-perceptual and the interpersonal scores). In the adult sample taken in the working people group, the total score and subscale scores of the SPQ-B did not significantly discriminate male subjects from female subjects. These findings indicate that sex differences of schizotypal personality traits may reflect differential age-related variation.     

Unpleasant and pleasant referential thinking: Relations with self-processing, paranoia, and other schizotypal traits

Referential thinking is the tendency to view innocuous stimuli as having a specific meaning for the self and is associated with personality traits and disorders. In three studies, this research examined the relations among referential thinking, self-processing, and paranoia. In Study 1, follow-up questions on the Referential Thinking Scale (Lenzenweger, Bennett, & Lilenfeld, 1997) revealed that referential thoughts are experienced as unpleasant and pleasant. In Study 2, unpleasant referential thinking was more strongly associated with paranoia and maladaptive self-processing and personality. CFAs in Studies 1 and 2 found that unpleasant and pleasant referential thinking loaded on different factors. In Study 3, a group of participants with elevated schizotypal personality reported more unpleasant and pleasant referential thoughts than a control group.     

Attentional window in schizophrenia and schizotypal personality: Insight from negative priming studies

One of the core deficits that characterizes schizophrenia is an increase in distractibility and disinhibition at all levels of information processing. Patients with schizophrenia seem unable to focus attention on the relevant events while ignoring the irrelevant stimuli. This pattern of behavior is also observed in unmedicated schizotypal individuals who may carry liability for schizophrenia. In this review, we focus on studies of attentional inhibition, as assessed by the negative priming paradigm, to elucidate the relationships among deficits in inhibition, clinical symptoms and medication effects. We then consider models of the etiology of deficits in negative priming in schizophrenia and schizotypal personality. Finally, we discuss the potential power of utilizing hypothesis-driven cognitive paradigms in psychiatric research.     

Latent inhibition in within-subject designs: The roles of masking, schizotypy, and gender

Latent inhibition (LI) is defined as poorer associative learning with a previously exposed, irrelevant stimulus than with a non-preexposed, novel stimulus. This study examined how type of within-subject procedure, class of schizotypal symptoms, and gender modulate LI. Two within-subject procedures were examined, one excluding, and one including a masking task. The former yielded a stronger stimulus preexposure effect than the latter. However, the stimulus preexposure effect was attenuated by total schizotypy score in the masked, but not in the non-masked procedure. The results with schizotypy factors (positive and negative symptoms) as well as with schizotypy factors × gender interactions were inconsistent with those of other studies. It was suggested that in addition to LI, interference and novel pop-out effects were also produced by the procedures, particularly in the non-masked condition.