Relationship between theta/beta ratio and mind wandering in schizotypy.

Negative association was found between the frontal theta/beta ratio and mind wandering in participants with high schizotypal traits, while no such association was found in participants with low schizotypal traits. These findings provide insights into the neural mechanism of mind wandering in individuals with high schizotypal traits.

Associations between intraindividual reaction time variability and prospective memory performance in patients with schizophrenia and healthy controls.

Introduction: Patients with schizophrenia exhibit prospective memory (PM) impairment. Intraindividual reaction time variability (IIRTV) is an index of attentional control that is required for PM. This study examined the differences in IIRTV between patients with schizophrenia and healthy controls and the relationship between IIRTV and PM performance.Method: Thirty-nine patients with schizophrenia and forty-two healthy controls were recruited to complete a PM task and the Sustained Attention to Response Task. IIRTV was calculated as the coefficient of variation (mean/SD) of reaction time over correctly responded trials in these tasks.Results: Patients with schizophrenia showed lower PM accuracy and increased IIRTV, while the associations between PM accuracy and IIRTV were significant in healthy controls but not in patients with schizophrenia.Conclusion: These findings suggest impaired PM and relationship between PM and attentional control in patients with schizophrenia.

Neural correlates of mental time travel in individuals with high level of schizotypy.

BACKGROUND: Mental time travel (MTT) is the ability to re-experience past events (autobiographic memory, AM) and pre-experience possible future events (episodic future thinking, EFT) through mental simulation. Empirical findings suggest that individuals with high level of schizotypy exhibit MTT impairment. However, the neural correlates of this impairment remain unclear. METHOD: Thirty-eight individuals with high level of schizotypy and 35 low level of schizotypy were recruited to complete an MTT imaging paradigm. Participants were required to recall past events (AM condition), imagine possible future events (EFT condition) related to cue words, or generate exemplars related to category words (control condition) while undergoing functional Magnetic Resonance Imaging (fMRI). RESULTS: AM showed greater activation in precuneus, bilateral posterior cingulate cortex, thalamus, and middle frontal gyrus than EFT. Individuals with high level of schizotypy exhibited reduced activation in the left anterior cingulate cortex during AM (vs. Control) and in the medial frontal gyrus during EFT (vs. Control) compared to individuals with low level of schizotypy. Although psychophysiological interaction analyses did not show any significant group difference, individuals with high level of schizotypy exhibited functional connectivity between left anterior cingulate cortex (seed) and right thalamus, between medial frontal gyrus (seed) and left cerebellum during MTT, whereas individuals with low level of schizotypy did not exhibit these functional connectivities. CONCLUSION: These findings suggest that decreased brain activations may underlie MTT deficits in individuals with high level of schizotypy.

Mental time travel for self and others in individuals with a high level of schizotypy.

Mental time travel (MTT) is the ability to project oneself to the past or future through mental simulation. Moreover, MTT can involve self-related or other-related information. This study aimed to compare MTT in individuals with high levels of schizotypy and that in their counterparts with low levels of schizotypy. Participants with high (n = 37) and low (n = 37) levels of schizotypy completed an MTT task with four conditions [2 (Condition: self vs. other) × 2 (Time orientation: past vs. future)]. They were required to recall past events that had happened to themselves or to a non-intimate person, and to imagine possible future events that might happen to themselves or to a non-intimate person, related to cue words. Outcome measures included specificity, vividness, sense of experience, emotional valence, emotional intensity, proportion of first-person visual perspective in events, and difficulty in event generation. A 2 (Group: high vs. low levels of schizotypy) × 2 (Condition) × 2 (Time orientation) mixed analysis of variance was conducted on each index. Results showed that self-related MTT was more specific than other-related MTT in low levels of schizotypy participants but not in high levels of schizotypy participants. Participants with a high level of schizotypy reported fewer specific events, and reported events with lower vividness and positive emotion than did those with a low level of schizotypy. Self-related MTT showed higher levels of phenomenological characteristics than did other-related MTT. In conclusion, individuals with a high level of schizotypy have altered MTT, and cannot benefit from the self-advantage effect on the specificity of MTT.

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.

Proactive and reactive response inhibition of individuals with high schizotypy viewing different facial expressions: An ERP study using an emotional stop-signal task.

The present study aimed to examine whether impairments in reactive (outright stopping) and proactive (preparation for stopping) response inhibition are affected by negative emotions in individuals with high schizotypy, a subclinical group at risk for schizophrenia, as well as the neural mechanisms underlying these processes. Twenty-seven participants with high schizotypy and 28 matched low-schizotypy individuals completed an emotional stop-signal task in which they responded to facial emotions (neutral or angry) or inhibited their responses (when the frame of the picture turned red). Electroencephalogram (EEG) data were also recorded during the task. At the neural level, analysis of go trials revealed that viewing angry faces impaired proactive inhibition. In addition, the high-schizotypy group exhibited a greater P3 amplitude in go trials in the neutral condition than the low-schizotypy group; however, no group difference was found in the angry condition. For stop trials (reactive inhibition), a smaller P3 amplitude was found in the angry condition than in the neutral condition. Moreover, high-schizotypy individuals showed smaller P3 amplitudes than low-schizotypy individuals. The current findings suggest that, at the neural level, viewing negative emotions impaired both proactive and reactive response inhibition. Individuals with high schizotypy exhibited impairments in proactive response inhibition in the neutral condition but not in the angry condition; they exhibited impaired reactive response inhibition in both emotion conditions. The present findings deepen our understanding of emotional response inhibition in individuals on the schizophrenia spectrum.

Prospective memory performance and its improvement in individuals with high schizotypal traits: Evidence from eye-tracking studies.

OBJECTIVE: This study aimed to examine prospective memory (PM) performance and the potential effect of implementation intention on PM performance and the underlying mechanisms in individuals with high schizotypyal traits (HSTs) using eye-tracking paradigms. METHODS: In Experiment 1, 30 individuals with HSTs and 30 individuals with low schizotypal traits (LSTs) underwent a visual search task that involved PM cues, and participants' eye movements were recorded. In Experiment 2, 50 individuals with HSTs were randomly assigned to the implementation intention group and typical instruction group. RESULTS: In Experiment 1, individuals with HSTs had a lower PM accuracy and performed less PM cue monitoring (indicated by fewer total fixation counts on distractor words) than individuals with LSTs. In Experiment 2, implementation intention significantly improved PM accuracy and increased total fixation counts on distractor words in individuals with HSTs compared to the HST group with typical instruction. CONCLUSIONS: Individuals with HSTs were impaired in PM and showed reduced cue monitoring compared to individuals with LSTs. Implementation intention improved PM performance and facilitated cue monitoring in individuals with HSTs. SIGNIFICANCE: Our findings indicate that cue monitoring may be an important process of intervention target for PM for individuals in the schizophrenia spectrum.

The relationship between schizotypal traits and satisfaction with life among Chinese young adults: The mediating effect of trait anxiety and mind wandering.

Schizotypal traits have been found to be negatively associated with satisfaction with life but the underlying mechanisms are not well understood. This study investigated the association between schizotypal traits and satisfaction with life and explored the mediating role of trait anxiety and mind wandering in the relationship between those two variables in a sample of Chinese young adults. One hundred and two individuals with high schizotypal traits and 104 individuals with low schizotypal traits were screened using the Schizotypal Personality Questionnaire. They completed a series of questionnaires including the Satisfaction with Life Scale, Trait Anxiety Inventory, and Mind Wandering Questionnaire. Results showed that: First, the high schizotypal trait group showed lower satisfaction with life, and higher trait anxiety and mind wandering frequency than the low schizotypal trait group. Second, the high schizotypal trait group, trait anxiety, and mind wandering negatively predicted satisfaction with life. Third, mediation analyses showed that all indirect effect paths in the mediation model were significant, that is, trait anxiety and mind wandering alone and together mediated the relationship between schizotypal trait group and satisfaction with life. In conclusion, high schizotypal trait is a risk factor for low satisfaction with life. The association between schizotypal traits and satisfaction with life was mediated by the combination of trait anxiety and mind wandering. This study has implications for improving life satisfaction in individuals with high schizotypal traits.

Dissociation of Proactive and Reactive Cognitive Control in Individuals with Schizotypy: An Event-Related Potential Study.

OBJECTIVE: Patients with schizophrenia and individuals with schizotypy, a subclinical group at risk for schizophrenia, have been found to have impairments in cognitive control. The Dual Mechanisms of Cognitive Control (DMC) framework hypothesises that cognitive control can be divided into proactive and reactive control. However, it is unclear whether individuals with schizotypy have differential behavioural impairments and neural correlates underlying these two types of cognitive control. METHOD: Twenty-five individuals with schizotypy and 26 matched healthy controls (HCs) completed both reactive and proactive control tasks with electroencephalographic data recorded. The proportion of congruent and incongruent trials was manipulated in a classic colour-word Stroop task to induce proactive or reactive control. Proactive control was induced in a context with mostly incongruent (MI) trials and reactive control in a context with mostly congruent (MC) trials. Two event-related potential (ERP) components, medial frontal negativity (MFN, associated with conflict detection) and conflict sustained potential (conflict SP, associated with conflict resolution) were examined. RESULTS: There was no significant difference between the two groups in terms of behavioural results. In terms of ERP results, in the MC context, HC exhibited significantly larger MFN (360-530 ms) and conflict SP (600-1000 ms) amplitudes than individuals with schizotypy. The two groups did not show any significant difference in MFN or conflict SP in the MI context. CONCLUSIONS: The present findings provide initial evidence for dissociation of neural activation between proactive and reactive cognitive control in individuals with schizotypy. These findings help us understand cognitive control deficits in the schizophrenia spectrum.

Applying network analysis to investigate the links between dimensional schizotypy and cognitive and affective empathy.

BACKGROUND: Although impairment in empathy has been reported in schizophrenia spectrum disorders, little is known about the relationship between empathy and schizotypal traits. This study examines this relationship by applying network analysis to a large sample collected at 18-months follow-up in a longitudinal dataset. METHODS: One thousand four hundred and eighty-six college students were recruited and completed a set of self-reported questionnaires on empathy, schizotypy, depression, anxiety and stress. Networks were constructed by taking the subscale scores of these measures as nodes and partial correlations between each pair of nodes as edges. Network Comparison Tests were performed to investigate the differences between individuals with high and low schizotypy. RESULTS: Cognitive and affective empathy were strongly connected with negative schizotypy in the network. Physical and social anhedonia showed high centrality measured by strength, closeness and betweenness while anxiety and stress showed high expected influence. Predictability ranged from 22.4% (personal distress) to 79.9% (anxiety) with an average of 54.4%. Compared with the low schizotypy group, the high schizotypy group showed higher global strength (S = 0.813, p < 0.05) and significant differences in network structure (M = 0.531, p < 0.001) and strength of edges connecting empathy with schizotypy (adjusted ps < 0.05). LIMITATIONS: Only self-rating scales were used, and disorganized schizotypy was not included. CONCLUSIONS: Our findings suggest that the cognitive and affective components of empathy and dimensions of schizotypy are closely related in the general population and their network interactions may play an important role in individuals with high schizotypy.