Affective dysfunction and affective interference in schizotypy

Affective dysfunction is a core feature of schizophrenia spectrum disorders. Schizophrenic and schizotypal participants report higher levels of unpleasant and lower levels of pleasant trait affect than controls. In response to pleasant stimuli, though, participants often report similar levels of pleasant emotion to controls, but heightened unpleasant emotion, suggesting pleasant experiences may be affected by intrusive unpleasant emotion. An emotional Stroop task was used to examine the relationship between affective interference and trait affect in schizotypy. No significant differences were found between schizotypal participants and controls on e-Stroop performance, but schizotypal participants did self-report more unpleasant trait affect and less pleasant trait affect than controls. Of the schizotypy symptom dimensions, only cognitive disorganization was significantly correlated with unpleasant interference on the e-Stroop. Self-reported trait affect was not correlated with e-Stroop performance, but unpleasant trait affect was correlated with positive schizotypy symptoms and pleasant trait affect was inversely correlated with negative symptoms. Results suggest avenues for future exploration of unpleasant trait bias and cognitive dysfunction in schizophrenia-spectrum disorders

Activation and Habituation of the Cingulate Cortex during Emotion Processing in Healthy Controls, Borderline, and Schizotypal Personality Disorder

Disturbances in emotional functioning are central features of the clinical profiles of both borderline and schizotypal personality disorder (BPD and SPD, respectively). BPD is characterized by a high sensitivity to emotional stimuli and unusually strong and long-lasting reactions, indicative of impaired habituation to emotional stimuli (Linehan, 1993). Previous research suggests that SPD patients demonstrate limbic hyper-reactivity to unpleasant stimuli, at least initially, but intact habituation to repeated presentation of unpleasant stimuli (Hazlett et al., 2012). The cingulate cortex supports various aspects of emotion processing and regulation, and abnormalities of this region have been related to emotion dysfunction in SPD and BPD (Koenigsberg, Fan, et al., 2009; Modinos, Ormel, & Aleman, 2010). However, findings of functional cingulate abnormalities in the context of emotion processing have been inconsistent in BPD and limited in SPD. The current study utilized event-related functional magnetic resonance imaging (fMRI) in three groups, BPD patients, SPD patients, and healthy control individuals, during a task involving an intermixed series of unpleasant, neutral, and pleasant pictures, each presented twice within their respective trial. This approach permitted the examination of reactivity to emotional stimuli and habituation of emotional responses within the cingulate. Blood-oxygen-level dependent response values were obtained within the manually delineated anterior cingulate cortex (ACC) and posterior cingulate cortex (PCC) and compared across groups. Compared to healthy controls and SPD patients, BPD patients exhibited significantly greater activity in the ACC during the presentation of neutral pictures. Heightened activity in the BPD group persisted across the initial and repeated presentations of neutral pictures. On the other hand, SPD patients exhibited greater activity in the ACC compared to healthy controls and BPD patients during the initial presentation of unpleasant pictures, but activity normalized when the pictures were repeated. The two patient groups demonstrated heightened ACC activation, but these abnormalities were differentiated by associated picture-type (neutral versus unpleasant) and attenuation of the response upon repeated presentation of the stimuli. Diagnostic differences in PCC activation did not reach significance. Overall results suggest unique involvement of the ACC in BPD and SPD symptomatology

Emotional Prosody Processing in the Schizophrenia Spectrum.

THESIS ABSTRACT Emotional prosody processing impairment is proposed to be a main contributing factor for the formation of auditory verbal hallucinations in patients with schizophrenia. In order to evaluate such assumption, five experiments in healthy, highly schizotypal and schizophrenia populations are presented. The first part of the thesis seeks to reveal the neural underpinnings of emotional prosody comprehension (EPC) in a non-clinical population as well as the modulation of prosodic abilities by hallucination traits. By revealing the brain representation of EPC, an overlap at the neural level between EPC and auditory verbal hallucinations (AVH) was strongly suggested. By assessing the influence of hallucinatory traits on EPC abilities, a continuum in the schizophrenia spectrum in which high schizotypal population mirrors the neurocognitive profile of schizophrenia patients was established. Moreover, by studying the relation between AVH and EPC in non-clinical population, potential confounding effects of medication influencing the findings were minimized. The second part of the thesis assessed two EPC related abilities in schizophrenia patients with and without hallucinations. Firstly, voice identity recognition, a skill which relies on the analysis of some of the same acoustical features as EPC, has been evaluated in patients and controls. Finally, the last study presented in the current thesis, assessed the influence that implicit processing of emotional prosody has on selective attention in patients and controls. Both patients studies demonstrate that voice identity recognition deficits as well as abnormal modulation of selective attention by implicit emotion prosody are related to hallucinations exclusively and not to schizophrenia in general. In the final discussion, a model in which EPC deficits are a crucial factor in the formation of AVH is evaluated. Experimental findings presented in the previous chapters strongly suggests that the perception of prosodic features is impaired in patients with AVH, resulting in aberrant perception of irrelevant auditory objects with emotional prosody salience which captures the attention of the hearer and which sources (speaker identity) cannot be recognized. Such impairments may be due to structural and functional abnormalities in a network which comprises the superior temporal gyrus as a central element

Emotion recognition in schizotypy

Deficits in social cognition are repeatedly found in individuals with schizophrenia. Facial emotion recognition is a major aspect of social cognition in which individuals with schizophrenia show consistent deficits. However, many questions about these deficits remain unanswered including whether they occur in individuals with schizotypy—those at high risk for the disorder that do not manifest full pathology. Examining emotion recognition in schizotypy eliminates many of the confounds associated with schizophrenia research such as medication effects, chronic institutionalization, and generalized cognitive deficits, and allows for the examination of whether emotion recognition deficits reflect vulnerability to schizophrenia. Prior research in this population has yielded mixed findings and is subject to a number of limitations including measurement of only a subset of schizotypy symptoms and use of non-validated or less sensitive emotion recognition measures. The current study examined emotion recognition in control and psychometrically-identified schizotypic individuals, employing a well-validated emotion recognition task that allowed for the examination of accuracy and bias scores. Of interest was whether individuals with schizotypy would show deficits when labeling emotional faces, whether they would exhibit biases when rating the emotional valence of faces, and how these variables relate to neurocognitive abilities, symptoms, and quality of life. Results indicate that individuals with schizotypy were significantly less accurate than controls when labeling facial emotions; however, they did not show generalized impairment on neurocognitive measures. Within the schizotypy sample, both disorganization symptoms and lower quality of life were associated with a bias toward perceiving facial expressions as more negative. Results support prior studies suggesting that poor emotion recognition is associated with vulnerability to psychosis even in the absence of neurocognitive impairment. Results also offer evidence of social cognitive biases in schizotypy, and suggest that these biases may be more related to overall functioning than accuracy labeling emotion

Timing the senses and sensing the time: Individual differences in subjective duration

Although the experimental investigation of the perception of time dates back to around 1864 (Lejeune & Wearden, 2009) the reasons for variation between individuals are still poorly understood. Advancing in this area has been identified as one of the most important issues for the modern investigation of time perception (Hancock & Block, 2012). Although various individual differences in time perception have been identified, these are usually based on comparisons between different groups depending on characteristics such as age or gender; clinical conditions such as schizophrenia or autism; or induced differences such as temperature or pharmacology. In this thesis we seek to investigate whether, and how, intrinsic individual differences in sensory processing within the general population influence individual timing behaviour. This is accomplished over four experiments. The first seeks a relationship between the EEG alpha rhythm, which is strongly associated with visual and audio-visual temporal integration, and behaviour on four timing tasks; while trends are in the expected directions no significant relationship emerges. The second responds to this null result by seeking a relationship between audio-visual integration and estimated, sub-second, durations in a purely behavioural paradigm, in this case the results show a significant association. The final two experiments are concerned with individual differences in interoceptive accuracy (sensitivity to ones own bodily signals), and how these influence the effect of arousal on time judgement. The first experiment, using supra-second durations, finds no effects, but the second, using shorter durations (under 1200ms) and addressing some methodological concerns, does find a significant moderation, by interoception, of the effect of emotional arousal upon time. We conclude that this provides substantial evidence that exteroceptive and interoceptive primary sensory processes play a role in individual variation in timing tasks, a finding that provides many further avenues of investigation

Threat-Related Attentional Bias in Relation to Anxiety and Depressive Symptoms in the General Population: The Potential Role of Sex Effects

Heightened sensitivity to relevant environmental stimuli (attentional bias) has been observed in relation to clinical and non-clinical anxiety and depression symptoms. While depression symptoms are associated with sensitivity to disorder and self-relevant words, hypervigilance to threatening stimuli is observed in relation to anxiety symptoms. Furthermore, attentional bias has been shown to play an important role in the development and maintenance of depressive and anxiety disorders. Accordingly, a large body of literature has examined threat-related attentional bias in relation to symptoms of anxiety and depression. However, several methodological inconsistencies exist across studies, including variability in definitions of threat, lack of consideration of differential aspects of anxiety (physical arousal versus general distress), and the overlooked potential role of sex effects. Therefore, the current study examined the specificity of threat-related attentional bias (for fear, disgust, anger, sadness), using a verbal emotional Stroop task (EST), among individuals from the general population reporting varying degrees of non-clinical symptoms of physical arousal, depression, and general distress (worry). The potential moderating effects of sex in the relationships of threat-related attentional bias with these symptoms were considered. One hundred twenty five (37 men/88 women) undergraduate students were asked to complete a self-report questionnaire of mood and anxiety symptoms and a computerized EST. In the total sample, symptoms of general distress (worry) alone predicted greater threat-related attentional bias to disgust words. Among women, symptoms of general distress predicted greater engagement with fear and disgust words, whereas physical arousal predicted greater engagement with disgust words alone. Among men, symptoms of physical arousal predicted greater avoidance of disgust words, whereas symptoms of general distress predicted greater avoidance of fear words. Accordingly, disgust and fear may both underlie threat in relation to symptoms of anxiety. Findings of the current study point to the importance of considering the specificity of negative emotions, subtypes of anxiety, and the effects of sex when examining threat-related attentional bias in relation to symptoms of mood and anxiety. Findings hold potential to delineate the specific nature of threat-related attentional bias observed in relation to anxiety symptoms and to inform treatment strategies that target threat bias in anxiety

Schizotypy and facial emotion processing

The ability to accurately interpret facial emotion is crucial to social being and our capacity to correctly interpret threat-related expressions has obvious adaptive value. Healthy individuals appear to process facial emotions rapidly, accurately and effortlessly, while individuals with schizophrenia often present with marked impairment in emotion processing. The hypothesis of continuity between schizophrenia and normal behaviour suggests that the signs and symptoms of the disorder also occur to varying, lesser degrees in the general population. This thesis presents a series of studies that explore the limits of facial emotion processing in healthy individuals, and its relationship with schizotypal personality traits. The first paper describes a set of three studies that use eye tracking techniques to explore the limits of rapid emotion processing. It is shown that we can quickly orient attention towards emotional faces even when the faces are task-irrelevant, presented for very brief intervals, and located well into peripheral vision. The remaining studies explore whether high schizotypes have similarities to individuals with schizophrenia in the way that they process facial emotion. High schizotypes were significantly less accurate at discriminating facial emotions and significantly more likely to misperceive neutral faces as angry, offering support for continuum models of visual hallucinatory experiences. A further study revealed that high relative to low schizoptypes feel as though they are exposed to angry faces for longer. It is argued that this experience itself may serve to maintain hypervigilance to social threat. Finally, laterality biases during face perception were explored. Contrary to the predictions of continuum models of schizophrenia, high schizotypes had an increased left side / right hemisphere bias for face processing. In summary, the thesis offers partial support for the hypothesis of continuity between the impairments in emotion discrimination observed in individuals with schizophrenia, and normal, healthy variation in facial emotion processing

Individual Differences in the Executive Control of Attention, Memory, and Thought, and Their Associations with Schizotypy

Reports an error in "Individual differences in the executive control of attention, memory, and thought, and their associations with schizotypy" by Michael J. Kane, Matt E. Meier, Bridget A. Smeekens, Georgina M. Gross, Charlotte A. Chun, Paul J. Silvia and Thomas R. Kwapil (Journal of Experimental Psychology: General, 2016[Aug], Vol 145[8], 1017-1048). There were errors in Table 3 and Table 7 (these transcription errors were limited to descriptive statistics in the Tables and did not affect any inferential statistics). In Table 3, the ARRO-TUT and LETT-TUT variables had incorrect values for Mean [95% CI], SD, Skew, Kurtosis, and N. In Table 7, the same values (plus Min and Max) were incorrect for the SEM-SART variable. The correct values for these measures are presented in the correction (the values for Min and Max were correct as set in Table 3, but are repeated below for clarity). (The following abstract of the original article appeared in record 2016-29680-001.) A large correlational study took a latent-variable approach to the generality of executive control by testing the individual-differences structure of executive-attention capabilities and assessing their prediction of schizotypy, a multidimensional construct (with negative, positive, disorganized, and paranoid factors) conveying risk for schizophrenia. Although schizophrenia is convincingly linked to executive deficits, the schizotypy literature is equivocal. Subjects completed tasks of working memory capacity (WMC), attention restraint (inhibiting prepotent responses), and attention constraint (focusing visual attention amid distractors), the latter 2 in an effort to fractionate the “inhibition” construct. We also assessed mind-wandering propensity (via in-task thought probes) and coefficient of variation in response times (RT CoV) from several tasks as more novel indices of executive attention. WMC, attention restraint, attention constraint, mind wandering, and RT CoV were correlated but separable constructs, indicating some distinctions among “attention control” abilities; WMC correlated more strongly with attentional restraint than constraint, and mind wandering correlated more strongly with attentional restraint, attentional constraint, and RT CoV than with WMC. Across structural models, no executive construct predicted negative schizotypy and only mind wandering and RT CoV consistently (but modestly) predicted positive, disorganized, and paranoid schizotypy; stalwart executive constructs in the schizophrenia literature—WMC and attention restraint—showed little to no predictive power, beyond restraint’s prediction of paranoia. Either executive deficits are consequences rather than risk factors for schizophrenia, or executive failures barely precede or precipitate diagnosable schizophrenia symptoms