Publications
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Sabatini S, Ukoumunne OC, Ballard C, et al., 2021, Cross-sectional association between objective cognitive performance and perceived age-related gains and losses in cognition, INTERNATIONAL PSYCHOGERIATRICS, Vol: 33, Pages: 727-741, ISSN: 1041-6102
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- Citations: 20
Lorenz R, Johal M, Dick F, et al., 2021, A Bayesian optimization approach for rapidly mapping residual network function in stroke, BRAIN, Vol: 144, Pages: 2120-2134, ISSN: 0006-8950
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- Citations: 5
Jolly AE, Hampshire A, 2021, A robust brain signature region approach for episodic memory performance in older adults., Brain, Vol: 144, Pages: 1038-1040, ISSN: 1460-2156
Soreq E, Violante IR, Daws R, et al., 2021, Neuroimaging evidence for a network sampling theory of individual differences in human intelligence, Nature Communications, Vol: 12, ISSN: 2041-1723
Despite a century of research, it remains unclear whether human intelligence should be studied as one dominant, several major, or many distinct abilities, and how such abilities relate to the functional organisation of the brain. Here, we combine psychometric and machine learning methods to examine in a data-driven manner how factor structure and individual variability in cognitive-task performance relate to dynamic-network connectomics. We report that 12 sub-tasks from an established intelligence test can be accurately multi-way classified (74%, chance 8.3%) based on the network states that they evoke. The proximities of the tasks in behavioural-psychometric space correlate with the similarities of their network states. Furthermore, the network states were more accurately classified for higher relative to lower performing individuals. These results suggest that the human brain uses a high-dimensional network-sampling mechanism to flexibly code for diverse cognitive tasks. Population variability in intelligence test performance relates to the fidelity of expression of these task-optimised network states.
Chamberlain SR, Grant JE, Trender W, et al., 2021, Post-traumatic stress disorder symptoms in COVID-19 survivors: online population survey, BJPSYCH OPEN, Vol: 7, ISSN: 2056-4724
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- Citations: 40
Necka E, Gruszka A, Hampshire A, et al., 2021, The Effects of Working Memory Training on Brain Activity, BRAIN SCIENCES, Vol: 11
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- Citations: 3
Mallas E-J, De Simoni S, Scott G, et al., 2021, Abnormal dorsal attention network activation in memory impairment after traumatic brain injury, Brain: a journal of neurology, Vol: 144, Pages: 114-127, ISSN: 0006-8950
Memory impairment is a common, disabling effect of traumatic brain injury. In healthy individuals, successful memory encoding is associated with activation of the dorsal attention network as well as suppression of the default mode network. Here, in traumatic brain injurypatients we examined whether: i) impairments in memory encoding are associated with abnormal brain activation in these networks; ii) whether changes in this brain activity predict subsequent memory retrieval; and iii) whether abnormal white matter integrity underpinningfunctional networks is associated with impaired subsequent memory. 35 patients with moderate-severetraumatic brain injury aged 23-65 years (74% males) in the post-acute/chronic phase after injury and 16 healthy controls underwent functional MRI during performance of an abstract image memory encoding task. Diffusion tensor imaging was used to assess structural abnormalities across patient groups compared to 28 age-matched healthy controls. Successful memory encoding across all participants was associated with activation of the dorsal attention network, the ventral visual stream and medial temporal lobes. Decreased activation was seen in the default mode network. Patients with preserved episodic memory demonstrated increased activation in areas of the dorsal attention network.Patients with impaired memory showed increased left anterior prefrontal activity. White matter microstructure underpinning connectivity between core nodes of the encoding networks was significantly reduced in patients with memory impairment. Our results show for the first time that patients with impaired episodic memory show abnormal activation of key nodes within the dorsal attention network and regions regulating default mode network activity during encoding. Successful encoding was associated with an opposite direction of signal
Leng F, Hinz R, Dani M, et al., 2020, Tau formation is associated with microglial activation in more widespread cortical areas than amyloid deposition: Multimodal neuroimaging comparison, Alzheimer's and Dementia, ISSN: 1552-5260
Edison P, Leng F, Hinz R, et al., 2020, Influence of microglial activation on structural and functional connectivity in mild cognitive impairment subjects: Development of new models and analysis methods/neuroinflammation, Alzheimer's and Dementia, ISSN: 1552-5260
Di Bella C, Trender W, Hellyer P, et al., 2020, Evaluating cognitive functioning in multiple sclerosis, compared to other neurological disorders, using an online cognitive battery, 8th Joint ACTRIMS-ECTRIMS Meeting (MSVirtual), Publisher: SAGE PUBLICATIONS LTD, Pages: 502-503, ISSN: 1352-4585
Mew BG, Custovic D, Soreq E, et al., 2020, Mapping the common and distinct neural correlates of visual, rule and motor conflict
<jats:title>Abstract</jats:title><jats:p>Flexible behaviour requires cognitive-control mechanisms to efficiently resolve conflict between competing information and alternative actions. Whether a global neural resource mediates all forms of conflict or this is achieved within domainspecific systems remains debated. We use a novel fMRI paradigm to orthogonally manipulate rule, response and stimulus-based conflict within a full-factorial design. Whole-brain voxelwise analyses show that activation patterns associated with these conflict types are distinct but partially overlapping within Multiple Demand Cortex (MDC), the brain regions that are most commonly active during cognitive tasks. Region of interest analysis shows that most MDC sub-regions are activated for all conflict types, but to significantly varying levels. We propose that conflict resolution is an emergent property of distributed brain networks, the functional-anatomical components of which place on a continuous, not categorical, scale from domain-specialised to domain general. MDC brain regions place towards one end of that scale but display considerable functional heterogeneity.</jats:p>
Hampshire A, Trender W, Chamberlain SR, et al., 2020, Cognitive deficits in people who have recovered from COVID-19 relative to controls: An N=84,285 online study
<jats:title>Abstract</jats:title><jats:p>Case studies have revealed neurological problems in severely affected COVID-19 patients. However, there is little information regarding the nature and broader prevalence of cognitive problems post-infection or across the full spread of severity. We analysed cognitive test data from 84,285 Great British Intelligence Test participants who completed a questionnaire regarding suspected and biologically confirmed COVID-19 infection. People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits when controlling for age, gender, education level, income, racial-ethnic group and pre-existing medical disorders. They were of substantial effect size for people who had been hospitalised, but also for mild but biologically confirmed cases who reported no breathing difficulty. Finer grained analyses of performance support the hypothesis that COVID-19 has a multi-system impact on human cognition.</jats:p><jats:sec><jats:title>Significance statement</jats:title><jats:p>There is evidence that COVID-19 may cause long term health changes past acute symptoms, termed ‘long COVID’. Our analyses of detailed cognitive assessment and questionnaire data from tens thousands of datasets, collected in collaboration with BBC2 Horizon, align with the view that there are chronic cognitive consequences of having COVID-19. Individuals who recovered from suspected or confirmed COVID-19 perform worse on cognitive tests in multiple domains than would be expected given their detailed age and demographic profiles. This deficit scales with symptom severity and is evident amongst those without hospital treatment. These results should act as a clarion call for more detailed research investigating the basis of cognitive deficits in people who have survived SARS-COV-2 infection.</jats:p></jats:sec>
Sabatini S, Ukoumunne OC, Ballard C, et al., 2020, International relevance of two measures of awareness of age-related change (AARC), BMC GERIATRICS, Vol: 20
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- Citations: 19
Stewart GR, Corbett A, Ballard C, et al., 2020, Sleep problems and mental health difficulties in older adults who endorse high autistic traits, Research in Autism Spectrum Disorders, Vol: 77, ISSN: 1750-9467
Background: Sleep problems and mental health difficulties are common in autistic children and young adults. However, these problems have seldom been studied in older autistic adults, or in older adults with elevated autistic traits. Method: Cross-sectional data was examined from 13,897 adults aged 50–81 years taking part in the PROTECT study, who reported whether they experienced persistent socio-communicative autistic traits. Approximately 1%, 187 individuals, were identified as endorsing high autistic traits in childhood and currently, henceforth ‘Autism Spectrum Trait’ (AST) group. An age- and gender-matched comparison group was formed of 6740 individuals who endorsed no autistic traits, henceforth ‘Control Older Adults’ (COA) group. Differences between AST and COA groups were explored in self-reported sleep behaviors, and in depression and anxiety symptoms. Results: AST and COA groups reported similar sleep duration and depth, and nighttime waking frequency. However, the AST group reported significantly more problems with falling asleep, morning drowsiness, and lower sleep quality/satisfaction than COA. More AST adults reported sleep problems past cut-off, as well as clinical levels of depression and anxiety, compared to COA. Adults in both groups who met criteria for high sleep problems experienced more mental health difficulties than those with few sleep problems. However, even amongst those without depression/anxiety, the AST group reported more sleep problems than the COA. Conclusions: These associations suggest that older adults with high autistic traits, like diagnosed autistic children/young adults, may experience poorer sleep and more mental health difficulties than those with low autistic traits. Further work is needed to see whether these results extend to older individuals meeting diagnostic criteria for autism.
Araña-Oiarbide G, Daws RE, Lorenz R, et al., 2020, Preferential activation of the posterior Default-Mode Network with sequentially predictable task switches
<jats:title>Abstract</jats:title><jats:p>The default-mode network (DMN) has been primarily associated with internally-directed and self-relevant cognition. This perspective is expanding to recognise its importance in executive behaviours like switching. We investigated the effect different task-switching manipulations have on DMN activation in two studies with novel fMRI paradigms. In the first study, the paradigm manipulated visual discriminability, visuo-perceptual distance and sequential predictability during switching. Increased posterior cingulate/precuneus (PCC/PrCC) activity was evident during switching; critically, this was strongest when the occurrence of the switch was predictable. In the second study, we sought to replicate and further investigate this switch-related effect with a fully factorial design manipulating sequential, spatial and visual-feature predictability. Whole-brain analysis again identified a PCC/PrCC-centred cluster that was more active for sequentially predictable versus unpredictable switches, but not for the other predictability dimensions. We propose PCC/PrCC DMN subregions may play a prominent executive role in mapping the sequential structure of complex tasks.</jats:p>
Edison P, Leng F, Hinz R, et al., 2020, Tau formation is associated with microglial activation in more widespread cortical areas than amyloid deposition does, 2020 Alzheimer's Association International Conference
Daws RE, Soreq E, Li Y, et al., 2020, Contrasting hierarchical and multiple-demand accounts of frontal lobe functional organisation during task-switching
<jats:title>Abstract</jats:title><jats:p>There is an unresolved discrepancy between popular hierarchical and multiple-demand perspectives on the functional organisation of the human frontal lobes. Here, we tested alternative predictions of these perspectives with a novel fMRI switching paradigm. Each trial involved switching attention between stimuli, but at different levels of difficulty and abstraction. As expected, increasing response times were evident when comparing low-level perceptual switching to more abstract dimension, rule and task-switching. However, there was no evidence of an abstraction hierarchy within the prefrontal cortex (PFC). Nor was there recruitment of additional anterior PFC regions under increased switching demand. Instead, switching activated a widespread network of frontoparietal and cerebellar regions. Critically, the activity within PFC sub-regions uniformly increased with behavioural switch costs. We propose that both perspectives have some validity, but neither is complete. Too many studies have reported dissociations within MD for this volume to be functionally uniform, and the recruitment of more anterior regions with increased general difficulty cannot explain those results. Conversely, whilst reproducible evidence for a hierarchical functional organisation has been reported, this cannot be explained in terms of abstraction of representation or reconfiguration <jats:italic>per se</jats:italic>, because those interpretations generalise poorly to other task contexts.</jats:p>
Beppi C, Violante IR, Hampshire A, et al., 2020, Patterns of Focal- and Large-Scale Synchronization in Cognitive Control and Inhibition: A Review, FRONTIERS IN HUMAN NEUROSCIENCE, Vol: 14, ISSN: 1662-5161
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- Citations: 5
Jolly A, Scott G, Sharp D, et al., 2020, Distinct patterns of structural damage underlie working memory and reasoning deficits after traumatic brain injury, Brain: a journal of neurology, Vol: 143, Pages: 1158-1176, ISSN: 0006-8950
It is well established that chronic cognitive problems after traumatic brain injury (TBI) relate to diffuse axonal injury (DAI) and the consequent widespread disruption of brain connectivity. However, the pattern of DAI varies between patients and they have a correspondingly heterogeneous profile of cognitive deficits. This heterogeneity is poorly understood, presenting a non-trivial challenge for prognostication and treatment. Prominent amongst cognitive problems are deficits in working memory and reasoning. Previous functional magnetic resonance imaging (fMRI) in controls has associated these aspects of cognition with distinct, but partially overlapping, networks of brain regions. Based on this, a logical prediction is that differences in the integrity of the white matter tracts that connect these networks should predict variability in the type and severity of cognitive deficits after TBI.We use diffusion-weighted imaging, cognitive testing and network analyses to test this prediction. We define functionally distinct sub-networks of the structural connectome by intersecting previously published fMRI maps of the brain regions that are activated during our working memory and reasoning tasks, with a library of the white-matter tracts that connect them. We examine how graph theoretic measures within these sub-networks relate to the performance of the same tasks in a cohort of 92 moderate-severe TBI patients. Finally, we use machine learning to determine whether cognitive performance in patients can be predicted using graph theoretic measures from each sub-network.Principal component analysis of behavioural scores confirm that reasoning and working memory form distinct components of cognitive ability, both of which are vulnerable to TBI. Critically, impairments in these abilities after TBI correlate in a dissociable manner with the information-processing architecture of the sub-networks that they are associated with. This dissociation is confirmed when examining degree
Stewart GR, Corbett A, Ballard C, et al., 2020, The Mental and Physical Health of Older Adults With a Genetic Predisposition for Autism., Autism Res, Vol: 13, Pages: 641-654
Autism commonly aggregates in families, with twin studies estimating heritability to be around 80%. Subclinical autism-like characteristics have also been found at elevated rates in relatives of autistic probands. Physical and psychiatric conditions have been reported at elevated rates in autistic children and adults, and also in their relatives. However, to date, there has been no exploration of how aging may affect this pattern. This study examined cross-sectional data from the ongoing online PROTECT study. A total of 20,220 adults aged 50 years and older reported whether they have an autistic first-degree relative. In total, 739 older adults reported having an autistic first-degree relative (AFDR group) and 11,666 were identified as having no family history of any neurodevelopmental disorder (NFD group). The AFDR group demonstrated significantly higher frequencies of self-reported psychiatric diagnoses and a greater total number of co-occurring psychiatric diagnoses than the NFD group. Furthermore, the AFDR group reported elevated current self-report symptoms of depression, anxiety, traumatic experience, and post-traumatic stress than the NFD group. By contrast, few differences between AFDR and NFD groups were observed in physical health conditions, and no differences were observed in the total number of co-occurring physical health diagnoses. These findings suggest that adults who have an AFDR may be at greater risk of poor mental, but not physical, health in later life. Older adults with autistic relatives may benefit from close monitoring to mitigate this susceptibility and to provide timely intervention. Autism Res 2020, 13: 641-654. © 2020 The Authors. Autism Research published by International Society for Autism Research published by Wiley Periodicals, Inc. LAY SUMMARY: Children and adults with an autistic relative have been found to experience more psychiatric difficulties than those with no family links to autism. However, a few studies have e
Hampshire A, Zadel A, Sandrone S, et al., 2020, Inhibition-Related Cortical Hypoconnectivity as a Candidate Vulnerability Marker for Obsessive-Compulsive Disorder, BIOLOGICAL PSYCHIATRY-COGNITIVE NEUROSCIENCE AND NEUROIMAGING, Vol: 5, Pages: 222-230, ISSN: 2451-9022
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- Citations: 9
Brooker H, Williams G, Hampshire A, et al., 2020, FLAME: A computerized neuropsychological composite for trials in early dementia, Alzheimer's and Dementia: Diagnosis, Assessment and Disease Monitoring, Vol: 12
Introduction: Sensitive neuropsychological tests are needed to improve power for clinical trials in early Alzheimer's disease (AD). Methods: To develop a neuropsychological composite (FLAME – Factors of Longitudinal Attention, Memory and Executive Function), we assessed, 10,714 participants over the age of 50 from PROTECT with validated computerized assessments for 2 years. A factorial analysis was completed to identify the key cognitive factors in all participants, and further analyses examined sensitivity to change in people with stage 2/3 early Alzheimer's disease (AD) according to the US Food and Drug Administration (FDA) framework. Results: The FLAME composite score (speed of attention, accuracy of attention, memory, and executive function) distinguished between normal cognition and stage 2/3 early AD at baseline, and was sensitive to cognitive and global/functional decline over 2 years, with the potential to improve power for clinical trials. Discussion: FLAME is sensitive to change, providing a straightforward approach to reduce sample size for RCTs in early AD. Conclusion: FLAME is a useful computerized neuropsychology composite with utility for clinical trials focusing on cognition.
Li W, Lao-Kaim NP, Roussakis A-A, et al., 2020, Longitudinal functional connectivity changes related to dopaminergic decline in Parkinson's disease, NeuroImage: Clinical, Vol: 28, Pages: 1-10, ISSN: 2213-1582
BackgroundResting-state functional magnetic resonance imaging (fMRI) studies have demonstrated that basal ganglia functional connectivity is altered in Parkinson’s disease (PD) as compared to healthy controls. However, such functional connectivity alterations have not been related to the dopaminergic deficits that occurs in PD over time.ObjectivesTo examine whether functional connectivity impairments are correlated with dopaminergic deficits across basal ganglia subdivisions in patients with PD both cross-sectionally and longitudinally.MethodsWe assessed resting-state functional connectivity of basal ganglia subdivisions and dopamine transporter density using 11C-PE2I PET in thirty-four PD patients at baseline. Of these, twenty PD patients were rescanned after 19.9 ± 3.8 months. A seed-based approach was used to analyze resting-state fMRI data. 11C-PE2I binding potential (BPND) was calculated for each participant. PD patients were assessed for disease severity.ResultsAt baseline, PD patients with greater dopaminergic deficits, as measured with 11C-PE2I PET, showed larger decreases in posterior putamen functional connectivity with the midbrain and pallidum. Reduced functional connectivity of the posterior putamen with the thalamus, midbrain, supplementary motor area and sensorimotor cortex over time were significantly associated with changes in DAT density over the same period. Furthermore, increased motor disability was associated with lower intraregional functional connectivity of the posterior putamen.ConclusionsOur findings suggest that basal ganglia functional connectivity is related to integrity of dopaminergic system in patients with PD. Application of resting-state fMRI in a large cohort and longitudinal scanning may be a powerful tool for assessing underlying PD pathology and its progression.
Krause-Utz A, Walther J-C, Schweizer S, et al., 2020, Effectiveness of an Emotional Working Memory Training in Borderline Personality Disorder: A Proof-of-Principle Study., Psychother Psychosom, Vol: 89, Pages: 122-124
Li L, Violante I, Zimmerman K, et al., 2019, Traumatic axonal injury influences the cognitive effect of non-invasive brain stimulation, Brain, Vol: 142, Pages: 3280-3293, ISSN: 1460-2156
Non-invasive brain stimulation has been widely investigated for as a potentialtreatment for a range of neurological and psychiatric conditions, including braininjury. However, the behavioural effects of brain stimulation are very variable, forreasons that are poorly understood. This is a particular challenge for traumatic braininjury, where patterns of damage and their clinical effects are heterogenous. Here wetest the hypothesis that the response to transcranial direct current stimulationfollowing traumatic brain injury is dependent on white matter damage within thestimulated network. We used a novel simultaneous stimulation-MRI protocolapplying anodal, cathodal and sham stimulation to 24 healthy and 35 moderate/severetraumatic brain injury patients. Stimulation was applied to the right inferior frontalgyrus/anterior insula node of the Salience Network, which was targeted because ourprevious work had shown its importance to executive function. Stimulation wasapplied during performance of the Stop Signal Task, which assesses responseinhibition, a key component of executive function. Structural MRI was used to assessthe extent of brain injury, including diffusion MRI assessment of post-traumaticaxonal injury. Functional MRI, which was simultaneously acquired to delivery ofstimulation, assessed the effects of stimulation on cognitive network function. Anodalstimulation improved response inhibition in control participants, an effect that was notobserved in the patient group. The extent of traumatic axonal injury within theSalience Network strongly influenced the behavioural response to stimulation.Increasing damage to the tract connecting the stimulated right inferior frontalgyrus/anterior insula to the rest of the SN was associated with reduced beneficialeffects of stimulation. In addition, anodal stimulation normalised Default ModeNetwork activation in patients with poor response inhibition, suggesting thatstimulation modulates communication between the networks invo
Hampshire A, Sandrone S, Hellyer P, 2019, A large-scale, cross-sectional investigation into the efficacy of brain training, Frontiers in Neuroscience, Vol: 13, Pages: 1-13, ISSN: 1662-4548
Brain training is a large and expanding industry, and yet there is a recurrent and ongoing debate concerning its scientific basis or evidence for efficacy. Much of evidence for the efficacy of brain training within this debate is from small-scale studies that do not assess the type of “brain training,” the specificity of transfer effects, or the length of training required to achieve a generalized effect. To explore these factors, we analyze cross-sectional data from two large Internet-cohort studies (total N = 60,222) to determine whether cognition differs at the population level for individuals who report that they brain train on different devices, and across different timeframes, with programs in common use circa 2010–2013. Examining scores for an assessment of working-memory, reasoning and verbal abilities shows no cognitive advantages for individuals who brain train. This contrasts unfavorably with significant advantages for individuals who regularly undertake other cognitive pursuits such as computer, board and card games. However, finer grained analyses reveal a more complex relationship between brain training and cognitive performance. Specifically, individuals who have just begun to brain train start from a low cognitive baseline compared to individuals who have never engaged in brain training, whereas those who have trained for a year or more have higher working-memory and verbal scores compared to those who have just started, thus suggesting an efficacy for brain training over an extended period of time. The advantages in global function, working memory, and verbal memory after several months of training are plausible and of clinically relevant scale. However, this relationship is not evident for reasoning performance or self-report measures of everyday function (e.g., employment status and problems with attention). These results accord with the view that although brain training programs can produce benefits, these might extend to tasks
Brooker H, Wesnes KA, Ballard C, et al., 2019, An online investigation of the relationship between the frequency of word puzzle use and cognitive function in a large sample of older adults., Int J Geriatr Psychiatry, Vol: 34, Pages: 921-931
OBJECTIVE: The identification of modifiable lifestyle factors to preserve cognitive function in older individuals becomes increasingly of importance. This study examines whether word puzzle use is related to cognitive function in older adults. METHODS: Cognitive data from 19 078 cognitively healthy individuals aged 50 to 93 years enrolled into the online PROTECT study were evaluated for self-reported frequency of performing word puzzles on a six-point scale, ranging from "more than once per day" to "never". Nine cognitive tests covered a range of domains including focussed and sustained attention, information processing, executive function, working memory, and episodic memory. Analyses of covariance were used to determine any differences between the six response groups. RESULTS: Each of the 14 cognitive measures analysed showed highly statistically significant main effects of the frequency of performing word puzzles. For each measure, the group who never performed word puzzles performed most poorly, with the group who reported occasional puzzle use also performing more poorly than virtually every other group. Measures of speed provided the greatest discriminations, with a grammatical reasoning score differentiating the two highest frequency groups, performing word puzzles daily or more than once daily. CONCLUSIONS: The frequency of word puzzle use is directly related to cognitive function in adults aged 50 and over. Future work needs to determine whether engaging in such puzzles can favourably influence cognitive trajectory with age.
Jenkins PO, De Simoni S, Bourke NJ, et al., 2019, Stratifying drug treatment of cognitive impairments after traumatic brain injury using neuroimaging, Brain, Vol: 142, Pages: 2367-2379, ISSN: 1460-2156
Cognitive impairment is common following traumatic brain injury. Dopaminergic drugs can enhance cognition after traumatic brain injury, but individual responses are highly variable. This may be due to variability in dopaminergic damage between patients. We investigate whether measuring dopamine transporter levels using 123I-ioflupane single-photon emission computed tomography (SPECT) predicts response to methylphenidate, a stimulant with dopaminergic effects. Forty patients with moderate-severe traumatic brain injury and cognitive impairments completed a randomized, double-blind, placebo-controlled, crossover study. 123I-ioflupane SPECT, MRI and neuropsychological testing were performed. Patients received 0.3 mg/kg of methylphenidate or placebo twice a day in 2-week blocks. Subjects received neuropsychological assessment after each block and completed daily home cognitive testing during the trial. The primary outcome measure was change in choice reaction time produced by methylphenidate and its relationship to stratification of patients into groups with normal and low dopamine transporter binding in the caudate. Overall, traumatic brain injury patients showed slow information processing speed. Patients with low caudate dopamine transporter binding showed improvement in response times with methylphenidate compared to placebo [median change = -16 ms; 95% confidence interval (CI): -28 to -3 ms; P = 0.02]. This represents a 27% improvement in the slowing produced by traumatic brain injury. Patients with normal dopamine transporter binding did not improve. Daily home-based choice reaction time results supported this: the low dopamine transporter group improved (median change -19 ms; 95% CI: -23 to -7 ms; P = 0.002) with no change in the normal dopamine transporter group (P = 0.50). The low dopamine transporter group also improved on self-reported and caregiver apathy assessments (P = 0.03 and P = 0.02, respectively). Both groups reported improvements in fatigue (P = 0.03
Holmes J, Woolgar F, Hampshire A, et al., 2019, Are Working Memory Training Effects Paradigm-Specific?, FRONTIERS IN PSYCHOLOGY, Vol: 10, ISSN: 1664-1078
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- Citations: 23
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, Vol: 192, Pages: 88-100, ISSN: 1053-8119
Diverse cortical networks and striatal brain regions are implicated in instruction-based learning (IBL); however, their distinct contributions remain unclear. We use a modified fMRI paradigm to test two hypotheses regarding the brain mechanisms that underlie IBL. One hypothesis proposes that anterior caudate and frontoparietal regions transiently co-activate when new rules are being bound in working memory. The other proposes that they mediate the application of the rules at different stages of the consolidation process. In accordance with the former hypothesis, we report strong activation peaks within and increased connectivity between anterior caudate and frontoparietal regions when rule-instruction slides are presented. However, similar effects occur throughout a broader set of cortical and sub-cortical regions, indicating a metabolically costly reconfiguration of the global brain state. The distinct functional roles of cingulo-opercular, frontoparietal and default-mode networks are apparent from their activation throughout, early and late in the practice phase respectively. Furthermore, there is tentative evidence of a peak in anterior caudate activity mid-way through the practice stage. These results demonstrate how performance of the same simple task involves a steadily shifting balance of brain systems as learning progresses. They also highlight the importance of distinguishing between regional specialisation and global dynamics when studying the network mechanisms that underlie cognition and learning.
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