Emotion processing deficits in the different dimensions of psychometric schizotypy

Schizotypy refers to a personality structure indicating “proneness” to schizophrenia. Around 10% of the general population has increased schizotypal traits, they also share other core features with schizophrenia and are thus at heightened risk for developing schizophrenia and spectrum disorders. A key aspect in schizophrenia‐spectrum pathology is the impairment observed in emotion‐related processes. This review summarizes findings on impairments related to central aspects of emotional processes, such as emotional disposition, alexithymia, facial affect recognition and speech prosody, in high schizotypal individuals in the general population. Although the studies in the field are not numerous, the current findings indicate that all these aspects of emotional processing are deficient in psychometric schizotypy, in accordance to the schizophrenia‐spectrum literature. A disturbed frontotemporal neural network seems to be the critical link between these impairments, schizotypy and schizophrenia. The limitations of the current studies and suggestions for future research are discussed.     

Towards a cognitive resource limitations model of diminished expression in schizotypy

Diminished expression of speech is a pernicious feature of both schizophrenia and schizotypy--defined as the personality organization reflecting a putative genetic schizophrenia liability. As yet, the mechanism underlying diminished expression is unclear. We tested the hypothesis that diminished expression reflects a cognitive resource issue--that is, as cognitive resources are depleted, expression becomes diminished in individuals with psychometrically defined schizotypy. Acoustic analysis of natural speech was procured during experimentally manipulated baseline and high cognitive-load dual tasks and examined in 38 individuals with psychometrically defined schizotypy and 34 controls. For both groups, expression significantly decreased as a function of increased task demands, although there were no group differences in expression or magnitude of change across baseline to high cognitive-load conditions. Participants with self-reported constricted affect showed significant reductions in expression under high-load versus baseline speaking conditions relative to other schizotypal and control participants. Moreover, psychometrically defined schizotypal participants with poor cognitive performance on the high-load task, suggestive of depleted cognitive resources, also showed expressivity reductions compared with other participants. These findings suggest that diminished expression occurs as a function of limited cognitive resources in psychometrically defined schizotypy.     

Schizotypy and sustained attention: confirming evidence from an adult community sample

Sustained attention deficits represent one of the most robust findings in the study of schizophrenia and schizotypy. However, very little is known about the nature of sustained attention performance and schizotypy in the general adult population. The present study assessed sustained attention performance in a large, normative adult community sample (N = 305) with no history of psychosis using the Continuous Performance Test-identical pairs version (CPT-IP). Associations between overall CPT-IP performance and schizotypal personality disorder features, controlling for the effects of age, sex, and educational level, revealed diminished sensitivity (d', discriminability), and increased random errors were related to increased reality distortion features. These data, drawn from a general population sample, provided support for overall sustained attention deficits as an endophenotype for schizophrenia liability.     

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.     

Neuropsychological profile in patients with schizotypal personality disorder or schizophrenia

Neuropsychological impairments have been consistently reported in patients with schizophrenia. As little is known whether subjects with schizotypal personality disorder exhibit neurocognitive dysfunction similar to that in schizophrenia, we assessed the neuropsychological profile of 15 subjects with schizotypal personality disorder and compared it with that for 15 patients with schizophrenia and for 15 psychiatrically normal volunteers. All participants were administered a standard neuropsychological battery assessing language ability, spatial ability, visuomotor function, verbal memory, visual memory, auditory attention, visual attention, and executive function. Performance on most of the cognitive domains was impaired in patients with schizotypal personality disorder but less than patients with schizophrenia. Specifically, impairment in verbal memory and visuomotor ability in patients with schizotypal personality disorder and patients with schizophrenia were comparable, while patients with schizophrenia performed worse on the test of executive function than did patients with schizotypal personality disorder. As a whole, cognitive deficits in patients with schizotypal personality disorder were qualitatively similar to, but quantitatively milder than, those for patients with schizophrenia. The results suggest that cognitive abilities related to frontotemporal lobe function are disturbed across these schizophrenia-spectrum disorders.     

Creative Activity,Personality, Mental Illness,and Short‐Term Mating Success

It has been argued that creativity evolved, at least in part, through sexual selection to attract mates. Recent research lends support to this view and has also demonstrated a link between certain dimensions of schizotypy, creativity, and short‐term mating. The current study delves deeper into these relationships by focusing on engagement in creative activity and employing an expansive set of personality and mental health measures (Five Factor Model, schizotypy, anxiety, and depression). A general tendency to engage in everyday forms of creative activity was related to number of sexual partners within the past year in males only. Furthermore, schizotypy, anxiety, and Neuroticism were all indirectly related to short‐term mating success, again for males only. The study provides additional support for predictions made by sexual selection theory that men have a higher drive for creative display, and that creativity is linked with higher short‐term mating success. The study also provides support for the contention that certain forms of mental illness may still exist in the gene pool because particular personality traits associated with milder forms of mental illness (i.e., Neuroticism & schizotypy) are also associated directly with creativity and indirectly with short‐term mating success.     

Schizotypy in relatives of patients with schizophrenia

Previous studies indicate that relatives of patients with schizophrenia are more likely to present characteristics of schizotypal personality than the general population. Few transcultural studies of schizotypy have been carried out. Most instruments constructed to measure schizotypy have been applied in specific cultures; conceivably, in other populations its components may be distributed in different ways. These cultural differences may affect the relations between schizotypy and schizophrenia. The objective of this study is to obtain data on schizotypy in relatives of patients with schizophrenia and relatives of patients with other disorders in a Latin American rural population. The results suggest that cultural factors must be taken into account in order to establish the relationship between schizotypy and schizophrenia.     

Psychometric schizotypy and motor performance

Motor abnormalities have long been a focus in discussions of schizophrenia. The present study used a newly developed line drawing task to examine fine motor performance and psychometrically assessed schizotypy in a large, randomly ascertained sample of young adults (N = 120) with no history of psychosis. Poor motor performance on the line drawing task, indexed by root-mean-square error (RMS), was significantly related to 4 separate psychometric measures of schizotypy in the overall sample. The psychometric schizotypy-RMS association remained significant for 2 of the schizotypy measures even when the effects of intellectual functioning, mental state factors, and sustained attention were statistically controlled in a regression analysis. The status of the line drawing index as a schizophrenia liability measure is discussed.     

A biometrical study of schizotypy in a normal population

A recently devised two-scale questionnaire (STQ) for measuring ‘borderline’ personality traits, together with the EPQ, was administered to 108 monozygotic and 102 dizygotic adult twin pairs. Initial item and scale analyses of the STQ indicated good internal consistency and acceptably high endorsement frequencies for individual items, as well as an absense of any marked skew in the scale distributions. The pattern of correlations with the EPQ closely resembled that seen in earlier, smaller-sized studies, the most notable feature being a positive correlation between the borderline scales and the N-scale. Biometrical analysis of the data suggested that, for the main STQ scale (‘schizotypal personality’), the best-fitting model was one assuming additive genetic variation combined with within-family environmental effects: results for the other (‘borderline personality’) scale were less clear cut. A number of sex differences were also observed: males had lower schizotypy scores than females, while the biometrical analysis suggested that schizotypy may be under greater genetic control in males than in females. The data are presented and discussed in the context of the dimensional/biological theory of disposition to psychosis.     

Peer victimization as a risk factor for schizotypal personality in childhood and adolescence

There has been no prior research on peer victimization and child or adolescent schizotypal personality. This study tests the hypothesis that increased peer victimization is associated with increased schizotypal personality. Schizotypy was assessed using the SPQ-C (Schizotypal Personality Questionnaire-Child) in 3,508 male and female schoolchildren aged 8 to 16 years. All forms of peer victimization (physical, verbal, social manipulation, attack on property) were associated with schizotypal personality in both males and females across all age groups. Significant victimization more than doubled schizotypy scores. It is hypothesized that peer victimization may predispose to paranoid ideation, social anxiety, and lack of close friends, and consequently heightened schizotypal personality.     

P50 sensory gating deficits in schizotypy

Sensory gating is the ability to filter out irrelevant stimuli from the environment. Individuals with schizophrenia consistently demonstrate deficits in this ability leading to sensory overload and cognitive fragmentation. This dysfunction has also been found in schizotypy, which is defined as a manifestation of nonclinical symptoms qualitatively similar to those found in schizophrenia. In the present study, auditory sensory gating was assessed in healthy individuals by testing the attenuation of the P50 event-related potential. The degree of suppression was then correlated with schizotypy by using the O-LIFE questionnaire. Relative to the low-scoring individuals, P50 suppression was significantly reduced in those with high levels of schizotypy. Furthermore, the degree of deficit in P50 gating correlated with both cognitive disorganisation and impulsive nonconformity dimensions of schizotypy. These results suggest that schizotypal individuals may have early sensory gating deficits similar to schizophrenia patients, especially if they display a disorganised or impulsive profile. As they do not exhibit overt psychotic symptoms, it is likely that such deficits represent an underlying core cognitive dysfunction within the schizophrenia spectrum.     

Schizotypy and pathological personality profile in siblings of patients with psychosis

Schizotypy has been proposed to be the expression of the genetic vulnerability to schizophrenia. Schizotypal features have been associated with personality dimensions found in patients with psychosis. In this study, we compared the Dimensional Assessment of Personality Pathology - Basic Questionnaire (DAPP-BQ) scores of patients with psychosis, siblings scoring higher on schizotypy (SSHS), and siblings scoring lower (SSLS). The SSHSs displayed a DAPP-BQ profile characterized by high scores in the dimensions of affective lability, anxiousness, submissiveness, social avoidance, identity problems, oppositionality, narcissism, and restricted expression, distinguishing them from the SSLS. Due to these dimensions, SSHSs are more similar to the patients' DAPP-BQ profile. The results suggest that this pathological personality profile might contribute to increase the risk of developing psychosis in siblings who have more schizotypal features.     

Religious experience,religious orientation and schizotypy

The present study examined the relationship between religious orientation and schizotypy, with the prediction that intrinsic religiosity would be negatively associated with schizotypy, and religious experience and extrinsic religiosity would be positively associated with schizotypy. A total of 308 UK adults (132 men; 176 women) completed measures of religious experience, intrinsic orientation towards religion, extrinsic orientation towards religion, schizotypal personality traits and borderline personality. Though the present findings also suggest that the significant relationships between religiosity and schizotypy traits are fragmented, particularly by sex, the findings are consistent with theory that an intrinsic orientation towards religion is associated with lower levels of schizotypy, and religious experience and an extrinsic orientation towards religion is associated with higher levels of schizotypy.     

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.     

Logical reasoning in schizotypal personality

It was examined whether psychotic-like personality traits in a sample of 205 college students could predict logical reasoning deficits, akin to those seen in schizophrenia. The participants were tested on their ability to assess the logical validity of premises (Logical Reasoning Task), and completed a multi-dimensional schizotypy inventory (O-LIFE). Low accuracy was associated with increased levels of disorganized schizotypy (‘Cognitive Disorganization’), while elevated errors were associated with increased levels of positive (‘Unusual Experiences’), negative (‘Introvertive Anhedonia’) and impulsive (‘Impulsivity Non-conformity’) schizotypy. Nevertheless, multiple regression analyses revealed that negative schizotypy was retained as the only significant predictor after performance was corrected for random guessing, and the contribution of the average amount of time spent on each premise was controlled. The results suggest that, although most schizotypy dimensions have a detrimental effect on reasoning performance, possibly due to disadvantageous test-taking strategies, negative schizotypy is the most reliable predictor of logical reasoning deficits. It is proposed that social/interpersonal schizotypal traits, like negative symptoms of schizophrenia, are accompanied by deficient executive functions of working memory, which appear to undermine, inter alia, logical reasoning processing.     

Skin-conductance orienting deficits and increased alcoholism in schizotypal criminals.

This study tested the interaction hypothesis that a subgroup of criminals with schizotypal personality would show skin-conductance orienting deficits and increased alcoholism. In a prospective, longitudinal study of alcoholism in 134 males, schizotypy was assessed during adolescence, skin-conductance orienting was assessed at ages 18-20 years, and criminal offending and alcohol abuse were assessed at ages 30-33 years. A significant interaction between schizotypy and criminality indicated that schizotypal criminals were characterized by autonomic orienting deficits. Furthermore, the rate of alcoholism in schizotypal criminals (54.8%) was significantly higher than in criminals (23.8%), schizotypal noncriminals (13.9%), and comparisons (21.7%). It is argued that schizotypal criminals are a relatively distinct group and that prefrontal dysfunction may underlie both orienting deficits and alcoholism in this group.     

Reaction time slowing during high-load, sustained-attention task performance in relation to psychometrically identified schizotypy

Prior research has demonstrated a reliable deficit in performance accuracy (e.g., d') on sustained-attention tasks in relation to psychometrically identified schizotypy and clinically diagnosed schizotypal psychopathology. The present study sought to expand the understanding of sustained-attention performance in relation to psychometric schizotypy through a study of reaction time (RT) performance. In this study, the author examined performance accuracy and RT on a high-load, sustained-attention task, the Continuous Performance Test-Identical Pairs (CPT-IP) version, in 31 high Perceptual Aberration Scale (PAS) and 26 normal control (control PAS) subjects from a large university population. High PAS (psychometric schizotypy) subjects displayed significantly longer RT performance on the CPT-IP relative to controls. The RT slowing was not explained by mental state or general intellectual ability factors. Contrary to expectation, a difference in performance accuracy (e.g., d') was not observed between the groups; however, power and other considerations cloud the interpretation of this finding. The meaning of the observed RT slowing is examined and its relation to current models of the development of schizophrenia is discussed.     

Six Subclinical Spectrum Traits in Normal Creativity

In this article, I explore conceptual and empirical connections between schizophrenia, schizotypy, psychotic-like traits, affective symptoms, and creativity. The focus is on 6 symptom-like characteristics: (a) positive schizotypal cognitive symptoms, (b) negative schizotypal cognitive symptoms, (c) negative schizotypal affective symptoms (flat affect), (d) hypomania, (e) depression, and (f) impulsivity. Attention is directed at research differentiating the cognitive symptoms associated with the schizophrenia spectrum from those of the core affective disorders, as well as distinguishing schizophrenic-like flat affect from depression. I present data on relations between paper-and-pencil measures of creativity and scales of subclinical deviant traits. I also discuss the importance of distinguishing creativity and eminence in different professional fields, artistic media, and genres, as well as the conceptual relation between continuous trait views of genius and madness and the temporal dynamics of the creative process.     

An investigation of schizotypy in injecting amphetamine users

A fully dimensional view of psychiatric disorder conceptualises schizotypy as both a continuous personality trait and an underlying vulnerability to the development of psychotic illness. Such a model would predict that the structure of schizotypal traits would closely parallel the structure of schizophrenia or psychosis. This was investigated in injecting amphetamine users (N = 322), a clinical population who have high rates of acute psychotic episodes and subclinical schizotypal experiences. Schizotypy was assessed using the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE), and psychotic symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). Using confirmatory factor analysis, O-LIFE subscale scores were mapped onto latent variables with their more clinical counterparts from the BPRS. A four-factor model comprising positive schizotypy, disorganisation, negative schizotypy, and disinhibition provided the best model fit, consistent with prior research into the structure of schizotypy. The model provided a good fit to the data, lending support to the theory that schizotypy and psychotic symptoms map onto common underlying dimensions.     

Genetically based correlates of serum oxytocin and testosterone in autism and schizotypy

The hormones oxytocin and testosterone have been implicated in autism spectrum and schizophrenia-spectrum cognition and disorders, but their roles in mediating these psychological phenotypes remain largely unknown. We genotyped a large set of healthy individuals for loci that represent established genetic indicators of serum testosterone and oxytocin levels, and tested for associations of these genetic indices of hormone levels with self-report measures of autistic and schizotypal cognition. A low genetic index of testosterone, a high genetic index of oxytocin, and/or a low ratio of testosterone to oxytocin indices were positively correlated with high imagination (by the Autism Quotient) and high positive and total schizotypy (by the Schizotypal Personality Questionnaire). The genetic indices for oxytocin, and testosterone relative to oxytocin, also showed significant correlations with a metric of positive schizotypy relative to autism, implicating higher oxytocin and lower testosterone in increased positively-schizotypal traits combined with decreased autism-associated traits. These results link genetic indicators of serum hormone levels with measures of schizotypy and autism among healthy individuals.