Mental State Decoding Research Articles

A meta-analytic review of theory of mind difficulties in behavioural-variant frontotemporal dementia

Theory of mind (ToM) refers broadly to our understanding of others' complex emotions and mental states. Deficits in ToM are widely regarded as one of the key defining features of the behavioural variant of frontotemporal dementia (bvFTD), which is unsurprising given the key role that frontal and temporal neural systems are considered to play in mental state decoding. Here we report the first meta-analysis of this literature, providing a timely summary of the breadth, magnitude and specificity of ToM difficulties in this population. Across 15 datasets involving 800 participants (312 with bvFTD and for comparative purposes, 325 non-clinical controls and 163 participants with Alzheimer's disease), several key results emerged. Collapsed across all types of task, people with bvFTD performed more poorly than non-clinical controls, with the degree of ToM difficulty they experienced large in magnitude (r=−.60). These deficits were greater than those observed on control tasks matched to the ToM task in their general cognitive demands, but which can be solved without any mentalistic inference. BvFTD-related ToM difficulties were also significantly larger than the ToM difficulties seen in people with Alzheimer's disease. However, ToM difficulties in people with bvFTD were of a similar magnitude to the difficulties seen on measures of more basic social cue perception (emotion recognition). These data have important implications for understanding the types of ToM difficulties associated with bvFTD.

The Influence of Dysphoria and Depression on Mental State Decoding

Prior research found conflicting results concerning the relationship between depression and mental state decoding ability as assessed by the ‘Eyes Test’ developed by Baron-Cohen and colleagues. In some studies the relationship is negative, suggesting that depressed persons are worse than controls in decoding mental states on the basis of information from the eye region of others' faces. Other research points to a positive relation between depression and mental state decoding. We report a study of mental state decoding ability in two samples of university students, one a group of students attending the university's counseling service, the other a group of normal college students. The results are consistent in showing a negative relation between depression and mental state decoding ability. Possible reasons for discrepancies in research results are discussed.

Social cognition in bipolar disorder versus schizophrenia: comparability in mental state decoding deficits

Neuropsychological studies comparing patients with bipolar disorder (BD) to patients with schizophrenia (SZ) suggest milder cognitive deficits in BD patients and across a smaller range of functions. The present study investigated whether this pattern is also true for social cognition - a range of socially relevant abilities, including emotion perception and recognition, theory of mind, and social attributions - by comparing performance on measures of social cognition in patients with BD, SZ, and healthy participants. One hundred and two patients with BD, 208 patients with SZ, and 132 healthy participants were assessed using a battery of tasks measuring basic neuropsychological and social cognition. We observed significant differences between patients with BD and healthy participants in a test of mental state decoding ('eyes task') that was at a level comparable to deficits seen in patients with SZ. By comparison, BD patients showed more subtle deficits in mental state reasoning ('hinting task') than those shown by patients with SZ. Mental state decoding difficulties are significant in BD. An important direction for further research will be to establish to what extent these deficits affect social and occupational functioning as a potential target for therapeutic intervention.

Mental state decoding and mental state reasoning in recently detoxified alcohol-dependent individuals

Impaired social cognition has been associated with interpersonal problems and with the development of and relapse into alcohol abuse. In the present study, self-reported trait empathy, decoding of complex mental states and cognitive and affective mental state reasoning were assessed in alcohol-dependent participants, and the association with executive function and psychopathological characteristics was investigated. Twenty recently detoxified alcohol-dependent patients and 20 matched healthy controls were assessed with an abbreviated German version of the Interpersonal Reactivity Index, the Revised Reading the Mind in the Eyes Test, the Faux Pas Story Test, the Trail Making Test and the Letter–Number-Sequencing Test. Patients were impaired relative to controls with regard to mental state decoding on the Eyes Test and showed reduced faux pas detection and impaired mental state reasoning reflected by lower faux pas understanding and faux pas empathy scores. There were no group differences regarding self-reported trait empathy. Performance on the sociocognitive measures was related to executive functioning and the severity of depressive symptoms. Although self-report measures might not always reliably detect impairments of social cognition, behavioural measures suggest pronounced impairments of mental state decoding and mental state reasoning in association with alcohol dependence. Findings ought to be incorporated into current treatment strategies.

Patients with bipolar disorder show impaired performance on complex tests of social cognition

The literature concerning social cognitive performance in people with bipolar disorder (BD) reveals a mixed pattern of findings. We compared performance between patients with BD and matched controls on two social cognitive tasks that involved: (i) the decoding of mental states from pictures of eyes (Reading the Mind in the Eyes Test), and (ii) a video-based test that requires participants to discriminate social cues to make interpersonal judgments (Interpersonal Perception Task-15; IPT-15). We also sought to evaluate the association between symptom severity, social functioning, and social cognitive ability in patients with BD. Relative to controls, patients with BD were impaired at discriminating mental states from pictures of eyes and in making complex social judgments. Impaired responding on the IPT-15 was also associated with reduced psychosocial functioning. These results provide evidence of impaired performance on complex tests of social cognition in patients with BD. Impairments in social cognition may be associated with well-documented declines in the frequency of social interactions and development of interpersonal relationships found in this patient population.

Electrophysiological difference between mental state decoding and mental state reasoning

Previous studies have explored the neural mechanism of Theory of Mind (ToM), but the neural correlates of its two components, mental state decoding and mental state reasoning, remain unclear. In the present study, participants were presented with various photographs, showing an actor looking at 1 of 2 objects, either with a happy or an unhappy expression. They were asked to either decode the emotion of the actor (mental state decoding task), predict which object would be chosen by the actor (mental state reasoning task), or judge at which object the actor was gazing (physical task), while scalp potentials were recorded. Results showed that (1) the reasoning task elicited an earlier N2 peak than the decoding task did over the prefrontal scalp sites; and (2) during the late positive component (240–440ms), the reasoning task elicited a more positive deflection than the other two tasks did at the prefrontal scalp sites. In addition, neither the decoding task nor the reasoning task has no left/right hemisphere difference. These findings imply that mental state reasoning differs from mental state decoding early (210ms) after stimulus onset, and that the prefrontal lobe is the neural basis of mental state reasoning.

Dynamic decoding of ongoing perception

Decoding of perceptual and mental states using multivariate analysis methods has received much recent attention. It relies on selective responses to experimental conditions in single trials, aggregated across voxels. In this study, we show that decoding is also possible when the state of interest changes continuously over time. It is shown that both orientation and rotation direction of a continuously rotating grating can be decoded with high accuracy using linear dynamical systems and hidden Markov models. These findings extend the decoding results for static gratings and are of importance in the decoding of ongoing changes in mental state.

Different aspects of theory of mind in paranoid schizophrenia: Evidence from a video-based assessment

In schizophrenia, impairments of theory of mind (ToM) may be due to excessive (‘overmentalizing’) or defective (‘undermentalizing’) attribution of mental states. However, most ToM tests differentiate neither between ‘overmentalizing’ and ‘undermentalizing’ nor between cognitive and affective ToM in schizophrenia. This study aimed at differentiating these aspects of ToM in 80 patients diagnosed with paranoid schizophrenia and 80 matched healthy controls using the ‘Movie for the Assessment of Social Cognition’ (MASC). Outcome parameters comprised 1) error counts representing ‘undermentalizing’ or ‘overmentalizing’, 2) decoding of cognitive or emotional mental states and 3) non-social inferencing. Multivariate analysis of covariance (MANCOVA) showed significantly abnormal scores for two dimensions of ‘undermentalizing’ as well as for cognitive and emotional ToM that were not explained by global cognitive deficits. Scores for ‘overmentalizing’ did not differ between groups, when age, gender, non-social reasoning and memory were controlled. In schizophrenic patients, negative symptoms were associated with a lack of a mental state concept, while positive symptoms like delusions were associated with ‘overmentalizing’, supporting respective etiological concepts of delusions.

Mental state decoding in past major depression: Effect of sad versus happy mood induction

Individuals with mild depression show an enhanced ability to read or “decode” others' mental states. The goal of the present study was to investigate whether this pattern of performance is related specifically to the pathology of depression or whether it is simply a feature of the transient dysphoric state. Forty-one undergraduates with a previous episode of major depression and 52 undergraduates with no depression history participated in a mental state decoding task following a sad versus happy mood induction. Previously depressed participants were significantly more accurate in their mental state judgements than were the never-depressed participants, suggesting that enhanced mental state decoding may be a specific feature of depression in remission. Furthermore, previously depressed participants whose positive mood increased in response to the happy mood induction showed a poorer level of performance on the task, similar to that observed in the never-depressed group. Thus, a happy mood may have induced a somewhat less accurate, but perhaps more adaptive, approach to processing social information. These findings were robust after controlling for current level of depression and anxiety symptoms, intensity of response to the mood induction, response times, and performance on a control task.

P02-258 - Theory of mind and borderline personality disorder : a pilot study

ObjectivesTo examine the theory of the mind (TOM) in BPD patients.MethodsFifteen BPD patients (age>18) meeting criteria for BPD were compared to 16 healthy matched controls on two measures of TOM: mental state decoding (MSD) and mental state reasoning (MSR). MSD is the ability to perceive social cues (faces expression, voices) while MSR is the ability to infer on mental states with experiment, learning, context. MSR was measured by the faux pas recognition task assessing the ability to identify a faux pas in a social situation (range 0-60) and a comic strips task measuring the ability to infer intention (range 0-28). MSD was assessed by a video task reporting the ability to infer false belief and intention of deceit on visual motor action. Depressive symptoms (Beck Depression Inventory) and axis II comorbidity traits (Personality Disorder Questionnaire-4+) were also assessed.ResultsMean (SD) age was 26.0 (4.1) and two participants were of male gender (6.5%). BPD patients scored significantly lower than controls on the both MSR measures: faux pas task mean (SD) scores of 46.6(14.1) vs 58.0(2.8) (p=0.002) and comic strips mean (SD) scores of 26.1(1.5) vs 27.4(1.3) (p=0.001). No significant differences were found on the video task. Multivariate analyses showed that faux pas score was predicted by BPD diagnosis independently from level of depressive symptoms, history of hypomanic episode, schizotypic and antisocial personality disorder traits (F=4.32, df=6, p< 0.01).ConclusionsBPD is associated with a TOM deficit on mental state reasoning tasks even after controlling for confounding variables.

Cross-cultural Reading the Mind in the Eyes: An fMRI Investigation

The ability to infer others' thoughts, intentions, and feelings is regarded as uniquely human. Over the last few decades, this remarkable ability has captivated the attention of philosophers, primatologists, clinical and developmental psychologists, anthropologists, social psychologists, and cognitive neuroscientists. Most would agree that the capacity to reason about others' mental states is innately prepared, essential for successful human social interaction. Whether this ability is culturally tuned, however, remains entirely uncharted on both the behavioral and neural levels. Here we provide the first behavioral and neural evidence for an intracultural advantage (better performance for same- vs. other-culture) in mental state decoding in a sample of native Japanese and white American participants. We examined the neural correlates of this intracultural advantage using fMRI, revealing greater bilateral posterior superior temporal sulci recruitment during same- versus other-culture mental state decoding in both cultural groups. These findings offer preliminary support for cultural consistency in the neurological architecture subserving high-level mental state reasoning, as well as its differential recruitment based on cultural group membership.

Theory of mind and verbal working memory deficits in parents of autistic children

The objective of this study was to investigate the potential values of executive function and social cognition deficits as endophenotypes of autism. While theory of mind (ToM) is generally accepted as a unitary concept, some have suggested that ToM may be separated into two components (mental state reasoning and decoding). In this study, both aspects of ToM and verbal working memory abilities were investigated with relatively demanding tasks. The authors used a neurocognitive battery to compare the executive function and social cognition skills of 76 parents of autistic probands with 41 parents of healthy children. Both groups were matched for IQ, age and gender. Index parents had verbal working memory deficits. They had also low performance on a mental state reasoning task. Index parents had difficulties in reasoning about others' emotions. In contrast to findings in the control group, low performance of mental state reasoning ability was not associated with working memory deficit in index parents. Social cognition and working memory impairments may represent potential endophenotypes, related to an underlying vulnerability for autistic spectrum disorders.

Mental state decoding v. mental state reasoning as a mediator between cognitive and social function in psychosis

Theory of mind deficits in schizophrenia have been parsed into mental state reasoning and mental state decoding components. We report that mental state decoding as measured by the ‘Eyes task’ better predicted social function than mental state reasoning as measured by the ‘Hinting task’ in 73 out-patients with chronic schizophrenia. Mental state decoding task performance also partly mediated the influence of basic neuropsychological performance on social function. We discuss these findings in terms of the accumulating evidence that mental state decoding has particular relevance for understanding deficits in social function in schizophrenia.

Abnormal spatiotemporal processing of emotional facial expressions in childhood autism: dipole source analysis of event‐related potentials

Previous studies of face processing in autism suggest abnormalities in anatomical development, functioning and connectivity/coordination of distributed brain systems involved in social cognition, but the spatial sequence and time course of rapid (sub-second) neural responses to emotional facial expressions have not been examined in detail. Source analysis of high-density event-related potentials (ERPs) is an optimal means to examine both the precise temporal profile and spatial location of early electrical brain activity in response to emotionally salient stimuli. Therefore, we recorded 128-channel ERPs from high-functioning males with autism (aged 6-10 years), and age-, sex- and IQ-matched typically developing controls during explicit and implicit processing of emotion from pictures showing happy, angry, fearful, sad and neutral facial expressions. Children with autism showed normal patterns of behavioural and ERP (P1, N170 and P2) responses. However, dipole source analysis revealed that ERP responses relating to face detection (visual cortex) and configural processing of faces (fusiform gyrus), as well as mental state decoding (medial prefrontal lobe), were significantly weaker and/or slower in autism compared with controls during both explicit and implicit emotion-processing tasks. Slower- and larger-amplitude ERP source activity in the parietal somatosensory cortices possibly reflected more effortful compensatory analytical strategies used by the autism group to process facial gender and emotion. Such aberrant neurophysiological processing of facial emotion observed in children with autism within the first 300 ms of stimulus presentation suggests abnormal cortical specialization within social brain networks, which would likely disrupt the development of normal social-cognitive skills.

Exploring the specificity of age-related differences in theory of mind tasks.

Tasks assessing theory of mind (ToM) and non-mental state control tasks were administered to young and older adults to examine previous contradictory findings about age differences in mental state decoding. Age differences were found on a verbal ToM task after controlling for vocabulary levels. Older adults achieved significantly lower scores than did younger adults on static and dynamic visual ToM tasks, and a similar pattern was found on non-ToM control tasks. Rather than a specific ToM deficit, older adults exhibited a more general impairment in the ability to decode cues from verbal and visual information about people.

A glimpse into your vision

Invasive recordings of local field potentials (LFPs) have been used to "read the mind" of monkeys in real time. Here we investigated whether noninvasive field potentials estimated from the scalp-recorded electroencephalogram (EEG) using the ELECTRA source localization algorithm could provide real-time decoding of mental states in healthy humans. By means of pattern recognition techniques on 500-ms EEG epochs, we were able to discriminate accurately from single trials which of four categories of visual stimuli the subjects were viewing. Our results show that it is possible to reproduce the decoding accuracy previously obtained in animals with invasive recordings. A comparison between the decoding results and the subjects' behavioral performance indicates that oscillatory activity (OA), elicited in specific brain regions) codes better for the visual stimulus category presented than the subjects' actual response, i.e., is insensitive to voluntary or involuntary errors. The identification of brain regions participating in the decoding process allowed us to construct 3D-functional images of the task-related OA. These images revealed the activation of brain regions known for their involvement in the processing of this type of visual stimuli. Electrical neuroimaging therefore appears to have the potential to establish what the brain is processing while the stimuli are being seen or categorized, i.e., concurrently with sensory-perceptual processes.

Social functioning, theory of mind and neurocognition in outpatients with schizophrenia; mental state decoding may be a better predictor of social functioning than mental state reasoning

Few studies have directly investigated the relationship between theory of mind (ToM) deficits and social functioning in schizophrenia. At the same time, the impact of mental state decoding tasks on social dysfunction has also not yet been investigated. In this study, the relationship between theory of mind deficits and social functioning was investigated among 50 patients with schizophrenia. A mental state decoding task known as ‘The Eyes test’ and a mental state reasoning task ‘The Hinting test’ were applied to assess ToM abilities, while the Social Functioning Scale (SFS) was used to assess social functioning. Non-ToM neurocognitive tests were also given to the patients. Results of the study show how theory of mind and working memory performances of patients with good functional outcome proved to be significantly better than those of inadequately functioning patients. Results also indicate that performance on the Eyes test was the best predictor of social functioning and that negative symptoms also contributed to poor social functioning. It is concluded in this study that mental state decoding skills appear to be the most important cognitive mediator of social functioning.

Mid-frontal EEG alpha asymmetries predict individual differences in one aspect of theory of mind: Mental state decoding

Mental state decoding is the aspect of theory-of-mind (ToM) reasoning that requires individuals to make judgments about others’ mental states based solely on immediately available information. We investigated whether individual differences in resting, task-independent frontal EEG alpha asymmetries predicted performance on the “Mind in the Eyes” (MIE) task, which is an established measure of mental state decoding skills. Group analyses showed that mental state decoding skills were stronger among those with right-lateralized frontal activation. Individual differences analyses showed that the degree of relative right mid-frontal activation predicted performance on the task. These findings establish a neural correlate of individual differences in one aspect of ToM, and hypotheses about the precise mechanism involved are discussed.

Enhanced accuracy of mental state decoding in dysphoric college students

A significant clinical feature of depression involves difficulties in social functioning. At the foundation of these difficulties may lie alterations in “theory of mind” reasoning—the ability to decode others' mental states. Participants included 124 undergraduates who participated in a theory of mind task that involved attributing emotion states (e.g., happy, embarrassed) to photographs of eyes. Across two studies, dysphoria was significantly positively associated with greater accuracy on this task, suggesting an increased sensitivity to the subtle social cues required to make theory of mind judgements. This association held regardless of the emotional valence of the judgement. Furthermore, this finding was robust after controlling for reaction time and level of anxiety. These findings are discussed in terms of their implications for developing a model of social cognition in depression.