Task-related Brain Activity Research Articles

Increased Amygdala Activation during Symptom Provocation Predicts Response to Combined Repetitive Transcranial Magnetic Stimulation and Exposure Therapy in Obsessive-Compulsive Disorder in a Randomized Controlled Trial.

Repetitive transcranial magnetic stimulation (rTMS), combined with exposure and response prevention (ERP), is a promising treatment modality for treatment-refractory obsessive-compulsive disorder (OCD). Yet, not all patients respond sufficiently to this treatment. We investigated whether brain activation during a symptom provocation task could predict treatment response. Sixty-one adults with OCD (22 male/ 39 female) underwent symptom provocation with OCD- and fear-related visual stimuli during fMRI prior to an 8-week combined rTMS and ERP treatment regimen. Participants received one of the three following rTMS treatments as part of a randomized controlled trial: (1) 10Hz rTMS (110% resting motor threshold (RMT)) to the left dorsolateral prefrontal cortex (DLPFC); (2) 10Hz rTMS (110% RMT) to the left pre-supplementary motor area (preSMA); or (3) 10Hz control rTMS (60% RMT) to the vertex. Multiple regression and correlation were used to examine the predictive value of task-related brain activation for treatment response in the following ROIs: dorsomedial prefrontal cortex, amygdala, DLPFC, and preSMA. The different treatment groups responded equally to treatment. Higher pre-treatment task-related activation of the right amygdala to OCD-related stimuli showed a positive association with treatment response in all groups. Exploratory whole-brain analyses showed positive associations between activation in multiple task-relevant regions and treatment response. Only dorsal anterior cingulate cortex activation to fear-related stimuli showed a negative association with treatment outcome. Higher pre-treatment right amygdala activation during symptom provocation predicts better treatment response to combined rTMS and ERP in OCD.

A neural implementation of cognitive reserve: Insights from a longitudinal fMRI study of set-switching in aging

Aging is often accompanied by changes in brain structure and executive functions, particularly in tasks involving cognitive flexibility, such as task-switching. However, substantial individual differences in the degree of cognitive impairment indicate that some individuals can cope with brain changes more effectively than others, suggesting higher cognitive reserve (CR). This study identified a neural basis for CR by examining the longitudinal relationship between task-related brain activation, structural brain changes, and changes in cognitive performance during an executive task-switching paradigm including single and dual conditions. Fifty-two older individuals were assessed at baseline and followed up after five years. Structural brain changes related to task-switching performance were analyzed using elastic net regression. Task-related functional brain activation was measured using ordinal trends canonical variate analysis (OrT CVA), capturing patterns of activation increasing from single to dual conditions. A differential task-related expression score (dOrT) was calculated as the difference in pattern expression scores between single and dual conditions at baseline. A linear regression model tested whether dOrT moderated the impact of brain changes on changes in switch cost over five years. Results showed a significant interaction between changes in brain structure and dOrT activation on switch cost change, indicating a moderation effect of task-related activation. Higher dOrT buffered the impact of brain structural decline on switch costs, enabling older adults to better cope with age-related brain structural changes and preserve cognitive flexibility. These findings suggest that these task-related activation patterns represent a neural basis for CR.

Brain-movement relationship during upper-limb functional movements in chronic post-stroke patients

BackgroundFollowing a stroke, brain activation reorganisation, movement compensatory strategies, motor performance and their evolution through rehabilitation are matters of importance for clinicians. Two non-invasive neuroimaging methods allow for recording task-related brain activation: functional near-infrared spectroscopy (fNIRS) and electroencephalography (fEEG), respectively based on hemodynamic response and neuronal electrical activity. Their simultaneous measurement during movements could allow a better spatiotemporal mapping of brain activation, and when associated to kinematic parameters could unveil underlying mechanisms of functional upper limb (UL) recovery. This study aims to depict the motor cortical activity patterns using combined fNIRS-fEEG and their relationship to motor performance and strategies during UL functional tasks in chronic post-stroke patients.MethodsTwenty-one healthy old adults and 21 chronic post-stroke patients were recruited and completed two standardised functional tasks of the UL: a paced-reaching task where they had to reach a target in front of them and a circular steering task where they had to displace a target using a hand-held stylus, as fast as possible inside a circular track projected on a computer screen. The activity of the bilateral motor cortices and motor performance were recorded simultaneously utilizing a fNIRS-fEEG and kinematics platform.Results and conclusionsKinematic analysis revealed that post-stroke patients performed worse in the circular steering task and used more trunk compensation in both tasks. Brain analysis of bilateral motor cortices revealed that stroke individuals over-activated during the paretic UL reaching task, which was associated with more trunk usage and a higher level of impairment (clinical scores). This work opens up avenues for using such combined methods to better track and understand brain-movement evolution through stroke rehabilitation.

An fMRI study on alexithymia and affective state recognition in the Reading the Mind in the Eyes Test.

Recognizing others' affective states is essential for successful social interactions. Alexithymia, characterized by difficulties in identifying and describing one's own emotions, has been linked to deficits in recognizing emotions and mental states in others. To investigate how neural correlates of affective state recognition are affected by different facets of alexithymia, we conducted a functional magnetic resonance imaging study with 53 healthy participants (aged 19-36 years, 51% female) using the Reading the Mind in the Eyes Test (RMET) and three different measures of alexithymia [Toronto Structured Interview for Alexithymia (TSIA), Toronto Alexithymia Scale (TAS-20), and Bermond-Vorst Alexithymia Questionnaire]. In addition, we examined brain activity during the RMET and replicated previous findings with task-related brain activation in the inferior frontal and temporal gyri, as well as the insula. No association was found between alexithymia and behavioral performance in the RMET, possibly due to the low number of participants with high alexithymia levels. Region of interest based analyses revealed no associations between alexithymia and amygdala or insula activity during the RMET. At the whole-brain level, both a composite alexithymia score and the unique variance of the alexithymia interview (TSIA) were associated with greater activity in visual processing areas during the RMET. This may indicate that affective state recognition performance in alexithymia relies on a higher compensatory activation in visual areas.

TMS-induced plasticity improving cognitive control in OCD II: Task-based neural predictors of treatment response

ObjectiveRepetitive transcranial magnetic stimulation (rTMS) has the potential to increase the clinical effect of exposure with response prevention (ERP) psychotherapy for obsessive-compulsive disorder (OCD). We investigated the use of task-based functional MRI (tb-fMRI) for predicting clinical outcomes to different rTMS protocols combined with ERP in OCD. Method61 adults with OCD underwent rTMS and ERP and were randomized to different high frequency rTMS conditions: left dorsolateral prefrontal cortex (DLPFC; n=19), left pre-supplementary motor area (preSMA; n=23), and control stimulation at the vertex at low intensity (n=19). The Tower of London task and Stop-Signal Task were used to assess pretreatment activation during planning and inhibitory control, respectively. We adopted a Bayesian region-based approach to test whether clinical improvement can be predicted by tb-fMRI-derived measures of task-related brain activation or functional connectivity between task-relevant regions and the bilateral amygdala. ResultsFor the vertex group, but not the DLPFC/preSMA rTMS conditions, higher activation in several task-relevant regions during planning and response inhibition, and lower error-related activation, corresponded with better short-term clinical improvement. Lower precuneus activation with increased planning taskload correlated with symptom reduction in the DLPFC group. In the preSMA group, higher error-related activation and lower inhibition-related insular-amygdalar connectivity was associated with symptom reduction. ConclusionsPretreatment tb-fMRI-derived measures of activation and connectivity during planning and inhibition-related processes are associated with clinical response for specific rTMS conditions in OCD. Future placebo-controlled trials with larger sample sizes should combine clinical information and neural correlates to improve prediction of clinical outcome.

Using Dual-Coil TMS-EEG to Probe Bilateral Brain Mechanisms in Healthy Aging and Mild Cognitive Impairment.

A widespread observation in the cognitive neuroscience of aging is that older adults show a more bilateral pattern of task-related brain activation. These observations are based on inherently correlational approaches. The current study represents a targeted assessment of the role of bilaterality using repetitive transcranial magnetic stimulation (rTMS). We used a novel bilateral TMS-stimulation paradigm, applied to a group of healthy older adults (hOA) and older adults with mild cognitive impairment (MCI), with two aims: First, to elucidate the neurophysiological effects of bilateral neuromodulation, and second to provide insight into the neurophysiological basis of bilateral brain interactions. Electroencephalography (EEG) was recorded while participants received six forms of transcranial magnetic stimulation (TMS): unilateral and bilateral rTMS trains at an alpha (8 Hz) and beta (18 Hz) frequency, as well as two sham conditions (unilateral, bilateral) mimicking the sounds of TMS. First, time-frequency analyses of oscillatory power induced by TMS revealed that unilateral beta rTMS elicited rhythmic entrainment of cortical oscillations at the same beta-band frequency. Second, both bilateral alpha and bilateral beta stimulation induced a widespread reduction of alpha power. Lastly, healthy older adults showed greater TMS-related reductions in alpha power in response to bilateral rTMS compared to the MCI cohort. Overall, these results demonstrate frequency-specific responses to bilateral rTMS in the aging brain, and provide support for inhibitory models of hemispheric interaction across multiple frequency bands.

Abnormal activation patterns in MT+ during visual motion perception in major depressive disorder.

Previous studies have found that patients with Major Depressive Disorder (MDD) exhibit impaired visual motion perception capabilities, and multi-level abnormalities in the human middle temporal complex (MT+), a key brain area for processing visual motion information. However, the brain activity pattern of MDD patients during the perception of visual motion information is currently unclear. In order to study the effect of depression on the activity and functional connectivity (FC) of MT+ during the perception of visual motion information, we conducted a study combining task-state fMRI and psychophysical paradigm to compare MDD patients and healthy control (HC). Duration threshold was examined through a visual motion perception psychophysical experiment. In addition, a classic block-design grating motion task was utilized for fMRI scanning of 24 MDD patients and 25 HC. The grating moved randomly in one of eight directions. We examined the neural activation under visual stimulation conditions compared to the baseline and FC. Compared to HC group, MDD patients exhibited increased duration threshold. During the task, MDD patients showed decreased beta value and percent signal change in left and right MT+. In the sample comprising MDD and HC, there was a significant negative correlation between beta value in right MT+ and duration threshold. And in MDD group, activation in MT+ were significantly correlated with retardation score. Notably, no such differences in activation were observed in primary visual cortex (V1). Furthermore, when left MT+ served as the seed region, compared to the HC, MDD group showed increased FC with right calcarine fissure and surrounding cortex and decreased FC with left precuneus. Overall, the findings of this study highlight that the visual motion perception function impairment in MDD patients relates to abnormal activation patterns in MT+, and task-related activity are significantly connected to the retardation symptoms of the disease. This not only provides insights into the potential neurobiological mechanisms behind visual motion perception disorder in MDD patients from the aspect of task-related brain activity, but also supports the importance of MT+ as a candidate biomarker region for MDD.

State-dependent connectivity in auditory-reward networks predicts peak pleasure experiences to music.

Music can evoke pleasurable and rewarding experiences. Past studies that examined task-related brain activity revealed individual differences in musical reward sensitivity traits and linked them to interactions between the auditory and reward systems. However, state-dependent fluctuations in spontaneous neural activity in relation to music-driven rewarding experiences have not been studied. Here, we used functional MRI to examine whether the coupling of auditory-reward networks during a silent period immediately before music listening can predict the degree of musical rewarding experience of human participants (N = 49). We used machine learning models and showed that the functional connectivity between auditory and reward networks, but not others, could robustly predict subjective, physiological, and neurobiological aspects of the strong musical reward of chills. Specifically, the right auditory cortex-striatum/orbitofrontal connections predicted the reported duration of chills and the activation level of nucleus accumbens and insula, whereas the auditory-amygdala connection was associated with psychophysiological arousal. Furthermore, the predictive model derived from the first sample of individuals was generalized in an independent dataset using different music samples. The generalization was successful only for state-like, pre-listening functional connectivity but not for stable, intrinsic functional connectivity. The current study reveals the critical role of sensory-reward connectivity in pre-task brain state in modulating subsequent rewarding experience.

Task-related brain activation associated with violence in patients with schizophrenia: A meta-analysis

This study investigates specific changes in brain function during cognitive and emotional tasks in patients with schizophrenia and a history of violence (VSCZ) compared with non-violent patients with schizophrenia and healthy controls. A comprehensive literature search was conducted at the Web of Science, Medline, and PubMed. Ten studies met the inclusion criteria. In which, eight studies compared brain activation between patients with VSCZ and non-violent patients with schizophrenia, and the former exhibited increased activation at the middle occipital gyrus and rectus compared with the latter. Seven studies compared brain activation between patients with VSCZ and controls, and the former exhibited increased activation at the anterior cingulate cortex, cerebellum VI region, lingual gyrus and fusiform. Subgroup analysis in five studies performing emotional tasks revealed that patients with VSCZ showed increased activation at the middle occipital gyrus compared with non-violent patients with schizophrenia. Our findings suggest that abnormal emotion perception and regulation significantly contribute to the increased risk of violence in patients with schizophrenia. Notably, the middle occipital gyrus and rectus emerge as key neurophysiological correlates associated with this phenomenon.

Youth-like brain activation linked with greater cognitive training gains in older adults: Insights from the ACTOP study

This study investigates the relationship between inter-individual neurofunctional differences in older adults and cognitive training efficacy, with a specific focus on the association between youth-like task-related brain activation and improvements in working memory (WM) training. The data is part of the Attentional Control Training for Older People (ACTOP) study, 30 older adults completed 12 half-hour WM training sessions. The WM performance slope, assessed at the conclusion of sessions 1 through 6 and sessions 7 to 12, determined early- and late-stage training gains, respectively. Transfer measures were taken before (PRE), midway (MID), and after (POST) training, and the differences in MID-PRE and POST-MID on transfer tasks were used to determine early- and late-stage transfer effects, respectively. The Goodness of Fit (GOF) metric was used to quantify the similarity between each older adult's activation pattern, as measured with functional magnetic resonance imaging (fMRI), to that of a group of younger adults. GOF scores were calculated for activation during low-load (1-0back) and high-load (2-0back) N-back tasks. The results indicated that larger GOF scores in the low-load condition were associated with greater training gains in both the early and late learning stages, and that larger GOF scores in the high-load condition were associated with greater training gains during the late-stage. These findings suggest that a youth-like brain activation pattern in older adults is associated with greater cognitive training benefits, underscoring the role of inter-individual neurofunctional differences to account for variations in training outcomes among older adults. Trial registrationClinicalTrials.gov NCT03532113; https://clinicaltrials.gov/ct2/show/NCT03532113.

Brain reserve affects the expression of cognitive reserve networks.

Cognitive reserve (CR) explains differential susceptibility of cognitive performance to neuropathology. However, as brain pathologies progress, cognitive decline occurs even in individuals with initially high CR. The interplay between the structural brain health (= level of brain reserve) and CR-related brain networks therefore requires further research. Our sample included 142 individuals aged 60-70 years. National Adult Reading Test intelligence quotient (NART-IQ) was our CR proxy. On an in-scanner Letter Sternberg task, we used ordinal trend (OrT) analysis to extract a task-related brain activation pattern (OrT slope) for each participant that captures increased expression with task load (one, three, and six letters). We assessed whether OrT slope represents a neural mechanism underlying CR by associating it with task performance and NART-IQ. Additionally, we investigated how the following brain reserve measures affect the association between NART-IQ and OrT slope: mean cortical thickness, total gray matter volume, and brain volumes proximal to the areas contained in the OrT patterns. We found that higher OrT slope was associated with better task performance and higher NART-IQ. Further, the brain reserve measures were not directly associated with OrT slope, but they affected the relationship between NART-IQ and OrT slope: NART-IQ was associated with OrT slope only in individuals with high brain reserve. The degree of brain reserve has an impact on how (and perhaps whether) CR can be implemented in brain networks in older individuals.

Examining the relationship between brain activation and proxies of disease severity using quantile regression in individuals at risk of Alzheimer's disease

Previous studies have reported a pattern of hyperactivation in the pre-dementia phase of Alzheimer's disease (AD), followed by hypoactivation in later stages of the disease. This pattern was modeled as an inverse U-shape function between activation and markers of disease severity. In this study, we used quantile regression to model the association between task-related brain activation in AD signature regions and three markers of disease severity (hippocampal volume, cortical thickness, and associative memory). This approach offers distinct advantages over standard regression models as it analyzes the relationship between brain activation and disease severity across various levels of brain activation. Participants were 54 older adults with subjective cognitive decline+ (SCD+) or mild cognitive impairment (MCI) from the CIMA-Q cohort. The analysis revealed an inverse U-shape quadratic function depicting the relationship between disease severity markers and the activation of the left superior parietal region, while a linear relationship was observed for activation of the hippocampal and temporal regions. Quantile differences were observed for temporal and parietal activation, with more pronounced effects observed in the higher quantiles of activation. When comparing quantiles, we found that higher quantile of activation featured a greater number of individuals with SCD+ compared to mild cognitive impairment (MCI). Results are globally consistent with the presence of an inverse-U shape function of activation in relation to disease severity. They study also underscores the utility of employing quantile regression modeling as the modeling approach revealed the presence of non-homogeneous effects across various quantiles.

Task-related brain activity in upper limb dystonia revealed by simultaneous fNIRS and EEG

ObjectiveThe aim of this study was to explore differences in brain activity and connectivity using simultaneous electroencephalography and near-infrared spectroscopy in patients with focal dystonia during handwriting and finger-tapping tasks. MethodsPatients with idiopathic right upper limb focal dystonia and controls were assessed by simultaneous near-infrared spectroscopy and electroencephalography during the writing and finger-tapping tasks in terms of the mu-alpha, mu-beta, beta and low gamma power and effective connectivity, as well as relative changes in oxyhemoglobin (oxy-Hb) and deoxyhemoglobin using a channel-wise approach with a mixed-effect model. ResultsPatients exhibited higher oxy-Hb levels in the right and left motor cortex and supplementary motor area during writing, but lower oxy-Hb levels in the left sensorimotor and bilateral somatosensory area during finger-tapping compared to controls. During writing, patients showed increased low gamma power in the bilateral sensorimotor cortex and less mu-beta and beta attenuation compared to controls. Additionally, patients had reduced connectivity between the supplementary motor area and the left sensorimotor cortex during writing. No differences were observed in terms of effective connectivity in either task. Finally, patients failed to attenuate the mu-alpha, mu-beta, and beta rhythms during the finger-tapping task. ConclusionsCortical blood flow and EEG spectral power differ between controls and dystonia patients, depending on the task. Writing increased blood flow and altered connectivity in dystonia patients, and it also decreased slow-band attenuation. Finger-tapping decreased blood flow and slow-band attenuation. SignificanceSimultaneous fNIRS and EEG may show relevant information regarding brain dynamics in movement disorders patients in unconstrained environments.

48 Should I Stay or Should I Go? Neural Circuits Underlying Decisions to Explore or Exploit

Objective:Adaptive decision-making is necessary to sustain functional independence. Maladaptive decisions are among the most prevalent features of psychological and neurological disorders. One crucial aspect of decision-making involves arbitrating between exploring new avenues with risky but potentially lucrative outcomes or exploiting prior knowledge and endorsing predictable outcomes. Balancing this dichotomy creates a behavioral tension that shapes all decisions and is termed the exploration-exploitation trade-off. This trade-off has been linked to reward and affective drives and associated neural circuitry as well as neuropsychological dysfunction. However, the neural mechanisms underlying the exploration-exploitation trade-off are still uncertain, due to the scarcity of literature and the heterogeneity of paradigms. This study aimed to systematically quantify and disambiguate neuroanatomical correlates of the exploration-exploitation tradeoff in a normative adult sample. These findings provide a necessary starting point for future investigations of this fundamental aspect of decision-making across clinical populations, with potential implications for assessment and intervention.Participants and Methods:We used the effect-location method of meta-analysis to analyze data from 10 functional neuroimaging studies investigating the exploration-exploitation tradeoff in non-clinical samples. We analyzed the location and frequency of significant neural activations across studies for both explorative and exploitative decisions and characterized them as core and non-core regions. Core activations were defined as those reported in over 50% of studies. Secondary and tertiary activations were defined as those reported in 40% and 30% of studies, respectively. The present review was conducted in accordance with the guidelines of the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.Results:The results revealed that explorative and exploitative choice behaviours differed markedly with respect to associated patterns of task-related brain activity. Exploration was associated with activity in brain regions implicated in externally directed, goal-based attentional processing and reward-related uncertainty, mainly tapping bilateral parietal and frontal circuitry, with relatively high consistency across studies. A core explorative network was revealed, consisting of activity in the frontal polar cortex, the dorsal anterior cingulate cortex, the bilateral medial frontal gyrus, the bilateral precuneus, and the bilateral intraparietal sulcus. Secondary and tertiary regions were also detected, including the bilateral anterior insula, the left precentral gyrus, the bilateral superior frontal gyrus, the right inferior frontal gyrus, the left supplementary motor area, the bilateral superior parietal lobule, and the bilateral thalamus. Exploitation was associated with brain regions implicated in internally directed processes including reward valuation, motivation, and memory. Core exploitative activations included the ventromedial prefrontal cortex, the bilateral anterior cingulate cortex, and the bilateral orbitofrontal cortex. Secondary and tertiary activations included the bilateral hippocampus, the left middle temporal gyrus, the bilateral angular gyrus, the left posterior cingulate cortex, the left superior frontal gyrus, and the bilateral superior temporal gyrus.Conclusions:The exploration-exploitation trade-off provides a novel paradigmatic approach to study adaptive and maladaptive decision-making behaviour in humans. Our findings support the neural dichotomization of exploration and exploitation and illuminate potential neural networks underlying this fundamental feature of decision-making. Understanding these mechanistic networks opens a new avenue of inquiry into decision-making deficits in clinical populations, including neurodegenerative, neurodevelopmental, and neuropsychiatric syndromes.

How far neuroscience is from understanding brains.

The cellular biology of brains is relatively well-understood, but neuroscientists have not yet generated a theory explaining how brains work. Explanations of how neurons collectively operate to produce what brains can do are tentative and incomplete. Without prior assumptions about the brain mechanisms, I attempt here to identify major obstacles to progress in neuroscientific understanding of brains and central nervous systems. Most of the obstacles to our understanding are conceptual. Neuroscience lacks concepts and models rooted in experimental results explaining how neurons interact at all scales. The cerebral cortex is thought to control awake activities, which contrasts with recent experimental results. There is ambiguity distinguishing task-related brain activities from spontaneous activities and organized intrinsic activities. Brains are regarded as driven by external and internal stimuli in contrast to their considerable autonomy. Experimental results are explained by sensory inputs, behavior, and psychological concepts. Time and space are regarded as mutually independent variables for spiking, post-synaptic events, and other measured variables, in contrast to experimental results. Dynamical systems theory and models describing evolution of variables with time as the independent variable are insufficient to account for central nervous system activities. Spatial dynamics may be a practical solution. The general hypothesis that measurements of changes in fundamental brain variables, action potentials, transmitter releases, post-synaptic transmembrane currents, etc., propagating in central nervous systems reveal how they work, carries no additional assumptions. Combinations of current techniques could reveal many aspects of spatial dynamics of spiking, post-synaptic processing, and plasticity in insects and rodents to start with. But problems defining baseline and reference conditions hinder interpretations of the results. Furthermore, the facts that pooling and averaging of data destroy their underlying dynamics imply that single-trial designs and statistics are necessary.

Increased integration of functional connectivity after cognitive intervention in preschoolers from low socioeconomic status.

Cognitive interventions that involve executive functions (EF)-demanding activities are effective in changing task-related brain activity in children from homes with low socioeconomic status (SES). However, less is known about the efficiency of EF-based interventions in modifying segregation and integration properties of the functional neural organization during a resting state. Further, the consideration of the initial cognitive performance in the design of interventions and its role in the outcome of cognitive training has been poorly studied. The present study aimed to examine the impact of two individualized cognitive interventions with EF-demanding activities on brain connectivity in preschoolers (n = 79) from low-SES homes in Argentina using complex network analysis. At baseline, participants were classified as high- or low-performers based on their performance in an inhibitory control task, and then they were assigned into intervention and control groups within each performance level. Before and after the intervention, the neural activity of each child was recorded at rest using a mobile electroencephalogram device. We found significant intervention-related changes in global efficiency, global strength, and the strength of long-range connections in the θ frequency band in the intervention low-performing group. These findings support the idea that patterns of processing crucial information in the brain may be modified in children from low-SES homes through an EF-based intervention. Finally, these findings show different intervention-related effects on neural activity between children with low and high initial cognitive performance and add new evidence about the interaction between individual characteristics and intervention approaches. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Executive Control and Associated Brain Activity in Children With Familial High-Risk of Schizophrenia or Bipolar Disorder: A Danish Register-based Study.

Impaired executive control is a potential prognostic and endophenotypic marker of schizophrenia (SZ) and bipolar disorder (BP). Assessing children with familial high-risk (FHR) of SZ or BP enables characterization of early risk markers and we hypothesize that they express impaired executive control as well as aberrant brain activation compared to population-based control (PBC) children. Using a flanker task, we examined executive control together with functional magnetic resonance imaging (fMRI) in 11- to 12-year-old children with FHR of SZ (FHR-SZ) or FHR of BP (FHR-BP) and PBC children as part of a register-based, prospective cohort-study; The Danish High Risk and Resilience study-VIA 11. We included 85 (44% female) FHR-SZ, 63 (52% female) FHR-BP and 98 (50% female) PBC in the analyses. Executive control effects, caused by the spatial visuomotor conflict, showed no differences between groups. Bayesian ANOVA of reaction time (RT) variability, quantified by the coefficient of variation (CVRT), revealed a group effect with similarly higher CVRT in FHR-BP and FHR-SZ compared to PBC (BF10 = 6.82). The fMRI analyses revealed no evidence for between-group differences in task-related brain activation. Post hoc analyses excluding children with psychiatric illness yielded same results. FHR-SZ and FHR-BP at age 11-12 show intact ability to resolve a spatial visuomotor conflict and neural efficacy. The increased variability in RT may reflect difficulties in maintaining sustained attention. Since variability in RT was independent of existing psychiatric illness, it may reflect a potential endophenotypic marker of risk.

Acute effects of mifepristone on emotional processing related brain activity: A functional MRI study

The Hypothalamic-pituitary-adrenal (HPA) axis plays an important role in the pathophysiology of mood disorders, and preliminary data suggests that glucocorticoid receptor (GR) antagonism may be an important therapeutic mechanism. The effects of modulating HPA axis function on emotional processing related brain activity, which may be abnormal in depressed mood, is poorly understood. This study used a pharmacological functional magnetic resonance imaging (fMRI) design to determine the effects of the GR and progesterone receptor antagonist mifepristone on emotional faces processing task related brain activations in 19 right-handed healthy male participants. Each participant received 600 mg mifepristone or placebo on two separate imaging days and then performed an emotional processing fMRI task four hours later. The effect of mifepristone on task related brain activations was determined using Region-of-Interest (ROI) analyses and an exploratory whole brain voxel-wise analyses. No significant changes were observed in the defined ROIs (amygdala, anterior cingulate cortex, insula) or in the exploratory whole brain analyses that was associated with mifepristone administration in either the angry vs happy faces or angry and happy faces vs implicit baseline contrasts. Task reaction times and accuracy were similar in both mifepristone and placebo conditions (all p > 0.05). Our study failed to show significant evidence of modulation of emotional processing related brain activity associated with acute mifepristone administration. Future research should use fMRI to investigate the longer-term administration effects of mifepristone on mood in healthy participants and people with mood disorders to provide a deeper understanding of the potential effects on depressive symptoms.

On how natural and urban soundscapes alter brain activity during cognitive performance

Listening to natural or urban soundscapes has previously been shown to differentially modulate performance in a subsequent cognitive task. The present study inquired the effect of listening to urban (traffic and machinery noise) vs. natural (birds, water and wind) soundscapes on cognitive performance, mood, stress reactivity and the consequences for brain activity during a cognitive task assessed before and after soundscape exposure. In a randomized experiment, 30 participants were exposed to three conditions on three separate testing days: urban, natural and no soundscape. Before and after the functional MRI session participants performed a dual n-back, a backward digit span task and filled out mood, stress reactivity and aesthetic preference questionnaires. The natural soundscapes did lead to better cognitive performance however, the effect did not reach significance. Exposure to the natural soundscapes resulted in a significant decrease of negative affect and participants rated them as significantly more aesthetic. On the brain level, listening to the urban soundscape was associated with an increase in superior temporal gyrus (STG) activity during the subsequent dual n-back task. However, this result was statistically not corrected and remains exploratory in nature. This result could potentially hint at information processing becoming less efficient in early primary sensory area as a result of exposure to the urban soundscape. Correlations between affect/cognition and task related brain activity revealed clusters in the attention-network.

Activation Map Reveals Language Impairment in Children with Benign Epilepsy with Centrotemporal Spikes (BECTS).

Neuropsychological evidence revealed language impairment in children with benign epilepsy with centrotemporal spikes (BECTS). This study investigates language function using task-activated fMRI. We conducted a language task fMRI study on three groups on a 3.0T MRI scanner, including a new onset drug naïve group (NODN-BECTS, n=11, age=9.6±1.6), an established epilepsy with medication-treated group (Med-BECTS, n=17, age=10.7±2.2) and a healthy control group (HC, n=18, age=10.8±1.7). We use MATLAB14 and SPM12 to pre-process and analyze the data. A one-sample t-test was used to identify task-related brain activation changes in each group, based on the general linear model (GLM). And, then two sample t-test was performed to compare different activated regions between groups. In addition, scores on the most recent Mandarin school exams were acquired to examine and contrast extra-scanner language performance. Statistical results show that some language-related brain regions (such as the left superior frontal gyrus and cerebellar vermis) were additionally activated in the NODN-BECTS group compared with the HC group. Compared with NODN-BECTS and HC groups, decreased activations were found in language-related regions in the Med-BECTS group, including the left insula, superior and middle frontal gyri, and bilateral middle occipital gyri. On the Mandarin school exams, the average score for HC was 87.3±8.2, NODN was 84.8±7.8, and Med was 78.2±13.2. There was a trend toward statistical significance between the Med and the HC (p = 0.074) as well as NODN (p = 0.092) groups. No statistically significant differences were found between the HC and the NODN-BECTS groups. Language task fMRI reveals additional areas of activation in new onset BECTS compared to healthy controls which may be compensatory in nature. Antiseizure medications (ASMs) and/or longer duration of BECTS additionally appears to affect language-related regions and reduce their functional ability.