Abnormal Perception Research Articles

Mild behavioural impairment in Parkinson’s disease: a systematic review

Abstract Behavioural symptoms are common manifestations of Parkinson’s disease (PD). Early behavioural symptoms characterise mild behavioural impairment (MBI). The prevalence and intensity of MBI in people with PD (PwP) have been studied across various cohorts. However, methodological differences have obscured our understanding of MBI in these individuals. This systematic review examines and synthesises findings from relevant studies, enhancing understanding of the symptoms and implications of MBI in PD. Nine studies from five separate research institutions were identified. The conceptualisation of MBI varied considerably, affecting the reported prevalence rates of MBI in individuals with early-stage PD. Among PwP, MBI was associated higher education and impaired cognition. Affective dysregulation and impulse control disorders were primary contributors to MBI; abnormal perception was least contributor. This systematic review underscores the specific characteristics and incidence of MBI in early-stage PD. Mood and impulse control disorders are primary concerns associated with MBI. Future longitudinal studies are required to clarify the progression of these symptoms and evaluate MBI’s potential as an indicator for PD-related dementia or increased dependency.

Bistable Perception Discriminates Between Depressive Patients, Controls, Schizophrenia Patients, and Their Siblings.

Individuals with schizophrenia have less priors than controls, meaning they rely less upon their prior experiences to interpret the current stimuli. These differences in priors are expected to show as higher alternation rates in bistable perception tasks like the Structure-from-Motion (SfM) paradigm. In this paradigm, continuously moving dots in two dimensions are perceived subjectively as traveling along a three-dimensional sphere, which results in a direction of motion (left or right) that shifts approximately every few seconds. Here, we tested healthy controls, patients with schizophrenia, siblings of patients with schizophrenia, and patients with depression with both the intermittent and continuous variants of the SfM paradigm. In the intermittent variant of the SfM paradigm, depressive patients exhibited the lowest alternation rate, followed by unaffected controls. In contrast, patients with schizophrenia and their unaffected siblings displayed significantly higher alternation rates. In the continuous variant of the SfM paradigm, patients with schizophrenia showed the lowest mean percept durations, while there were no differences between the other three groups. The intermittent SfM paradigm is a candidate endophenotype for schizophrenia. The aberrant processing in the patients may stem from alterations in adaptation and/or cross-inhibition mechanisms leading to changes in priors, as suggested by current models in the field. The intermittent SfM paradigm is, hence, a trait marker that offers the great opportunity to investigate perceptual abnormalities across the psychiatry spectrum, ranging from depression to psychosis.

Abnormalities in pain perception among individuals with depressive disorders: Evidence from meta-analysis

Abnormalities in pain perception among individuals with depressive disorders: Evidence from meta-analysis

Irregularity of visual motion perception and negative symptoms in schizophrenia.

Schizophrenia (SZ) is a severe psychiatric disorder characterized by perceptual, emotional, and behavioral abnormalities, with cognitive impairment being a prominent feature of the disorder. Recent studies demonstrate irregularity in SZ with increased variability on the neural level. Is there also irregularity on the psychophysics level like in visual perception? Here, we introduce a methodology to analyze the irregularity in a trial-by-trial way to compare the SZ and healthy control (HC) subjects. In addition, we use an unsupervised clustering algorithm K-means + + to identify SZ subgroups in the sample, followed by validation of the subgroups based on intraindividual visual perception variability and clinical symptomatology. The K-means + + method divided SZ patients into two subgroups by measuring durations across trials in the motion discrimination task, i.e., high, and low irregularity of SZ patients (HSZ, LSZ). We found that HSZ and LSZ subgroups are associated with more negative and positive symptoms respectively. Applying a mediation model in the HSZ subgroup, the enhanced irregularity mediates the relationship between visual perception and negative symptoms. Together, we demonstrate increased irregularity in visual perception of a HSZ subgroup, including its association with negative symptoms. This may serve as a promising marker for identifying and distinguishing SZ subgroups.

Cognitive Mechanisms of Aberrant Self-Referential Social Perception in Psychosis and Bipolar Disorder: Insights From Computational Modeling.

Individuals with schizophrenia (SZ) and bipolar disorder (BD) show disruptions in self-referential gaze perception-a social perceptual process related to symptoms and functioning. However, our current mechanistic understanding of these dysfunctions and relationships is imprecise. The present study used mathematical modeling to uncover cognitive processes driving gaze perception abnormalities in SZ and BD, and how they relate to cognition, symptoms, and social functioning. We modeled the behavior of 28 SZ, 38 BD, and 34 controls (HC) in a self-referential gaze perception task using drift-diffusion models parameterized to index key cognitive components: drift rate (evidence accumulation efficiency), drift bias (perceptual bias), start point (expectation bias), threshold separation (response caution), and nondecision time (encoding/motor processes). Results revealed that aberrant gaze perception in SZ and BD was driven by less efficient evidence accumulation, perceptual biases predisposing self-referential responses, and greater caution (SZ only). Across SZ and HC, poorer social functioning was related to greater expectation biases. Within SZ, perceptual and expectancy biases were associated with hallucination and delusion severity, respectively. These findings indicate that diminished evidence accumulation and perceptual biases may underlie altered gaze perception in patients and that SZ may engage in compensatory cautiousness, sacrificing response speed to preserve accuracy. Moreover, biases at the belief and perceptual levels may relate to symptoms and functioning. Computational modeling can, therefore, be used to achieve a more nuanced, cognitive process-level understanding of the mechanisms of social cognitive difficulties, including gaze perception, in individuals with SZ and BD.

Multisensory perceptual and causal inference is largely preserved in medicated post-acute individuals with schizophrenia.

Hallucinations and perceptual abnormalities in psychosis are thought to arise from imbalanced integration of prior information and sensory inputs. We combined psychophysics, Bayesian modeling, and electroencephalography (EEG) to investigate potential changes in perceptual and causal inference in response to audiovisual flash-beep sequences in medicated individuals with schizophrenia who exhibited limited psychotic symptoms. Seventeen participants with schizophrenia and 23 healthy controls reported either the number of flashes or the number of beeps of audiovisual sequences that varied in their audiovisual numeric disparity across trials. Both groups balanced sensory integration and segregation in line with Bayesian causal inference rather than resorting to simpler heuristics. Both also showed comparable weighting of prior information regarding the signals' causal structure, although the schizophrenia group slightly overweighted prior information about the number of flashes or beeps. At the neural level, both groups computed Bayesian causal inference through dynamic encoding of independent estimates of the flash and beep counts, followed by estimates that flexibly combine audiovisual inputs. Our results demonstrate that the core neurocomputational mechanisms for audiovisual perceptual and causal inference in number estimation tasks are largely preserved in our limited sample of medicated post-acute individuals with schizophrenia. Future research should explore whether these findings generalize to unmedicated patients with acute psychotic symptoms.

Visual hallucinations in Parkinson's disease: spotlight on central cholinergic dysfunction.

Visual hallucinations are a common non-motor feature of Parkinson's disease and have been associated with accelerated cognitive decline, increased mortality and early institutionalisation. Despite their prevalence and negative impact on patient outcomes, the repertoire of treatments aimed at addressing this troubling symptom is limited. Over the last two decades, significant contributions have been made in uncovering the pathological and functional mechanisms of visual hallucinations, bringing us closer to the development of a comprehensive neurobiological framework. Convergent evidence now suggests that degeneration within the central cholinergic system may play a significant role in the genesis and progression of visual hallucinations. Here, we outline how cholinergic dysfunction may serve as a potential unifying neurobiological substrate underlying the multifactorial and dynamic nature of visual hallucinations. Drawing upon previous theoretical models, we explore the impact that alterations in cholinergic neurotransmission has on the core cognitive processes pertinent to abnormal perceptual experiences. We conclude by highlighting that a deeper understanding of cholinergic neurobiology and individual pathophysiology may help to improve established and emerging treatment strategies for the management of visual hallucinations and psychotic symptoms in Parkinson's disease.

NAO robot promoting sensorimotor synchronization in high-functioning autism spectrum disorder children

Objectives Sensorimotor synchronization (SMS) refers to an individual’s motor rhythm is temporally coordinated with a predictable external rhythm. Autism spectrum disorder (ASD) children have weakened SMS performance than typically developing (TD) children, which may affect their relationship with peers and caregivers, and social cognition abilities. Synchronization referent (e.g. an adult or a non-social beat) and the length of inter-stimulus interval (ISI) would influence SMS performance. Methods In this study, we adapted a tapping task to investigate the SMS ability in twenty-one 5–8-year-old high-functioning ASD and twenty-one age-, gender- and IQ-matched TD children. Children were asked to tap on a computer keyboard with videos of a woman or a robot tapping with one finger. We compared the synchronization performance of the two groups when they synchronized with different partners (an adult or an NAO robot) and under different ISIs (800 ms or 1500 ms). The relationships with participants’ autistic traits (Social Responsiveness Scale (SRS-2) and Autism Spectrum Quotient), and cognitive ability (IQ) were also examined. Results We found that ASD children had an overall attenuated synchronizing accuracy and stability than TD children only when ISI was longer than one second. Both groups performed better when synchronized with the NAO robot than the adult partner. The synchronization performance was correlated with the cognitive ability of ASD children when ISI was 1500 ms. Conclusions Results show that tapping with the robot could improve the SMS performance of ASD children since it promoted a higher motivation level. ASD children have an attenuated SMS ability, which may be caused by abnormal temporal perceptions when ISI is longer than one second, while their SMS ability may be intact in sub-second ISIs.

Altered Effective Connectivity of the Pain Matrix in Herpes Zoster and Postherpetic Neuralgia Patients: Granger Causality Analysis of Resting-State fMRI.

Shingles can cause long-term pain and negative emotions, along with changes in brain function. In this study, Granger Causality Analysis (GCA) was used to compare herpes zoster (HZ) and postherpetic neuralgia (PHN) differences in effective connections within the "pain matrix" between patients and healthy controls to further understand patterns of interaction between brain regions and explore the relationship between changes in effective connections and clinical features. Resting-state functional magnetic resonance imaging (fMRI) scans were performed on 55 HZ; 55 PHN; and 50 age-, sex- matched healthy controls (HCs). The brain regions associated with the pain matrix are used as the seeds of effective connectivity. GCA was used to analyze effective connections in brain regions that differed significantly between groups. Then the correlation between GCA values and clinical indicators was studied. Compared with HC, GCA values between the thalamus and the amygdala, between the thalamus and the precentral gyrus, from the thalamus to the postcentral gyrus, and from the parahippocampal gyrus to the amygdala, anterior cingulate gyrus were significantly reduced in HZ patients. Compared with HC, GCA values between the insular and the postcentral gyrus, from the insular to the inferior parietal lobe, and from the postcentral gyrus to the amygdala were significantly reduced in PHN patients. Compared with HZ, GCA values between the inferior parietal lobe and the parahippocampal gyrus, between the inferior parietal lobe and the anterior cingulate gyrus, and from the anterior cingulate gyrus to the amygdala were significantly increased in PHN patients. The visual analogue scale (VAS) score of PHN patients was positively correlated with the GCA value from the central posterior lobe to the insula. PHN and HZ patients showed a broad reduction in effective connections, mainly reflected in abnormal pain pathway regulation, pain perception, negative emotion and memory production, providing new perspectives to understand the neuroimaging mechanisms of shingles.

The Relationship between Clinical and Psychophysical Assessments of Visual Perceptual Disturbances in Individuals at Clinical High Risk for Psychosis: A Preliminary Study.

This study investigated relations between a measure of early-stage visual function and self-reported visual anomalies in individuals at clinical high risk for psychosis (CHR-P). Eleven individuals at CHR identified via the Structured Interview for Psychosis-Risk Syndromes (SIPS) were recruited from a CHR-P research program in NYC. The sample was ~36% female, ranging from 16 to 33 years old (M = 23.90, SD = 6.14). Participants completed a contrast sensitivity task on an iPad with five spatial frequencies (0.41-13 cycles/degree) and completed the self-report Audio-Visual Abnormalities Questionnaire. Higher contrast sensitivity (better performance) to low spatial frequencies was associated with higher perceptual (r = 0.616, p = 0.044) and visual disturbances (r = 0.667, p = 0.025); lower contrast sensitivity to a middle spatial frequency was also associated with higher perceptual (r = -0.604, p = 0.049) and visual disturbances (r = -0.606, p = 0.048). This relation between the questionnaire and contrast sensitivity to low spatial frequency may be indicative of a reduction in lateral inhibition and "flooding" of environmental stimuli. The association with middle spatial frequencies, which play a critical role in face processing, may result in a range of perceptual abnormalities. These findings demonstrate that self-reported perceptual anomalies occur in these individuals and are linked to performance on a measure of early visual processing.

A Latent Profile Analysis of Emotion Regulation in Relation to Distress of Symptoms in Youth with Prodromal Psychotic Symptoms.

(1) Background: Although abnormal emotion regulation is a key characteristic of youth with prodromal psychotic symptoms and is closely related to the degree of distress caused by these symptoms, research on the internal heterogeneity of emotion regulation within this clinically high-risk population has been insufficient. (2) Methods: The current study analyzed data from 394 college students with prodromal psychotic symptoms, using latent profile analysis (LPA) to identify emotion regulation profiles based on differences in expressive suppression and cognitive reappraisal. One-way ANOVA was employed to examine the relationship between the identified latent profiles and distress of symptoms. (3) Results: Three latent profiles were identified: "high cognitive reappraisal group" (n = 117, 29.70%), "moderate cognitive reappraisal group" (n = 233, 59.14%), and "low cognitive reappraisal group" (n = 44, 11.16%). Significant differences in distress of negative symptoms (F = 9.122, p < 0.05) and perceptual abnormalities (F = 3.103, p < 0.05) were observed across the latent profiles but not in unusual thought content and specific perceptual abnormalities (both p > 0.05). The "low cognitive reappraisal group" exhibited the most severe distress of symptoms, followed by the "moderate cognitive reappraisal group", while the "high cognitive reappraisal group" experienced the least distress. (4) Conclusions: The current study provides evidence for the heterogeneity of emotion regulation among youth with prodromal psychotic symptoms and reveals differences in distress of perceptual abnormalities and negative symptoms between the latent profiles of emotion regulation. These findings support the development of targeted psychological interventions to alleviate the distress of symptoms and improve quality of life.

Dysregulation of parvalbumin expression and neurotransmitter imbalance in the auditory cortex of the BTBR mouse model of autism spectrum disorder.

Individuals diagnosed with autism spectrum disorder (ASD) frequently exhibit abnormalities in auditory perception, a phenomenon potentially attributed to alterations in the excitatory and inhibitory cells constituting cortical circuits. However, the exact genetic factors and cell types affected by ASD remain unclear. The present study investigated the balance of excitatory and inhibitory activity in the auditory cortex using BTBR T+ Itpr3tf/J (BTBR) mice, a well-established model for autism research. Our investigation unveiled a reduction in parvalbumin-positive (PV+) neurons within the AC of BTBR mice. Remarkably, in vivo magnetic resonance spectroscopy studies disclosed an elevation in glutamate (Glu) levels alongside a decrement in γ-aminobutyric acid (GABA) levels in this cortical region. Additionally, transcriptomic analysis of the mouse model facilitated the classification of several ASD-associated genes based on their cellular function and pathways. By comparing autism risk genes with RNA transcriptome sequencing data from the ASD mouse model, we identified the recurrent target gene Scn1a and performed validation. Intriguingly, we uncovered the specific expression of Scn1a in cortical inhibitory neurons. These findings hold significant value for understanding the underlying neural mechanisms of abnormal sensory perception in animal models of ASD.

ASD-similar social behaviour scores affect stimulus generalization in family dogs

Generalization, the tendency to respond in the same way to different but similar stimuli, is one of the main cognitive abilities that make category formation possible and thus is a prerequisite for efficiency in learning. Individuals with autism spectrum disorder (ASD) experience pervasive difficulty with producing generalized responses across materials, people, places, and contexts. Increasing evidence suggests that “ASD-like” social impairments appear endogenously and spontaneously in family dogs providing a high-validity model for understanding the phenotypic expression of human ASD. The present study aims to further investigate the dog model of ASD by the approach of searching for analogues in dogs showing “ASD-like” social impairments of cognitive phenomena in humans specific to ASD, specifically impairments of generalization abilities. We have tested 18 family dogs with formerly established “ASD-like” behaviour scores (F1, F2, F3) in a generalization task involving three conditions (size, colour and texture). We found a significant association between F1 scores and test performance as well as improvement during testing sessions. Our study provides further support for the notion that dogs with lower social competence—similarly to humans with ASD—exhibit attentional and perceptual abnormalities, such as being sensitive to minor changes to a non-adaptive extent.

Comparison of clinical characteristics in intermittent exotropia patients with different visual perception and oculomotor control

Objective: To explore the clinical characteristics of intermittent exotropia (IXT) patients with different visual perception and oculomotor control. Methods: A cross-sectional study was conducted. Minor IXT patients between March 2021 and May 2023 at Beijing Tongren Hospital were enrolled. Demographic characteristics were recorded, and visual perception and oculomotor control were evaluated. The patients were divided into simultaneous vision disappearing and existing groups, fusion disappearing and existing groups, distant stereoscopic vision disappearing and normal groups, and near stereoscopic vision injury and normal groups. Statistical description was performed by using M (Q1, Q3). Rank sum test was used to compare the Revised Newcastle Control Score (RNCS), near and far strabismus degree, duration of disease, and age of onset among different groups. The correlation between visual perception and oculomotor control and the correlation of duration of disease and age of onset with visual perception and oculomotor control were analyzed by Pearson correlation analysis. Results: A total of 381 patients were enrolled, including 189 males and 192 females, with a median age of 7 (6, 9) years. The incidence of normal visual perception was 19.4% (74/381). Compared with simultaneous vision and fusion existing groups and distant and near stereoscopic vision normal groups, the RNCS [7 (5, 9) vs 4 (3, 6), 6 (5, 8) vs 4 (3, 6), 5 (4, 7) vs 3 (3, 5), and 5 (3, 6) vs 4 (3, 6)], near strabismus degree [65Δ (60Δ, 80Δ) vs 40Δ (30Δ, 50Δ), 60Δ (45Δ, 65Δ) vs 40Δ (30Δ, 50Δ), 50Δ (40Δ, 60Δ) vs 35Δ (30Δ, 45Δ), and 45Δ (30Δ, 60Δ) vs 40Δ (30Δ, 50Δ)] and far strabismus degree [60Δ (50Δ, 75Δ) vs 35Δ (25Δ, 50Δ), 55Δ (41Δ, 65Δ) vs 35Δ (25Δ, 45Δ), 45Δ (30Δ, 60Δ) vs 35Δ (25Δ, 45Δ), and 40Δ (30Δ, 60Δ) vs 35Δ (25Δ, 45Δ)] increased significantly in disappearing simultaneous vision, fusion, and distant stereoscopic vision groups and injury near stereoscopic vision group (all P<0.05). Compared with simultaneous vision and fusion existing groups and distant stereoscopic vision normal group, duration of disease was significant longer in disappearing simultaneous vision, fusion, and distant stereoscopic vision groups [3 (1, 5) years vs 2 (1, 3) years, 2 (1, 4) years vs 1 (1, 3) years, 2 (1, 4) years vs 1 (1, 3) years, all P<0.05]. The age of onset in disappearing distant stereoscopic vision group was significantly lower than normal distant stereoscopic vision group [5 (3, 7) years vs 6 (4, 8) years, P=0.005]. Pearson correlation analysis showed that subjective angle and random dot stereogram (RDS) stereoacuity were positive correlation with RNCS, and the near and far strabismus degree (r=0.414, 0.516, and 0.559, all P<0.001; r=0.153, 0.142, and 0.173, all P<0.05). Subjective angle, RNCS, and the near and far strabismus degree were positive correlation with duration of disease (r=0.238, 0.195, 0.236, 0.239, all P<0.001) and negative correlation with age of onset (r=-0.184, -0.279, -0.112, -0.147, all P<0.05). Conclusions: Nearly 20% of IXT patients have normal visual perception. With the longer duration of disease or lower age of onset, the incidence of abnormal visual perception is higher and injury of visual perception and oculomotor control is more serious.

Irritable bowel syndrome: When food is a pain in the gut.

Irritable bowel syndrome (IBS) is a chronic gastrointestinal condition associated with altered bowel habits and recurrent abdominal pain, often triggered by food intake. Current treatments focus on improving stool pattern, but effective treatments for pain in IBS are still lacking due to our limited understanding of pathophysiological mechanisms. Visceral hypersensitivity (VHS), or abnormal visceral pain perception, underlies abdominal pain development in IBS, and mast cell activation has been shown to play an important role in the development of VHS. Our work recently revealed that abdominal pain in response to food intake is induced by the sensitization of colonic pain-sensing neurons by histamine produced by activated mast cells following a local IgE response to food. In this review, we summarize the current knowledge on abdominal pain and VHS pathophysiology in IBS, we outline the work leading to the discovery of the role of histamine in abdominal pain, and we introduce antihistamines as a novel treatment option to manage chronic abdominal pain in patients with IBS.

Cognitive Mechanisms of Aberrant Self-Referential Social Perception in Psychosis and Bipolar Disorder: Insights from Computational Modeling.

Individuals with schizophrenia (SZ) and bipolar disorder (BD) show disruptions in self-referential gaze perception-a social perceptual process related to symptoms and functioning. However, our current mechanistic understanding of these dysfunctions and relationships is imprecise. The present study used mathematical modeling to uncover cognitive processes driving gaze perception abnormalities in SZ and BD, and how they relate to cognition, symptoms, and social functioning. We modeled the behavior of 28 SZ, 38 BD, and 34 controls (HC) in a self-referential gaze perception task using drift-diffusion models (DDM) parameterized to index key cognitive components: drift rate (evidence accumulation efficiency), drift bias (perceptual bias), start point (expectation bias), threshold separation (response caution), and non- decision time (encoding/motor processes). Results revealed that aberrant gaze perception in SZ and BD was driven by less efficient evidence accumulation, perceptual biases predisposing self-referential responses, and greater caution (SZ only). Across SZ and HC, poorer social functioning was related to greater expectation biases. Within SZ, perceptual and expectancy biases were associated with hallucination and delusion severity, respectively. These findings indicate that diminished evidence accumulation and perceptual biases may underlie altered gaze perception in patients and that SZ may engage in compensatory cautiousness, sacrificing response speed to preserve accuracy. Moreover, biases at the belief and perceptual levels may relate to symptoms and functioning. Computational modeling can, therefore, be used to achieve a more nuanced, cognitive process-level understanding of the mechanisms of social cognitive difficulties, including gaze perception, in individuals with SZ and BD.

Clinical safety of daridorexant in insomnia treatment: Analysis of FDA adverse event reports

ObjectiveDaridorexant, a novel dual orexin receptor antagonist, was approved by the FDA in 2022 for the treatment of insomnia in adults. The aim of this study is to delve into the adverse events (AEs) of daridorexant by analyzing data from the FAERS database, to assess its safety and effectiveness in clinical applications. MethodsThis study selected data from the FAERS database from the first quarter of 2022 to the third quarter of 2023. Various data analysis methods were used, including the Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Empirical Bayesian Geometric Mean (EBGM), to assess AEs related to daridorexant. ResultsThe study analyzed a total of 2,624,030 AE reports, of which 1318 were related to daridorexant. It identified 59 preferred terms (PTs) involving 23 system organ classes (SOCs). Signal mining identified new potential AEs related to daridorexant, including sleep-related psychiatric symptoms (nightmare, abnormal dreams, sleep terror, etc.), emotional and perceptual abnormalities (hallucination, depression, agitation), physiological and behavioral responses (palpitations, dry mouth, energy increased, etc.), suicide risk (suicidal ideation, intentional overdose), and other special concern AEs (tachyphrenia, sleep-related eating disorder, hypersensitivity). ConclusionAlthough some new potential AEs have been identified, these findings need further verification in broader datasets and long-term studies due to limitations in data sources and analysis methods. Future research should comprehensively assess the safety and effectiveness of daridorexant, providing more accurate guidance for medical professionals in the treatment of insomnia.

Sensitivity and Specificity of a Screening Test for the Detection of Deficiencies in Visuo-Perceptual Skills.

This study determines the sensitivity and specificity of a screening test to detect perceptual abnormalities and whether there are differences between gender. Vision is a complex process involving visual perception. Any alterations can affect learning, so having a screening test in Spanish that is easy to use and reliable for timely diagnosis will reduce the percentage of visuo-perceptual interference during learning process. A total of 200 subjects participated, aged between 8 and 15 years old, with good visual acuity, and no strabismus, amblyopia, ocular pathology, or neurological damage. The Petrosyan questionnaire (screening test) was employed to identify symptoms associated with perceptual impairment, and a subsequent assessment was conducted to evaluate perceptual abilities. The mean age was 11.5 years (57% male; 44% female). The screening test indicated that 30% of the subjects were suspected of having perceptual alteration, while 24% were diagnosed with a real alteration in perceptual abilities. The sensitivity was 1 and the specificity was 0.92. The Spanish version of the Petrosyan questionnaire has high sensitivity and specificity values and is therefore considered very accurate for identifying the need for a perceptual assessment. There are statistically significant differences in perceptual abilities according to gender. The female group shows more symptomatology and a higher percentage of alteration in perceptual skills.

Positive and negative schizotypy personality traits are lower in individuals on ketogenic diet in a non-clinical sample

Schizotypal personality comprises traits such as odd beliefs, perceptual abnormalities, and social difficulties; these traits are distributed throughout the general population. While not meeting the clinical threshold for schizophrenia or schizotypal personality disorder, schizotypal personality traits still provide insights for understanding early clinical risk factors. Ketogenic diet reportedly reduces psychotic symptoms in preclinical and clinical studies. Therefore, we investigated whether ketogenic diet is associated with lower schizotypal traits in the general population. Participants following a ketogenic or other diet were recruited using opportunity sampling. Individuals completed a survey investigating general demographic, socioeconomic, health, diet and lifestyle questions, followed by the Schizotypal Personality Questionnaire – Brief Revised version (SPQ-BR). We found that individuals following a ketogenic diet (n = 118) had lower ideas of reference, magical thinking, suspiciousness, unusual perceptions, constricted affect, social anxiety scores, cognitive (positive) perceptual scores, interpersonal (negative) scores and total SPQ-BR compared to individuals on the other diets (n = 139). Magical thinking, constricted affect, social anxiety, cognitive perceptual, interpersonal scores and total SPQ-BR scores remained significant when we controlled for body mass index (BMI) and age. Disorganised features were not influenced by ketogenic diet. The longer individuals adhered to a ketogenic diet the lower their positive and negative schizotypy traits. These findings highlight that ketogenic diet is associated with lower non-clinical schizotypal personality traits. Our results suggest that ketogenic diet might have potential prophylactic properties for individuals at-risk for psychosis.

Cognitive complaint inversely associated to UHR transition

The aim of this study was to identify the impact of staging on a six-months transition in Ultra-High Risk (UHR) youth.Subjects were enrolled at assessment; evolution was monitored for six months. Clinical determinants (unusual thought content, perceptual abnormalities, cognitive complaint, etc.) were collected.37 non-psychotic and 39 UHR subjects were included. 13 UHR (35.2 %) experienced psychotic transition, while none of non-psychotic subjects did log-rank p < 0.001. Self-reported cognitive complaint was inversely associated to transition OR 0.13 95 % IC [0.03–0.64]. Unusual Thought Content was associated to psychotic transition 0R 8.57 95 % IC [1.17–63]. Self-reported cognitive complaint could be a protective transition marker in UHR.