77 results found
Haijen ECHM, Kaelen M, Roseman L, et al., 2018, Predicting Responses to Psychedelics: A Prospective Study, FRONTIERS IN PHARMACOLOGY, Vol: 9, ISSN: 1663-9812
Li W, Lao-Kaim NP, Roussakis A, et al., 2018, Functional connectivity changes in relation to dopaminergic decline in Parkinson's over time: a resting-state fMRI and 11C-PE2I PET imaging study, 4th Congress of the European-Academy-of-Neurology (EAN), Publisher: WILEY, Pages: 345-345, ISSN: 1351-5101
Lorenz R, Violante IR, Monti RP, et al., 2018, Dissociating frontoparietal brain networks with neuroadaptive Bayesian optimization, NATURE COMMUNICATIONS, Vol: 9, ISSN: 2041-1723
Mason SL, Daws RE, Soreq E, et al., 2018, Predicting clinical diagnosis in Huntington's disease: An imaging polymarker, ANNALS OF NEUROLOGY, Vol: 83, Pages: 532-543, ISSN: 0364-5134
Huntley J, Corbett A, Wesnes K, et al., 2018, Online assessment of risk factors for dementia and cognitive function in healthy adults., Int J Geriatr Psychiatry, Vol: 33, Pages: e286-e293
OBJECTIVE: Several potentially modifiable risk factors for cognitive decline and dementia have been identified, including low educational attainment, smoking, diabetes, physical inactivity, hypertension, midlife obesity, depression, and perceived social isolation. Managing these risk factors in late midlife and older age may help reduce the risk of dementia; however, it is unclear whether these factors also relate to cognitive performance in older individuals without dementia. METHOD: Data from 14 201 non-demented individuals aged >50 years who enrolled in the online PROTECT study were used to examine the relationship between cognitive function and known modifiable risk factors for dementia. Multivariate regression analyses were conducted on 4 cognitive outcomes assessing verbal and spatial working memory, visual episodic memory, and verbal reasoning. RESULTS: Increasing age was associated with reduced performance across all tasks. Higher educational achievement, the presence of a close confiding relationship, and moderate alcohol intake were associated with benefits across all 4 cognitive tasks, and exercise was associated with better performance on verbal reasoning and verbal working memory tasks. A diagnosis of depression was negatively associated with performance on visual episodic memory and working memory tasks, whereas being underweight negatively affected performance on all tasks apart from verbal working memory. A history of stroke was negatively associated with verbal reasoning and working memory performance. CONCLUSION: Known modifiable risk factors for dementia are associated with cognitive performance in non-demented individuals in late midlife and older age. This provides further support for public health interventions that seek to manage these risk factors across the lifespan.
Daws RE, Hampshire A, 2017, The Reasoning and Religiosity Is Underpinned by a Bias for Intuitive Responses Specifically When Intuition and Logic Are in Conflict, FRONTIERS IN PSYCHOLOGY, Vol: 8, ISSN: 1664-1078
, 2017, Hypoactivation and Dysconnectivity of a Frontostriatal Circuit During Goal-Directed Planning as an Endophenotype for Obsessive-Compulsive Disorder, Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, Vol: 2, Pages: 655-663, ISSN: 2451-9022
© 2017 Society of Biological Psychiatry Background The symptoms of obsessive-compulsive disorder (OCD) have been postulated to result from impaired executive functioning and excessive habit formation at the expense of goal-directed control and have been objectively demonstrated using neuropsychological tests in such patients. This study tested whether there is functional hypoactivation as well as dysconnectivity of discrete frontostriatal pathways during goal-directed planning in patients with OCD and in their unaffected first-degree relatives. Methods In total, 21 comorbidity-free patients with OCD, 19 clinically asymptomatic first-degree relatives of these patients, and 20 control participants were tested on a functional magnetic resonance optimized version of the Tower of London task. Group differences in brain activation during goal-directed planning were measured together with associated frontostriatal functional connectivity. Results Patients with OCD and their clinically asymptomatic relatives manifested hypoactivation of the right dorsolateral prefrontal cortex during goal-directed planning coupled with reduced functional connectivity between this cortical region and the basal ganglia (putamen). Conclusions Hypoactivation of cortical regions associated with goal-directed planning and associated frontostriatal dysconnectivity represent a candidate endophenotype for OCD. These findings accord with abnormalities in neural networks supporting the balance between goal-directed and habitual behavior, with implications for recent neuropsychological theories of OCD and the major neurobiological model for this disorder.
Fallon SJ, Bor D, Hampshire A, et al., 2017, Spatial structure normalises working memory performance in Parkinson's disease., Cortex, Vol: 96, Pages: 73-82
Cognitive deficits are a frequent symptom of Parkinson's disease (PD), particularly in the domain of spatial working memory (WM). Despite numerous demonstrations of aberrant WM in patients, there is a lack of understanding about how, if at all, their WM is fundamentally altered. Most notably, it is unclear whether span - the yardstick upon which most WM models are built - is compromised by the disease. Moreover, it is also unknown whether WM deficits occur in all patients or only exist in a sub-group who are executively impaired. We assessed the factors that influenced spatial span in medicated patients by varying the complexity of to-be-remembered items. Principally, we manipulated the ease with which items could enter - or be blocked from - WM by varying the level of structure in memoranda. Despite having similar levels of executive performance to controls, PD patients were only impaired when remembering information that lacked spatial, easy-to-chunk, structure. Patients' executive function, however, did not influence this effect. The ease with which patients could control WM was further examined by presenting irrelevant information during encoding, varying the level of structure in irrelevant information and manipulating the amount of switching between relevant and irrelevant information. Disease did not significantly alter the effect of these manipulations. Rather, patients' executive performance constrained the detrimental effect of irrelevant information on WM. Thus, PD patients' spatial span is predominantly determined by level of structure in to-be-remembered information, whereas their level of executive function may mitigate against the detrimental effect of irrelevant information.
Metzler-Baddeley C, Foley S, de Santis S, et al., 2017, Dynamics of White Matter Plasticity Underlying Working Memory Training: Multimodal Evidence from Diffusion MRI and Relaxometry., J Cogn Neurosci, Vol: 29, Pages: 1509-1520
Adaptive working memory (WM) training may lead to cognitive benefits that are associated with white matter plasticity in parietofrontal networks, but the underlying mechanisms remain poorly understood. We investigated white matter microstructural changes after adaptive WM training relative to a nonadaptive comparison group. Microstructural changes were studied in the superior longitudinal fasciculus, the main parietofrontal connection, and the cingulum bundle as a comparison pathway. MRI-based metrics were the myelin water fraction and longitudinal relaxation rate R1 from multicomponent relaxometry (captured with the mcDESPOT approach) as proxy metrics of myelin, the restricted volume fraction from the composite hindered and restricted model of diffusion as an estimate of axon morphology, and fractional anisotropy and radial diffusivity from diffusion tensor imaging. PCA was used for dimensionality reduction. Adaptive training was associated with benefits in a "WM capacity" component and increases in a microstructural component (increases in R1, restricted volume fraction, fractional anisotropy, and reduced radial diffusivity) that predominantly loaded on changes in the right dorsolateral superior longitudinal fasciculus and the left parahippocampal cingulum. In contrast, nonadaptive comparison activities were associated with the opposite pattern of reductions in WM capacity and microstructure. No group differences were observed for the myelin water fraction metric suggesting that R1 was a more sensitive "myelin" index. These results demonstrate task complexity and location-specific white matter microstructural changes that are consistent with tissue alterations underlying myelination in response to training.
Sliwinska MW, Violante IR, Wise RJS, et al., 2017, Stimulating Multiple-Demand Cortex Enhances Vocabulary Learning, JOURNAL OF NEUROSCIENCE, Vol: 37, Pages: 7606-7618, ISSN: 0270-6474
Gruszka A, Hampshire A, Barker RA, et al., 2017, Normal aging and Parkinson's disease are associated with the functional decline of distinct frontal-striatal circuits., Cortex, Vol: 93, Pages: 178-192
Impaired ability to shift attention between stimuli (i.e. shifting attentional 'set') is a well-established part of the dysexecutive syndrome in Parkinson's Disease (PD), nevertheless cognitive and neural bases of this deficit remain unclear. In this study, an fMRI-optimised variant of a classic paradigm for assessing attentional control (Hampshire and Owen 2006) was used to contrast activity in dissociable executive circuits in early-stage PD patients and controls. The results demonstrated that the neural basis of the executive performance impairments in PD is accompanied by hypoactivation within the striatum, anterior cingulate cortex (vACC), and inferior frontal sulcus (IFS) regions. By contrast, in aging it is associated with hypoactivation of the anterior insula/inferior frontal operculum (AI/FO) and the pre-supplementary motor area (preSMA). Between group behavioural differences were also observed; whereas normally aging individuals exhibited routine-problem solving deficits, PD patients demonstrated more global task learning deficits. These findings concur with recent research demonstrating model-based reinforcement learning deficits in PD and provide evidence that the AI/FO and IFS circuits are differentially impacted by PD and normal aging.
Huntley JD, Hampshire A, Bor D, et al., 2017, The importance of sustained attention in early Alzheimer's disease., Int J Geriatr Psychiatry, Vol: 32, Pages: 860-867
INTRODUCTION: There is conflicting evidence regarding impairment of sustained attention in early Alzheimer's disease (AD). We examine whether sustained attention is impaired and predicts deficits in other cognitive domains in early AD. METHODS: Fifty-one patients with early AD (MMSE > 18) and 15 healthy elderly controls were recruited. The sustained attention to response task (SART) was used to assess sustained attention. A subset of 25 patients also performed tasks assessing general cognitive function (ADAS-Cog), episodic memory (Logical memory scale, Paired Associates Learning), executive function (verbal fluency, grammatical reasoning) and working memory (digit and spatial span). RESULTS: AD patients were significantly impaired on the SART compared to healthy controls (total error β = 19.75, p = 0.027). SART errors significantly correlated with MMSE score (Spearman's rho = -0.338, p = 0.015) and significantly predicted deficits in ADAS-Cog (β = 0.14, p = 0.004). DISCUSSIONS: Patients with early AD have significant deficits in sustained attention, as measured using the SART. This may impair performance on general cognitive testing, and therefore should be taken into account during clinical assessment, and everyday management of individuals with early AD. Copyright © 2016 John Wiley & Sons, Ltd.
Geranmayeh F, Chau T, Wise RJS, et al., 2017, Domain-general subregions of the medial prefrontal cortex contribute to recovery of language after stroke, BRAIN, Vol: 140, Pages: 1947-1958, ISSN: 0006-8950
Lorenz R, Hampshire A, Leech R, 2017, Neuroadaptive Bayesian Optimization and Hypothesis Testing, TRENDS IN COGNITIVE SCIENCES, Vol: 21, Pages: 155-167, ISSN: 1364-6613
Huntley JD, Hampshire A, Bor D, et al., 2017, Adaptive working memory strategy training in early Alzheimer's disease: randomised controlled trial, BRITISH JOURNAL OF PSYCHIATRY, Vol: 210, Pages: 61-66, ISSN: 0007-1250
, 2017, A Functional Network Perspective on the Role of the Frontal Lobes in Executive Cognition, Executive Functions in Health and Disease, Pages: 71-104, ISBN: 9780128037058
© 2017 Elsevier Inc. All rights reserved. The past decade of functional magnetic resonance imaging research has enabled a rapid series of advances in our understanding of the brain mechanisms that underlie executive cognition. During this time-dominant theories within the neuroimaging field have evolved from simple modular perspectives that attribute specific cognitive functions to individual brain regions, toward more complex network-based perspectives that consider cognitive information processing to be supported by networks distributed throughout the brain. With the application of computational modeling to simulate such large-scale network interactions, a novel fusion of these two perspectives has begun to crystallize; cognitive information processing is increasingly being seen an emergent property of widespread network interactions, but certain nodes within these networks play prominent executive roles, for example, orchestrating network connectivity states or integrating information products from multiple brain regions. This fusion of network and modular perspectives provides a powerful new framework for determining what the distinct aspects of executive cognition are and how they are supported within the dynamic brain. When combined with machine learning analysis techniques that can handle rich multivariate data, this framework is also enabling the development of clinically useful diagnostic tools.
Li L, Violante I, Ross E, et al., 2016, BRAIN NETWORK MODULATION WITH NON-INVASIVE BRAIN STIMULATION, Annual Meeting of the Association-of-British-Neurologists (ABN), Publisher: BMJ PUBLISHING GROUP, ISSN: 0022-3050
Connell L, Daws R, Hampshire A, et al., 2016, Validating a participant-led computerised cognitive battery in people with multiple sclerosis, 32nd Congress of the European-Committee-for-Treatment-and-Research-in-Multiple-Sclerosis (ECTRIMS), Publisher: SAGE PUBLICATIONS LTD, Pages: 140-141, ISSN: 1352-4585
Fallon SJ, Hampshire A, Barker RA, et al., 2016, Learning to be inflexible: Enhanced attentional biases in Parkinson's disease., Cortex, Vol: 82, Pages: 24-34
Impaired attentional flexibility is considered to be one of the core cognitive deficits in Parkinson's disease (PD). However, the mechanisms that underlie this impairment are contested. Progress in resolving this dispute has also been hindered by the fact that cognitive deficits in PD are heterogeneous; therefore, it is unclear whether attentional impairments are only present in a subgroup of patients. Here, we demonstrate that what differentiates PD patients from age-matched controls is an inability to shift attention away from previously relevant information (perseveration) and an inability to shift attention towards previously irrelevant information (learned irrelevance). In contrast, there was no evidence that PD patients, compared to controls, were impaired in being able to appropriately attend to, or ignore, novel information. Furthermore, when patients were stratified according to their level of executive impairment, the executively impaired group showed a selective deficit in set formation compared to the unimpaired group, a behavioural pattern reminiscent of cortical dopamine depletion. Cumulatively, these results suggest that cognitive inflexibility in PD relates to a specific form of attentional dysfunction, in which learned attentional biases cannot be overcome.
Matthews PM, Hampshire A, 2016, Clinical Concepts Emerging from fMRI Functional Connectomics, NEURON, Vol: 91, Pages: 511-528, ISSN: 0896-6273
Odlaug BL, Hampshire A, Chamberlain SR, et al., 2016, Abnormal brain activation in excoriation (skin-picking) disorder: evidence from an executive planning fMRI study., Br J Psychiatry, Vol: 208, Pages: 168-174
BACKGROUND: Excoriation (skin-picking) disorder (SPD) is a relatively common psychiatric condition whose neurobiological basis is unknown. AIMS: To probe the function of fronto-striatal circuitry in SPD. METHOD: Eighteen participants with SPD and 15 matched healthy controls undertook an executive planning task (Tower of London) during functional magnetic resonance imaging (fMRI). Activation during planning was compared between groups using region of interest and whole-brain permutation cluster approaches. RESULTS: The SPD group exhibited significant functional underactivation in a cluster encompassing bilateral dorsal striatum (maximal in right caudate), bilateral anterior cingulate and right medial frontal regions. These abnormalities were, for the most part, outside the dorsal planning network typically activated by executive planning tasks. CONCLUSIONS: Abnormalities of neural regions involved in habit formation, action monitoring and inhibition appear involved in the pathophysiology of SPD. Implications exist for understanding the basis of excessive grooming and the relationship of SPD with putative obsessive-compulsive spectrum disorders.
Lorenz R, Monti RP, Hampshire A, et al., 2016, Towards tailoring non-invasive brain stimulation using real-time fMRI and Bayesian optimization, 6th International Workshop on Pattern Recognition in Neuroimaging (PRNI), Publisher: IEEE, Pages: 49-52, ISSN: 2330-9989
Hampshire A, Sharp D, 2015, Inferior PFC Subregions Have Broad Cognitive Roles, TRENDS IN COGNITIVE SCIENCES, Vol: 19, Pages: 712-713, ISSN: 1364-6613
Corbett A, Owen A, Hampshire A, et al., 2015, The Effect of an Online Cognitive Training Package in Healthy Older Adults: An Online Randomized Controlled Trial, Journal of the American Medical Directors Association, Vol: 16, Pages: 990-997, ISSN: 1525-8610
Jenkins P, Fleminger J, De-Simoni S, et al., 2015, HOME COMPUTERISED COGNITIVE TESTING FOR TBI IS FEASIBLE AND POPULAR, Annual Meeting of the Association-of-British-Neurologists (ABN), Publisher: BMJ PUBLISHING GROUP, ISSN: 0022-3050
Hampshire A, Sharp DJ, 2015, Contrasting network and modular perspectives on inhibitory control, TRENDS IN COGNITIVE SCIENCES, Vol: 19, Pages: 445-452, ISSN: 1364-6613
BACKGROUND: It is well established that some patients who are diagnosed as being in a vegetative state or a minimally conscious state show reliable signs of volition that may only be detected by measuring neural responses. A pertinent question is whether these patients are capable of higher cognitive processes. METHODS: Here, we develop a series of EEG paradigms that probe several core aspects of cognition at the bedside without the need for motor responses and explore the sensitivity of this approach in a group of healthy controls. RESULTS: Using analysis of ERPs alone, this method can determine with high reliability whether individual participants are able to attend a stimulus stream, maintain items in working memory, or solve complex grammatical reasoning problems. CONCLUSION: We suggest that this approach could form the basis of a brain-based battery for assessing higher cognition in patients with severe motor impairments or disorders of consciousness.
Hampshire A, 2015, Putting the brakes on inhibitory models of frontal lobe function., Neuroimage, Vol: 113, Pages: 340-355
There has been much recent debate regarding the neural basis of motor response inhibition. An influential hypothesis from the last decade proposes that a module within the right inferior frontal cortex (RIFC) of the human brain is dedicated to supporting response inhibition. However, there is growing evidence to support the alternative view that response inhibition is just one prominent example of the many cognitive control processes that are supported by the same set of 'domain general' functional networks. Here, I test directly between the modular and network accounts of motor response inhibition by applying a combination of data-driven, event-related and functional connectivity analyses to fMRI data from a variety of attention and inhibition tasks. The results demonstrate that there is no inhibitory module within the RIFC. Instead, response inhibition recruits a functionally heterogeneous ensemble of RIFC networks, which can be dissociated from each other in the context of other task demands.
Parkin BL, Hellyer PJ, Leech R, et al., 2015, Dynamic Network Mechanisms of Relational Integration, JOURNAL OF NEUROSCIENCE, Vol: 35, Pages: 7660-7673, ISSN: 0270-6474
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