Association of temporal discounting with transdiagnostic symptom dimensions.

Temporal discounting (TD), the tendency to devalue future rewards as a function of delay until receipt, is aberrant in many mental disorders. Identifying symptom patterns and transdiagnostic dimensions associated with TD could elucidate mechanisms responsible for clinically impaired decision-making and facilitate identifying intervention targets. Here, we tested in a general population sample (N = 731) the extent to which TD was related to different symptom patterns and whether effects of time framing (dates/delay units) and monetary magnitude (large/small) had particularly strong effects in people scoring higher on specific symptom patterns. Analyses revealed that TD was related to symptom patterns loading on anxious-depression and inattention-impulsivity-overactivity dimensions. Moreover, TD was lower in the date than the delay version and with higher magnitudes, especially in people scoring higher on the inattention-impulsivity-overactivity dimension. Overall, this study provides evidence for TD as a transdiagnostic process across affective and impulsivity-related dimensions. Future studies should test framing interventions in clinical populations characterized by impulsivity.Preregistration: This research was preregistered at https://osf.io/fg9sc .

The date/delay effect in intertemporal choice: A combined fMRI and eye-tracking study.

Temporal discounting, the tendency to devalue future rewards as a function of delay until receipt, is influenced by time framing. Specifically, discount rates are shallower when the time at which the reward is received is presented as a date (date condition; e.g., June 8, 2023) rather than in delay units (delay condition; e.g., 30 days), which is commonly referred to as the date/delay effect. However, the cognitive and neural mechanisms of this effect are not well understood. Here, we examined the date/delay effect by analysing combined fMRI and eye-tracking data of N = 31 participants completing a temporal discounting task in both a delay and a date condition. The results confirmed the date/delay effect and revealed that the date condition led to higher fixation durations on time attributes and to higher activity in precuneus/PCC and angular gyrus, that is, areas previously associated with episodic thinking. Additionally, participants made more comparative eye movements in the date compared to the delay condition. A lower date/delay effect was associated with higher prefrontal activity in the date > delay contrast, suggesting that higher control or arithmetic operations may reduce the date/delay effect. Our findings are in line with hypotheses positing that the date condition is associated with differential time estimation and the use of more comparative as opposed to integrative choice strategies. Specifically, higher activity in memory-related brain areas suggests that the date condition leads to higher perceived proximity of delayed rewards, while higher frontal activity (middle/superior frontal gyrus, posterior medial frontal cortex, cingulate) in participants with a lower date/delay effect suggests that the effect is particularly pronounced in participants avoiding complex arithmetic operations in the date condition.

Emotions under control? Better cognitive control is associated with reduced negative emotionality but increased negative emotional reactivity within individuals.

Associations between impaired cognitive control and maladaptive emotion regulation have been extensively studied between individuals. However, it remains unclear if this relationship holds within individuals. In this study, we tested the assumption that momentary within-person fluctuation in cognitive control (working memory updating and response inhibition) is associated with emotional reactivity in everyday life. We conducted an experience sampling study (eight two-hourly prompts daily) where participants repeatedly performed short 2-back and Go/no-go tasks in daily life. We assessed negative and positive affective states, and unpleasantness of a recent event to capture emotional reactivity. We analyzed two overlapping samples: a Go/no-go and a 2-back dataset (N = 161/158). Our results showed that better momentary working memory updating was associated with decreased negative affect if the recent event was on average unpleasant for the given individual. However, better-than-average working memory updating in interaction with higher event-unpleasantness predicted higher negative affect levels (i.e., higher negative emotional reactivity). These findings may challenge the account of better cognitive control being universally related to adaptive emotion regulation. Although it is unlikely that emotional reactivity boosts working memory, future studies should establish the direction of causality.

The effects of creatine supplementation on cognitive performance-a randomised controlled study.

BACKGROUND: Creatine is an organic compound that facilitates the recycling of energy-providing adenosine triphosphate (ATP) in muscle and brain tissue. It is a safe, well-studied supplement for strength training. Previous studies have shown that supplementation increases brain creatine levels, which might increase cognitive performance. The results of studies that have tested cognitive performance differ greatly, possibly due to different populations, supplementation regimens, and cognitive tasks. This is the largest study on the effect of creatine supplementation on cognitive performance to date. METHODS: Our trial was preregistered, cross-over, double-blind, placebo-controlled, and randomised, with daily supplementation of 5 g for 6 weeks each. We tested participants on Raven's Advanced Progressive Matrices (RAPM) and on the Backward Digit Span (BDS). In addition, we included eight exploratory cognitive tests. About half of our 123 participants were vegetarians and half were omnivores. RESULTS: Bayesian evidence supported a small beneficial effect of creatine. The creatine effect bordered significance for BDS (p = 0.064, η2P = 0.029) but not RAPM (p = 0.327, η2P = 0.008). There was no indication that creatine improved the performance of our exploratory cognitive tasks. Side effects were reported significantly more often for creatine than for placebo supplementation (p = 0.002, RR = 4.25). Vegetarians did not benefit more from creatine than omnivores. CONCLUSIONS: Our study, in combination with the literature, implies that creatine might have a small beneficial effect. Larger studies are needed to confirm or rule out this effect. Given the safety and broad availability of creatine, this is well worth investigating; a small effect could have large benefits when scaled over time and over many people. TRIAL REGISTRATION: The trial was prospectively registered (drks.de identifier: DRKS00017250, https://osf.io/xpwkc/ ).

Positive schizotypy and Motor Impulsivity correlate with response aberrations in ventral attention network during inhibitory control.

Inhibitory control (IC) aberrations are present in various psychopathologies, including schizophrenia spectrum and personality disorders, especially in association with antisocial or violent behaviour. We investigated behavioural and neural associations between IC and psychopathology-related traits of schizotypy [Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE)], psychopathy [Triarchic Psychopathy Measure (TriPM)], and impulsivity [Barratt Impulsiveness Scale (BIS-11)], using a novel Go/No-Go Task (GNG) featuring human avatars in 78 healthy adults (25 males, 53 females; mean age = 25.96 years, SD = 9.85) and whole-brain functional magnetic resonance imaging (fMRI) in a separate sample of 22 right-handed healthy individuals (7 males, 15 females; mean age = 24.13 years, SD = 5.40). Behaviourally, O-LIFE Impulsive Nonconformity (impulsive, anti-social, and eccentric behaviour) significantly predicted 16 % of variance in false alarms (FAs). O-LIFE Unusual Experiences (positive schizotypy) and BIS-11 Motor Impulsivity predicted 15 % of d prime (d') (sensitivity index) for the fastest (400 ms) GNG trials. When examined using fMRI, higher BIS-11 Motor Impulsivity uniquely, and also together with Unusual Experiences, was associated with lower activity in the left lingual gyrus during successful inhibition (correct No-Go over baseline). Additionally, higher Impulsive Nonconformity was associated with lower activity in the caudate nucleus and anterior cingulate during No-Go compared to Go stimuli reactions. Positive schizotypy, motor, and antisocial-schizotypal impulsivity correlate with some common but mostly distinct neural activation patterns during response inhibition in areas within or associated with the ventral attention network.

Effects of NMDA-receptor blockade by ketamine on mentalizing and its neural correlates in humans: a randomized control trial.

Schizophrenia is associated with various deficits in social cognition that remain relatively unaltered by antipsychotic treatment. While faulty glutamate signaling has been associated with general cognitive deficits as well as negative symptoms of schizophrenia, no direct link between manipulation of glutamate signaling and deficits in mentalizing has been demonstrated thus far. Here, we experimentally investigated whether ketamine, an uncompetitive N-methyl-D-aspartate receptor antagonist known to induce psychotomimetic effects, influences mentalizing and its neural correlates. In a randomized, placebo-controlled between-subjects experiment, we intravenously administered ketamine or placebo to healthy participants performing a video-based social cognition task during functional magnetic resonance imaging. Psychotomimetic effects of ketamine were assessed using the Positive and Negative Syndrome Scale. Compared to placebo, ketamine led to significantly more psychotic symptoms and reduced mentalizing performance (more "no mentalizing" errors). Ketamine also influenced blood oxygen level dependent (BOLD) response during mentalizing compared to placebo. Specifically, ketamine increased BOLD in right posterior superior temporal sulcus (pSTS) and increased connectivity between pSTS and anterior precuneus. These increases may reflect a dysfunctional shift of attention induced by ketamine that leads to mentalizing deficits. Our findings show that a psychotomimetic dose of ketamine impairs mentalizing and influences its neural correlates, a result compatible with the notion that deficient glutamate signaling may contribute to deficits in mentalizing in schizophrenia. The results also support efforts to seek novel psychopharmacological treatments for psychosis and schizophrenia targeting glutamatergic transmission.

Minimal reporting guideline for research involving eye tracking (2023 edition).

A guideline is proposed that comprises the minimum items to be reported in research studies involving an eye tracker and human or non-human primate participant(s). This guideline was developed over a 3-year period using a consensus-based process via an open invitation to the international eye tracking community. This guideline will be reviewed at maximum intervals of 4 years.

Metacognitive monitoring in schizotypy: Systematic literature review and new empirical data.

BACKGROUND AND OBJECTIVES: Deficits in metacognition, the ability to monitor one's own mental states, are key elements of the functional pathology of schizophrenia spectrum disorders. Little is known, however, about the integrity of metacognitive processes in subclinical schizotypy. The purpose of the present investigation was two-fold: First, we conducted a preregistered, systematic literature review to synthesize previous research efforts on the role of metacognition in schizotypy. Second, we investigated the relationship between self-reported dimensions of schizotypy and psychometric as well as behavioral measures of metacognition in a preregistered online study. METHODS: A large sample (N = 330) completed a questionnaire battery and an episodic memory experiment; task-based metacognition was tapped via trial-by-trial confidence ratings. RESULTS: In keeping with findings from our literature review, higher schizotypy was associated with diminished introspective insight and an overly self-referential and maladaptive metacognitive style in metacognition questionnaires. Importantly, low task-based metacognitive efficiency was predictive of high levels of cognitive disorganization, whereas task-related overconfidence (i.e., increased metacognitive bias) was linked with positive schizotypy. LIMITATIONS: Due to the comparatively small number of k = 20 studies meeting our inclusion criteria, the systematic literature review provides only preliminary indications for potential conclusions. Furthermore, control over potential disturbing influences in the experimental study was limited due to its online format. CONCLUSIONS: Overall, we provide evidence for specific metacognitive deficits in schizotypy and discuss a potential continuity of preserved and impaired aspects of metacognitive monitoring along the psychosis continuum.

Increased structural connectivity in high schizotypy.

The link between brain structural connectivity and schizotypy was explored in two healthy participant cohorts, collected at two different neuroimaging centres, comprising 140 and 115 participants, respectively. The participants completed the Schizotypal Personality Questionnaire (SPQ), through which their schizotypy scores were calculated. Diffusion-MRI data were used to perform tractography and to generate the structural brain networks of the participants. The edges of the networks were weighted with the inverse radial diffusivity. Graph theoretical metrics of the default mode, sensorimotor, visual, and auditory subnetworks were derived and their correlation coefficients with the schizotypy scores were calculated. To the best of our knowledge, this is the first time that graph theoretical measures of structural brain networks are investigated in relation to schizotypy. A positive correlation was found between the schizotypy score and the mean node degree and mean clustering coefficient of the sensorimotor and the default mode subnetworks. The nodes driving these correlations were the right postcentral gyrus, the left paracentral lobule, the right superior frontal gyrus, the left parahippocampal gyrus, and the bilateral precuneus, that is, nodes that exhibit compromised functional connectivity in schizophrenia. Implications for schizophrenia and schizotypy are discussed.

Pineal Abnormalities in Psychosis and Mood Disorders: A Systematic Review.

The pineal gland (PG) is a small interhemispheric brain structure that influences human physiology in many ways, most importantly via secretion of the hormone melatonin which is known to regulate sleep and wakefulness. Here, we systematically reviewed existing neuroimaging studies of PG structure, and/or melatonin release (MLT) in psychosis and mood disorders. Medline, PubMed, and Web of Science databases were searched (on 3 February 2023), yielding 36 studies (8 PG volume, 24 MLT). The findings showed smaller-than-normal PG volume in people with schizophrenia, regardless of symptom severity and illness stage; and smaller-than-normal PG volume in major depression, with some indication of this being present only in certain subgroups, or in those with high scores on the 'loss of interest' symptom. There was considerable evidence of lower-than-normal MLT as well as aberrant MLT secretion pattern in schizophrenia. A similar picture, though less consistent than that seen in schizophrenia, emerged in major depression and bipolar disorder, with some evidence of a transient lowering of MLT following the initiation of certain antidepressants in drug-withdrawn patients. Overall, PG and MLT aberrations appear to represent transdiagnostic biomarkers for psychosis and mood disorders, but further work is needed to establish their clinical correlates and treatment implications.

Multimodal assessment of adult attention-deficit hyperactivity disorder: A controlled virtual seminar room study.

In the assessment of adult attention-deficit hyperactivity disorder (ADHD) symptoms, the diagnostic value of neuropsychological testing is limited. Partly, this is due to the rather low ecological validity of traditional neuropsychological tests, which usually present abstract stimuli on a computer screen. A potential remedy for this shortcoming might be the use of virtual reality (VR), which enables a more realistic and complex, yet still standardized test environment. The present study investigates a new VR-based multimodal assessment tool for adult ADHD, the virtual seminar room (VSR). Twenty-five unmedicated ADHD patients, 25 medicated ADHD patients, and 25 healthy controls underwent a virtual continuous performance task (CPT) in the VSR with concurrent visual, auditive, and audiovisual distractions. Simultaneously, head movements (actigraphy), gaze behaviour (eye tracking), subjective experience, electroencephalography (EEG), and functional near-infrared spectroscopy (fNIRS) were recorded. Significant differences between unmedicated patients with ADHD and healthy controls were found in CPT performance, head actigraphy, distractor gaze behaviour, and subjective experience. Moreover, CPT performance parameters demonstrated potential utility for assessing medication effects within the ADHD population. No group differences were found in the Theta-Beta-Ratio (EEG) or dorsolateral-prefrontal oxy-haemoglobin (fNIRS). Overall, the results are very promising regarding the potential of the VSR as an assessment tool for adult ADHD. In particular, the combined assessment of CPT, actigraphy, and eye tracking parameters appears to be a valid approach to more accurately capture the heterogeneous symptom presentation of the disorder.

GABAergic Involvement in Selective Attention.

Animals need to cope with abundant sensory information, and one strategy is to selectively direct attention to only the most relevant part of the environment. Although the cortical networks of selective attention have been studied extensively, its underlying neurotransmitter systems, especially the role of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA), remain less well understood. Increased GABAA receptor activity because of administration of benzodiazepines such as lorazepam is known to slow reactions in cognitive tasks. However, there is limited knowledge about GABAergic involvement in selective attention. Particularly, it is unknown whether increased GABAA receptor activity slows the build-up of selectivity or generally widens attentional focus. To address this question, participants (n = 29) received 1 mg lorazepam and placebo (within-subjects, double-blind) and performed an extended version of the flanker task. The spatial distribution of selective attention was studied by systematically manipulating number and position of incongruent flankers; the temporal build-up was characterized using delta plots. An online task version was presented to an independent, unmedicated sample (n = 25) to verify task effects. Under placebo and in the unmedicated sample, only the number of incongruent flankers, but not their position, influenced RTs. Incongruent flankers impaired RTs more strongly under lorazepam than placebo, especially when adjacent to the target. Delta plot analyses of RT showed that this effect persisted even when participants reacted slowly, indicating that lorazepam-induced impairments in selective attention do not result from simply slowed down build-up of selectivity. Instead, our data indicate that increased GABAA receptor activity widens the attentional focus.

Beyond sleep: A multidimensional model of chronotype.

Chronotype can be defined as an expression or proxy for circadian rhythms of varied mechanisms, for example in body temperature, cortisol secretion, cognitive functions, eating and sleeping patterns. It is influenced by a range of internal (e.g., genetics) and external factors (e.g., light exposure), and has implications for health and well-being. Here, we present a critical review and synthesis of existing models of chronotype. Our observations reveal that most existing models and, as a consequence, associated measures of chronotype have focused solely or primarily on the sleep dimension, and typically have not incorporated social and environmental influences on chronotype. We propose a multidimensional model of chronotype, integrating individual (biological and psychological), environmental and social factors that appear to interact to determine an individual's true chronotype with potential feedback loops between these factors. This model could be beneficial not only from a basic science perspective but also in the context of understanding health and clinical implications of certain chronotypes as well as designing preventive and therapeutic approaches for related illnesses.

Insights into the molecular genetic basis of individual differences in metacognition.

There is a striking lack of studies on the molecular genetic basis of metacognition, i.e., the higher-order ability to monitor mental processes. Here, an initial step toward resolving this issue was undertaken by investigating functional polymorphisms from three genes of the dopaminergic or serotonergic systems (DRD4, COMT, and 5-HTTLPR) in relation to behaviorally assessed metacognition in six paradigms across three cognitive domains. We report evidence for a task-dependent higher average confidence level (metacognitive bias) in carriers of at least one S or LG-allele in the 5-HTTLPR genotype and integrate these findings within a differential susceptibility framework.

Latent state-trait and latent growth curve modeling of inhibitory control.

The reliability of inhibitory control task performance as well as the existence of an underlying unitary inhibitory construct have been questioned. The present study is the first to use a trait and state decomposition approach to formally quantify the reliability of inhibitory control and to examine its hierarchical structure. N = 150 participants carried out antisaccade, Eriksen flanker, go/nogo, Simon, stop-signal, and Stroop tasks on three occasions. By applying latent state-trait modeling and latent growth-curve modeling, reliability was estimated and divided into the amount of variance explained by trait effects and trait changes (consistency) and the amount of variance explained by situational effects and effects of Situation × Person interaction (occasion specificity). Mean reaction times for all tasks revealed excellent reliabilities (.89-.99). Importantly, on average, 82% of variance was accounted for by consistency while specificity was rather small. Although primary inhibitory variables revealed lower reliabilities (.51-.85), the majority of explained variance was again trait determined. Trait changes were observed for most variables and were strongest when comparing the first occasion to later ones. In addition, in some variables, those improvements were particularly high in initially underperforming subjects. An analysis of the construct of inhibition on trait level showed that communality between tasks was low. We conclude that most variables in inhibitory control tasks are mainly affected by stable trait effects, but there is only little evidence of a common, underlying inhibitory control construct at trait level. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Gaze-based attention refocusing training in virtual reality for adult attention-deficit/hyperactivity disorder.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is characterized by substantial interindividual heterogeneity that challenges the systematic assessment and treatment. Considering mixed evidence from previous neurofeedback research, we present a novel feedback system that relies on gaze behavior to detect signs of inattention while performing a neuropsychological attention task in a virtual seminar room. More specifically, an audiovisual feedback was given whenever participants averted their gaze from the given task. METHODS: Eighteen adults with ADHD and 18 healthy controls performed a continuous performance task (CPT) in virtual reality under three counterbalanced conditions in which either gaze-based feedback, sham feedback, or no feedback was provided. In all conditions, phases of high and low virtual distraction alternated. CPT errors and reaction times, proportions of gaze dwell times (e.g., task focus or distraction focus), saccade characteristics, EEG theta/beta ratios, head movements, and an experience sampling of ADHD symptoms were analyzed. RESULTS: While patients can be discriminated well from healthy controls in that they showed more omission errors, higher reaction times, higher distraction-related dwell times, and more head movements, the feedback did not immediately improve task performance. It was also indicated that sham feedback was rather associated with an aggravation of symptoms in patients. CONCLUSIONS: Our findings demonstrate sufficient suitability and specificity for this holistic ADHD symptom assessment. Regarding the feedback, a single-session training was insufficient to achieve learning effects based on the proposed metacognitive strategies. Future longitudinal, multi-session trials should conclusively examine the therapeutic efficacy of gaze-based virtual reality attention training in ADHD. TRIAL REGISTRATION: drks.de (identifier: DRKS00022370).

Multimodal Virtual Reality-Based Assessment of Adult ADHD: A Feasibility Study in Healthy Subjects.

Neuropsychological assessments are often surprisingly inaccurate in mapping clinically-reported attention-deficit hyperactivity disorder (ADHD) symptoms, presumably due to their low ecological validity. Virtual reality (VR) might offer a potential solution for this problem, given its capability to generate standardized and yet highly realistic virtual environments. As the first adaptation of existing virtual classroom scenarios to an adult population, we developed a Virtual Seminar Room (VSR) for multimodal characterization of ADHD symptoms. To test its feasibility, N = 35 healthy participants were immersed into the VSR via a head-mounted display and carried out a VR-embedded continuous performance task (CPT) under varying levels of distractions in two experimental blocks (24 min each). CPT performance, electroencephalography (EEG) measures, and head movements (actigraphy) were simultaneously recorded and analyzed offline. Although CPT performance remained constant throughout the task, head movements increased significantly from Block 1 to Block 2. In addition, EEG theta (4-7 Hz) and beta (13-30 Hz) power was higher during Block 1 than Block 2, and during distractor-present than distractor-absent phases. Moreover, P300 amplitudes were higher during Block 1 than Block 2, and P300 latencies were prolonged in distractor-absent compared with distractor-present phases. Although the paradigm awaits further improvements, this study confirms the general feasibility of the VSR and provides a first step toward a multimodal, ecologically valid, and reliable VR-based adult ADHD assessment.

Eye tracking: empirical foundations for a minimal reporting guideline.

In this paper, we present a review of how the various aspects of any study using an eye tracker (such as the instrument, methodology, environment, participant, etc.) affect the quality of the recorded eye-tracking data and the obtained eye-movement and gaze measures. We take this review to represent the empirical foundation for reporting guidelines of any study involving an eye tracker. We compare this empirical foundation to five existing reporting guidelines and to a database of 207 published eye-tracking studies. We find that reporting guidelines vary substantially and do not match with actual reporting practices. We end by deriving a minimal, flexible reporting guideline based on empirical research (Section "An empirically based minimal reporting guideline").

Polygenic risk scores for schizophrenia are associated with oculomotor endophenotypes.

BACKGROUND: Schizophrenia is a heterogeneous disorder with substantial heritability. The use of endophenotypes may help clarify its aetiology. Measures from the smooth pursuit and antisaccade eye movement tasks have been identified as endophenotypes for schizophrenia in twin and family studies. However, the genetic basis of the overlap between schizophrenia and these oculomotor markers is largely unknown. Here, we tested whether schizophrenia polygenic risk scores (PRS) were associated with oculomotor performance in the general population. METHODS: Analyses were based on the data of 2956 participants (aged 30-95) of the Rhineland Study, a community-based cohort study in Bonn, Germany. Genotyping was performed on Omni-2.5 exome arrays. Using summary statistics from a recent meta-analysis based on the two largest schizophrenia genome-wide association studies to date, we quantified genetic risk for schizophrenia by creating PRS at different p value thresholds for genetic markers. We examined associations between PRS and oculomotor performance using multivariable regression models. RESULTS: Higher PRS were associated with higher antisaccade error rate and latency, and lower antisaccade amplitude gain. PRS showed inconsistent patterns of association with smooth pursuit velocity gain and were not associated with saccade rate during smooth pursuit or performance on a prosaccade control task. CONCLUSIONS: There is an overlap between genetic determinants of schizophrenia and oculomotor endophenotypes. Our findings suggest that the mechanisms that underlie schizophrenia also affect oculomotor function in the general population.