Neural evidence for compromised mental imagery in individuals with chronic schizophrenia

A whole-brain neuromark resting-state fMRI analysis of first-episode and early psychosis: Evidence of aberrant cortical-subcortical-cerebellar functional circuitry

Psychosis (including symptoms of delusions, hallucinations, and disorganized conduct/speech) is a main feature of schizophrenia and is frequently present in other major psychiatric illnesses. Studies in individuals with first-episode (FEP) and early psychosis (EP) have the potential to interpret aberrant connectivity associated with psychosis during a period with minimal influence from medication and other confounds. The current study uses a data-driven whole-brain approach to examine patterns of aberrant functional network connectivity (FNC) in a multi-site dataset comprising resting-state functional magnetic resonance images (rs-fMRI) from 117 individuals with FEP or EP and 130 individuals without a psychiatric disorder, as controls. Accounting for age, sex, race, head motion, and multiple imaging sites, differences in FNC were identified between psychosis and control participants in cortical (namely the inferior frontal gyrus, superior medial frontal gyrus, postcentral gyrus, supplementary motor area, posterior cingulate cortex, and superior and middle temporal gyri), subcortical (the caudate, thalamus, subthalamus, and hippocampus), and cerebellar regions. The prominent pattern of reduced cerebellar connectivity in psychosis is especially noteworthy, as most studies focus on cortical and subcortical regions, neglecting the cerebellum. The dysconnectivity reported here may indicate disruptions in cortical-subcortical-cerebellar circuitry involved in rudimentary cognitive functions which may serve as reliable correlates of psychosis.

Mental rotation and schizotypal personality traits: A Bayesian approach

People diagnosed with schizophrenia exhibit mental rotation differences, suggesting that clinical levels of positive symptoms, such as psychotic hallucinations, are related to disruptions in their monitoring and manipulation of mental representations. According to the psychosis continuum, findings in people with a high level of schizotypal personality traits are expected to be qualitatively similar, but research concerning this topic is scarce. A spared mental imagery manipulation in this population only could suggest that this ability might be a possible protective factor, or that the emergence of clinical-level positive symptoms could be paired with disruptions in this capacity. To explore this issue, 205 undergraduate students (122 women) completed a novel mental rotation task identifying the stimulus that was a 90, 180, or 270° rotation of a black circle with colored portions and were assessed with the Schizotypal Personality Questionnaire. Men performed better in most conditions. No relationship was detected between schizotypal personality traits and accuracy in the task. These results do not support that mental imagery manipulation disruptions may be related to schizotypal personality traits in non-clinical populations. Thus, they might instead be associated with the onset of psychosis disorders as mental representation handling is hindered. However, additional research is required including the general population, as well as those with higher levels of psychotic symptoms and psychosis disorders. Future research could also focus on working memory processes related to mental representation manipulations of different sensory modalities such as auditory mental representations and their relationship with schizotypal personality traits and clinical populations.

Flights and Perchings of the BrainMind: A Temporospatial Approach to Psychotherapy

This article introduces a process-oriented approach for improving present moment conceptualization in psychotherapy that is in alignment with neuroscience: the Temporospatial movements of mind (TSMM) model. We elaborate on seven temporal movements that describe the moment-to-moment morphogenesis of emotional feelings and thoughts from inception to maturity. Temporal refers to the passage of time through which feelings and thoughts develop, and electromagnetic activity, that among other responsibilities, bind information across time. Spatial dynamics extend from an undifferentiated to three dimensional experiences of emotional and cognitive processes. Neurophysiologically, spatial refers to structures within the brain and their varying interactions with one another. This article culminates in the development of an atheoretical temporospatial grid that may help clinicians conceptualize where patients are in their cognitive and emotional development to further guide technique.

Viewer and object mental rotation in young adults with psychotic disorders

Schizophrenia patients have difficulty with processing visuo-spatial information, which may explain their deficits with considering other people's point-of-view. Processing visuo-spatial information operates on egocentric and allocentric frames of reference. Here, we tested the ability of individuals at different stages of psychotic disorders, specifically ultra-high-risk for psychosis individuals, as well as first-episode psychosis, and chronic schizophrenia patients, to perform a viewer mental rotation task and an object mental rotation task. The two tasks were differentiated only by the instruction given. Healthy individuals and patients with a diagnosis of anxiety/depressive mood disorder served as non-patient and patient controls, respectively. The results show that first-episode psychosis and chronic schizophrenia patients, but not ultra-high-risk individuals, had more errors and longer response times with both mental rotation tasks than the two control groups. In addition, chronic schizophrenia patients had additional difficulty with the object rotation task. The difference in performance between groups and tasks remained significant even after controlling for age, IQ, and antipsychotic medication dose. The results indicate that patients with psychotic disorders have a deficit of mental spatial imagery that include both egocentric and allocentric representations. This deficit may explain the difficulty of these patients with perspective-taking, and inferring other people's point of view, thoughts or intentions which is at the core of the pathogenesis of schizophrenia.

The effect of handedness on mental rotation of hands: a systematic review and meta-analysis

Body-specific mental rotation is thought to rely upon internal representations of motor actions. Handedness is a source of distinctly different motor experience that shapes the development of such internal representations. Yet, the influence of handedness upon hand mental rotation has never been systematically evaluated. Five databases were searched for studies evaluating hand left/right judgement tasks in adults. Two independent reviewers performed screening, data extraction, and critical appraisal. Eighty-seven datasets were included, with 72 datasets pooled; all had unclear/high risk of bias. Meta-analyses showed that right-handers were faster, but not more accurate, than left-handers at hand mental rotation. A unique effect of handedness was found on performance facilitation for images corresponding to the dominant hand. Meta-analyses showed that right-handers were quicker at identifying images of right hands than left hands-a dominance advantage not evident in left-handers. Differing hand representations (more lateralised hand dominance in right-handers) likely underpin these findings. Given potential differences between hand preference and motor performance, future research exploring their distinct contributions to mental rotation is warranted.

Cognitive mechanisms of episodic simulation in psychiatric populations

Episodic simulation is the construction of a mental representation of a specific autobiographical future event. Episodic simulation has increasingly been studied in psychiatric populations. Here we 1) review evidence indicating that episodic simulation is compromised in patients with depression, anxiety, schizophrenia, bipolar disorder, and PTSD; and 2) consider several potential cognitive mechanisms of episodic simulation in psychiatric populations: episodic retrieval, scene construction, mental imagery, components of the CaRFAX model (i.e., capture and rumination, functional avoidance, and executive functioning), and narrative style. We evaluate evidence regarding these mechanisms across psychiatric populations, and identify areas of future research. Understanding the factors that contribute to episodic simulation impairment in psychiatric populations may lead to targeted and effective treatment approaches.

Manipulation ability of internal representation in patients with euthymic bipolar I disorder and schizophrenia using a mental rotation task

BACKGROUND

A growing body of literature has suggested that effective emotion regulation is influenced by cognitive function. Maintenance and manipulation of internal representations occur in working memory (WM), and impairments of WM have been reported in patients with bipolar disorder.

METHODS

We examined the manipulation ability of internal representations in WM using mental rotation (MR) tasks, and compared the task performances of euthymic bipolar I disorder patients to those of schizophrenia patients and healthy controls. In this study, 20 euthymic bipolar I disorder patients, 20 schizophrenia patients, and 38 healthy controls were recruited. People and letter MR tasks were employed to evaluate the ability of WM manipulation.

RESULTS

Compared to healthy controls, euthymic bipolar I disorder patients showed substantially higher error rates of people MR task and slower responses in both people and letter MR tasks. Schizophrenia patients showed no difference in error rate and response time in MR tasks compared to healthy controls; however, they showed significantly slower responses in people MR task compared to controls. MR task performance was not different between euthymic bipolar and schizophrenia patients.

CONCLUSION

Our study results indicate that manipulation of internal representation, especially in the egocentric MR, is impaired in bipolar disorder even in the emotionally-stable state. We speculate that impaired imagery manipulation might be related to alterations in empathic ability, susceptibility of mental imagery, and emotion regulation strategies observed in bipolar disorder.