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Valerie Voon

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https://www.readbyqxmd.com/read/29440410/ridding-fmri-data-of-motion-related-influences-removal-of-signals-with-distinct-spatial-and-physical-bases-in-multiecho-data
#1
Jonathan D Power, Mark Plitt, Stephen J Gotts, Prantik Kundu, Valerie Voon, Peter A Bandettini, Alex Martin
"Functional connectivity" techniques are commonplace tools for studying brain organization. A critical element of these analyses is to distinguish variance due to neurobiological signals from variance due to nonneurobiological signals. Multiecho fMRI techniques are a promising means for making such distinctions based on signal decay properties. Here, we report that multiecho fMRI techniques enable excellent removal of certain kinds of artifactual variance, namely, spatially focal artifacts due to motion...
February 12, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29207006/distal-functional-connectivity-of-known-and-emerging-cortical-targets-for-therapeutic-noninvasive-stimulation
#2
Nuria Doñamayor, Kwangyeol Baek, Valerie Voon
Noninvasive stimulation is an emerging modality for the treatment of psychiatric disorders, including addiction. A crucial element in effective cortical target selection is its distal influence. We approached this question by examining resting-state functional connectivity patterns in known and potential stimulation targets in 145 healthy adults. We compared connectivity patterns with distant regions of particular relevance in the development and maintenance of addiction. We used stringent Bonferroni-correction for multiple comparisons...
December 1, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/29062685/loss-of-inhibition-in-sensorimotor-networks-in-focal-hand-dystonia
#3
Cecile Gallea, Priyantha Herath, Valerie Voon, Alicja Lerner, John Ostuni, Ziad Saad, Shantalaxmi Thada, Jeffrey Solomon, Silvina G Horovitz, Mark Hallett
OBJECTIVE: To investigate GABA-ergic receptor density and associated brain functional and grey matter changes in focal hand dystonia (FHD). METHODS: 18 patients with FHD of the right hand and 18 age and gender matched healthy volunteers (HV) participated in this study. We measured the density of GABA-A receptors using [ 11 C] Flumazenil and perfusion using [ 15 O] H 2 O. Anatomical images were also used to measure grey matter volume with voxel-based morphometry (VBM)...
2018: NeuroImage: Clinical
https://www.readbyqxmd.com/read/29036632/mapping-compulsivity-in-the-dsm-5-obsessive-compulsive-and-related-disorders-cognitive-domains-neural-circuitry-and-treatment
#4
Naomi A Fineberg, Annemieke M Apergis-Schoute, M Matilde Vaghi, Paula Banca, Claire M Gillan, Valerie Voon, Samuel R Chamberlain, Cinosi Eduardo, Reid Jemma, Sonia Shahper, Edward T Bullmore, Barbara J Sahakian, Trevor W Robbins
Compulsions are repetitive, stereotyped thoughts and behaviors designed to reduce harm. Growing evidence suggests that the neurocognitive mechanisms mediating behavioural inhibition (motor inhibition, cognitive inflexibility) reversal learning and habit formation (shift from goal-directed to habitual responding) contribute toward compulsive activity in a broad range of disorders. In obsessive compulsive disorder (OCD), distributed network perturbation appears focussed around the pre-frontal cortex, caudate, putamen and associated neuro-circuitry...
September 23, 2017: International Journal of Neuropsychopharmacology
https://www.readbyqxmd.com/read/29032922/serotonin-transporter-density-in-binge-eating-disorder-and-pathological-gambling-a-pet-study-with-11-c-madam
#5
Joonas Majuri, Juho Joutsa, Jarkko Johansson, Valerie Voon, Riitta Parkkola, Hannu Alho, Eveliina Arponen, Valtteri Kaasinen
Behavioral addictions, such as pathological gambling (PG) and binge eating disorder (BED), appear to be associated with specific changes in brain dopamine and opioid function, but the role of other neurotransmitter systems is less clear. Given the crucial role of serotonin in a number of psychiatric disorders, we aimed to compare brain serotonergic function among individuals with BED, PG and healthy controls. Seven BED patients, 13 PG patients and 16 healthy controls were scanned with high-resolution positron emission tomography (PET) using the serotonin transporter (SERT) tracer [(11)C]MADAM...
October 9, 2017: European Neuropsychopharmacology: the Journal of the European College of Neuropsychopharmacology
https://www.readbyqxmd.com/read/29020291/reward-sensitivity-and-waiting-impulsivity-shift-towards-reward-valuation-away-from-action-control
#6
Daisy J Mechelmans, Daniela Strelchuk, Nuria Donamayor-Alonso, Paula Banca, Trevor W Robbins, Kwangyeol Baek, Valerie Voon
Background: Impulsivity and reward expectancy are commonly inter-related. Waiting impulsivity, measured using the rodent 5-Choice Serial Reaction Time (5-CSRT) task, predicts compulsive cocaine seeking and sign (or cue) tracking. Here we assess human waiting impulsivity using a novel translational task, the 4-CSRT, and the relationship with reward cues. Methods: Healthy volunteers (n=29) performed the monetary incentive delay task as a functional MRI study where subjects observe a cue predicting reward (cue) and wait to respond for high (£5), low (£1) or no reward...
August 8, 2017: International Journal of Neuropsychopharmacology
https://www.readbyqxmd.com/read/28876969/noncognitive-behavioral-changes-associated-with-alzheimer-s-disease-implications-of-neuroimaging-findings
#7
Jeff Victoroff, Feng V Lin, Kerry L Coburn, Samuel D Shillcutt, Valerie Voon, Simon Ducharme
Alzheimer's disease (AD) is commonly associated with noncognitive behavioral changes (NCBCs). The authors systematically reviewed whether neuroimaging has helped with understanding the pathophysiology, diagnosis, or management of NCBCs associated with AD, including depression, aggression or agitation, anxiety, apathy, psychosis, and sleep disorder. The authors identified dissociable neural substrates with multimodal imaging: depression implicates the lateral and superior prefrontal cortex; apathy and agitation implicate the dorsal anterior cingulate; psychosis implicates right lateralized frontal and medial temporal areas; and anxiety implicates mesial temporal regions...
September 6, 2017: Journal of Neuropsychiatry and Clinical Neurosciences
https://www.readbyqxmd.com/read/28856091/disrupted-avoidance-learning-in-functional-neurological-disorder-implications-for-harm-avoidance-theories
#8
Laurel S Morris, Benjaman To, Kwangyeol Baek, Yee-Chien Chang-Webb, Simon Mitchell, Daniela Strelchuk, Yevheniia Mikheenko, Wendy Phillips, Michael Zandi, Allison Jenaway, Cathy Walsh, Valerie Voon
BACKGROUND: Functional neurological disorder (FND) is an elusive disorder characterized by unexplained neurological symptoms alongside aberrant cognitive processing and negative affect, often associated with amygdala reactivity. METHODS: We examined the effect of negative conditioning on cognitive function and amygdala reactivity in 25 FND patients and 20 healthy volunteers (HV). Participants were first conditioned to stimuli paired with negative affective or neutral (CS +/CS -) information...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28606495/personality-traits-in-psychogenic-nonepileptic-seizures-pnes-and-psychogenic-movement-disorder-pmd-neuroticism-and-perfectionism
#9
Vindhya Ekanayake, Sarah Kranick, Kathrin LaFaver, Arshi Naz, Anne Frank Webb, W Curt LaFrance, Mark Hallett, Valerie Voon
OBJECTIVE: Psychogenic movement disorder (PMD) and psychogenic nonepileptic seizures (PNES) are two subtypes of conversion disorder (CD). In this case-control study, we asked whether these subtypes varied as a function of personality and history of childhood abuse. METHODS: Fifty-nine patients with PMD from the Human Motor Control Section Clinic at the National Institutes of Health, 43 patients with PNES from the Rhode Island Hospital Neuropsychiatry and Behavioral Neurology Division, and 26 healthy volunteers (HC) received a battery of neurological, psychiatric and psychological assessments, including the NEO Personality Inventory Revised (NEO PI-R), the Childhood Trauma Questionnaire (CTQ), and the Traumatic Life Events Questionnaire (TLEQ)...
June 2017: Journal of Psychosomatic Research
https://www.readbyqxmd.com/read/28599832/model-based-control-in-dimensional-psychiatry
#10
REVIEW
Valerie Voon, Andrea Reiter, Miriam Sebold, Stephanie Groman
We use parallel interacting goal-directed and habitual strategies to make our daily decisions. The arbitration between these strategies is relevant to inflexible repetitive behaviors in psychiatric disorders. Goal-directed control, also known as model-based control, is based on an affective outcome relying on a learned internal model to prospectively make decisions. In contrast, habit control, also known as model-free control, is based on an integration of previous reinforced learning autonomous of the current outcome value and is implicit and more efficient but at the cost of greater inflexibility...
April 23, 2017: Biological Psychiatry
https://www.readbyqxmd.com/read/28458999/magnetization-transfer-imaging-identifies-basal-ganglia-abnormalities-in-adult-adhd-that-are-invisible-to-conventional-t1-weighted-voxel-based-morphometry
#11
Arjun Sethi, Edwin Evelyn-Rahr, Nicholas Dowell, Sanjay Jain, Valerie Voon, Hugo D Critchley, Neil A Harrison, Mara Cercignani
In childhood, Attention Deficit Hyperactivity Disorder (ADHD) is reliably associated with reduced volume of the striatum. In contrast, striatal abnormalities are infrequently detected in voxel-based morphometry (VBM) neuroimaging studies of adults with ADHD. This discrepancy has been suggested to reflect normalisation of striatal morphology with age and prolonged treatment of symptoms. If so, this would indicate that while striatal abnormalities are linked to symptom expression in childhood, they cannot explain the persistence of these symptoms in adulthood...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28419776/the-involuntary-nature-of-binge-drinking-goal-directedness-and-awareness-of-intention
#12
Nuria Doñamayor, Daniela Strelchuk, Kwangyeol Baek, Paula Banca, Valerie Voon
Binge drinking represents a public health issue and is a known risk factor in the development of alcohol use disorders. Previous studies have shown behavioural as well as neuroanatomical alterations associated with binge drinking. Here, we address the question of the automaticity or involuntary nature of the behaviour by assessing goal-directed behaviour and intentionality. In this study, we used a computational two-step task, designed to discern between model-based/goal-directed and model-free/habitual behaviours, and the classic Libet clock task, to study intention awareness, in a sample of 31 severe binge drinkers (BD) and 35 matched healthy volunteers...
April 16, 2017: Addiction Biology
https://www.readbyqxmd.com/read/28363836/multi-echo-fmri-a-review-of-applications-in-fmri-denoising-and-analysis-of-bold-signals
#13
Prantik Kundu, Valerie Voon, Priti Balchandani, Michael V Lombardo, Benedikt A Poser, Peter A Bandettini
In recent years the field of fMRI research has enjoyed expanded technical abilities related to resolution, as well as use across many fields of brain research. At the same time, the field has also dealt with uncertainty related to many known and unknown effects of artifact in fMRI data. In this review we discuss an emerging fMRI technology, called multi-echo (ME)-fMRI, which focuses on improving the fidelity and interpretability of fMRI. Where the essential problem of standard single-echo fMRI is the indeterminacy of sources of signals, whether BOLD or artifact, this is not the case for ME-fMRI...
July 1, 2017: NeuroImage
https://www.readbyqxmd.com/read/28247526/naltrexone-ameliorates-functional-network-abnormalities-in-alcohol-dependent-individuals
#14
Laurel S Morris, Kwangyeol Baek, Roger Tait, Rebecca Elliott, Karen D Ersche, Remy Flechais, John McGonigle, Anna Murphy, Liam J Nestor, Csaba Orban, Filippo Passetti, Louise M Paterson, Ilan Rabiner, Laurence Reed, Dana Smith, John Suckling, Eleanor M Taylor, Edward T Bullmore, Anne R Lingford-Hughes, Bill Deakin, David J Nutt, Barbara J Sahakian, Trevor W Robbins, Valerie Voon
Naltrexone, an opioid receptor antagonist, is commonly used as a relapse prevention medication in alcohol and opiate addiction, but its efficacy and the mechanisms underpinning its clinical usefulness are not well characterized. In the current study, we examined the effects of 50-mg naltrexone compared with placebo on neural network changes associated with substance dependence in 21 alcohol and 36 poly-drug-dependent individuals compared with 36 healthy volunteers. Graph theoretic and network-based statistical analysis of resting-state functional magnetic resonance imaging (MRI) data revealed that alcohol-dependent subjects had reduced functional connectivity of a dispersed network compared with both poly-drug-dependent and healthy subjects...
February 28, 2017: Addiction Biology
https://www.readbyqxmd.com/read/28238272/psychiatric-presentations-of-c9orf72-mutation-what-are-the-diagnostic-implications-for-clinicians
#15
Simon Ducharme, Sepideh Bajestan, Bradford C Dickerson, Valerie Voon
The C9orf72 mutation was identified as the most frequent genetic cause of frontotemporal dementia (FTD). In light of multiple reports of predominant psychiatric presentations of FTD secondary to C9orf72 mutation, the American Neuropsychiatric Association Committee on Research reviewed all studies on psychiatric aspects of this mutation to identify clinically relevant features for diagnosis. The most common psychiatric presentation is psychosis (21%-56%), with delusions, and/or multimodal hallucinations. Other presentations include late-onset mania and depression with cognitive impairment or catatonia...
February 27, 2017: Journal of Neuropsychiatry and Clinical Neurosciences
https://www.readbyqxmd.com/read/28229895/impulse-control-disorders-and-levodopa-induced-dyskinesias-in-parkinson-s-disease-an-update
#16
REVIEW
Valerie Voon, T Celeste Napier, Michael J Frank, Veronique Sgambato-Faure, Anthony A Grace, Maria Rodriguez-Oroz, Jose Obeso, Erwan Bezard, Pierre-Olivier Fernagut
Dopaminergic medications used in the treatment of patients with Parkinson's disease are associated with motor and non-motor behavioural side-effects, such as dyskinesias and impulse control disorders also known as behavioural addictions. Levodopa-induced dyskinesias occur in up to 80% of patients with Parkinson's after a few years of chronic treatment. Impulse control disorders, including gambling disorder, binge eating disorder, compulsive sexual behaviour, and compulsive shopping occur in about 17% of patients with Parkinson's disease on dopamine agonists...
March 2017: Lancet Neurology
https://www.readbyqxmd.com/read/28121259/neurobiology-of-the-premonitory-urge-in-tourette-s-syndrome-pathophysiology-and-treatment-implications
#17
REVIEW
Andrea E Cavanna, Kevin J Black, Mark Hallett, Valerie Voon
Motor and vocal tics are relatively common motor manifestations identified as the core features of Tourette's syndrome (TS). Although traditional descriptions have focused on objective phenomenological observations, such as anatomical location, number and frequency of tics, patients' first-person accounts have consistently reported characteristic subjective correlates. These sensory phenomena are often described as a feeling of mounting inner tension or urge to move ("premonitory urge"), which is transiently relieved by tic expression...
2017: Journal of Neuropsychiatry and Clinical Neurosciences
https://www.readbyqxmd.com/read/28105707/binge-drinking-differentially-affects-cortical-and-subcortical-microstructure
#18
Laurel S Morris, Nicholas G Dowell, Mara Cercignani, Neil A Harrison, Valerie Voon
Young adult binge drinkers represent a model for endophenotypic risk factors for alcohol misuse and early exposure to repeated binge cycles. Chronic or harmful alcohol use leads to neurochemical, structural and morphological neuroplastic changes, particularly in regions associated with reward processing and motivation. We investigated neural microstructure in 28 binge drinkers compared with 38 matched healthy controls. We used a recently developed diffusion magnetic resonance imaging acquisition and analysis, which uses three-compartment modelling (of intracellular, extracellular and cerebrospinal fluid) to determine brain tissue microstructure features including neurite density and orientation dispersion index (ODI)...
January 20, 2017: Addiction Biology
https://www.readbyqxmd.com/read/28103527/distinct-cortico-striatal-connections-with-subthalamic-nucleus-underlie-facets-of-compulsivity
#19
Laurel S Morris, Kwangyeol Baek, Valerie Voon
The capacity to flexibly respond to contextual changes is crucial to adapting to a dynamic environment. Compulsivity, or behavioural inflexibility, consists of heterogeneous subtypes with overlapping yet discrete neural substrates. The subthalamic nucleus (STN) mediates the switch from automatic to controlled processing to slow, break or stop behaviour when necessary. Rodent STN lesions or inactivation are linked with perseveration or repetitive, compulsive responding. However, there are few studies examining the role of latent STN-centric neural networks and compulsive behaviour in healthy individuals...
March 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28040671/decisional-impulsivity-and-the-associative-limbic-subthalamic-nucleus-in-obsessive-compulsive-disorder-stimulation-and-connectivity
#20
RANDOMIZED CONTROLLED TRIAL
Valerie Voon, Fabien Droux, Laurel Morris, Stephan Chabardes, Thierry Bougerol, Olivier David, Paul Krack, Mircea Polosan
Why do we make hasty decisions for short-term gain? Rapid decision-making with limited accumulation of evidence and delay discounting are forms of decisional impulsivity. The subthalamic nucleus is implicated in inhibitory function but its role in decisional impulsivity is less well-understood. Here we assess decisional impulsivity in subjects with obsessive compulsive disorder who have undergone deep brain stimulation of the limbic and associative subthalamic nucleus. We show that stimulation of the subthalamic nucleus is causally implicated in increasing decisional impulsivity with less accumulation of evidence during probabilistic uncertainty and in enhancing delay discounting...
February 2017: Brain: a Journal of Neurology
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