Source Monitoring Deficits Research Articles

Innovative strategies for managing hallucinations by exploring effects of tDCS on source monitoring abilities

This randomised, crossover, sham-controlled study explored the neural basis of source-monitoring, a crucial cognitive process implicated in schizophrenia. Left superior temporal gyrus (STG) and dorsolateral prefrontal cortex (DLPFC) were the key focus areas. Thirty participants without neurological or psychological disorders underwent offline sham and active tDCS sessions with specific electrode montage targeting the left STG and DLPFC. Source-monitoring tasks, reality monitoring (Hear-Imagine), internal source-monitoring (Say-Imagine), and external source monitoring (Virtual–Real) were administered. Paired t-test and estimation statistics was performed with Graphpad version 10.1.0. The Benjamini–Hochberg procedure was employed to control the false discovery rate in multiple hypothesis testing. A significant improvement in internal source monitoring tasks (p = 0.001, Cohen's d = 0.97) was observed, but reality monitoring tasks demonstrated moderate improvement (p = 0.02, Cohen's d = 0.44). The study provides insights into the neural mechanisms of source monitoring in healthy individuals and proposes tDCS as a therapeutic intervention, laying the foundation for future studies to refine tDCS protocols and develop individualized approaches to address source monitoring deficits in schizophrenia.

Unraveling the brain mechanisms of source monitoring with non-invasive brain stimulation: A systematic review

Background/ObjectiveSource monitoring refers to the ability to determine the source of memories and encompasses three subprocesses: internal source monitoring, reality monitoring, and external source monitoring. Neuroimaging studies provide valuable insights about neural correlates of source monitoring, but the causal relationship between brain and behavior is lacking. This study aimed to identify brain circuits involved in source monitoring by synthesizing the effects of brain stimulation on source monitoring as a function of the targeted brain regions or circuits. MethodWe conducted a systematic review of interventional studies that have examined the effects of brain stimulation on source monitoring across six databases. The principal outcome was the difference of source monitoring performance between active and control stimulation conditions. Results23 studies (920 healthy participants and 54 patients with schizophrenia) were included. Our findings revealed the involvement of i) the lateral prefrontal and temporoparietal cortices in internal source monitoring, ii) the medial prefrontal and temporoparietal cortices in reality monitoring, and iii) the precuneus and the left angular gyrus in external source monitoring. ConclusionsThese findings deepen our understanding of the brain mechanisms of source monitoring and highlight specific stimulation targets to alleviate source monitoring deficits.

Negative-emotion-induced reduction in speech-in-noise recognition is associated with source-monitoring deficits and psychiatric symptoms in mandarin-speaking patients with schizophrenia

BackgroundPatients with schizophrenia (SCH) have deficits in source monitoring (SM), speech-in-noise recognition (SR), and auditory prosody recognition. This study aimed to test the covariation between SM and SR alteration induced by negative prosodies and their association with psychiatric symptoms in SCH. MethodsFifty-four SCH patients and 59 healthy controls (HCs) underwent a speech SM task, an SR task, and the assessment of positive and negative syndrome scale (PANSS). We used the multivariate analyses of partial least squares (PLS) regression to explore the associations among SM (external/internal/new attribution error [AE] and response bias [RB]), SR alteration/release induced by four negative-emotion (sad, angry, fear, and disgust) prosodies of target speech, and psychiatric symptoms. ResultsIn SCH, but not HCs, a profile (linear combination) of SM (especially the external-source RB) was positively associated with a profile of SR reductions (induced especially by the angry prosody). Moreover, two SR reduction profiles (especially in the anger and sadness conditions) were related to two profiles of psychiatric symptoms (negative symptoms, lack of insight, and emotional disturbances). The two PLS components explained 50.4% of the total variances of the release-symptom association. ConclusionCompared to HCs, SCH is more likely to perceive the external-source speech as internal/new source speech. The SM-related SR reduction induced by the angry prosody was mainly associated with negative symptoms. These findings help understand the psychopathology of SCH and may provide a potential direction to improve negative symptoms via minimizing emotional SR reduction in schizophrenia.

Source monitoring deficits in inpatients with schizophrenia and bipolar disorder in acute disorder phase

Source monitoring deficits in inpatients with schizophrenia and bipolar disorder in acute disorder phase

Understanding source monitoring subtypes and their relation to psychosis: a systematic review and meta-analysis.

AimsSource monitoring (SM) is the metacognitive ability to determine the origin of one's experiences. SM is altered in primary psychiatric psychosis, although relationships between SM subtypes, other cognitive domains and symptoms are unclear. Our aims were to synthesize evidence comparing psychosis ‐with and without hallucinations‐ and healthy controls classifying SM subtypes by source discrimination (internal/external/reality monitoring) and stimulus modality (visual/auditory/imagined/performed).MethodsThis systematic review adopted Preferred Reporting Items for Systematic Reviews and Meta‐Analyses, Meta‐analyses Of Observational Studies in Epidemiology and Population, Intervention, Comparison and Outcomes guidelines. Core demographical and clinical parameters were extracted. Newcastle‐Ottawa Scale was used as quality check. SM differences between (i) psychosis patients versus healthy controls and (ii) patients with versus without hallucinations were investigated via random‐effect model meta‐analysis. The primary effect size measure was standardized mean difference (SMD) in each SM subtype performance (error or accuracy). Heterogeneity, publication biases and meta‐regressions were assessed.ResultsFive thousand two hundred and fifty‐six records were screened to finally include 44 studies (1566 patients, 1175 controls). Mean Newcastle‐Ottawa score was 7.41 out of 9. Few studies measured SM associations with cognition (n = 9) and symptoms (n = 19), with heterogeneous findings. SM performance across all measures was reduced in psychosis versus healthy controls (SMD = 0.458). Internal SM (SMD: errors = 0.513; accuracy = 0.733) and imagined stimuli (SMD: errors = 0.688; accuracy = 0.978) were specifically impaired. Patients with versus without hallucinations showed SM deficits only for externalizing (SMD = 0.410) and imagined/auditory (SMD = 0.498/0.277) errors.ConclusionThe proposed classifications highlight specific SM deficits for internal/imagined stimuli in psychosis, providing evidence‐based indications to design and interpret future studies.

Negative-Emotion-Induced Reduction in Speech-in-Noise Recognition is Associated with Source-Monitoring Deficits and Psychotic Symptoms in Schizophrenia

Negative-Emotion-Induced Reduction in Speech-in-Noise Recognition is Associated with Source-Monitoring Deficits and Psychotic Symptoms in Schizophrenia

Two Faces of a Coin? A Systematic Review of Source Monitoring and Its Relationship with Memory in Autism.

The ability to discriminate the origin of stimuli, known as source monitoring, is crucial for self–other distinction and the integration of internally generated and externally generated experiences. Despite its valence, evidence on source monitoring in autism is yet scarce and unclear. We systematically reviewed literature concerning source monitoring in autism and its relationship with other constructs, such as memory type, encoding effects, social cognition, general intelligence, and clinical factors. Source-monitoring performance (operationalized as error or accuracy) was reduced in autistic participants in 9 of the 15 studies that met the inclusion criteria. When explicitly investigated, free-recall memory impairments in autism were shown to influence source monitoring deficits. General intelligence was another important factor linked to source-monitoring performance. Conversely, other memory types or encoding effects were not impaired in autism, and no univocal association could be found with source monitoring. Social cognition and clinical symptoms were rarely assessed in spite of their possible involvement in source monitoring. The heterogeneity of the task design, outcome measures and demographical factors limited study comparability. As a research framework on source monitoring as a construct of primary interest in autism is still lacking, we propose preliminary indications for future investigations based on the collected findings.

Distinguishing schizophrenia spectrum from non-spectrum disorders among young patients with first episode psychosis and at high clinical risk: The role of basic self-disturbance and neurocognition

IntroductionThe distinction between the schizophrenia spectrum and other types of disorders may be clinically relevant in terms of its predictive validity as suggested by studies showing schizophrenia spectrum patients have more unfavourable outcomes compared to other psychotic disorders. The present study aimed to investigate whether basic self-disturbances and neurocognitive processes that have been linked to psychosis risk have discriminative power for schizophrenia spectrum disorders in patients presenting with first episode psychosis (FEP) and at ultra-high risk for psychosis (UHR). Methods38 FEP patients, 48 UHR patients, and 33 healthy controls were assessed for basic self-disturbances (using the Examination of Anomalous Self-Experience, EASE, interview), source monitoring and aberrant salience (behavioural tasks to measure neurocognitive constructs). Clinical groups were divided into patients with schizophrenia spectrum disorders and those with other non-spectrum disorders and were further compared on measures controlling for symptom severity and age. ResultsBasic self-disturbances distinguished schizophrenia spectrum from non-spectrum disorders in the ‘FEP only’ sample, F = 19.76, p < 0.001, η2partial = 0.37, and also in the combined UHR/FEP sample, F = 23.56, p < 0.001, η2partial = 0.22. Additionally, some processes related to source monitoring deficits were elevated in schizophrenia spectrum disorders. In contrast, the two groups (schizophrenia spectrum vs other diagnoses) performed similarly in aberrant salience tasks. Comparable results were obtained for analyses performed with an FEP/UHR combined sample and the ‘FEP only’ sample. DiscussionBasic self-disturbances at the phenomenological level and source monitoring deficits on the neurocognitive level may be useful in identifying risk of schizophrenia spectrum disorders at the earliest clinical presentation.

Review of source-monitoring processes in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a severe mental illness characterized by persistent, intrusive and distressing obsessions and/or compulsions. Such symptoms have been conceptualized as resulting from a failure in source-monitoring processes, suggesting that patients with OCD fail to distinguish actions they perform from those they just imagine doing. In this study, we aimed to provide an updated and exhaustive review of the literature examining the relationship between source-monitoring and OCD. A systematic search in the literature through January 2019 allowed us to identify 13 relevant publications investigating source-monitoring abilities in patients with OCD or participants with subclinical compulsive symptoms. Most of the retrieved studies did not report any source-monitoring deficits in clinical and subclinical subjects compared with healthy volunteers. However, most of the studies reported that patients with OCD and subclinical subjects displayed reduced confidence in source-monitoring judgments or global cognitive confidence compared to controls. The present review highlighted some methodological and statistical limitations. Consequently, further studies are needed to explore source monitoring with regard to the subcategories of OCD symptoms (i.e., symmetry-ordering, contamination-washing, hoarding, aggressive obsession-checking, sexual-religious thoughts) and to clarify the relationship between source-monitoring subtypes (i.e., reality or internal source-monitoring) and confidence in these populations.

Dissociable source-monitoring impairments in obsessive-compulsive disorder and schizophrenia.

Based on the observed clinical overlap between obsessive-compulsive disorder (OCD) and schizophrenia (SCZ), both conditions may share, at least in part, common cognitive underpinnings. Among the cognitive deficits that could be involved, it has been hypothesized that patients share a failure in their abilities to monitor their own thoughts (source monitoring), leading to confusion between what they actually did or perceived and what they imagined. Although little is known regarding source-monitoring performances in patients with OCD, numerous studies in patients with SCZ have observed a relationship between delusions and/or hallucinations and deficits in both internal source- and reality-monitoring abilities. The present work compared source-monitoring performances (internal source and reality monitoring) between patients with OCD (n = 32), patients with SCZ (n = 38), and healthy controls (HC; n = 29). We observed that patients with OCD and patients with SCZ displayed abnormal internal source-monitoring abilities compared to HC. Only patients with SCZ displayed abnormalities in reality monitoring compared to both patients with OCD and HC. Internal source-monitoring deficits are shared by patients with OCD and SCZ and may contribute to the shared cognitive deficits that lead to obsessions and delusions. In contrast, reality-monitoring performance seems to differentiate patients with OCD from patients with SCZ.

The neurophenomenology of early psychosis: An integrative empirical study.

The integration of various domains or levels of analysis (clinical, neurobiological, genetic, etc.) has been a challenge in schizophrenia research. A promising approach is to use the core phenomenological features of the disorder as an organising principle for other levels of analysis. Minimal self-disturbance (fragility in implicit first-person perspective, presence and agency) is emerging as a strong candidate to play this role. This approach was adopted in a previously described theoretical neurophenomenological model that proposed that source monitoring deficits and aberrant salience may be neurocognitive/neurobiological processes that correlate with minimal self-disturbance on the phenomenological level, together playing an aetiological role in the onset of schizophrenia spectrum disorders. The current paper presents full cross-sectional data from the first empirical test of this model. Fifty ultra-high risk for psychosis patients, 39 first episode psychosis patients and 34 healthy controls were assessed with a variety of clinical measures, including the Examination of Anomalous Self-Experience (EASE), and neurocognitive and neurophysiological (EEG) measures of source monitoring deficits and aberrant salience. Linear regression indicated that source monitoring (composite score across neurocognitive and neurophysiological measures), with study group as an interaction term, explained 39.8% of the variance in EASE scores (R2 = 0.41, F(3,85) = 14.78, p < 0.001), whereas aberrant salience (composite score) explained only 6% of the variance in EASE scores (R2 = 0.06, F(3,85) = 1.44, p = 0.93). Aberrant salience measures were more strongly related to general psychopathology measures, particularly to positive psychotic symptoms, than to EASE scores. A neurophenomenological model of minimal self-disturbance in schizophrenia spectrum disorders may need to be expanded from source monitoring deficits to encompass other relevant constructs such as temporal processing, intermodal/multisensory integration, and hierarchical predictive processing. The cross-sectional data reported here will be expanded with longitudinal analysis in subsequent reports. These data and other related recent research show an emerging picture of neuro-features of core phenomenological aspects of schizophrenia spectrum disorders beyond surface-level psychotic symptoms.

Are basic auditory processes involved in source-monitoring deficits in patients with schizophrenia?

Patients with schizophrenia (SZ) display deficits in both basic non-verbal auditory processing and source-monitoring of speech. To date, the contributions of basic auditory deficits to higher-order cognitive impairments, such as source-monitoring, and to clinical symptoms have yet to be elucidated. The aim of this study was to investigate the deficits and relationships between basic auditory functions, source-monitoring performances, and clinical symptom severity in SZ.Auditory processing of 4 psychoacoustic features (pitch, intensity, amplitude, length) and 2 types of source-monitoring (internal and reality monitoring) performances were assessed in 29 SZ and 29 healthy controls. Clinical symptoms were evaluated in patients with the Positive And Negative Syndrome Scale.Compared to the controls, SZ individuals in showed significant reductions in both global basic auditory processing (p < .0005, d = 1.16) and source-monitoring (p < .0005, d = 1.24) abilities. Both deficits correlated significantly in patients and across groups (all p < .05). Pitch processing skills were negatively correlated with positive symptom severity (r = −0.4, p < .05). A step-wise regression analysis showed that pitch discrimination was a significant predictor of source-monitoring performance.These results suggest that cognitive mechanisms associated with the discrimination of basic auditory features are most compromised in patients with source-monitoring disability. Basic auditory processing may index pathophysiological processes that are critical for optimal source-monitoring in schizophrenia and that are involved in positive symptoms.

Source monitoring task in a sample of in-patients with verbal auditory hallucinations compared to control sample.

Patients with psychosis, especially those with specific positive symptoms such as auditory verbal hallucinations, show a source monitoring deficit, the cognitive process involved in the recognition of the information source. This defect can lead to the erroneous conclusion that self-generated thoughts are not "proper" but derive from an external source. We evaluated 37 patients diagnosed with psychotic disorder and 40 healthy controls using a modified version of the Reality Monitoring Task developed by Larøi et al. in 2004. The patients were also evaluated with PANSS, VGF, PSP. We have found that the performance of the Source Monitoring Task differs between patients with hallucinations and controls. According to the literature we can therefore state that patients with hallucinations are characterized by a difficulty in identifying the source of the information they perceive. Our study also adds a new finding to the literature: the source monitoring dysfunction is not due to the presence of current hallucinatory symptomatology but could be considered a stable trait in psychotic patients.

T82. THE RELATIONSHIP BETWEEN SOURCE MONITORING DEFICITS AND NEUROPSYCHOLOGICAL FUNCTIONING IN SCHIZOPHRENIA

BackgroundSource monitoring (SM) is a metacognitive process involved in making judgments about the origin of memories, knowledge and beliefs. Many studies have demonstrated that people with schizophrenia perform more poorly on tasks of source monitoring when compared to non-schizophrenic. Although source of monitoring is considered as an important cognitive biases implicated in reality distortions/psychotic symptoms, the knowledge on its neurocognitive mechanisms is far from being conclusive. The main aim of our study was to investigate the relationship between SM and neuropsychological functioning in schizophrenia.MethodsA total of 84 (43 females; mean age 42.01, SD=11.55) patients diagnosed with schizophrenia were assessed with neuropsychological tests, including executive functions, verbal memory, working memory, processing speed and attention. SM was assessed with an action memory task. Simple actions were presented to the participant verbally (text) or non-verbally (icons). Some actions were physically performed and others were imagined. Following the learning phase, participants were presented with each action as well as new ones, were asked whether the action was presented verbally or non-verbally (action’s presentation type discrimination), and whether the action was performed or imagined (self-monitoring). A knowledge corruption for self-monitoring (proportion of high confident errors on all high confident responses) was also obtained. The symptoms severity was assessed with the PANSS. The relationship between SM biases and neuropsychological functioning was investigated with correlation analyses.ResultsThe correlations were found between incorrect action’s presentation type discrimination and the results of test such as CTT 1 (r=-0.22, p<0.05), D2 (r=-0.25, p<0.05) and Block Design (r= -0.40, p<0.01). Correlational analyses showed no relations between incorrect self-monitoring and neuropsychological functioning. Knowledge corruption for self-monitoring turned out to be correlated with WCST (r=0,22, p<0.05), CVLT (r= -0.26, p<0.05) and Backward Digit Span (r= -0.27, p<0.05). These correlations remain significant when controlled for positive symptoms severity. Incorrect self-monitoring showed a significant relation with the PANSS positive subscale (r=0.23, p<0.05). Knowledge corruption was related to PANSS disorganization subscale (r=0.25, p<0.05).DiscussionIn line with previous studies we found that deficits in self-monitoring are related to symptoms severity and not to neuropsychological functioning. On the other hand, deficits in action’s presentation discrimination are related exclusively to neuropsychological functioning. These results suggest that the relationship between SM and neuropsychological functioning depends on the type of SM deficits. The conclusions of the study may be of clinical importance - in light of our results it might be advisable to combine cognitive remediation techniques with those interventions that focus on cognitive biases like source monitoring deficits

Self-reported cognitive distortions in the psychosis continuum: A Polish 18-item version of the Davos Assessment of Cognitive Biases Scale (DACOBS-18)

AimThe aim of this study was to provide a short version of the Davos Assessment of Cognitive Biases Scale (DACOBS), which is a self-report tool to assess cognitive distortions related to psychosis. MethodsA principal component analysis (PCA) was conducted on a large non-clinical sample (n=1207) and cross-validated with a confirmatory factor analysis on an independent non-clinical sample (n=653). Discriminative validity was performed by contrasting the high risk for psychosis non-clinical sample (n=63), low risk for psychosis non-clinical sample (n=152), patients with schizophrenia (n=105), and patients with depression (n=56). Correlations between symptoms, cognitive functions, source monitoring deficits, and jumping to conclusions were performed among a subgroup of patients with schizophrenia. ResultsAn 18-item scale (DACOBS-18) with a four-factor solution was established. Internal consistency (α=0.84) and test-retest reliability (r=0.84, p<0.001) were good. The DACOBS-18 has satisfactory discriminative power, with 99.1% sensitivity and 74.3% specificity in discriminating low risk for psychosis from schizophrenia patients. The DACOBS-18 subscales correlate significantly with psychotic symptoms and psychotic-like experiences. After Bonferroni correction, significant correlations between Safety Behaviors and neuropsychological functioning were found. ConclusionsThe DACOBS-18 is a reliable scale with satisfactory discriminative power and thus may be a valuable self-report screening tool for use in everyday clinical practice with psychotic patients and with people at risk for psychosis. Further research on its relationship to objective cognitive measures is needed.

Towards integrating phenomenology and neurocognition: Possible neurocognitive correlates of basic self-disturbance in schizophrenia

AbstractPhenomenological research indicates that disturbance of the basic sense of self may be a core phenotypic marker of schizophrenia spectrum disorders. Basic self-disturbance refers to disruption of the sense of ownership of experience and agency of action and is associated with a variety of anomalous subjective experiences. Little is known about the neurocognitive correlates of basic self-disturbance. In this paper, we review recent phenomenological and neurocognitive research and point to a convergence of these approaches around the concept of self-disturbance. Specifically, we propose that subjective anomalies associated with basic self-disturbance may be associated with: 1. source monitoring deficits, which may contribute particularly to disturbances of “ownership” and “mineness” (the phenomenological notion ofpresence) and 2. aberrant salience, and associated disturbances of memory, prediction, and attention processes, which may contribute to hyper-reflexivity, disturbed “grip” or “hold” on the perceptual and conceptual field, and disturbances of intuitive social understanding (“common sense”). These two streams of research are reviewed in turn before considering ways forward in integrative models, particularly regarding the role of early neurodevelopmental disturbances, primary versus secondary disturbances, and the state versus trait nature of such pathology. Empirical studies are required in a variety of populations in order to test the proposed associations between phenomenological and neurocognitive aspects of self-disturbance in schizophrenia. An integration of findings across the phenomenological and neurocognitive domains would represent a significant advance in the understanding of schizophrenia and possibly enhance early identification and intervention strategies.

Deficits in reality and internal source monitoring of actions are associated with the positive dimension of schizotypy

People with schizophrenia have deficits in retrieving the source of memory information. Research has focused on two types of judgements: reality monitoring (discriminating internally-generated stimuli from external information) and internal source monitoring (distinguishing two different internal sources). The aim of the current study was to assess the relation between schizotypy and both types of source memory in healthy volunteers. One hundred and two participants completed two source memory tasks: one involved the completion of well-known word pairs (e.g. Fish and? ) and the other was an action based task (e.g. nod your head). At test participants needed to indicate whether the act had been performed or imagined by themselves, performed by the experimenter, or was new. The positive dimension of schizotypy was positively correlated with errors in internal source monitoring i.e. confusing participant performed and imagined acts. Furthermore, the same dimension of schizotypy was also positively associated with reality monitoring errors i.e. confusing participant performed/imagined with experimenter performed items. However, these relationships were not found in the word pair task. Our findings suggest that there might be overlap in the processes required to retrieve source information from memory, particularly for actions, and the occurrence of unusual experiences in healthy volunteers.

Age and active navigation effects on episodic memory: A virtual reality study.

We investigated the navigation-related age effects on learning, proactive interference semantic clustering, recognition hits, and false recognitions in a naturalistic situation using a virtual apartment-based task. We also examined the neuropsychological correlates (executive functioning [EF] and episodic memory) of navigation-related age effects on memory. Younger and older adults either actively navigated or passively followed the computer-guided tour of an apartment. The results indicated that active navigation increased recognition hits compared with passive navigation, but it did not influence other memory measures (learning, proactive interference, and semantic clustering) to a similar extent in either age group. Furthermore, active navigation helped to reduce false recognitions in younger adults but increased those made by older adults. This differential effect of active navigation for younger and older adults was accounted for by EF score. Like for the subject-performed task effects, the effects from the navigation manipulation were well accounted for by item-specific/relational processing distinction, and they were also consistent with a source monitoring deficit in older adults.

The Spectra of Soundless Voices and Audible Thoughts: Towards an Integrative Model of Auditory Verbal Hallucinations and Thought Insertion

Patients with psychotic disorders experience a range of reality distortions. These often include auditory-verbal hallucinations (AVHs), and thought insertion (TI) to a lesser degree; however, their mechanisms and relationships between each other remain largely elusive. Here we attempt to establish a integrative model drawing from the phenomenology of both AVHs and TI and argue that they in fact can be seen as ‘spectra’ of experiences with varying degrees of agency and ownership, with ‘silent and internal own thoughts’ on one extreme and ‘fully external and clearly audible voices’ in the absence of a speaker on the other. We believe a spectral model will add emphasis to the continuity of experience and help to better understand how one type of psychotic symptom may interact with another, and put forward the argument that the experience of TI itself is not sufficient to classify as a delusion. In addition we aim to discuss some of the conceptual issues surrounding AVHs and TI with first-person accounts and current philosophical and neuropsychological theories in mind. We propose that the mechanisms behind AVHs and TI are more complex than source-monitoring deficits; indeed, to understand such phenomena one must appreciate that their very ‘existence’ and ‘reality’ as experienced by the individual have much deeper implications and meaning, both philosophically and clinically.

Elevated striatal dopamine attenuates nigrothalamic inputs and impairs transthalamic cortico-cortical communication in schizophrenia: A hypothesis

Schizophrenia has been found to involve source-monitoring deficits, whereby perceptions that result from self-initiated motor output become attributed to outside sources. One example of this phenomenon are the so called passivity experiences, such as delusions of control, during which the individual feels that own actions are controlled remotely by someone else. To explain these phenomena, it has been proposed that this illness involves efference copy failure. In other words, brain mechanism that prepare perceptual processes for the sensory consequences of self-initiated actions are impaired leading to their misattribution and to psychosis. In earlier work, it was argued that efference copy failure in schizophrenia is related to thalamic abnormalities. Namely, the thalamus can be thought of as a hub for cortico-cortical interactions, and these transthalamic cortico-cortical interactions were found to play a part in internal motor monitoring. Cortico-cortical communication via the thalamus can be impaired in a number of ways. For example, one way to impair these interactions is by interfering with the ability of the thalamus to display bursts of firing. As the burst firing mode in the thalamus requires a preceding period of prolonged hyperpolarization (100ms), one way to reduce the burst propensity of thalamic neurons is to interfere with the ability to display prolonged hyperpolarizations. In this paper, we argue that elevated striatal dopaminergic activity in schizophrenia attenuates nigrothalamic GABAergic inputs, and thereby reduces burst propensity of the mediodorsal (MD) thalamic nucleus in schizophrenia, with the ultimate result of reduced transthalamic cortico-cortical communication, relative disconnection between functionally associated cortical areas and to psychosis. Conversely, dopamine D2 receptor blockers (antipsychotics) may help restore nigrothalamic GABAergic inputs, thereby increasing the burst propensity in the thalamus.