Rationale Although the study of emotions can look back to over 100 years of research, it is unclear which information the brain uses to construct the subjective experience of an emotion. Objective In the current study, we assess the role of the peripheral and central adrenergic system in this respect. Methods Healthy volunteers underwent a double inhalation of 35% CO 2 , which is a well-validated procedure to induce an intense emotion, namely panic. In a randomized, cross-over design, 34 participants received either a β 1 -blocker acting selectively in the peripheral nervous system (atenolol), a β 1 -blocker acting in the peripheral and central nervous system (metoprolol), or a placebo before the CO 2 inhalation. Results Heart rate and systolic blood pressure were reduced in both β-blocker conditions compared to placebo, showing effective inhibition of the adrenergic tone. Nevertheless, the subjective experience of the induced panic was the same in all conditions, as measured by self-reported fear, discomfort, and panic symptom ratings. Conclusions These results indicate that information from the peripheral and central adrenergic system does not play a major role in the construction of the subjective emotion.
BACKGROUND:Neurological complications in COVID-19 patients admitted to an intensive care unit (ICU) have been previously reported. As the pandemic progressed, therapeutic strategies were tailored to new insights. This study describes the incidence, outcome, and types of reported neurological complications in invasively mechanically ventilated (IMV) COVID-19 patients in relation to three periods during the pandemic.METHODS:IMV COVID-19 ICU patients from the Dutch Maastricht Intensive Care COVID (MaastrICCht) cohort were included in a single-center study (March 2020 - October 2021). Demographic, clinical, and follow-up data were collected. Electronic medical records were screened for neurological complications during hospitalization. Three distinct periods (P1, P2, P3) were defined, corresponding to periods with high hospitalization rates. ICU survivors with and without reported neurological complications were compared in an exploratory analysis.RESULTS:IMV COVID-19 ICU patients (n=324; median age 64 [IQR 57-72] years; 238 males (73.5%)) were stratified into P1 (n=94), P2 (n=138), and P3 (n=92). ICU mortality did not significantly change over time (P1=38.3%; P2=41.3%; P3=37.0%; p=.787). The incidence of reported neurological complications during ICU admission gradually decreased over the periods (P1=29.8%; P2=24.6%; P3=18.5%; p=.028). Encephalopathy/delirium (48/324 (14.8%)) and ICU-acquired weakness (32/324 (9.9%)) were most frequently reported and associated with ICU treatment intensity. ICU survivors with neurological complications (n=53) were older (p=.025), predominantly male (p=.037), and had a longer duration of IMV (p<.001) and ICU stay (p<.001), compared to survivors without neurological complications (n=132). A multivariable analysis revealed that only age was independently associated with the occurrence of neurological complications (ORadj=1.0541; 95% CI=1.0171-1.0925; p=.004). Health-related quality-of-life at follow-up was not significantly different between survivors with and without neurological complications (n = 82, p=.054).CONCLUSIONS:A high but decreasing incidence of neurological complications was reported during three consecutive COVID-19 periods in IMV COVID-19 patients. Neurological complications were related to the intensity of ICU support and treatment, and associated with prolonged ICU stay, but did not lead to significantly worse reported health-related quality-of-life at follow-up.
Task-free brain activity exhibits spontaneous fluctuations between functional states, characterized by synchronized activation patterns in distributed resting-state (RS) brain networks. The temporal dynamics of the networks’ electrophysiological signatures reflect individual variations in brain activity and connectivity linked to mental states and cognitive functions and can predict or monitor vulnerability to develop psychiatric or neurological disorders. In particular, RS alpha fluctuations modulate perceptual sensitivity, attentional shifts, and cognitive control, and could therefore reflect a neural correlate of increased vulnerability to sensory distortions, including the proneness to hallucinatory experiences. We recorded 5 min of RS EEG from 33 non-clinical individuals varying in hallucination proneness (HP) to investigate links between task-free alpha dynamics and vulnerability to hallucinations. To this end, we used a dynamic brain state allocation method to identify five recurrent alpha states together with their spatiotemporal dynamics and most active brain areas through source reconstruction. The dynamical features of a state marked by activation in somatosensory, auditory, and posterior default-mode network areas predicted auditory and auditory-verbal HP, but not general HP, such that individuals with higher vulnerability to auditory hallucinations spent more time in this state. The temporal dynamics of spontaneous alpha activity might reflect individual differences in attention to internally generated sensory events and altered auditory perceptual sensitivity. Altered RS alpha dynamics could therefore instantiate a neural marker of increased vulnerability to auditory hallucinations.
During fMRI neurofeedback participants learn to self-regulate activity in relevant brain areas and networks based on ongoing feedback extracted from measured responses in those regions. This closed-loop approach has been successfully applied to reduce symptoms in mood disorders such as depression by showing participants a thermometer-like display indicating the strength of activity in emotion-related brain areas. The hitherto employed conventional neurofeedback is, however, ‘blind’ with respect to emotional content, i.e. patients instructed to engage in a specific positive emotion could drive the neurofeedback signal by engaging in a different (positive or negative) emotion. In this future perspective, we present a new form of neurofeedback that displays semantic information of emotions to the participant. Semantic information is extracted online using real-time representational similarity analysis of emotion-specific activity patterns. The extracted semantic information can be provided to participants in a two-dimensional semantic map depicting the current mental state as a point reflecting its distance to pre-measured emotional mental states (e.g. ‘happy’, ‘content’, ‘sad’, ‘angry’). This new approach provides transparent feedback during self-regulation training, and it has the potential to enable more specific training effects for future therapeutic applications such as clinical interventions in mood disorders. This article is part of the theme issue ‘Neurofeedback: new territories and neurocognitive mechanisms of endogenous neuromodulation’.
•DBS impacts the life of OCD patients beyond changes in their core symptoms.•Qualitative methods allow gathering in-depth knowledge of DBS-related experiences.•Positive and negative psychological and physical experiences are reported.•Attention should be given to each individual treatment trajectory.•Proper assessment tools should be developed for continuous monitoring and support.
BackgroundResting state (RS) brain activity is inherently non-stationary. Hidden Semi-Markov Models (HsMM) can characterize continuous RS data as a sequence of recurring and distinct brain states along with their spatio-temporal dynamics.New methodRecent explorations suggest that HsMM state dynamics in the alpha frequency band link to auditory hallucination proneness (HP) in non-clinical individuals. The present study aimed to replicate these findings to elucidate robust neural correlates of hallucinatory vulnerability. Specifically, we aimed to investigate the reproducibility of HsMM states across different data sets and within-data set variants as well as the replicability of the association between alpha brain state dynamics and HP.ResultsWe found that most brain states are reproducible in different data sets, confirming that the HsMM characterized robust and generalizable EEG RS dynamics on a sub-second timescale. Brain state topographies and temporal dynamics of different within-data set variants showed substantial similarities and were robust against reduced data length and number of electrodes. However, the association with HP was not directly reproducible across data sets.Comparison with existing methodsThe HsMM optimally leverages the high temporal resolution of EEG data and overcomes time-domain restrictions of other state allocation methods.ConclusionThe results indicate that the sensitivity of brain state dynamics to capture individual variability in HP may depend on the data recording characteristics and individual variability in RS cognition, such as mind wandering. Future studies should consider that the order in which eyes-open and eyes-closed RS data are acquired directly influences an individual’s attentional state and generation of spontaneous thoughts, and thereby might mediate the link to hallucinatory vulnerability.
Ample research explored changes in sensory feedback processing of the self-voice as well as the control of attention allocation in voice hearers, including both non-clinical voice hearers and voice hearers with a psychotic disorder. While the attentional bias toward negative emotional information in voice hearers with a psychotic disorder due to heightened sensitivity towards threat/danger is well established, it remains unclear how positive emotion captures or controls attention. Manipulating the certainty of sensory feedback to the self-voice, transitioning from fully neutral to entirely positive (100% neutral, 60-40% neutral-pleasure, 50-50% neutral-pleasure, 40-60% neutral-pleasure, 100% pleasure), provides an opportunity to investigate attentional control and sensory feedback processing in positive self-voice as a function of hallucination proneness (HP). Participants with different HP scores self-generated and passively listened to their own voices during EEG recordings. N100 or P200 responses to self-generated and externally-generated self-voices did not differ. Further, HP did not modulate N100/P200 responses. These null findings might result from the minimal perceptual discriminability among the five types of voices varying in pleasure content. This might have led to less variation in certainty regarding the sensory feedback to self-voice, and consequently a lack of differential engagement of attentional resources. The lack of a global N100 suppression effect prompts inquiry into the association of sense of ownership/agency and pleasure. ### Competing Interest Statement The authors have declared no competing interest.
22q11.2 copy number variants (22q11.2 CNVs) are associated with either an increased or a reduced risk of developing psychotic disorders and impaired cognitive functioning. Glutamatergic and GABAergic pathways are hypothesized to be disrupted in 22q11.2 CNV patients. Although a balance between glutamate and GABA is necessary for optimal brain functioning, to date, GABA has not been studied in 22q11.2 CNVs. Here, we investigated glutamate and GABA concentrations in the anterior cingulate cortex in patients with 22q11.2 CNVs using 7-Tesla 1H-MRS. Our results showed no significant differences in glutamate and GABA concentrations between 22q11.2 CNV patients and healthy controls.
In the era of system neuroscience, characterizing functional network dynamics is fundamental to understand how the brain appropriately or inappropriately responds to the environment. For example, when presented with a stressor, the salience network (SN) reportedly increases its activation at the cost of the executive control network (ECN). However, little is known on how these networks interact over the course of fear learning.
Introduction Auditory verbal hallucinations (AVH) are a transdiagnostic phenomenon but also occur in the general population. The disposition to experience AVH is considered a continuous expression from non-clinical to clinical hallucination proneness (HP). Currently, little is known about the neurophysiology of the non-clinical HP part of the continuum. AVH might result from a heightened sensitivity to sensory inputs and a decreased ability to differentiate between externally and internally generated input. Resting state (RS) alpha band activity is associated with perceptual sensitivity, attentional shifts, and cognitive control. Accordingly, spontaneous alpha fluctuations might present as a HP correlate. To investigate the time-varying dynamics of alpha band activity, we deployed a novel method for brain state allocation. Methods We recorded RS electroencephalography (EEG) data from 33 individuals with varying levels of HP but without clinically relevant hallucinations and used a Hidden Semi-Markov Model (HsMM) to identify five recurrent alpha states with unique temporal dynamics and topographies. The states’ mean duration and occupancy were analyzed as a function of HP. The sources of each state were reconstructed to identify the most active brain areas and their correspondence with known resting state networks. Results Occupancy and mean duration of a state corresponding to sensorimotor, auditory, and default-mode network (DMN) areas significantly predicted auditory and auditory-verbal HP, but not general HP. The temporal dynamics of all other states did not relate to HP. Conclusion Alpha brain state sources align with prior results on the role of the alpha in the DMN. The temporal dynamics of alpha might reflect individual differences for attentional biases to internally generated sensory events and altered auditory perceptual sensitivity. Thus, changes in the temporal brain state dynamics of RS alpha oscillations could present as a neural marker of increased vulnerability to auditory hallucinatory experiences.
Research studies based on tractography have revealed a prominent reduction of asymmetry in some key white-matter tracts in schizophrenia (SCZ). However, we know little about the influence of common genetic risk factors for SCZ on the efficiency of routing on structural brain networks (SBNs). Here, we use a novel recall-by-genotype approach, where we sample young adults from a population-based cohort (ALSPAC:N genotyped = 8,365) based on their burden of common SCZ risk alleles as defined by polygenic risk score (PRS). We compared 181 individuals at extremes of low (N = 91) or high (N = 90) SCZ-PRS under a robust diffusion MRI-based graph theoretical SBN framework. We applied a semi-metric analysis revealing higher SMR values for the high SCZ-PRS group compared with the low SCZ-PRS group in the left hemisphere. Furthermore, a hemispheric asymmetry index showed a higher leftward preponderance of indirect connections for the high SCZ-PRS group compared with the low SCZ-PRS group (P-FDR < 0.05). These findings might indicate less efficient structural connectivity in the higher genetic risk group. This is the first study in a population-based sample that reveals differences in the efficiency of SBNs associated with common genetic risk variants for SCZ.
Cerebrovascular dysregulation is a hallmark feature of Alzheimer’s disease (AD), where alterations in cerebral blood flow (CBF) are observed decades prior to symptom onset. Genome-wide association studies (GWAS) show that AD has a polygenic aetiology, providing a tool for studying AD susceptibility across the lifespan. Here, we ascertain whether AD genetic risk effects on CBF previously observed (Chandler et al., 2019) remain consistent across the lifespan. We further provide a causal mechanism to AD genetic risk scores (AD-GRS) effects by establishing spatial convergence between AD-GRS associated regional reductions in CBF and mRNA expression of the proximal AD transcripts using independent data from the Allen Brain Atlas. We analysed grey matter (GM) CBF in a young cohort (N=75; aged 18-35) and an older cohort (N=90; aged 55-85). Critically, we observed that AD-GRS was negatively associated with whole brain GM CBF in the older cohort (standardised β −0.38 [−0.68 – −0.09], P = 0.012), consistent with our prior observation in younger healthy adults (Chandler et al., 2019). We then demonstrate that the regional impact of AD-GRS on GM CBF was spatially consistent across the younger and older samples (r = 0.233, P = 0.035). Finally, we show that CBF across the cortex was related to the regional expression of the genes proximal to SNP’s used to estimate AD-GRS in both younger and older cohorts (ZTWO-TAILED = −1.99, P= 0.047; ZTWO-TAILED = −2.153 P = 0.032, respectively). These observations collectively demonstrate that AD risk alleles have a negative influence on brain vascular function and likely contribute to cerebrovascular changes preceding the onset of clinical symptoms, potentially driven by regional expression of proximal AD risk genes across the brain. Our observations suggest that reduced CBF is an early antecedent of AD and a key modifiable target for therapeutic intervention in individuals with a higher cumulative genetic risk for AD. This study will further enable identification of key molecular processes that underpin AD genetic risk related reductions in CBF that could be targeted decades prior to the onset of neurodegeneration.
Stress-related mental health issues are not only highly prevalent world-wide, but are also associated with a very high disease burden. Moreover, efforts to reduce their prevalence through standard therapy have remained largely unsuccessful, making stress-related disorders a fast-progressing global societal problem that needs urgent attention and new solutions to mitigate it. One potential solution might come from recent advances in neuroscience which have opened the door for new innovative approaches that embrace new insights about the underlying neural working mechanisms of stress and combine them with non-invasive neuro-technology. One particularly promising approach in this field is that of neurofeedback. In this article, we argue that neurofeedback has a unique set of properties which can give a neurofeedback-based therapy approach an advantage over other (standard) treatment approaches, and might make it especially suited for mitigating stress-related mental health issues.
Background: Non-invasive neurofeedback training is currently explored as a potential add-on therapy to treat patients suffering from major depressive disorder, and first trials show promising clin-ical effects. The temporal evolution of therapeutic change, however, remains unclear. Methods: Profile of mood states (POMS) questionnaire ratings were collected immediately before and after five sessions of real-time fMRI neurofeedback training (rt-fMRI-NFT) in a randomised controlled trial (RCT). Data were analysed for within and between treatment sessions ef-fects. Results: Trajectories of mood profiles varied between subscales. Total mood disturbance and the subscales depression and tension showed both within and between treatment sessions ef-fects, although within-session effects were descriptively larger. Limitations: The sample size was relatively small owed to the current state of the rt-fMRI-NFT field. No data from a sham-neurofeedback control group was available. Conclusions: The presented data provides a better understanding of when changes in mood states occur. The POMS questionnaire allows monitoring rapid and slowly evolving changes in mood states and can thus inform future study designs for neuromodulation and psychological in-terventions for mental disorders.
Background Impulsive and irritable behaviour have been reported in HD from the earliest clinical descriptions of the condition, and abnormalities on various measures of impulsive behaviour have been demonstrated. However these studies had small sample sizes, and did not account for potential confounding effects in the HD population such as IQ and medication. Furthermore, the links between impulsive and irritable behaviour in HD remain unclear. Aims Determine which cognitive mechanisms contribute to irritable behaviour in HD Determine which aspects of impulsive behaviour are seen in HD Methods/Techniques We recruited HD patients and familial controls from the South Wales HD Service and performed a battery of established and novel cognitive tasks, including questionnaire measures of impulsive behavour and irritability (UPPSP, Barrett Impulsivity Scale, PBAs and Snaith), motor inhibition (stop signal task), delay discounting (Kirby instrument) and cognitive impulsivity (Iowa Gambling task). We also performed tasks of provocation (a previously reported task, and a novel task) to determine the relative contributions of impaired inhibition and excessive response to provocation in mediating irritability in HD. Results We recruited 51 HD patients and 26 controls. We found differences in response to provocation and also impaired motor inhibition on the stop signal task in the HD population, even after correcting for relevant confounders such as IQ, medication, motor impairment and psychiatric comorbidity. However, only the response to provocation was associated with irritability in HD. The tasks of delay discounting, and cognitive impulsivity did not demonstrate any differences between HD patients and controls after controlling for relevant confounders. Conclusions Irritability in HD is mediated by excessive response to provocation rather than the known impairments in motor inhibition. Other aspects of impulsivity to contribute to impulsive behaviour in HD.
Background. It is not clear to what extent associations between schizophrenia, cannabis use and cigarette use are due to a shared genetic etiology. We, therefore, examined whether schizophrenia genetic risk associates with longitudinal patterns of cigarette and cannabis use in adolescence and mediating pathways for any association to inform potential reduction strategies. Methods. Associations between schizophrenia polygenic scores and longitudinal latent classes of cigarette and cannabis use from ages 14 to 19 years were investigated in up to 3925 individuals in the Avon Longitudinal Study of Parents and Children. Mediation models were estimated to assess the potential mediating effects of a range of cognitive, emotional, and behavioral phenotypes. Results. The schizophrenia polygenic score, based on single nucleotide polymorphisms meeting a training-set p threshold of 0.05, was associated with late-onset cannabis use (OR = 1.23; 95% CI = 1.08,1.41), but not with cigarette or early-onset cannabis use classes. This association was not mediated through lower IQ, victimization, emotional difficulties, antisocial behavior, impulsivity, or poorer social relationships during childhood. Sensitivity analyses adjusting for genetic liability to cannabis or cigarette use, using polygenic scores excluding the CHRNA5-A3-B4 gene cluster, or basing scores on a 0.5 training-set p threshold, provided results consistent with our main analyses. Conclusions. Our study provides evidence that genetic risk for schizophrenia is associated with patterns of cannabis use during adolescence. Investigation of pathways other than the cognitive, emotional, and behavioral phenotypes examined here is required to identify modifiable targets to reduce the public health burden of cannabis use in the population.
Background Depression is common in HD, with major effects on quality of life. However, our knowledge of the most efficacious treatments and contributory cognitive mechanisms are limited. Aims Use the Enroll–HD periodic dataset to compare efficacy of major antidepressant classes in HD. Use a battery of cognitive tasks in a local cohort of x manifest HD patients to determine mechanisms contributing to depression in HD. Methods/Techniques Study 1) included any participant in ENROLL-HD started on an antidepressant for depression and recorded depression score at follow-up. Using the propensity scoring packages in R, we determined the probability of being assigned to different antidepressant classes based on known variables, and then included this in models of treatment outcome. Study 2) used established and novel tasks measuring a) effort for reward, b) reward value, c) reward learning and d) response to negative outcome to determine mechanisms leading to depression in HD. Results/Outcome Study 1) 5486 (37.71%) of participants received an antidepressant for depression. SSRIs and Bupropion had the highest probability of being free of depression at first follow-up and all subsequent follow-ups (32.70% and in 37.31%). Outcome models including the propensity score showed that SNRIs performed worse than SSRIs and Bupropion on both outcome measures. Study 2) We found deficits of effort for reward in HD participants compared with controls, and an association between depression score on the HADS and reduced effort for reward. We did not see an association of depression scores on the HADS and any other measure. Conclusions Antidepressants that are most effective in treating depression in HD differ from the most efficacious treatments for depression in the general population. A deficit in effort for reward is the major contributor to depression in HD. The most effective antidepressants in HD are also those with the largest effect on motivational anhedonia.
Previous studies on olfactory function in patients with bipolar disorder (BD) are limited and contradictory. The current study aimed to comprehensively analyze the olfactory function of patients with euthymic BD using psychophysical, electrophysiological and neuroimaging techniques. Twenty-one patients with BD in remission and 20 healthy controls were tested with the “Sniffin’ Sticks” olfactory test. Block-design fMRI data to a pleasant and an unpleasant stimulus were acquired while recording intensity and hedonic ratings. Olfactory event-related potentials (OERP) to the same stimuli were additionally recorded. Results show no differences between patients and healthy controls in terms of self-rated olfactory function and tested olfactory domains (odor threshold, discrimination or identification) (p>0.05). Compared to healthy controls, patients showed an increased fMRI activation in multiple cortical and subcortical regions as a response to olfactory stimulation, as well as larger amplitudes of OERPs regardless of the hedonic valence of the odor. All in all, patients with euthymic BD showed a stronger central responsiveness to odorous stimuli in fMRI and OERPs despite of normal psychophysical results, indicating the probable existence of an odor-related over-reactive brain network in the remission phase of BD.
Polygenicity and pleiotropy are key properties of the genomic architecture of psychiatric disorders. An optimistic interpretation of polygenicity is that genomic variants converge on a limited set of mechanisms at some level from genes to behavior. Alternatively, convergence may be minimal or absent. We took advantage of brain connectivity, measured by resting-state functional MRI (rs-fMRI), as well as rare and common genomic variants to understand the effects of polygenicity and pleiotropy on large-scale brain networks, a distal step from genes to behavior. We processed ten rs-fMRI datasets including 32,988 individuals, to examine connectome-wide effects of 16 copy number variants (CNVs), 10 polygenic scores, 6 cognitive and brain morphometry traits, and 4 idiopathic psychiatric conditions. Although effect sizes of CNVs on connectivity were correlated to cognition and number of genes, increasing polygenicity was associated with decreasing effect sizes on connectivity. Accordingly, the effect sizes of polygenic scores on connectivity were 6-fold lower compared to CNVs. Despite this heterogeneity of connectivity profiles, multivariate analysis identified convergence of genetic risks and psychiatric disorders on the thalamus and the somatomotor network. Based on spatial correlations with transcriptomic data, we hypothesize that excitatory thalamic neurons may be primary contributors to brain alteration profiles shared across genetic risks and conditions. Finally, pleiotropy measured by genetic and transcriptomic correlations between 38 pairs of conditions/traits showed significant concordance with connectomic correlations, suggesting a substantial causal genetic component for shared connectivity. Such findings open avenues to delineate general mechanisms - amenable to intervention - across conditions and genetic risks.