85 results found
Hampshire A, Daws RE, Neves ID, et al., 2019, Probing cortical and sub-cortical contributions to instruction-based learning: Regional specialisation and global network dynamics, NeuroImage, ISSN: 1053-8119
Soreq E, Leech R, Hampshire A, 2019, Dynamic network coding of working-memory domains and working-memory processes, NATURE COMMUNICATIONS, Vol: 10, ISSN: 2041-1723
Li LM, Violante IR, Leech R, et al., 2019, Brain state and polarity dependent modulation of brain networks by transcranial direct current stimulation, HUMAN BRAIN MAPPING, Vol: 40, Pages: 904-915, ISSN: 1065-9471
Li LM, Violante IR, Leech R, et al., 2019, Cognitive enhancement with Salience Network electrical stimulation is influenced by network structural connectivity, NEUROIMAGE, Vol: 185, Pages: 425-433, ISSN: 1053-8119
Brooker H, Wesnes KA, Ballard C, et al., 2019, The relationship between the frequency of number-puzzle use and baseline cognitive function in a large online sample of adults aged 50 and over, International Journal of Geriatric Psychiatry, ISSN: 0885-6230
© 2019 John Wiley & Sons, Ltd. Objective: Establishing affordable lifestyle interventions that might preserve cognitive function in the aging population and subsequent generations is a growing area of research focus. Data from the PROTECT study has been utilised to examine whether number-puzzle use is related to cognitive function in older adults. Methods: Data from 19 078 healthy volunteers aged 50 to 93 years old enrolled on the online PROTECT study were evaluated for self-reported frequency of performing number puzzles. Two cognitive-test batteries were employed to assess core aspects of cognitive function including reasoning, focussed and sustained attention, information processing, executive function, working memory, and episodic memory. Analysis of covariance was used to establish the differences between the six frequency groups. Results: Highly statistically significant main effects of the frequency of performing number puzzles were seen on all 14 cognitive measures, with P values of less than 0.0004. Interestingly, participants who reported engaging in number puzzles more than once a day had superior cognitive performance on 10 core measures compared with all other frequency groups, although not all were statistically significant. Conclusions: This study has identified a close relationship between frequency of number-puzzle use and the quality of cognitive function in adults aged 50 to 93 years old. In order to determine the value of these findings as a potential intervention, further research should explore the type and difficulty of the number puzzles. These findings further contribute to the growing evidence that engaging in mentally stimulating activities could benefit the brain function of the ageing population.
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 N, 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, International Congress of Parkinson's Disease and Movement Disorders, Publisher: WILEY, Pages: S682-S683, ISSN: 0885-3185
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.
Peers PV, Astle DE, Duncan J, et al., 2018, Dissociable effects of attention vs working memory training on cognitive performance and everyday functioning following fronto-parietal strokes, Neuropsychological Rehabilitation, ISSN: 0960-2011
© 2018, © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Difficulties with attention are common following stroke, particularly in patients with frontal and parietal damage, and are associated with poor outcome. Home-based online cognitive training may have the potential to provide an efficient and effective way to improve attentional functions in such patients. Little work has been carried out to assess the efficacy of this approach in stroke patients, and the lack of studies with active control conditions and rigorous evaluations of cognitive functioning pre and post-training means understanding is limited as to whether and how such interventions may be effective. Here, in a feasibility pilot study, we compare the effects of 20 days of cognitive training using either novel Selective Attention Training (SAT) or commercial Working Memory Training (WMT) programme, versus a waitlist control on a range of attentional and working memory tasks. We demonstrate separable effects of each training condition, with SAT leading to improvements in spatial and non-spatial aspects of attention and WMT leading to improvements on closely related working memory tasks. In addition, both training groups reported improvements in everyday functioning, which were associated with improvements in attention, suggesting that improving attention may be of particular importance in maximising functional improvements in this patient group.
Grant JE, Daws R, Hampshire A, et al., 2018, An fMRI Pilot Study of Cognitive Flexibility in Trichotillomania., J Neuropsychiatry Clin Neurosci, Vol: 30, Pages: 318-324
Trichotillomania is a relatively common psychiatric condition, although its neurobiological basis is unknown. Abnormalities of flexible responding have been implicated in the pathophysiology of obsessive-compulsive disorder and thus may be relevant in trichotillomania. The purpose of this study was to probe reversal learning and attentional set-shifting in trichotillomania. Twelve adults with trichotillomania and 13 matched healthy control subjects undertook a functional MRI task of cognitive flexibility. Group-level activation maps for extradimensional and reversal switches were independently parcellated into discrete regions of interest using a custom watershed algorithm. Activation magnitudes were extracted from each region of interest and study subject and compared at the group level. Reversal events evoked the expected patterns of insula and parietal regions and activity in the frontal dorsal cortex extending anterior to the frontal poles, whereas extradimensional shifts evoked the expected frontal dorsolateral and parietal pattern of activity. Trichotillomania was associated with significantly increased right middle frontal and reduced right occipital cortex activation during reversal and set-shifting. Elevated frontal activation coupled with reduced activation in more posterior brain regions was identified. These pilot data suggest potentially important neural dysfunction associated with trichotillomania.
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
Vaghi MM, Hampshire A, Fineberg NA, et al., 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
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.
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.
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
Hampshire A, 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: 9780128036761
© 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.
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
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.
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