Cognitive Neuropsychiatry[JOURNAL]
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200 papers
FDG-PET in Cotard syndrome before and after treatment: can functional brain imaging support a two-factor hypothesis of nihilistic delusions?
Restrepo-Martínez M, Espinola-Nadurille M, Bayliss L … +4 more , Díaz-Meneses I, Kerik NE, Mendez MF, Ramírez-Bermúdez J
Cogn Neuropsychiatry · 2019 Nov · PMID 31597522 · Publisher ↗
Cotard syndrome is a neuropsychiatric entity recognised by the presence of nihilistic delusions. Although different models have been proposed for the development of monothematic delusions, including Cotard syndrome, func...
Cotard syndrome is a neuropsychiatric entity recognised by the presence of nihilistic delusions. Although different models have been proposed for the development of monothematic delusions, including Cotard syndrome, functional neuroanatomical models are lacking. A case report of a 19-year old male with autoimmune encephalitis and Cotard syndrome, in whom Positron Emission Tomography (F-FDG-PET) scans were performed before and after successful treatment with electroconvulsive therapy (ECT), is presented. Literature review on brain imaging is provided to discuss a functional neuroanatomical model of Cotard syndrome, in accordance with the two-factor theory of delusions. The patient's F-FDG-PET showed marked insular and prefrontal metabolic abnormalities. Except for insular hypometabolism, metabolic abnormalities improved after ECT. Previously reported structural neuroimaging studies in Cotard syndrome showed a predominance of right hemisphere lesions, in which frontal lobes were more frequently involved, followed by parietal and temporal lesions. Functional neuroimaging studies reported abnormalities in frontoparietal circuits as well as midline structures included in the "default mode network". Abnormalities in the functioning of the insular cortex and the prefrontal cortex could be related to the development of nihilistic delusions when a two-factor theory of delusions is considered.
The remediation effects of working memory training in schizophrenia patients with prominent negative symptoms.
Li X, Chu MY, Lv QY … +9 more , Hu HX, Li Z, Yi ZH, Wang JH, Zhang JY, Lui SSY, Cheung EFC, Shum DHK, Chan RCK
Cogn Neuropsychiatry · 2019 Nov · PMID 31583951 · Publisher ↗
Negative symptoms, particularly amotivation and anhedonia, are important predictors of poor functional outcome in patients with schizophrenia. There has been interest in the efficacy and mechanism of non-pharmacological...
Negative symptoms, particularly amotivation and anhedonia, are important predictors of poor functional outcome in patients with schizophrenia. There has been interest in the efficacy and mechanism of non-pharmacological interventions to alleviate these symptoms. The present study aimed to examine the remediation effect of working memory (WM) training in patients with schizophrenia with prominent negative symptoms. Thirty-one schizophrenia patients with prominent negative symptoms were recruited and assigned to either a WM training group or a treatment-as-usual (TAU) control group. The WM training group underwent 20 sessions of training using the dual n-back task over one month. A functional neuroimaging paradigm of the Affective Incentive Delay (AID) task was administered before and after the training intervention to evaluate the remediation effect of the intervention. Our results showed that the WM training group demonstrated significant improvement in the WM training task and inattention symptoms. Compared with the TAU group, increased brain activations were observed at the right insula and the right frontal sub-gyral after WM training in the training group. These findings support the efficacy of WM training in ameliorating hedonic dysfunction in schizophrenia patients with prominent negative symptoms.
Theory of mind in schizophrenia and bipolar disorder: psychometric properties of the Norwegian version of the Hinting Task.
Frøyhaug M, Andersson S, Andreassen OA … +2 more , Ueland T, Vaskinn A
Cogn Neuropsychiatry · 2019 Nov · PMID 31578118 · Publisher ↗
The quality of measures used to assess theory of mind (ToM) in severe mental illness has not been sufficiently investigated. This study evaluated the psychometric properties of the Norwegian version of the Hinting Task i...
The quality of measures used to assess theory of mind (ToM) in severe mental illness has not been sufficiently investigated. This study evaluated the psychometric properties of the Norwegian version of the Hinting Task in schizophrenia, bipolar I and II disorder and healthy controls. The study included 90 patients and 183 healthy controls. Internal consistency, ceiling effects, discriminatory power and concurrent and construct validity were investigated. The Hinting Task displayed adequate levels of internal consistency for schizophrenia and bipolar I disorder. Ceiling effects emerged in all groups except the schizophrenia group. Schizophrenia patients scored significantly lower than all other groups, but no other significant group differences were detected. In the schizophrenia group, the Hinting Task's concurrent validity was substantiated by significant correlations with measures of neurocognition, symptoms and functional capacity. In the bipolar disorder groups, however, only a few significant relationships were found. Correlations between the Hinting Task and a measure of emotion recognition indicated that construct validity was higher for schizophrenia than bipolar disorder. The results suggest that the Norwegian Hinting Task is suited for use in schizophrenia research and assessment, but caution is warranted when using the test for other populations.
Reframing PTSD for computational psychiatry with the active inference framework.
Linson A, Friston K
Cogn Neuropsychiatry · 2019 Sep · PMID 31564212 · Full text
Recent advances in research on stress and, respectively, on disorders of perception, learning, and behaviour speak to a promising synthesis of current insights from (i) neurobiology, cognitive neuroscience and psychology...
Recent advances in research on stress and, respectively, on disorders of perception, learning, and behaviour speak to a promising synthesis of current insights from (i) neurobiology, cognitive neuroscience and psychology of stress and post-traumatic stress disorder (PTSD), and (ii) computational psychiatry approaches to pathophysiology (e.g. of schizophrenia and autism). Specifically, we apply this synthesis to PTSD. The framework of active inference offers an embodied and embedded lens through which to understand neuronal mechanisms, structures, and processes of cognitive function and dysfunction. In turn, this offers an explanatory model of how healthy mental functioning can go awry due to psychopathological conditions that impair inference about our environment and our bodies. In this context, auditory phenomena-known to be especially relevant to studies of PTSD and schizophrenia-and traditional models of auditory function can be viewed from an evolutionary perspective based on active inference. We assess and contextualise a range of evidence on audition, stress, psychosis, and PTSD, and bring some existing partial models of PTSD into multilevel alignment. The novel perspective on PTSD we present aims to serve as a basis for new experimental designs and therapeutic interventions that integrate fundamentally biological, cognitive, behavioural, and environmental factors.
Testing whether cognitive reserve as measured by self-rating of stimulating activities moderates the association of polysubstance use and neurocognitive disorder.
Toledo-Fernández A, Marín-Navarrete R, Villalobos-Gallegos L … +3 more , Salvador-Cruz J, Benjet C, Roncero C
Cogn Neuropsychiatry · 2019 Nov · PMID 31554497 · Publisher ↗
The objectives were to identify a latent factor of cognitive reserve (CR) assessed by self-rating of cognitively stimulating activities, to analyze the association between this factor and educational attainment, and to t...
The objectives were to identify a latent factor of cognitive reserve (CR) assessed by self-rating of cognitively stimulating activities, to analyze the association between this factor and educational attainment, and to test whether CR moderates the association between polysubstance use and neurocognitive disorder (NCD). Cross-sectional data of 753 participants was collected in Mexico City. A questionnaire for self-rating of stimulating activities (work/education, leisure, physical, social, usual- and current environments) was designed. Confirmatory factor analysis was performed to test unifactoriality. This CR factor was then used within a structural equation model of moderation between recent- and years of substance use and indicators of NCD (Montreal Cognitive Assessment and an interview for subjective cognitive deficits). We found acceptable goodness-of-fit values for the unifactorial model, but no association of this factor with educational attainment, nor with recent- and years of substance use (suggesting independence of CR and severity of neuropathology). We did not find a moderation effect of CR between substance use and indicators of NCD; CR was negatively associated with subjective cognitive deficits only. Moderation effect of self-rated CR should be further tested using direct measures of substance-induced neuropathology. Measurement of self-rated CR may complement self-reported cognitive examination.
Language in schizophrenia and aphasia: the relationship with non-verbal cognition and thought disorder.
Little B, Gallagher P, Zimmerer V … +9 more , Varley R, Douglas M, Spencer H, Çokal D, Deamer F, Turkington D, Ferrier IN, Hinzen W, Watson S
Cogn Neuropsychiatry · 2019 Nov · PMID 31550981 · Publisher ↗
To determine the relationship between language abnormalities and broader cognitive impairment and thought disorder by examining language and cognition in schizophrenia and aphasia (a primary language disorder). Cognitive...
To determine the relationship between language abnormalities and broader cognitive impairment and thought disorder by examining language and cognition in schizophrenia and aphasia (a primary language disorder). Cognitive and linguistic profiles were measured with a battery of standardised tests, and compared in a clinical population of = 50 ( = 30 with schizophrenia and = 20 with aphasia) and = 61 non-clinical comparisons ( = 45 healthy controls and = 16 non-affected first-degree relatives of patients with schizophrenia). Both clinical groups showed linguistic deficits. Verbal impairment was more severe in participants with aphasia, whereas non-verbal performance was more affected in participants with schizophrenia. In schizophrenia, but not in aphasia, verbal and non-verbal performance were associated. Formal thought disorder was associated with impairment in executive function and in grammatical, but not naming, tasks. While patients with schizophrenia and aphasia showed language impairments, the nature and cognitive basis of these impairments may be different; language performance disassociates from broader cognitive functioning in aphasia but may be an intrinsic expression of a broader cognitive impairment in schizophrenia. Thought disorder may represent a core malfunction of grammatical processing. Results suggests that communicative ability may be a valid target in cognitive remediation strategies in schizophrenia.
Affective and cognitive factors associated with hallucination proneness in the general population: the role of shame and trauma-related intrusions.
Bortolon C, Raffard S
Cogn Neuropsychiatry · 2019 Nov · PMID 31549568 · Publisher ↗
Feelings of shame may be an important factor implicated in the onset and maintenance of hallucination (or hearing voices). Shame has been shown to increase trauma-related intrusions and avoidance and may reinforce negati...
Feelings of shame may be an important factor implicated in the onset and maintenance of hallucination (or hearing voices). Shame has been shown to increase trauma-related intrusions and avoidance and may reinforce negative beliefs about the self, which in turn may contribute to hallucinations in clinical and non-clinical populations. To our knowledge, no study has so far explored the role of shame in hallucination-proneness. Therefore, the main goal of the present study is to explore the mediation role of shame, trauma-related intrusions and avoidance in the association between childhood trauma and hallucination-proneness. Self-report questionnaires were used to assess past traumatic experiences, trauma-related symptoms, shame, and hallucination proneness in 175 participants from the general population. Mediation analyses (joint-significance test and Monte Carlo test) showed that both shame and intrusions mediated the association between childhood trauma and hallucination-proneness. Our results reinforce the importance of considering previous experiences of trauma and trauma-related symptoms, including feelings of shame in individuals experiencing hallucinations. Moreover, this study reinforces previous studies showing some preliminary evidence that compassion-focused therapy, whose primary goal is to reduce shame by increasing self-compassion, could have a significant effect on voices whose content is hostile.
Thinking about other's mistakes: contrasting patterns of performance in groups high or low in autistic or psychopathic traits.
Jameel L, Vyas K, Bellesi G … +2 more , Crawford S, Channon S
Cogn Neuropsychiatry · 2019 Sep · PMID 31522604 · Publisher ↗
Counterfactual thinking refers to thoughts such as, "What if … ?" or "If only … " that hypothesise about how past events might have turned out differently. It is a functional process, allowing us to reflect upon and solv...
Counterfactual thinking refers to thoughts such as, "What if … ?" or "If only … " that hypothesise about how past events might have turned out differently. It is a functional process, allowing us to reflect upon and solve problems, and to evoke appropriate responses. It is thought to involve both cognitive and emotional processes, and is linked to the development of false belief and moral emotions. The present study compared responses to a novel task, "Counterfactual Judgments", in students who scored high or low on self-report measures of autistic or psychopathic traits, two conditions putatively associated with deficits in empathy. Contrasting patterns of performance were revealed: those with high versus low autistic traits gave harsher ratings of blame for others' mistakes and showed reduced sensitivity to punitive counterfactual alternatives, whereas those with high versus low psychopathic traits gave lower ratings for moral judgments of regret and guilt. A self-report questionnaire measure of empathy also provided some evidence of reduced empathic processing in both the high trait groups. The findings are considered in the light of the possible contributions of cognitive versus emotional processes to counterfactual thinking. The possible implications for managing social dysfunction in clinical populations are also discussed.
Explaining delusional beliefs: a hybrid model.
Miyazono K, McKay R
Cogn Neuropsychiatry · 2019 Sep · PMID 31502494 · Publisher ↗
In this paper we present and defend a hybrid theory of the development of delusions that incorporates the central ideas of two influential (yet sometimes bitterly opposing) theoretical approaches to delusions-the two-fac...
In this paper we present and defend a hybrid theory of the development of delusions that incorporates the central ideas of two influential (yet sometimes bitterly opposing) theoretical approaches to delusions-the two-factor theory and the prediction error theory. After introducing the central ideas of the two-factor theory and the prediction error theory, we describe the motivations for our conciliatory project, explain the theoretical details of the hybrid theory we propose, and answer potential objections to our proposal. According to the hybrid theory we advance, the first factor of a delusion is physically grounded in an abnormal prediction error, and the second factor is physically grounded in the overestimation of the precision of the abnormal prediction error. Against anticipated objections, we argue that the hybrid theory is internally coherent, and that it constitutes a genuine hybrid between the two-factor theory and the prediction error theory. A rapprochement between the two-factor theory and the prediction error theory is both possible and desirable. In particular, our hybrid theory provides a parsimonious and unified account of delusions, whether monothematic or polythematic, across a wide variety of medical conditions.
Searchlight classification based on Amplitude of Low Frequency Fluctuation and functional connectivity in individuals with obsessive-compulsive symptoms.
Wang YM, Cai XL, Zhang RT … +6 more , Wang Y, Madsen KH, Sørensen TA, Møller A, Cheung EFC, Chan RCK
Cogn Neuropsychiatry · 2019 Sep · PMID 31451062 · Publisher ↗
INTRODUCTION: Investigating obsessive-compulsive symptoms in subclinical populations provides a useful framework for understanding the early development of obsessive-compulsive spectrum disorders. The present study aimed...
INTRODUCTION: Investigating obsessive-compulsive symptoms in subclinical populations provides a useful framework for understanding the early development of obsessive-compulsive spectrum disorders. The present study aimed to apply searchlight classification analysis on resting-state functional magnetic resonance imaging data to identify potential brain markers in subclinical individuals with obsessive-compulsive symptoms. METHODS: In this observational study, 40 college students with high obsessive-compulsive symptom scores and 40 with low obsessive-compulsive symptom scores were recruited from universities in China. We conducted searchlight classification and comparison analysis between the two groups based on Amplitude of Low Frequency Fluctuation (ALFF), fraction ALFF (fALFF) and resting-state functional connectivity using searchlight classification. RESULTS: We found that the highest accuracy rate in differentiating between the two groups was 85.00%. Significant discriminating features included the ALFF of the left medial superior frontal gyrus and the functional connectivity between the right thalamus and the bilateral medial superior frontal gyrus, and the right putamen, as well as the functional connectivity between the left caudate and the right insula. CONCLUSIONS: These findings highlight the specific and distinguishing brain functional abnormalities associated with obsessive-compulsive symptoms.
Metacognition in functional cognitive disorder- a potential mechanism and treatment target.
Bhome R, McWilliams A, Huntley JD … +2 more , Fleming SM, Howard RJ
Cogn Neuropsychiatry · 2019 Sep · PMID 31389291 · Publisher ↗
Functional Cognitive Disorder (FCD) is common. Despite this, there is no evidence-based consensus on how to treat FCD. Poor metacognitive ability has been suggested as a key mechanism underlying the disorder. This paper...
Functional Cognitive Disorder (FCD) is common. Despite this, there is no evidence-based consensus on how to treat FCD. Poor metacognitive ability has been suggested as a key mechanism underlying the disorder. This paper evaluates the proposal that strategies which improve metacognition could provide a mechanistically plausible translational therapy. We reviewed the existing literature relating to metacognition in FCD, previous strategies to improve metacognitive ability in FCD and whether metacognitive performance can be modulated. Though limited, there is evidence to suggest that metacognition is impaired in FCD. Converging evidence from neuroimaging studies suggests that metacognitive performance can be modulated. The effectiveness of existing strategies to improve metacognition including cognitive training, psychoeducation and lifestyle interventions have been equivocal. Recently, a potential treatment option has emerged in the form of a computer-based metacognitive training paradigm. There is an urgent need for effective treatments in FCD. Impaired metacognition may be a plausible therapeutic target but, in the first instance, further research is required to demonstrate deficits in "local" metacognitive ability in FCD patients when measured objectively. If so, clinical trials of interventions, such as computerised metacognitive training, are required to evaluate their effectiveness in improving FCD symptoms.
Continuing commentary: challenges or misunderstandings? A defence of the two-factor theory against the challenges to its logic.
Nie C
Cogn Neuropsychiatry · 2019 Jul · PMID 31378169 · Publisher ↗
Corlett, P. R. (2019. Factor one, familiarity and frontal cortex: A challenge to the two-factor theory of delusions. , (3), 165-177. doi: 10.1080/13546805.2019.1606706 ) raises two groups of challenges against the two-fa...
Corlett, P. R. (2019. Factor one, familiarity and frontal cortex: A challenge to the two-factor theory of delusions. , (3), 165-177. doi: 10.1080/13546805.2019.1606706 ) raises two groups of challenges against the two-factor theory of delusions: One focuses on weighing "the evidence for … the two-factor theory"; the other aims to question "the logic of the two-factor theory" (ibid., p. 166). McKay, R. (2019. Measles, magic and misidentifications: A defence of the two-factor theory of delusions. , (3), 183-190. doi: 10.1080/13546805.2019.1607273 ) has robustly defended the two-factor theory against the first group. But the second group, which Corlett believes is in many aspects independent of the first group and Darby, R. R. (2019. A network-based response to the two-factor theory of delusion formation. , (3), 178-182. doi: 10.1080/13546805.2019.1606709 , p. 180) takes as "[t]he most important challenge to the two-factor theory raised by Dr. Corlett", has by large remained. Here I offer my two cents in response to the second group. More specifically, I argue that Corlett's challenges to the logic of the two-factor theory, concerning modularity, double dissociation and cognitive penetration, seem to be based on some misunderstandings of the two-factor theory.
Does uncertainty breed conviction? On the possible role of compensatory conviction in jumping to conclusions and overconfidence in psychosis.
Moritz S, Stojisavlevic M, Göritz AS … +2 more , Riehle M, Scheunemann J
Cogn Neuropsychiatry · 2019 Jul · PMID 31311460 · Publisher ↗
Jumping to conclusions (JTC) and overconfidence in errors are well established in individuals with a liability to psychosis. Experimental research suggests that subjecting individuals to dilemmas and doubt prompts a subs...
Jumping to conclusions (JTC) and overconfidence in errors are well established in individuals with a liability to psychosis. Experimental research suggests that subjecting individuals to dilemmas and doubt prompts a subsequent hardening of attitudes and may foster delusion-like convictions. For the present study, we examined whether this compensatory conviction process is exaggerated in individuals with a liability to psychosis and might in part explain JTC and overconfidence. A large sample of participants from the general population were screened for psychotic experiences with the Community Assessment of Psychic Experiences scale (CAPE) and then randomly allocated to either a condition in which they should experience doubt or a control condition. Participants (final sample, = 650) were then tested on JTC and overconfidence. Participants who scored high on the positive subscale of the CAPE made fewer draws to decision, showed greater confidence, and made more errors relative to low scorers. Yet, none of the parameters was modulated by experimental condition. Our results at present do not support the idea that JTC is elevated by a prior experience of a dilemma or doubt. Yet, this possibility should not be entirely dismissed as the presumed process may take time to evolve and perhaps needs to be more pervasive.
A look into hallucinations: the relationship between visual imagery and hallucinations in Alzheimer's disease.
El Haj M, Badcock JC, Jardri R … +4 more , Larøi F, Roche J, Sommer IE, Gallouj K
Cogn Neuropsychiatry · 2019 Jul · PMID 31213139 · Publisher ↗
We investigated the relationship between visual hallucinations and vividness of visual imagery in patients with Alzheimer's disease (AD). We recruited 28 patients with AD and 30 healthy control participants, matched for...
We investigated the relationship between visual hallucinations and vividness of visual imagery in patients with Alzheimer's disease (AD). We recruited 28 patients with AD and 30 healthy control participants, matched for age and education. We evaluated proneness towards hallucinations with the Launay-Slade Hallucinations Scale, which includes items assessing visual and auditory hallucinations. We also evaluated vividness of visual imagery with the Vividness of Visual Imagery Questionnaire on which participants had to imagine four images (i.e., imagining the face of a friend, the rising sun, a familiar shop-front, and a country scene) and report the vividness of the images they generated. Analysis demonstrated significant positive correlations between visual hallucinations and vividness of visual imagery in AD patients, however, no significant correlations were observed between auditory hallucinations and vividness of visual imagery in these participants. No significant correlations were observed between hallucinations and vividness of visual imagery in healthy control participants, probably due to the lack of hallucinations in these participants. These results demonstrate a selective relationship between the occurrence of visual (but not auditory) hallucinations and the ability to generate vivid visual images in AD.
Testing a model of auditory hallucinations: the role of negative emotions and cognitive resources.
Laloyaux J, De Keyser F, Pinchard A … +2 more , Della Libera C, Larøi F
Cogn Neuropsychiatry · 2019 Jul · PMID 31188062 · Publisher ↗
Models of auditory hallucinations (AH) state that AH arise through an interaction between negative emotions and limited available cognitive resources. However, this hypothesis has never been directly tested. A two-by-tw...
Models of auditory hallucinations (AH) state that AH arise through an interaction between negative emotions and limited available cognitive resources. However, this hypothesis has never been directly tested. A two-by-two factorial design was used to examine the effect of emotions (neutral VS negative) and available cognitive resources (high VS low) on the elicitation of false alarms in an auditory signal detection paradigm. One hundred and seventy four healthy participants were assigned to one of the four experimental conditions. While participants were listening to white noise, their emotional state was manipulated using affective pictures and the level of available cognitive resources was manipulated using a visual N-back task. Results revealed significant interaction effects between emotions and cognitive resources on the number of false alarms. In particular, participants with fewer available cognitive resources and at the same time who were in a negative emotional state, tended to hear significantly more false alarms. In addition, the degree of certitude was significantly correlated with a higher degree of hallucination proneness. Such results are in agreement with models of AH and they provide new data for the understanding of the emotional and cognitive mechanisms that underpin AH.
Self-voice perception and its relationship with hallucination predisposition.
Pinheiro AP, Farinha-Fernandes A, Roberto MS … +1 more , Kotz SA
Cogn Neuropsychiatry · 2019 Jul · PMID 31177920 · Publisher ↗
Auditory verbal hallucinations (AVH) are a core symptom of psychotic disorders such as schizophrenia but are also reported in 10-15% of the general population. Impairments in self-voice recognition are frequently reporte...
Auditory verbal hallucinations (AVH) are a core symptom of psychotic disorders such as schizophrenia but are also reported in 10-15% of the general population. Impairments in self-voice recognition are frequently reported in schizophrenia and associated with the severity of AVH, particularly when the self-voice has a negative quality. However, whether self-voice processing is also affected in nonclinical voice hearers remains to be specified. Thirty-five nonclinical participants varying in hallucination predisposition based on the Launay-Slade Hallucination Scale, listened to prerecorded words and vocalisations differing in identity (self/other) and emotional quality. In Experiment 1, participants indicated whether words were spoken in their own voice, another voice, or whether they were unsure (recognition task). They were also asked whether pairs of words/vocalisations were uttered by the same or by a different speaker (discrimination task). In Experiment 2, participants judged the emotional quality of the words/vocalisations. In Experiment 1, hallucination predisposition affected voice discrimination and recognition, irrespective of stimulus valence. Hallucination predisposition did not affect the evaluation of the emotional valence of words/vocalisations (Experiment 2). These findings suggest that nonclinical participants with high HP experience altered voice identity processing, whereas HP does not affect the perception of vocal emotion. Specific alterations in self-voice perception in clinical and nonclinical voice hearers may establish a core feature of the psychosis continuum.
The impact of social and sensory stress on cognitive biases and delusions in schizophrenia.
Urbańska D, Moritz S, Gawęda Ł
Cogn Neuropsychiatry · 2019 May · PMID 31043127 · Publisher ↗
INTRODUCTION: Stress aggravates delusional symptoms, but the exact underlying mechanisms are still not fully understood. One of the routes may be via exacerbation of information processing distortions frequently observed...
INTRODUCTION: Stress aggravates delusional symptoms, but the exact underlying mechanisms are still not fully understood. One of the routes may be via exacerbation of information processing distortions frequently observed in psychosis. The aim of the present study was thus to investigate the impact of social and sensory stress on specific cognitive processes along with different dimensions of delusional thinking. METHODS: Nineteen individuals affected by schizophrenia and 15 healthy controls were assessed under 3 experimental conditions (social stress, neutral, noise stress), with counter-balanced presentation of stress conditions across participants of both groups. Under each condition participants performed parallel versions of experimental tasks and had to report their level of paranoid thinking and subjective distress. RESULTS: Irrespective of condition, patients showed significant impairments in metacognitive accuracy compared with controls. When social stress was applied first, mentalising accuracy decreased significantly in the subsequent condition among patients only. Following exposure to either social or sensory stress, patients reported significantly higher conviction in their paranoid ideas in the subsequent condition. CONCLUSIONS: Only limited evidence was found for the negative impact of stress on cognitive processes in schizophrenia patients. However, this may not be true for those with more severe information processing abnormalities and/or delusions.
Factor one, familiarity and frontal cortex: a challenge to the two-factor theory of delusions.
Corlett PR
Cogn Neuropsychiatry · 2019 May · PMID 31010382 · Full text
INTRODUCTION: Two-factor theory suggests delusions require two neuropsychological impairments, one in perception (which furnishes content), and a second in belief evaluation (that augers formation and maintenance). Capgr...
INTRODUCTION: Two-factor theory suggests delusions require two neuropsychological impairments, one in perception (which furnishes content), and a second in belief evaluation (that augers formation and maintenance). Capgras delusion; the belief that one's loved one has been replaced by an imposter, then entails two independent processes; first a lack of skin conductance response to familiar faces so the loved one feels different. This has been demonstrated in four patients with damage to the ventromedial prefrontal cortex (vmPFC) but who do not have delusions. Thus two-factor theorists demand a second factor: a change in belief evaluation, which is associated with damage to the right dorsolateral prefrontal cortex (rDLPFC). METHODS: Literature review of foundational and related papers on the cognitive neuropsychology of delusions, perception and belief. RESULTS: The four vmPFC patients appear together in another publication, uncited by two-factor theorists, in which the full extent of their damage is documented. These four cases not only lack skin responses to familiar faces, but lack responses to salient psychological stimuli more generally, which challenges factor one. They also have damage outside vmPFC, including damage to rDLPFC, which challenges factor two. CONCLUSION: Two-factor theory is found lacking and should be reappraised.
Investigating the jumping to conclusion bias in bipolar disorder.
Can SS, Atagün Mİ, Korkmaz ŞA … +1 more , Soykan Ç
Cogn Neuropsychiatry · 2019 May · PMID 30987559 · Publisher ↗
INTRODUCTION: Hemsley and Garety described the "jumping to conclusions bias" in which patients with delusions may reach unreasonable results with insufficient information. In this study patients with bipolar disorder and...
INTRODUCTION: Hemsley and Garety described the "jumping to conclusions bias" in which patients with delusions may reach unreasonable results with insufficient information. In this study patients with bipolar disorder and healthy volunteers were compared in terms of jumping to conclusions bias using the beads in the jar task. METHODS: 37 patients with DSM-5 diagnosis of bipolar disorder and 30 healthy controls were tested with the Beads Task (BT), Tower of London Test (ToL) and Barrat Impulsiveness Scale (BIS). RESULTS: In the BT, the mean score of DtD (draws to decision) and JTC (jumping to conclusions) scores were not statistically different between the two groups. In the ToL test, the duration of the total execution and the total time were significantly longer in the bipolar group than the control group. BIS scores were significantly higher in the bipolar group. YMRS (Young Mania Rating Scale) scores were not correlated with BT. CONCLUSIONS: This study is the first clinical study to assess the jumping to conclusions bias in patients with bipolar disorder. No JTC bias was detected in bipolar disorder. Further studies may assess JTC in larger samples to determine the effects of clinical state changes, psychotic symptoms, medication and impulsivity.
A network-based response to the two-factor theory of delusion formation.
Darby RR
Cogn Neuropsychiatry · 2019 May · PMID 30987557 · Publisher ↗
In response to Dr. Corlett's paper regarding the two factor theory of delusional misidentifications, I discuss further evidence that VMPFC damaged patients do not have an isolated factor 1 defect. I then discuss more bro...
In response to Dr. Corlett's paper regarding the two factor theory of delusional misidentifications, I discuss further evidence that VMPFC damaged patients do not have an isolated factor 1 defect. I then discuss more broadly the limitations in the modular view of brain function that leads to the 2-factor theory. Finally, I propose a connectionist based interpretation of delusional misidentifications that better fits with the clinical data from patients with focal brain lesions showing how these lesion locations relate to complex brain networks.
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