Specificity of emotion-related effects on attentional processing in schizotypy

Proactive and reactive cognitive control for emotional conflict in individuals with high schizotypy: An ERP study

OBJECTIVE

The present study aimed to examine how individuals with high schizotypy, a high risk group of schizophrenia patients, resolve emotional conflict in proactive and reactive control and the underlying neural mechanisms.

METHODS

Thirty-two individuals with high schizotypy and 30 matched individuals with low schizotypy completed an emotional face-word Stroop task with electroencephalographic data recorded. The proportion of incongruent trials was manipulated in the task to induce proactive control (mostly incongruent trials context, MI context) or reactive control (mostly congruent trials context, MC context). Two event-related potential (ERP) components (N170 and N2) were examined, which represent face processing and cognitive control processes, respectively.

RESULTS

In the MC context, significantly decreased N2 and N170 amplitudes were found in high schizotypy individuals compared with low schizotypy individuals, suggesting abnormal neural activity of reactive control in high schizotypy individuals. No significant differences were found between the two groups in the MI context.

CONCLUSIONS

These results provide initial evidence for dissociation of neural activity of proactive and reactive control on emotional conflict in individuals with high schizotypy.

SIGNIFICANCE

The current findings provide important insight into the emotional conflict resolution in the schizophrenia spectrum.

Linking RDoC and HiTOP: A new interface for advancing psychiatric nosology and neuroscience

The Research Domain Criteria (RDoC) and the Hierarchical Taxonomy of Psychopathology (HiTOP) represent major dimensional frameworks proposing two alternative approaches to accelerate progress in the way psychopathology is studied, classified, and treated. RDoC is a research framework rooted in neuroscience aiming to further the understanding of transdiagnostic biobehavioral systems underlying psychopathology and ultimately inform future classifications. HiTOP is a dimensional classification system, derived from the observed covariation among symptoms of psychopathology and maladaptive traits, which seeks to provide more informative research and treatment targets (i.e., dimensional constructs and clinical assessments) than traditional diagnostic categories. This article argues that the complementary strengths of RDoC and HiTOP can be leveraged in order to achieve their respective goals. RDoC's biobehavioral framework may help elucidate the underpinnings of the clinical dimensions included in HiTOP, whereas HiTOP may provide psychometrically robust clinical targets for RDoC-informed research. We present a comprehensive mapping between dimensions included in RDoC (constructs and subconstructs) and HiTOP (spectra and subfactors) based on narrative review of the empirical literature. The resulting RDoC-HiTOP interface sheds light on the biobehavioral correlates of clinical dimensions and provides a broad set of dimensional clinical targets for etiological and neuroscientific research. We conclude with future directions and practical recommendations for using this interface to advance clinical neuroscience and psychiatric nosology. Ultimately, we envision that this RDoC-HiTOP interface has the potential to inform the development of a unified, dimensional, and biobehaviorally-grounded psychiatric nosology.

The subjective-objective deficit paradox in schizotypy extends to emotion regulation and awareness

There is an emerging subjective-objective deficit paradox in schizotypy. Individuals with schizotypy report severe subjective complaints in several key functional domains commensurate with that of individuals with schizophrenia. However, objective assessments of the same domains show relatively intact performance. We examined whether this subjective-objective deficit paradox extends to two closely linked affective processes: emotion regulation and awareness. Individuals with elevated social anhedonia (SocAnh; n = 61) and elevated perceptual aberration/magical ideation (PerMag; n = 73) were compared to control participants (n = 81) on subjective and objective measures of emotion regulation and awareness. Subjective measures included self-report questionnaires assessing regulatory ability, attention to emotion, and emotional clarity. Implicit emotion regulation was assessed by the Emotion Regulation-Implicit Association Test (ER-IAT) while objective emotional awareness was assessed by the Levels of Emotional Awareness Scale (LEAS), a performance-based test. Results showed that both SocAnh and PerMag groups reported notable deficits in almost all subjective measures relative to controls (composite ds > 0.55). In contrast, performance on ER-IAT and LEAS was very similar to controls (composite ds < 0.11). The current study suggests that the subjective-objective deficit paradox extends to emotion regulation and awareness, highlighting the importance of higher-order cognitive bias in understanding emotional abnormalities in schizotypy.

Do complaints of everyday cognitive failures in high schizotypy relate to emotional working memory deficits in the lab?

BACKGROUND

Individuals high on schizotypy complain of increased cognitive failures in everyday life. However, the neuropsychological performance of this group does not consistently indicate underlying ability deficits. It is possible that current neuropsychological tests lack ecological validity. Given the increased affective reactivity of high schizotypes, they may be more sensitive to emotional content interfering with cognitive ability. This study sought to explore whether an affective n-back working memory task would elicit impaired performance in schizotypy, echoing complaints concerning real world cognition.

METHODS

127 healthy participants completed self-report measures of schizotypy and cognitive failures and an affective n-back working memory task. This task was varied across three levels of load (1- to 3-back) and four types of stimulus emotion (neutral, fearful, happy, sad). Differences between high (n=39) and low (n=48) schizotypy groups on performance outcomes of hits and false alarms were examined, with emotion and load as within-groups variables.

RESULTS

As expected, high schizotypes reported heightened vulnerability to cognitive failures. They also demonstrated a relative working memory impairment for emotional versus neutral stimuli, whereas low schizotypes did not. High schizotypes performed most poorly in response to fearful stimuli. For false alarms, there was an interaction between schizotypy, load, and emotion, such that high schizotypy was associated with deficits in response to fearful stimuli only at higher levels of task difficulty. Inclusion of self-reported cognitive failures did not account for this.

CONCLUSION

These findings suggest that the "gap" between subjective and objective cognition in schizotypy may reflect the heightened emotional demands associated with cognitive functioning in the real world, although other factors also seem to play a role. There is a need to improve the ecological validity of objective assessments, whilst also recognizing that self-reported cognitive failures tap into a range of factors difficult to assess in the lab, including emotion. Cognitive interventions for at-risk individuals will likely be more beneficial if they address emotional processing alongside other aspects of cognition.

Neuropsychological correlates of schizotypy: a systematic review and meta-analysis of cross-sectional studies

INTRODUCTION

Cognitive deficits can precede the onset of psychotic episodes and predict the onset of the illness in individuals with schizotypy traits. In some studies, high levels of schizotypy were associated with impairments in memory, attention, executive functions, and verbal fluency. This review provides a more comprehensive understanding of cognitive impairments related to schizoytpy.

METHODS

 A systematic review of "schizotypy and neuropsychological measures" was conducted, and it retrieved 67 studies. All papers with case-control design showing means and standard deviations from neuropsychological measures were included in a meta-analysis (n = 40). A comparison between our finding and another metaanalysis with patients with schizophrenia-spectrum disorders [Fatouros-Bergman, H., Cervenka, S., Flyckt, L., Edman, G., & Farde, L. (2014). Meta-analysis of cognitive performance in drugnaive patients with schizophrenia. Schizophrenia Research. doi: 10.1016/j.schres.2014.06.034 ] was performed to study the similarities on the MATRICS domains between the two disorders.

RESULTS

We found evidence of worse functioning of verbal and visual-spatial working memory, and of language in people with schizotypy or with schizotypal traits. Working memory deficit is present in both schizotypy and schizophrenia with larger effect sizes compared to other domains.

CONCLUSIONS

 Working memory deficit might be a cognitive marker of the risk of psychosis. Interventions targeting cognitive deficits early may be crucial to the prevention of psychosis.

Transdiagnostic neural markers of emotion-cognition interaction in psychotic disorders

Deficits in working memory (WM) and emotion processing are prominent impairments in psychotic disorders, and have been linked to reduced quality of life and real-world functioning. Translation of knowledge regarding the neural circuitry implementing these deficits into improved diagnosis and targeted treatments has been slow, possibly because of categorical definitions of disorders. Using the dimensional Research Domain Criteria (RDoC) framework, we investigated the clinical and practical utility of transdiagnostic behavioral and neural measures of emotion-related WM disruption across psychotic disorders. Behavioral and functional MRI data were recorded while 53 participants with psychotic disorders and 29 participants with no history of psychosis performed a modified n-back task with fear and neutral distractors. Hierarchical regression analyses showed that psychotic symptoms entered after diagnosis accounted for unique variance in fear versus neutral accuracy and activation in the ventrolateral, dorsolateral, and dorsomedial prefrontal cortex, but diagnostic group entered after psychotic symptoms did not. These results remained even after controlling for negative symptoms, disorganized symptoms, and dysphoria. Finally, worse accuracy and greater prefrontal activity were associated with poorer social functioning and unemployment across diagnostic groups. Present results support the transdiagnostic nature of behavioral and neuroimaging measures of emotion-related WM disruption as they relate to psychotic symptoms, irrespective of diagnosis. They also provide support for the practical utility of these markers in explaining real-world functioning. Overall, these results elucidate key aspects of the RDoC construct of WM maintenance by clarifying its transdiagnostic importance and clinical utility in psychotic disorders. (PsycINFO Database Record

Distribution of Response Time, Cortical, and Cardiac Correlates during Emotional Interference in Persons with Subclinical Psychotic Symptoms

A psychosis phenotype can be observed below the threshold of clinical detection. The study aimed to investigate whether subclinical psychotic symptoms are associated with deficits in controlling emotional interference, and whether cortical brain and cardiac correlates of these deficits can be detected using functional near-infrared spectroscopy (fNIRS). A data set derived from a community sample was obtained from the Zurich Program for Sustainable Development of Mental Health Services. 174 subjects (mean age 29.67 ± 6.41, 91 females) were assigned to four groups ranging from low to high levels of subclinical psychotic symptoms (derived from the Symptom Checklist-90-R). Emotional interference was assessed using the emotional Stroop task comprising neutral, positive, and negative conditions. Statistical distributional methods based on delta plots [behavioral response time (RT) data] and quantile analysis (fNIRS data) were applied to evaluate the emotional interference effects. Results showed that both interference effects and disorder-specific (i.e., group-specific) effects could be detected, based on behavioral RTs, cortical hemodynamic signals (brain correlates), and heart rate variability (cardiac correlates). Subjects with high compared to low subclinical psychotic symptoms revealed significantly reduced amplitudes in dorsolateral prefrontal cortices (interference effect, p < 0.001) and middle temporal gyrus (disorder-specific group effect, p < 0.001), supported by behavioral and heart rate results. The present findings indicate that distributional analyses methods can support the detection of emotional interference effects in the emotional Stroop. The results suggested that subjects with high subclinical psychosis exhibit enhanced emotional interference effects. Based on these observations, subclinical psychosis may therefore prove to represent a valid extension of the clinical psychosis phenotype.

Deficits in attentional processing of fearful facial expressions in schizophrenic patients

Impaired attentional processing of negative facial expressions is prominent in schizophrenia and has been shown to be associated with patients’ social dysfunctions. However, little is known about when and which specific attention deficits influence social functions. Given the dynamic feature of attention, it is necessary to investigate the attention deficits in negative emotional processing unfolding in time. The current study used event-related potentials (ERPs) to investigate the temporal dynamics of attention deficits in emotion perception and their potential relationship with emotional/social impairments in neuroleptic naive schizophrenic patients. Two specific attention deficits were identified and were found to be associated with emotional/social impairments. More specifically, the deficit in orienting attention (evidenced with the reduced P1 amplitude) was correlated with expressive deficits, while the deficit in executive control of attention (evidenced with the reduced P3 amplitude) was correlated with avolition/asociality. Together, these findings may provide novel insights into the core pathophysiological processes and offer objective biomarkers for specific emotional/social impairments in schizophrenia. It is also hoped that this study helps to bridge the gap between basic cognitive deficits and relative high-level social dysfunctions in schizophrenic patients.

Schizotypy and specificity of negative emotions on an emotional Stroop paradigm in the general population

Attentional-interference using emotional Stroop tasks (ESTs) is greater among individuals in the general population with positive (versus negative) schizotypal traits; specifically in response to negatively (versus positively) valenced words, potentially capturing threat-sensitivity. Variability in attentional-interference as a function of subcategories of negatively valenced words (and in relation to schizotypal traits) remains underexplored in EST studies. We examined attentional-interference across negative word subcategories (fear/anger/sadness/disgust), and in relation to positive schizotypy, among non-clinical individuals in the general population reporting varying degrees of schizotypal traits. As hypothesized, performance differed across word subcategories, though the pattern varied from expectation. Attentional-interference was greater for fear and sadness compared to anger; and analogous for fear, disgust, and sadness. In the high schizotypy group, positive schizotypal traits were directly associated with attentional-interference to disgust. Attentional-interference was comparable between high- and low-positive schizotypy. Results suggest negative emotion subcategories may differentially reflect threat-sensitivity. Disgust-sensitivity may be particularly salient in (non-clinical) positive schizotypy. Findings have implications for understanding negative emotion specificity and variability in stimulus presentation modality when studying threat-related attentional-interference. Finally, disgust-related attentional-interference may serve as a cognitive correlate of (non-clinical) positive schizotypy. Expanding this research to prodromal populations will help explore disgust-related attentional-interference as a potential cognitive marker of positive symptoms.

The fear of other persons' laughter: Poor neuronal protection against social signals of anger and aggression

The fear of other persons' laughter (gelotophobia) occurs in the context of several psychiatric conditions, particularly in the schizophrenia spectrum and social phobia. It entails severe personal and inter-personal problems including heightened aggression and possibly violence. Individuals with gelotophobia (n=30; 24 with social phobia or Cluster A diagnosis) and matched symptom-free controls (n=30) were drawn from a large screening sample (n=1440). EEG coherences were recorded during the confrontation with other people's affect expressions, to investigate the brain's modulatory control over the emotionally laden perceptual input. Gelotophobia was associated with more loose functional coupling of prefrontal and posterior cortex during the processing of expressions of anger and aggression, thus leaving the individual relatively unprotected from becoming affected by these social signals. The brain's response to social signals of anger/aggression and the accompanied heightened permeability for this kind of information explains the particular sensitivity to actual or supposed malicious aspects of laughter (and possibly of other ambiguous social signals) in individuals with gelotophobia, which represents the core feature of the condition. Heightened perception of stimuli that could be perceived as offensive, which is inherent in several psychiatric conditions, may be particularly evident in the fear of other persons' laughter.

The relation between schizotypy and early attention to rejecting interactions: The influence of neuroticism

OBJECTIVES

Schizotypy relates to rejection sensitivity (anxiety reflecting an expectancy of social exclusion) and neuroticism (excessive evaluation of negative emotions). Positive schizotypy (e.g., perceptual aberrations and odd beliefs) and negative schizotypy (e.g., social and physical anhedonia) could relate to altered attention to rejection because of neuroticism.

METHODS

Forty-one healthy individuals were assessed on positive and negative schizotypy and neuroticism, and event-related potentials during rejecting, accepting and neutral scenes. Participants were categorised into high, moderate and low neuroticism groups. Using temporo-spatial principal components analyses, P200 (peak latency = 290 ms) and P300 amplitudes (peak latency = 390 ms) were measured, reflecting mobilisation of attention and early attention, respectively.

RESULTS

Scalp-level and cortical source analysis revealed elevated fronto-parietal N300/P300 amplitude and P200-related dorsal anterior cingulate current density during rejection than acceptance/neutral scenes. Positive schizotypy related inversely to parietal P200 amplitude during rejection. Negative schizotypy related positively to P200 middle occipital current density. Negative schizotypy related positively to parietal P300, where the association was stronger in high and moderate, than low, neuroticism groups.

CONCLUSIONS

Positive and negative schizotypy relate divergently to attention to rejection. Positive schizotypy attenuates, but negative schizotypy increases rejection-related mobilisation of attention. Negative schizotypy increases early attention to rejection partly due to elevated neuroticism.

Magical ideation associated social cognition in adolescents: signs of a negative facial affect recognition deficit

BACKGROUND

Studies provide evidence for impaired social cognition in schizotypy and its association with negative symptoms. Cognitive features related to magical ideation - a component of the positive dimension of schizotypy - have been less investigated. We aimed to assess social cognitive functioning among adolescents with high magical ideation scores, mainly focusing on face and emotion recognition.

METHODS

22 subjects with magical ideation scale scores above the cut off level and 22 controls with lowest scores from among 250 students screened with this scale were included in the study. A face and emotion recognition n-back test, the empathy quotient, theory of mind tests and the Physical Anhedonia Scale were applied to both magical ideation and control groups.

RESULTS

The magical ideation group performed significantly worse than controls on both face and emotion recognition tests. Emotion recognition performance was found to be affected by memory load, with sadness, among emotions, revealing a difference between the two groups. Empathy and theory of mind tests did not distinguish the magical ideation group from controls.

CONCLUSION

Our findings provide evidence for a deficit in negative emotion recognition affected by memory load associated with magical ideation in adolescents.

Perception of emotion-related conflict in human communications: what are the effects of schizophrenia?

Our ability to make sense of emotional cues is of paramount importance for understanding state of mind and communicative intent. However, emotional cues often conflict with each other; this presents a significant challenge for people with schizophrenia. We conducted a theoretical review to determine the extent and types of impaired processing of emotion-related conflict in schizophrenia; we evaluated the relationship with medication and symptoms, and considered possible mediatory mechanisms. The literature established that people with schizophrenia demonstrated impaired function: (i) when passively exposed to emotion cues whilst performing an unrelated task, (ii) when selectively attending to one source of emotion cues whilst trying to ignore interference from another source, and (iii) when trying to resolve conflicting emotion cues and judge meta-communicative intent. These deficits showed associations with both negative and positive symptoms. There was limited evidence for antipsychotic medications attenuating impaired emotion perception when there are conflicting cues, with further direct research needed. Impaired attentional control and context processing may underlie some of the observed impairments. Neuroanatomical correlates are likely to involve interhemispheric transfer via the corpus callosum, limbic regions such as the amygdala, and possibly dorsolateral prefrontal and anterior cingulate cortex through their role in conflict processing.

Emotional prosody modulates attention in schizophrenia patients with hallucinations

Recent findings have demonstrated that emotional prosody (EP) attracts attention involuntarily (Grandjean et al., 2008). The automat shift of attention toward emotionally salient stimuli can be overcome by attentional control (Hahn et al., 2010). Attentional control is impaired in schizophrenia, especially in schizophrenic patients with hallucinations because the "voices" capture attention increasing the processing load and competing for top-down resources. The present study investigates how involuntary attention is driven by implicit EP in schizophrenia with auditory verbal hallucinations (AVH) and without (NAVH). Fifteen AVH patients, 12 NAVH patients and 16 healthy controls (HC) completed a dual-task dichotic listening paradigm, in which an emotional vocal outburst was paired with a neutral vocalization spoken in male and female voices. Participants were asked to report the speaker's gender while attending to either the left or right ear. NAVH patients and HC revealed shorter response times for stimuli presented to the attended left ear than the attended right ear. This laterality effect was not present in AVH patients. In addition, NAVH patients and HC showed faster responses when the EP stimulus was presented to the unattended ear, probably because of less interference between the attention-controlled gender voice identification task and involuntary EP processing. AVH patients did not benefit from presenting emotional stimuli to the unattended ear. The findings suggest that similar to HC, NAVH patients show a right hemispheric bias for EP processing. AVH patients seem to be less lateralized for EP and therefore might be more susceptible to interfering involuntary EP processing; regardless which ear/hemisphere receives the bottom up input.

The processing of emotional stimuli during periods of limited attentional resources in schizophrenia

When participants are asked to attend to two target stimuli in a rapid serial visual presentation sequence, the successful identification of the 1st target (T1) leads to transient impairment in reporting the 2nd target (T2)--this effect is known as the attentional blink (AB). In healthy individuals, this AB effect is either diminished or accentuated when emotional stimuli are presented in the T2 or T1 positions, respectively, suggesting that affective content influences bottom-up (i.e., exogenous) attention. In the current study, we conducted two separate experiments using the Emotional Attentional Blink paradigm where emotional words were presented in the T2 or T1 position to determine whether schizophrenia patients with high and low negative symptoms differ from controls in the extent to which emotional stimuli influence bottom-up attentional processes. Participants included 33 schizophrenia patients and 28 controls in Experiment 1 (T2 Task), and 30 schizophrenia patients and 24 controls in Experiment 2 (T1 Task). In both experiments, patients were divided into high (HI-NEG) and low (LOW-NEG) negative symptom subgroups using the Scale for the Assessment of Negative Symptoms. Results of Experiment 1 indicated that controls and LOW-NEG patients displayed the typical pattern of AB sparing at early lags for emotional relative to neutral words; however, HI-NEG patients showed no difference in T2 accuracy between emotional and neutral stimuli. Results of Experiment 2 indicated that controls and LOW-NEG patients displayed reduced T2 accuracy following unpleasant T1 stimuli, while HI-NEG patients showed no decrement in T2 accuracy after emotional T1s. Across both experiments, findings suggest that emotional stimuli have a bottom-up competitive advantage in LOW-NEG patients and controls; however, this bottom-up advantage is absent in HI-NEG patients.

Impaired executive control of emotional information in social anhedonia

We examined the executive control of emotional information and its relationship to social functioning in individuals at risk for schizophrenia, defined by high social anhedonia (SA). Using the same structure as the Attentional Network Test (ANT), we developed a measure of executive control of emotional information (ANT-Emotion) in which subjects identify the direction of an arrow flanked by irrelevant angry or neutral faces. Subjects completed the ANT, ANT-Emotion, and the Social Adjustment Scale, Self-Report (SAS-SR), a measure of social functioning. While there were no group differences in the alerting, orienting, and executive control networks assessed by the ANT, high SA individuals exhibited a specific impairment in the executive control of emotional information. High SA individuals also reported poorer social functioning. However, executive control of emotional information did not mediate the relationship between SA and social functioning. These findings indicate that, in high-risk populations, the impaired ability to inhibit emotional information allows negative affective stimuli to exert inappropriate influence on cognitive processes. These results are consistent with studies indicating similar findings in schizophrenia patients, suggesting that impaired inhibition of negative emotion may be part of the liability for the disorder.

Affective disturbances in psychometrically defined schizotypy across direct, but not indirect assessment modes

Affective disturbances in social domains are characteristic features and potential vulnerability markers of schizophrenia-spectrum pathology. The present study employed a comprehensive and multidimensional approach to understanding affect in individuals with psychometrically defined schizotypy and the controls. Measures were employed assessing trait and state social affective experiences across direct--involving explicit deliberative responses, and indirect domains--involving implicit, behavioral or otherwise non-deliberative responses. The indirect assessments included a modified Implicit Association Test and computerized lexical analysis of natural speech procured during a laboratory speech task. Our affect measures were also unique in that they allowed for separate measurement of pleasant and unpleasant affect. On all direct trait and "in-the-moment" state measures of social affect, individuals with schizotypy reported dramatically decreased pleasant and increased unpleasant affect compared to controls. This was not the case for the indirect measures, which indicated no significant group differences. This pattern was generally consistent regardless of positive, negative and disorganized schizotypal trait severity. These data suggest that affective deficits in schizotypy reflect deliberative rather than implicit/automatic processes. Implications of these findings are discussed.

Altered activation and functional connectivity of neural systems supporting cognitive control of emotion in psychosis proneness

Emotion regulation processes, such as reappraisal, are thought to operate through interactions between prefrontal emotion-control regions and subcortical emotion-generation regions such as the amygdala. Impairments in emotional processing and regulation have been reported in schizophrenia and at-risk populations. Psychometric measures may be used to detect vulnerability to schizophrenia in non-clinical samples, or psychosis proneness (PP). It has been shown that individuals with PP have a more than tenfold increased risk of developing a schizophrenia-spectrum disorder. In the present study, we used fMRI to examine the neural dynamics underlying reappraisal in such a sample. 600 undergraduate students completed the Community Assessment of Psychic Experiences Questionnaire (CAPE), positive subscale. Two groups were subsequently formed from the extremes of the distribution (total N=34). Blood-oxygenated-level-dependent activity elicited with a task involving 3 conditions was analyzed: viewing neutral pictures, viewing negative pictures, and reappraising negative pictures. Subjects reported the strength of experienced negative affect after each trial. Functional connectivity between prefrontal control regions and amygdala was investigated. At the behavioral level, both groups reported successful diminishment of experienced negative emotion. However, high psychosis-prone subjects showed stronger activation than low subjects in a number of prefrontal regions during reappraisal, relative to attending to negative pictures. The amygdala response to negative stimuli was decreased through reappraisal only in the low group. Functional connectivity analysis revealed less prefrontal-amygdala coupling in high psychosis-prone subjects. Thus, reduced cognitive control of emotion at a neural level appeared to be associated with PP. These findings extend the hypothesis of emotion dysregulation in schizophrenia to PP, and suggest that emotion regulation difficulties may be at the core of a vulnerability to psychosis.

Neural correlates of irony comprehension: the role of schizotypal personality traits

To detect that a conversational turn is intended to be ironic is a difficult challenge in everyday language comprehension. Most authors suggested a theory of mind deficit is crucial for irony comprehension deficits in psychiatric disorders like schizophrenia; however, the underlying pathophysiology and neurobiology are unknown and recent research highlights the possible role of language comprehension abnormalities. Fifteen female right-handed subjects completed personality testing as well as functional magnetic resonance imaging (fMRI) and neuropsychology. Subjects were recruited from the general population. No subject had a lifetime history of relevant psychiatric disorder; however, subjects differed in their score on the German version of the schizotypal personality questionnaire (SPQ). During fMRI scans, the subjects silently read 44 short text vignettes that ended in either an ironic or a literal statement. Imaging was performed using a 3 T Siemens scanner. The influence of schizotypy on brain activation was investigated by using an SPM5 regression analysis with the SPQ total score and the SPQ cognitive-perceptual score as regressors. Reading ironic in contrast to literal sentences activated a bilateral network including left medial prefrontal and left inferior parietal gyri. During reading of ironic sentences, brain activation in the middle temporal gyrus of both hemispheres showed a significant negative association with the SPQ total score and the SPQ cognitive-perceptual score. Significant positive correlation with the SPQ total score was present in the left inferior frontal gyrus. We conclude schizotypal personality traits are associated with a dysfunctional lateral temporal language rather than a theory of mind network.

A risk PRODH haplotype affects sensorimotor gating, memory, schizotypy, and anxiety in healthy male subjects

BACKGROUND

Significant associations have been shown for haplotypes comprising three PRODH single nucleotide polymorphisms (SNPs; 1945T/C, 1766A/G, 1852G/A) located in the 3' region of the gene, suggesting a role of these variants in the etiopathogenesis of schizophrenia. We assessed the relationship between these high-risk PRODH polymorphisms and schizophrenia-related endophenotypes in a large and highly homogeneous cohort of healthy males.

METHODS

Participants (n = 217) were tested in prepulse inhibition (PPI), verbal and working memory, trait anxiety and schizotypy. The QTPHASE from the UNPHASED package was used for the association analysis of each SNP or haplotype data. This procedure revealed significant phenotypic impact of the risk CGA haplotype. Subjects were then divided in two groups; levels of PPI, anxiety, and schizotypy, verbal and working memory were compared with analysis of variance.

RESULTS

CGA carriers (n = 32) exhibited attenuated PPI (p < .001) and verbal memory (p < .001) and higher anxiety (p < .004) and schizotypy (p < .008) compared with the noncarriers (n = 185). There were no differences in baseline startle, demographics, and working memory. The main significant correlations were schizotypy x PPI [85-dB, 120-msec trials] in the carriers and schizotypy x anxiety in the entire group and the noncarriers but not the carriers group.

CONCLUSIONS

Our results strongly support PPI as a valid schizophrenia endophenotype and highlight the importance of examining the role of risk haplotypes on multiple endophenotypes and have implications for understanding the continuum from normality to psychosis, transitional states, and the genetics of schizophrenia-related traits.