Cognitive Neuropsychiatry最新文献

Objective: Abnormal visual processing has been proposed as a mechanism underlying excessive focus on minor appearance flaws in body dysmorphic disorder (BDD). Existing BDD research has not differentiated the various stages of face processing (featural, first-order configural, holistic and second-order configural) that are required for higher-order processes such as emotion recognition. This study investigated a hierarchical visual processing model to examine the nature of abnormalities in face processing in BDD.

Method: Thirty BDD participants and 27 healthy controls completed the Navon task, a featural and configural face processing task and a facial emotion labelling task.

Results: BDD participants performed similarly to controls when processing global and local non-face stimuli on the Navon task, when detecting subtle changes in the features and spacing of a target face, and when labelling emotional faces. However, BDD participants displayed poorer performance when viewing inverted faces, indicating difficulties in configural processing.

Conclusions: The findings only partially support prior work. However, synthesis of results with previous findings indicates that heterogenous task methodologies may contribute to inconsistent findings. Recommendations are provided regarding the task parameters that appear most sensitive to abnormalities in BDD.

Introduction: Vivid mental imagery has been proposed to increase the likelihood of experiencing hallucinations. Typically, studies have employed a modality general approach to mental imagery which compares imagery across multiple domains (e.g., visual, auditory and tactile) to hallucinations in multiple senses. However, modality specific imagery may be a better predictor of hallucinations in the same domain. The study examined the contribution of imagery to hallucinations in a non-clinical sample and specifically whether imagery best predicted hallucinations at a modality general or modality specific level.

Methods: In study one, modality general and modality specific accounts of the imagery-hallucination relationship were contrasted through application of self-report measures in a sample of 434 students. Study two used a subsample (n = 103) to extend exploration of the imagery-hallucinations relationship using a performance-based imagery task.

Results: A small to moderate modality general relationship was observed between self-report imagery and hallucination proneness. There was only evidence of a modality specific relationship in the tactile domain. Performance-based imagery measures were unrelated to hallucinations and self-report imagery.

Conclusions: Mental imagery may act as a modality general process increasing hallucination proneness. The observed distinction between self-report and performance-based imagery highlights the difficulty of accurately measuring internal processes.

Introduction: Hallucinations can be experienced across multiple sensory modalities, but psychiatric studies investigating the cognitive mechanisms of hallucinations have been somewhat restricted to the auditory domain. This study explored the cognitive profiles of individuals experiencing multisensory hallucinations (MH) in schizophrenia-spectrum disorders (SSD) and compared these to those experiencing unimodal auditory hallucinations (AH) or no hallucinations (NH).

Methods: Participants included SSD patients (n = 119) stratified by current hallucination status (NH, AH, MH) and nonclinical controls (NCs; n = 113). Group performance was compared across several cognitive domains: speed of processing, attention, working memory, verbal learning, visual learning, reasoning and problem-solving, social cognition, and inhibition.

Results: The clinical groups performed worse than NCs but differences between the clinical groups were not evident across most cognitive domains. Exploratory analyses revealed that the MH group was more impaired on the visual learning task compared to the NH (but not AH) group.

Conclusions: Preliminary results suggest that impaired visual learning may be related to MH. This could be attributed to the presence of visual hallucinations (VH), or greater psychopathology, in this group. However, replication is needed, as well as the investigation of other potential cognitive mechanisms of MH.

Introduction: Koro is a delusion whereby a man believes his penis is shrinking into his abdomen and this may result in his death. This socially-transmitted non-neuropsychological delusional belief occurs (in epidemic form) in South-East and South Asia. We investigated whether the two-factor theory of delusion could be applied to epidemic Koro.

Methods: We scrutinised the literature on epidemic Koro to isolate features relevant to the two questions that must be answered to provide a two-factor account: What could initially prompt the Koro delusional hypothesis? Why is this hypothesis adopted as a belief?

Results: We concluded that the Koro hypothesis is usually prompted by the surprising observation of actual penis shrinkage-but only if the man has access to background beliefs about Koro. Whether the hypothesis is then adopted as a belief will depend on individual factors such as prior belief in the Koro concept or limited formal education and sociocultural factors such as deference to culture, to media, or to rumours spread by word of mouth. Social transmission can influence how the first factor works and how the second factor works.

Conclusion: The two-factor theory of delusion can be applied to a socially-transmitted delusion that occurs in epidemic form.

Introductions: Reduplicative paramnesia (RP) is a rare and poorly understood phenomenon in which a person believes the place they are in has been replicated and exists in two places at once. There is minimal extant theoretical work addressing possible cognitive mechanisms subtending RP.Method: We present a new case of RP and discuss the therapeutic and theoretical implications of this case for the management and understanding of this phenomenon. Using the hypothetico-deductive approach to a neuropsychological case, we examine the phenomenon in the light of one and two-factor approaches to understanding the genesis of delusions.Results: The individual discussed in this case showed some evidence of relatively efficient incorporation of new evidence (belief updating) despite concurrently maintaining a delusional belief system.Conclusion: This case raises novel challenges for the two-factor account of neurological delusions.

Introduction: Post-Traumatic Stress Disorder (PTSD) is a condition characterised by several disturbances in an individual's executive functioning. We were interested in the link between executive functions and the presence of anxiety and depression in a clinical population with post-traumatic stress disorder.Methods: Our sample comprised 180 participants divided into three groups: 60 with PTSD, 60 trauma-exposed without PTSD, and 60 controls. All participants were assessed on the following dimensions: PTSD, dissociation, executive functions, anxiety, and depression.Results: Consistent with the literature, the results of our study suggest that individuals with PTSD have difficulties in executive functioning. These disturbances are related to levels of anxiety and depression.Conclusion: The severity of PTSD is positively correlated with executive function disturbances, but the observed disturbances, especially in working memory updating, can be explained mainly by the high level of depression, rather than by PTSD alone.

Introduction: Evidence has shown that neurological soft signs are strongly associated with neurocognitive dysfunction. Therefore, the primary objective of this study was to assess the association between NSS and cognitive impairments in a sample of inpatients with schizophrenia. The secondary objective was to explore the association between NSS total scores and functioning.Methods: The study enrolled 95 inpatients diagnosed with schizophrenia disorders and 45 healthy controls. The neurological evaluation scale (NES) was used to assess neurological soft sign while the Brief Assessment of Cognition in Schizophrenia (BACS) was used to evaluate cognitive functioning in patients with schizophrenia.Results: Patients with schizophrenia had significantly higher mean scores on the NES total test and subtests than the control group. Higher cognition was significantly associated with lower NES total and subtest scores. Higher functional independence was significantly associated with a lower NES total score (Beta = -.25), lower motor coordination subtest score (Beta = -.04), and lower others subtest (Beta = -.12). When taking the functional independence scale as the dependent variable, a higher NES total score was significantly associated with lower functioning (Beta = -0.03).Conclusion: NSS were associated to neurocognitive impairments in almost every domain among patients with schizophrenia. Further prospective research is still needed to confirm this role.

Background: While affective disturbances are a key symptomatic indicator of behavioural variant frontotemporal dementia (bvFTD), little is known about how patients process the emotional load of their autobiographical (i.e. personal) memories.

Methods: We assessed the interplay of emotional regulation and autobiographical memory by inviting 18 bvFTD and 20 control participants to remember past personal events. For each memory, participants rated its emotional valence "then" (i.e. when the event has occurred) vs "now" (i.e. when retrieving the event).

Results: Patients with bvFTD described their memories as neutral at both times (p = .85), while control participants rated their memories as more positive during "then" than during "now" (p = .013). Autobiographical retrieval triggered fewer emotional words (p < .001) and less specificity (p < .001) in bvFTD patients compared to control participants.

Conclusions: The lack of significant differences between the emotional characteristics during "then" than "now" in patients with bvFTD (and the flattening of both) may mirror their hampered ability for emotional generation, which may be associated with difficulties in reframing their past experiences to modify and adapt their meaning. The hampered emotional regulation in bvFTD may also be associated with an avoidance strategy and a passive attitude toward the past.

Introduction: The study explored associations between the accuracy of post assessment judgements of cognitive performance with global self-assessments of psychosocial functioning compared to evaluations generated by observers in schizophrenia and bipolar disorder.

Methods: An abbreviated cognitive assessment based on the MATRICS Consensus Cognitive Battery was administered to 122 individuals with schizophrenia and 113 with bipolar disorder. They provided self-estimates of their performance after each subtest. In addition, self-reports on cognition, social cognition, and everyday functioning were collected and compared to observer ratings.

Results: Both groups overestimated their cognitive function, but in bipolar disorder, there was 30% shared variance between task performance and self-rated task performance (vs. 5% in schizophrenia). Significant correlations were found between self-reported everyday outcomes and both actual and self-assessed performance. In schizophrenia, immediate judgements were only related to self-rated functioning, not to observer rated functioning. In bipolar disorder, impairments in self-assessment of performance correlated with observer ratings of cognitive ability, which was not observed in schizophrenia.

Conclusions: While both groups showed correlations between cognitive performance and introspective accuracy, individuals with bipolar disorder showed higher accuracy in assessing their cognitive performance and other outcomes. Notably, impairments in introspective accuracy were associated with observer-rated functioning exclusively in bipolar disorder.