Theory Of Mind Deficits In Schizophrenia Research Articles

Increased Functional Connectivity Involving the Parahippocampal Gyrus in Patients with Schizophrenia during Theory of Mind Processing: A Psychophysiological Interaction Study

Theory of Mind (ToM) is an ability to infer the mental state of others, which plays an important role during social events. Previous studies have shown that ToM deficits exist frequently in schizophrenia, which may result from abnormal activity in brain regions related to sociality. However, the interactions between brain regions during ToM processing in schizophrenia are still unclear. Therefore, in this study, we investigated functional connectivity during ToM processing in patients with schizophrenia, using functional magnetic resonance imaging (fMRI). A total of 36 patients with schizophrenia and 33 healthy controls were recruited to complete a ToM task from the Human Connectome Project (HCP) during fMRI scanning. Psychophysiological interaction (PPI) analysis was applied to explore functional connectivity. Patients with schizophrenia were less accurate than healthy controls in judging social stimuli from non-social stimuli (Z = 2.31, p = 0.021), and displayed increased activity in the right inferior frontal gyrus and increased functional connectivity between the bilateral middle temporal gyrus and the ipsilateral parahippocampal gyrus during ToM processing (AlphaSim corrected p < 0.05). Here, we showed that the brain regions related to sociality interact more with the parahippocampal gyrus in patients with schizophrenia during ToM processing, which may reflect a possible compensatory pathway of ToM deficits in schizophrenia. Our study provides a new idea for ToM deficits in schizophrenia, which could be helpful to better understand social cognition of schizophrenia.

White Matter Correlates of Theory of Mind in Patients With First-Episode Psychosis.

Deficits in theory of mind (ToM) are considered as a distinctive feature of schizophrenia. Functional magnetic resonance imaging (fMRI) studies have suggested that aberrant activity among the regions comprising the mentalizing network is related to observed ToM deficits. However, the white matter structures underlying the ToM functional network in schizophrenia remain unclear. To investigate the relationship between white matter integrity and ToM impairment, 35 patients with first-episode psychosis (FEP) and 29 matched healthy controls (HCs) underwent diffusion tensor imaging (DTI). Using tract-based spatial statistics (TBSS), fractional anisotropy (FA) values of the two regions of interest (ROI)–the cingulum and superior longitudinal fasciculus (SLF)–were acquired, and correlational analysis with ToM task scores was performed. Among the patients with FEP, ToM strange story scores were positively correlated with the FA values of the left cingulum and left SLF. There was no significant correlation between FA and ToM task scores in HCs. These results suggest that the left cingulum and SLF constitute a possible neural basis for ToM deficits in schizophrenia. Our study is the first to demonstrate the white matter connectivity underlying the mentalizing network, as well as its relation to ToM ability in patients with FEP.

Persons With Schizophrenia Misread Hemingway: A New Approach to Study Theory of Mind in Schizophrenia.

IntroductionTheory of Mind (ToM) is a key component of social cognition. Recently the Short Story Task (SST) was developed as a new measurement of ToM. SST uses a short story of Ernest Hemingway to assess ToM skills. SST proved to be a suitable tool, and sensitive to individual differences among healthy subjects. Our aim was to test SST to evaluate the ToM skills of persons with schizophrenia.Materials and MethodsSST was used to assess ToM skills. After reading the short story “The End of Something” a structured interview was done with 14 questions. Spontaneous mental state reasoning, explicit mental state inference and comprehension of nonmental aspects of the story were evaluated. 47 persons with schizophrenia in remission and 48 healthy controls were assessed and compared.ResultsPersons with schizophrenia performed significantly more poorly in the explicit mental state inference questions. Ceiling effect was not detectable in explicit ToM scores. Patients made less spontaneous mental state references as well, although the occurrence of spontaneous mental state terms was infrequent in both groups. Patients were also less accurate in answering comprehension questions, but the difference was not significant after Bonferroni correction.DiscussionOur results lined up with the original findings and we found SST to be a sensitive tool to explore the individual differences in ToM performance, not only among healthy subjects, but also among persons with schizophrenia especially in explicit mental state inferences without observing the ceiling effect. We found, however, SST to be less sensitive to measure spontaneous mental state reasoning and also the lack of the use of another ToM test to assess convergent validity of SST for indicating ToM deficits in schizophrenia stands as a limitation of current study.

Theory of mind in a first-episode psychosis population using the Hinting Task

Deficiencies in theory of mind (ToM) are common in psychosis and may largely explain impaired social functioning. Currently, it is unclear whether impairments in ToM are explained by the more general cognitive deficits related to psychosis or whether ToM is impaired in psychosis independently of other cognitive deficits. This study examined ToM using the Hinting Task in young adults (n = 66) with first-episode psychosis and matched controls (n = 62). The participants were administered a broad neuropsychological assessment. Participants with psychosis performed worse than controls on the Hinting Task. However, 75% of the variance between the groups was explained by general cognitive deficits, especially impaired processing speed and episodic memory. Hinting Task performance of the best functioning patient group did not differ from that of the control group. When the psychosis group was divided according to diagnosis, the Hinting Task difference between individuals with schizophrenia and controls remained significant even when general cognitive performance was controlled for, suggesting specific verbal ToM deficits in schizophrenia. In contrast, those with other psychotic disorders did not differ from controls. Our results suggest that ToM deficits can be seen in early phases of psychotic disorders, schizophrenia in particular, and are partly independent of other cognitive functions.

Cognitive Correlates of Different Mentalizing Abilities in Individuals with High and Low Trait Schizotypy: Findings from an Extreme-Group Design.

Mentalizing or Theory of Mind (ToM) deficits in schizophrenia have been studied to great extent, but studies involving samples of trait schizotypy yield ambiguous results. Executive functions like cognitive inhibition, cognitive flexibility, and agency are all prerequisites of mentalizing, and it is assumed that the impairment of these functions contributes to ToM deficits in schizophrenia. Whether these impairments influence the ToM performance of people with high trait schizotypy remains unclear. Although impaired self-agency has repeatedly been identified in people with schizotypy, its role in mentalizing is yet to be investigated. The main aim of this study was to explore whether deficits in cognitive and affective ToM can be found in high trait schizotypy, and to identify in what way these deficits are related to the positive and negative dimensions of schizotypy. The secondary aim was to examine whether these deficits correlate with executive functions. Based on the dimensional view of the schizophrenia spectrum, an extreme-group design was applied to non-clinical volunteers demonstrating high (N = 39) and low (N = 47) trait schizotypy. Affective and cognitive ToM were investigated using the Movie for Assessment of Social Cognition, a sensitive and video-based measurement. Cognitive inhibition was assessed using the Stroop Test, and cognitive flexibility was analyzed using the Trail-Making Test. Agency was measured using a computerized self-agency paradigm. Participants in the high-schizotypy group performed significantly worse in the affective ToM task (d = 0.79), and their overall ToM performance was significantly impaired (d = 0.60). No between-group differences were found with regards to cognitive ToM, executive functions, and self-agency. Cognitive flexibility correlated negatively with positive schizotypy, and contributed to a worse overall and affective ToM. Impaired cognitive inhibition contributed to undermentalizing-type errors. It was found that non-clinical participants with high trait (positive) schizotypy – especially those with slight executive-function deficits – may have difficulties in understanding the emotional state of others and consequently in functioning in social situations.

Dissociation of understanding from applying others’ false beliefs in remitted schizophrenia: evidence from a computerized referential communication task

BackgroundIn research on theory of mind (ToM), false belief paradigms are commonly used. Previous studies have reported that there is heterogeneity in the magnitude of impairment on false belief tasks. Moreover, intact ability to attribute others’ false beliefs has been widely reported in patients with remitted schizophrenia. Increasingly, evidence suggests that there may be different cognitive mechanisms underlying the understanding others’ false beliefs versus applying one’s knowledge of others’ false beliefs. Since the role of psychotic symptoms in ToM impairments is an important issue in the study of ToM deficits in schizophrenia, we examined both remitted schizophrenia and non-remitted schizophrenia, with the aim to investigate whether psychotic symptoms in schizophrenia are associated with deficits in understanding others’ mental states or difficulties in applying this understanding.MethodsThe present study investigated 29 patients with non-remitted schizophrenia, 19 patients with remitted schizophrenia, and 22 healthy controls with a revised computerized referential communication task. The ability to understand others’ false beliefs and the ability to apply others’ false beliefs were measured separately.ResultsPatients with non-remitted schizophrenia performed significantly worse than patients with remitted schizophrenia and healthy controls on a task of understanding others’ false beliefs, whereas no significant difference was found between the patients with remitted schizophrenia and healthy controls. Both the patients with non-remitted schizophrenia and patients with remitted schizophrenia performed significantly worse than healthy controls on a task of applying others’ false beliefs.ConclusionsOur findings suggested a dissociation of understanding others’ false beliefs from applying others’ false beliefs in remitted schizophrenia. We preliminarily conclude that deficits in the ToM ability of applying knowledge of others’ mental states might be state-dependent.

Mentalizing impairment in schizophrenia: A functional MRI study

BackgroundA deficit in Theory of mind (ToM) or ‘mentalizing’ has been purported to underlie the poor social functioning seen in patients with schizophrenia. To understand the neural basis of this deficit studies have primarily used tasks requiring ‘off-line’ or explicit mentalizing but, in daily life, successful social interactions depend upon implicit or ‘on-line’ mentalizing. Therefore in the present study we used functional neuroimaging and a task that elicits ‘on-line’ mentalizing to investigate the neural basis of ToM deficits in schizophrenia. MethodsFunctional MRI images were acquired from 20 male patients with established schizophrenia and 19 age and gender matched healthy controls while they watched animated sequences involving two triangles. In the control condition the two triangles moved at random whereas in the experimental condition they moved interactively with implied intentions. The identification of ToM networks and differential responses between groups, within this network, was investigated using a random effects model. To account for differences in educational status between the groups this was included as a covariate in the between group analysis. Correlation analysis was performed to examine the relationship between neural activity change during mentalizing and the clinical and functional outcomes of patients. ResultsPatients with schizophrenia had significantly diminished activity in the right superior temporal gyrus (STG) at the temporoparietal junction (TPJ) and bilaterally within the inferior frontal gyri (IFG). Interestingly, frontal neural activity showed significant correlation with functional outcomes in patients with schizophrenia. ConclusionsFindings from this novel study suggest that the ToM deficit in male schizophrenia patients may reflect impairment in the automatic or implicit processing of mentalizing. If replicated, this is an important finding that provides additional insight into the neural basis of impairments in social functioning that are experienced by patients with schizophrenia.

Theory of mind deficits for processing counterfactual information in persons with chronic schizophrenia

Interpersonal communication problems are common among persons with schizophrenia and may be linked, in part, to deficits in theory of mind (ToM), the ability to accurately perceive the attitudes, beliefs and intentions of others. Particular difficulties might be expected in the processing of counterfactual information such as sarcasm or lies. The present study included 50 schizophrenia or schizo-affective out-patients and 44 demographically comparable healthy adults who were administered Part III of The Awareness of Social Inference Test (TASIT; a measure assessing comprehension of sarcasm versus lies) as well as measures of positive and negative symptoms and community functioning. TASIT data were analyzed using a 2 (group: patients versus healthy adults) x 2 (condition: sarcasm versus lie) repeated-measures ANOVA. The results show significant effects for group, condition, and the group x condition interaction. Compared to controls, patients performed significantly worse on sarcasm but not lie scenes. Within-group contrasts showed that patients performed significantly worse on sarcasm versus lie scenes; controls performed comparably on both. In patients, performance on TASIT showed a significant correlation with positive, but not negative, symptoms. The group and interaction effects remained significant when rerun with a subset of patients with low-level positive symptoms. The findings for a relationship between TASIT performance and community functioning were essentially negative. The findings replicate a prior demonstration of difficulty in the comprehension of sarcasm using a different test, but are not consistent with previous studies showing global ToM deficits in schizophrenia.

Theory of mind deficits in chronic schizophrenia: Evidence for state dependence

There is evidence that people with schizophrenia show specific deficits in theory of mind (ToM). However, it is a matter of debate whether these are trait or state dependent, and the nature of the relationship between ToM deficits and particular symptoms is controversial. This study aimed to shed further light on these issues by (1) examining ToM abilities in 61 individuals with chronic schizophrenia during a stable phase as compared with 51 healthy controls matched by gender, age, educational level and current IQ, and (2) exploring the relationship between ToM and symptoms. Second order verbal stories and a non-verbal picture-sequencing task were used as ToM measures. Results showed no differences in ToM performance between patients and controls on either measure. Subsequent subgrouping of patients into remitted and non-remitted showed a worse performance of non-remitted patients only on second order ToM tasks. Specific ToM deficits were found associated with delusions. Association with negative symptoms was found to be less specific and accounted for by illness chronicity and general cognitive impairment. The results from the present study are in line with models which hypothesise that specific ToM deficits in schizophrenia are state dependent and associated with delusions. Such associations may also be task specific.

Self-face recognition and theory of mind in patients with schizophrenia and first-degree relatives

Objective The hypothesized relationship between theory of mind (ToM) and self-face recognition as well as its potential genetic associations has not been previously explored in patients with schizophrenia and in first-degree relatives with schizotypal personality traits. Method Ten patients diagnosed with schizophrenia, 10 of their first-degree relatives and 10 healthy controls were included. To assess self-face recognition (SFR), participants were presented images of faces of themselves and others and asked to make rapid ‘unfamiliar’, ‘familiar’ and ‘self’ judgments. As a measure of ToM, subjects were administered the Revised Mind in the Eyes Test (MET [Baron-Cohen, S., Wheelwright, S., Hill, J., Raste, Y., and Plumb, I., 2001. The “Reading the Mind in the Eyes” Test revised version: a study with normal adults, and adults with Asperger syndrome or high-functioning autism. J Child Psychol Psychiatry 42(2), 241–251.]). Schizotypal characteristics in relatives and controls were assessed using a modified version of the Schizotypal Personality Questionnaire (SPQ [Raine, A., 1991. The SPQ: a scale for the assessment of schizotypal personality based on DSM-III-R criteria. Schizophrenia Bulletin 17(4), 555–564.]). Results Patients took longer and were less accurate on the SFR task than their relatives who in turn performed worse than healthy controls. Specific ToM deficits in schizophrenia were replicated. There was a relationship between accuracy rates on the MET and SFR tasks. High levels of schizotypal traits such as social anxiety, constricted affect and no close friends were important for both tasks. Conclusions Face recognition deficits and ToM deficits in schizophrenia are apparent. The critical influence of high levels of select schizotypal traits is also highlighted. A deficit in relatives of schizophrenia patients raises the possibility that ToM and face recognition deficits may be candidate endophenotypes for schizophrenia. Support for the hypothesized link between ToM and face recognition is provided.

Theory of mind and perceptual context‐processing in schizophrenia

Introduction. A series of studies have suggested that schizophrenia patients are deficient in theory of mind (ToM). However, the cognitive mechanisms underlying ToM deficits in schizophrenia are largely unknown. The present study examined the hypothesis that impaired ToM in schizophrenia can be understood as a deficit in context processing. Methods. Disorganised schizophrenia patients (N = 12), nondisorganised schizophrenia patients (N = 36), and nonpsychotic psychiatric patients (N = 26) were tested on three ToM tasks and a visual size perception task, a measure of perceptual context processing. In addition, statistical analyses were carried out which compared chronic, treatment‐refractory schizophrenia patients (N = 28) to those with an episodic course of illness (N = 20). Results. Overall, ToM performance was linked to deficits in context processing in schizophrenia patients. Statistical comparisons showed that disorganised as well as chronic schizophrenia patients were more impaired in ToM but more accurate in a visual size perception task where perceptual context is misleading. Conclusions. This pattern of results is interpreted as indicating a possible link between deficits in ToM and perceptual context processing, which together with deficits in perceptual grouping, are part of a broader dysfunction in cognitive coordination in schizophrenia.