INTRODUCTION: The study aims to use power spectrum changes in subjective cognitive decline (SCD) and amnestic mild cognitive impairment (aMCI), preclinical stages of Alzheimer's disease (AD), for future biomarker studies...INTRODUCTION: The study aims to use power spectrum changes in subjective cognitive decline (SCD) and amnestic mild cognitive impairment (aMCI), preclinical stages of Alzheimer's disease (AD), for future biomarker studies in early AD diagnosis. METHODS: We recruited 23 SCD and 32 aMCI subjects and conducted comparative analysis using relative power spectral density (PSD). Automated preprocessing and statistical analysis were performed using iSync Brain® (iMediSync Inc., Republic of Korea) (https://isyncbrain.com/). RESULTS: Theta band power in the temporal region was 14.826 ± 7.2394 for the SCD group and 20.003 ± 10.1768 for the aMCI group. In the parietal region, theta band power was 13.614 ± 7.5689 for SCD and 19.894 ± 11.1387 for aMCI. Beta1 band power in the frontal region was 6.639 ± 2.2904 for SCD and 5.465 ± 1.8907 for aMCI, and in the temporal region it was 7.359 ± 2.5619 for SCD and 5.921 ± 2.1605 for aMCI. CONCLUSION: PSD analysis of resting-state EEG predicted SCD, a preclinical stage of AD. This cross-sectional study observed electrical-physiological characteristics of preclinical AD; however, follow-up studies are needed to evaluate predictive value for future cognitive decline.
INTRODUCTION: In schizophrenia, social functioning and personal recovery are pivotal outcomes potentially influenced by cognitive biases such as Jumping to Conclusions (JTC). Despite their significance, the relationship...INTRODUCTION: In schizophrenia, social functioning and personal recovery are pivotal outcomes potentially influenced by cognitive biases such as Jumping to Conclusions (JTC). Despite their significance, the relationship between JTC, social functioning, and personal recovery remains unclear. This study aims to investigate this relationship to inform tailored interventions for schizophrenia management. METHODS: Data were collected from 94 schizophrenia patients using standardised measures. The Beads Task assessed JTC, whereas the Brief PANSS, TMT-J, SLOF-J, and RAS-J evaluated psychiatric symptoms, neurocognitive functioning, social functioning, and personal recovery, respectively. Statistical analyses included correlation and hierarchical regression. RESULTS: Correlation analyses revealed a significant negative correlation between JTC and personal recovery ( = -0.27, < 0.05). Hierarchical regression indicated JTC as a significant negative predictor of personal recovery ( = -0.33, = 0.01). No significant correlation was found between JTC and social functioning. DISCUSSION: Increased JTC was associated with lower levels of personal recovery in schizophrenia patients, independent of demographic and clinical factors. In the case of individuals with schizophrenia who demonstrate JTC, there is a potential to suggest the paradox of insight or apparent personal recovery scores.
We report an epileptic patient who experienced hallucinatory visual experiences of autobiographical memories from her past. These visual experiences were confined to the lower left quadrant of her visual field. We carrie...We report an epileptic patient who experienced hallucinatory visual experiences of autobiographical memories from her past. These visual experiences were confined to the lower left quadrant of her visual field. We carried out a single-case study that used brain-imaging, EEG and behavioural methods to study this patient. We found that this patient had an incomplete left inferior homonymous quadrantanopia due to a lesion of right occipital cortex, and also that she showed neurological abnormalities in right temporal cortex, a region that is part of the brain's autobiographical-memory circuit. We attribute the occurrence of this patient's autobiographical-memory hallucinations to the combination of degraded visual input to right temporal cortex plus hyperexcitability of that region.
INTRODUCTION: We investigated the degree of cognitive insight in patients with Alzheimer's Disease (AD) regarding their hallucinations, aiming to elucidate the subjective experiences and perceptions associated with this...INTRODUCTION: We investigated the degree of cognitive insight in patients with Alzheimer's Disease (AD) regarding their hallucinations, aiming to elucidate the subjective experiences and perceptions associated with this phenomenon. METHODS: Using a cross-sectional design, we invited both AD patients ( = 31) and their informants to evaluate the occurrence of hallucinations. Degree of cognitive insight was based upon the discrepancy between the patients' and informants' evaluations. RESULTS: Analysis demonstrated that AD patients rated the occurrence of hallucinations lower than their informants, indicating that patients tended to underestimate the frequency of their hallucinations. The discrepancy between the ratings of patients and informants was negatively correlated with cognitive functioning, suggesting that a greater discrepancy (indicating poorer insight) was associated with lower cognitive functioning in patients. DISCUSSION: Our findings highlight the deficits in insight into hallucinations among AD patients, specifically indicating that AD patients have limited awareness of their own hallucinations. Furthermore, our findings support the idea that deficits in insight into hallucinations are associated with the progression of AD.
INTRODUCTION: Post-stroke fatigue is an often overlooked problem that hinders recovery. Therefore, stroke patients should be evaluated for fatigue during the recovery period. This study aimed to adapt the Neurological Fa...INTRODUCTION: Post-stroke fatigue is an often overlooked problem that hinders recovery. Therefore, stroke patients should be evaluated for fatigue during the recovery period. This study aimed to adapt the Neurological Fatigue Index for Stroke (NFI-Stroke) into the Turkish language. METHODS: This methodological study was carried out on 110 stroke patients admitted to a university hospital in Istanbul. In addition to the NFI-Stroke, Functional Independence Measure, National Institutes of Health Stroke Scale, modified-Rankin Scale, Fatigue Severity-Scale, and Stroke Self Efficacy Questionnaire were used to collect data. RESULTS: Since the linguistic validity study of the scale has already been carried out, only psychometric properties were evaluated. The items in the scale were grouped under two factors. The Cronbach`s alpha coefficient was found to be 0.96 for the physical sub-dimension and 0.84 for the cognitive sub-dimension. Item-total correlation coefficients were found between 0.74-0.91 for the physical sub-dimension, and 0.82-0.91 for the cognitive sub-dimension. The test-retest evaluation confirmed the consistency of the responses to the scale against time. The scale was correlated with other scales used in the study as expected. CONCLUSIONS: The NFI-Stroke will be useful in clinical practice in assessment of fatigue, which may affect the adaptation of patients to rehabilitation.
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 stag...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.
Torrens WA, Pablo JN, Berryhill ME
… +1 more, Haigh SM
Cogn Neuropsychiatry
· 2024 May · PMID 38551240
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INTRODUCTION: Schizophrenia and autism spectrum disorder are distinct neurodevelopmental disorders sharing clinically relevant behaviours. However, early sensory responses show divergent responses. Individuals with schiz...INTRODUCTION: Schizophrenia and autism spectrum disorder are distinct neurodevelopmental disorders sharing clinically relevant behaviours. However, early sensory responses show divergent responses. Individuals with schizophrenia typically exhibit cortical whereas individuals with autism show cortical . Identifying reliable neurobiological differences between the disorders can diminish misdiagnosis and optimise treatments. METHODS: The pattern glare test (PGT) is a simple measure of behavioural hyperexcitability. It measures the number of illusions seen in a static horizontal grating. We collected PGT data from non-clinical adults varying in traits of autism and schizophrenia (schizotypy). 576 undergraduate students completed an online survey consisting of the Schizotypal Personality Questionnaire - Brief Revised, the Autism Spectrum Quotient, and the PGT. RESULTS: Subclinical autism and schizotypy traits were highly correlated. However, only schizotypy scores were significantly predictive of reporting more pattern glare (PG) illusions. When assessing the subcomponents of the schizotypy and autism scores, positive and disorganised schizotypy traits were predictive of reporting more PG illusions. Whereas, subclinical autism factors were not predictive of PG illusions. CONCLUSIONS: High schizotypy performed the PGT in a manner consistent with behavioural hyperexcitability. The PGT distinguished subclinical autistic traits from schizotypy, suggesting potential clinical application.
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...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 ( = 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: 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 for...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.
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. T...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 ( = 119) stratified by current hallucination status (NH, AH, MH) and nonclinical controls (NCs; = 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: Bipolar disorder (BD) is associated with cognitive abnormalities that may persist during euthymia and are linked to poor occupational performance. The cognitive differences between phases of BD are not well...INTRODUCTION: Bipolar disorder (BD) is associated with cognitive abnormalities that may persist during euthymia and are linked to poor occupational performance. The cognitive differences between phases of BD are not well known. Therefore, a cross-sectional study with a relatively large population was conducted to evaluate the differences among BD phases in a wide range of neurocognitive parameters. METHODS: Neuropsychological profile of 169 patients with a diagnosis of BD in manic, depressive, mixed, and euthymic phases between the ages of 18 and 70 years were compared to 45 healthy individuals' between ages of 24 and 69 years. The working memory (digit-span backward test), face recognition, executive functions (verbal fluency and Stroop test), face recognition, and visual and verbal memory (immediate and delayed recall) were evaluated. For BD subgroup analyses, we used the Kruskal-Wallis (KW) test. Then, for the comparison of BD versus healthy individuals, we used the Mann-Whitney U (MWU) test. RESULTS: Analyses based on non-parametric tests showed impairments in BD for all tests. There were no significant differences between phases. CONCLUSION: Cognitive performance in patients with BD appears to be mostly unrelated to the phase of the disorder, implying that cognitive dysfunction in BD is present even during remission.
INTRODUCTION: Individuals with high schizotypy or schizophrenia exhibit difficulties in distributing their attention across space, leading to a reduction in their "perceptual span" - the extent of visual space that can b...INTRODUCTION: Individuals with high schizotypy or schizophrenia exhibit difficulties in distributing their attention across space, leading to a reduction in their "perceptual span" - the extent of visual space that can be attended to at once. In this study, we aim to explore the correlation between schizotypy and perceptual span in a non-clinical sample to investigate whether perceptual span correlates with schizotypy across its range. METHODS: Schizotypy was assessed in fifty-five participants using the Schizotypy Personality Questionnaire (SPQ; Raine, 1991). Participants were required to attend to two dynamic targets displayed in a head-mounted virtual reality display. Perceptual span was estimated as the lateral angle of separation between the two targets beyond which performance in the task dropped to threshold. RESULTS: Participants with higher schizotypy scores performed significantly worse on the task. Of all the factors associated with schizotypy, the shared variance between Disorganisation and Cognitive/Perceptual Factors was most predictive of task performance. CONCLUSION: The results support the hypothesis that schizotypy predicts perceptual span in non-clinical samples. Furthermore, the demonstration of a reduced perceptual span in individuals with higher trait schizotypy shows that variations in an individual's capacity to divide attention across space can be accurately captured using a virtual reality head-mounted display.
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...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. 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. 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. 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.
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 add...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. 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. 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. This case raises novel challenges for the two-factor account of neurological delusions.
Dalkner N, Moore RC, Depp CA
… +3 more, Ackerman RA, Pinkham AE, Harvey PD
Cogn Neuropsychiatry
· 2023 Nov · PMID 37942934
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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 obse...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.
INTRODUCTION: Visual hallucinations are often considered to be suggestive of a secondary cause of psychosis, however, this association has never been assessed meta-analytically. We aimed to compare the presence of visual...INTRODUCTION: Visual hallucinations are often considered to be suggestive of a secondary cause of psychosis, however, this association has never been assessed meta-analytically. We aimed to compare the presence of visual hallucinations in patients with psychosis due to a primary or secondary cause. METHOD: We conducted a meta-analysis of case-control studies directly comparing primary and secondary psychosis. A random-effects model, following the DerSimonian and Laird method, was used to pool studies and generate overall odds ratios (OR), 95% confidence intervals (CI) and prediction intervals (PI). RESULTS: Fourteen studies (904 primary and 804 secondary psychosis patients) were included. Visual hallucinations were significantly associated with secondary psychosis (OR = 3.0, 95% CI = 1.7-5.1, < 0.001) with moderate between-study heterogeneity (I= 70%). Subgroup analysis by type of secondary psychosis (organic, drug-induced, mixed) was non-significant. Analysis of the content of visual hallucinations (51 primary and 142 secondary psychosis patients) found hallucinations of inanimate objects were significantly more likely to be associated with secondary psychosis (OR = 0.1, 95% CI = 0.01-0.8, = 0.03). CONCLUSIONS: Visual hallucinations were strongly associated with a secondary cause of psychosis. The presence of visual hallucinations in a patient presenting with psychosis may serve as a potential "red flag" for a secondary cause and warrant further investigation.
Cogn Neuropsychiatry
· 2023 Nov · PMID 37897319
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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....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 (= .85), while control participants rated their memories as more positive during "then" than during "now" (= .013). Autobiographical retrieval triggered fewer emotional words (< .001) and less specificity (< .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: Patients with functional disorders (FD) often experience cognitive problems such as forgetfulness and distractibility alongside physical symptoms that cannot be attributed to a known somatic disease. METHOD...INTRODUCTION: Patients with functional disorders (FD) often experience cognitive problems such as forgetfulness and distractibility alongside physical symptoms that cannot be attributed to a known somatic disease. METHOD: Test scores of cognitive tests and psychiatric rating scales of 100 outpatients diagnosed with a functional disorder were compared to a control group (n = 300) of patients with other diagnoses and to test norms for the general population. RESULTS: Out of the 100 patients with functional disorders, 59 reported significant subjective cognitive symptoms. A moderate difference (d = 0.5-0.7) was found between the FD group mean and the population mean in processing speed tests, as well as in four psychiatric rating scales (depression, anxiety, phobias, somatisation) but there were no statistically significant differences in verbal and nonverbal reasoning or in logical memory. Somatisation and logical verbal memory scores were higher in the FD group compared to the control group. CONCLUSION: The findings of the study suggest that a decline in processing speed is a central feature in the cognitive profile of patients with functional disorders.
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...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. 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. 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). NSS were associated to neurocognitive impairments in almost every domain among patients with schizophrenia. Further prospective research is still needed to confirm this role.