Comparison of trait and state mind wandering among schizotypal, subclinically depressed, and control individuals.

BACKGROUND: Mind wandering is a common phenomenon in daily life. However, the manifestations and cognitive correlates of mind wandering in different subclinical populations remain unclear. In this study, these aspects were examined in individuals with schizotypal traits and individuals with depressive symptoms, i.e., subclinical populations of patients with schizophrenia and depression. METHODS: Forty-two individuals with schizotypal traits, 42 individuals with subclinical depression, and 42 controls were recruited to complete a mind wandering thought sampling task (state level) and a mind wandering questionnaire (trait level). Measures of rumination and cognitive functions (attention, inhibition, and working memory) were also completed by participants. RESULTS: Both subclinical groups exhibited more state and trait mind wandering than did the control group. Furthermore, individuals with schizotypal traits demonstrated more trait mind wandering than individuals with subclinical depression. Rumination, sustained attention, and working memory were associated with mind wandering. In addition, mind wandering in individuals with subclinical depression can be accounted for by rumination or attention, while mind wandering in individuals with high schizotypal traits cannot be accounted for by rumination, attention, or working memory. CONCLUSIONS: The results suggest that individuals with high schizotypal traits and subclinical depression have different patterns of mind wandering and mechanisms. These findings have implications for understanding the unique profile of mind wandering in subclinical individuals.

The Future-oriented Repetitive Thought (FoRT) scale: Validation in Chinese samples and application in the schizophrenia spectrum.

BACKGROUND: Repetitive thoughts are usually associated with psychopathology. The Future-oriented Repetitive Thought (FoRT) Scale is a measure designed to capture frequency of repetitive thought about positive and negative future events. However, the validity of the scale in Chinese population and its application in the schizophrenia spectrum have not been examined. METHODS: The current study aimed to examine the psychometric properties of the Chinese version of the FoRT scale and to apply it to the schizophrenia spectrum. In Study 1, three samples (total N = 1875) of university students were recruited for exploratory factor analysis, confirmatory factor analysis, and validity test, respectively. In Study 2, we identified subsamples with high schizotypal traits (N = 89) and low schizotypal traits (N = 89), and recruited 36 inpatients with schizophrenia and 41 matched healthy controls. RESULTS: The three-factor (pessimistic repetitive future thinking, repetitive thinking about future goals, and positive indulging about the future) structure of the FoRT scale with one item deleted, fitted the Chinese samples. And the scale could distinguish patients with schizophrenia and individuals with high schizotypal traits from controls. CONCLUSION: These findings support that the Chinese version of the FoRT scale is a valid tool and provide evidence for the potential applications in the schizophrenia spectrum.

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.

Preparation facilitates response inhibition based on a stop-signal task.

This study demonstrated that the higher stop-signal probability condition showed a longer go reaction time and shorter stop-signal reaction time (SSRT) compared with the lower stop-signal probability condition. In addition, preparation cost was correlated with SSRT. These results suggest that preparation facilitates response inhibition.

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.

Neural correlates of schizotypal traits: Findings from connectome-based predictive modelling.

Schizotypal traits can be conceptualized as a phenotype for schizophrenia spectrum disorders. As such, a better understanding of schizotypal traits could potentially improve early identification and treatment of schizophrenia. We used connectome-based predictive modelling (CPM) based on whole-brain resting-state functional connectivity to predict schizotypal traits in 82 healthy participants. Results showed that only the negative network could reliably predict an individual's schizotypal traits (r = 0.29). The 10 nodes with the highest edges in the negative network were those known to play a key role in sensation and perception, cognitive control as well as motor control. Our findings suggest that CPM might be a promising approach to improve early identification and prevention of schizophrenia from a spectrum perspective.

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.

A Meta-analysis of Mental Time Travel in Individuals with Autism Spectrum Disorders.

Autism spectrum disorders (ASD) are associated with cognitive dysfunctions, including mental time travel (MTT). However, findings on diminished MTT ability may be confounded by a number of factors, including the individuals' language ability, factors related to the MTT task and the demographic factors of participants. The present study provided a meta-analysis of MTT ability in people with ASD. The results showed significant overall reductions in MTT ability in people with ASD. Moderator analyses revealed that the variables examined did not explain the reduction in MTT ability. These findings suggest that MTT ability is diminished in people with ASD and that the degree of this diminishment may not depend on the characteristics of measures or demographic variables of people with ASD.

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.

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.

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.

Functional Coupling between the Fronto-Parietal Network and Default Mode Network Is Associated with Balanced Time Perspective.

Balanced time perspective refers to the ability to flexibly switch between different temporal foci in an adaptive manner according to the current context. Functional connectivity within the default mode network (DMN) has been suggested to support balanced time perspective. The coupling between the DMN and fronto-parietal network (FPN) may drive many important expressions of internally directed cognition. However, it remains unclear whether balanced time perspective is supported by the interaction between the FPN and DMN. To examine these issues, we recruited 91 participants (52 males with mean age of 19.6, and 39 females with mean age of 20.0) to undergo resting-state brain imaging scan and to complete a questionnaire measuring balanced time perspective. Seed-based voxel-wise functional connectivity analyses implicated midline DMN regions including the anterior medial prefrontal cortex (amPFC) and posterior cingulate cortex (PCC) along with the anterior cingulate cortex (ACC), precuneus, and cerebellum in supporting a balanced time perspective. More importantly, functional connectivity between the right amPFC and right dorsal lateral prefrontal cortex (DLPFC) in the FPN was found to associate with balanced time perspective. Our findings suggest the importance of coordinated brain activity in supporting a balanced time perspective.

The neural substrates of sex differences in balanced time perspective: A unique role for the precuneus.

Sex differences in various aspects of behaviour and cognition have been widely observed. Few studies, however, have explored potential sex differences in maintaining a balanced time perspective or their underlying neural correlates. To address these questions, two studies were conducted. In Study 1, time perspective was assessed in 1913 college students (796 males and 1117 females), revealing that females had a significantly more balanced time perspective relative to males. In Study 2, 58 males and 47 females underwent an assessment of time perspective and structural brain imaging. Voxel-based morphometry analysis and cortical thickness analysis were conducted to explore associations between the structural imaging data and balanced time perspective. Compared with males, females demonstrated a more balanced time perspective in the context of lower grey matter volume in the bilateral precuneus, right cerebellum, right putamen and left supplementary motor area. Analysis of cortical thickness failed to reveal any significant sex differences. Furthermore, lower grey matter volume of bilateral precuneus was associated with more balanced time perspective among all participants. Our findings point to a critical role for the precuneus in modulating a balanced time perspective, and extend our understanding of sex differences in human cognition. Future studies are required to determine whether sex differences in balanced time perspective are predictive of functional outcomes in daily life.

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.

A meta-analysis of the effects of episodic future thinking on delay discounting.

Delay discounting (DD) refers to the phenomenon in which the subjective value of future rewards is reduced over time. There are individual differences in the DD rate, and increased discounting has been observed in those with various psychiatric disorders. Episodic future thinking (EFT) is the act of vividly imagining events that may happen in the future. Studies have shown that EFT could reduce DD, although inconsistent results have been reported. The aim of this meta-analysis was to clarify the efficacy with which EFT reduces DD and to identify potential moderators. Forty-seven studies (including 63 contrasts) were included in the final analysis. EFT was found to significantly reduce DD (Hedges' g = 0.52). Moderator analysis showed that positive EFT (g = 0.64) was more effective in reducing DD than EFT with the valence not specifically mentioned (g = 0.28) and EFT with neutral or negative valence (g = -0.03). In addition, several factors related to the control task and DD task were related to the efficacy of EFT to reduce DD. These findings have implications for using EFT to reduce DD in the future.

An ERP study on proactive and reactive response inhibition in individuals with schizotypy.

Schizotypy, a subclinical group at risk for schizophrenia, has been found to show impairments in response inhibition. However, it remains unclear whether this impairment is accompanied by outright stopping (reactive inhibition) or preparation for stopping (proactive inhibition). We recruited 20 schizotypy and 24 non-schizotypy individuals to perform a modified stop-signal task with electroencephalographic (EEG) data recorded. This task consists of three conditions based on the probability of stop signal: 0% (no stop trials, only go trials), 17% (17% stop trials), and 33% (33% stop trials), the conditions were indicated by the colour of go stimuli. For proactive inhibition (go trials), individuals with schizotypy exhibited significantly lesser increase in go response time (RT) as the stop signal probability increasing compared to non-schizotypy individuals. Individuals with schizotypy also exhibited significantly increased N1 amplitude on all levels of stop signal probability and increased P3 amplitude in the 17% stop condition compared with non-schizotypy individuals. For reactive inhibition (stop trials), individuals with schizotypy exhibited significantly longer stop signal reaction time (SSRT) in both 17% and 33% stop conditions and smaller N2 amplitude on stop trials in the 17% stop condition than non-schizotypy individuals. These findings suggest that individuals with schizotypy were impaired in both proactive and reactive response inhibition at behavioural and neural levels.

Horizontal but not vertical saccades enhance memory retrieval: A meta-analysis and systematic review.

Saccade-induced retrieval enhancement (SIRE) refers to the phenomenon that actively engaging in horizontal eye movements before recall enhances subsequent memory performance. This effect is thought to be the result of interhemispheric interactions stimulated by saccades. An alternative explanation is that saccades promote memory retrieval by improving top-down attention control. Thus, the mechanisms of SIRE are unclear, and the present meta-analysis quantitatively analysed the effect of saccades on memory performance and examined the mechanisms of SIRE. We searched "Web of Science," "PubMed," and "Springer" for peer-reviewed papers using the keywords "eye movements + memory" and "saccades + memory." Twenty-two papers were included in the final analysis. There was a significant facilitation of horizontal saccades on overall memory performance, with a pooled effect size (Cohen's d) of 0.45 (p < .001). However, the overall effect of vertical saccades was not significant (d = 0.1, p = .14). Moderation analysis showed that the handedness of participants was a significant moderator of SIRE, with strongly right-handed individuals benefitting more from horizontal saccades than non-strongly right-handed individuals (p < .01). Horizontal saccades improved memory performance, particularly for strongly right-handed individuals. These results support the interhemispheric interaction hypothesis.

Schizophrenia patients with poor clinical insight report less subjective memory problems.

This study aimed to explore the relationships among clinical insight, subjective memory complaints, and objective memory performance in patients with schizophrenia. We recruited 205 patients with schizophrenia and 221 healthy controls in this study. The participants were administered a subjective-report scale on memory (the Prospective and Retrospective Memory Questionnaire), and several objective memory tasks measuring verbal memory, visual memory, and working memory. Clinical insight was measured with an item in the Positive and Negative Syndrome Scale. We found that when patients with schizophrenia were divided into subgroups with good and poor insight, both subgroups showed impairment in memory performance compared with controls. The schizophrenia patients with good insight reported similar memory complaints as controls whereas patients with poor insight reported less memory complaints than did the controls. These findings suggest that clinical insight may be related to subjective memory complaints, but not objective memory performance.