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Data Repository


This page shows all 234 data sets currently available in our Data repository

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Sequence learning recodes cortical representations instead of strengthening initial ones
Authors:
KALM, K., NORRIS, D.
Reference:
PLOS Computational Biology, 17(5): e1008969
Year of publication:
2021
CBU number:
8720
URL:
Data for this project is available at: https://gitlab.com/kristjankalm/fmri_seq_ltm
Left egocentric neglect in early subacute right-stroke patients is related to damage of the superior longitudinal fasciculus
Authors:
Spanò, B., NARDO, D., Giulietti, G., Matano, A., Salsano, I., Briani, C., Vadalà, R., Marzi, C., De Luca, M., Caltagirone, C., Santangelo, V.
Reference:
Brain Imaging and Behavior
Year of publication:
In Press
CBU number:
8716
Abstract:
typical consequence of stroke in the right hemisphere is unilateral spatial neglect. Distinct forms of neglect have been described, such as space-based (egocentric) and object-based (allocentric) neglect. However, the relationship between these two forms of neglect is still far from being understood, as well as their neural substrates. Here, we further explore this issue by using voxel lesion symptoms mapping (VLSM) analyses on a large sample of early subacute right-stroke patients assessed with the Apples Cancellation Test. This is a sensitive test that simultaneously measures both egocentric and allocentric neglect. Behaviourally, we found no correlation between egocentric and allocentric performance, indicating independent mechanisms supporting the two forms of neglect. This was confirmed by the VLSM analysis that pointed out a link between a damage in the superior longitudinal fasciculus and left egocentric neglect. By contrast, no association was found between brain damage and left allocentric neglect. These results indicate a higher probability to observe egocentric neglect as a consequence of white matter damages in the superior longitudinal fasciculus, while allocentric neglect appears more “globally” related to the whole lesion map. Overall, these findings on early subacute right-stroke patients highlight the role played by white matter integrity in sustaining attention-related operations within an egocentric frame of reference.
Data for this project is held by an external institution. Please contact the authors to request a copy.
Temporal variabilities provide additional category-related information in object category decoding: a systematic comparison of informative EEG features
Authors:
KARIMI-ROUZBAHANI, H., Shahmohammadi, M., Vahab, E., Setayeshi, S., Carlson, T.
Reference:
Neural Computation
Year of publication:
In Press
CBU number:
8715
Abstract:
How does the human brain encode visual object categories? Our understanding of this has advanced substantially with the development of multivariate decoding analyses. However, conventional electroencephalography (EEG) decoding predominantly use the “mean” neural activation within the analysis window to extract category information. Such temporal averaging overlooks the within-trial neural variability which is suggested to provide an additional channel for the encoding of information about the complexity and uncertainty of the sensory input. The richness of temporal variabilities, however, has not been systematically compared with the conventional “mean” activity. Here we compare the information content of 31 variability-sensitive features against the “mean” of activity, using three independent highly-varied datasets. In whole-trial decoding, the classical event-related potential (ERP) components of “P2a” and “P2b” provided information comparable to those provided by “Original Magnitude Data (OMD)” and “Wavelet Coefficients (WC)”, the two most informative variability-sensitive features. In time-resolved decoding, the “OMD” and “WC” outperformed all the other features (including “mean”), which were sensitive to limited and specific aspects of temporal variabilities, such as their phase or frequency. The information was more pronounced in Theta frequency band, previously suggested to support feed-forward visual processing. We concluded that the brain might encode the information in multiple aspects of neural variabilities simultaneously e.g. phase, amplitude and frequency rather than “mean” per se. In our active categorization dataset, we found that more effective decoding of the neural codes corresponds to better prediction of behavioral performance. Therefore, the incorporation of temporal variabilities in time-resolved decoding can provide additional category information and improved prediction of behavior.
Data for this project is available at: https://osf.io/ganw3
Sensing and seeing associated with overlapping occipitoparietal activation in simultaneous EEG-fMRI
Authors:
SCRIVENER, C., Malik, A., Linder, M., Roesch, E.
Reference:
Neuroscience of Consciousness, 2021(1):niab008
Year of publication:
2021
CBU number:
8713
Abstract:
The presence of a change in a visual scene can influence brain activity and behaviour, even in the absence of full conscious report. It may be possible for us to sense that such a change has occurred, even if we cannot specify exactly where or what it was. Despite existing evidence from electroencephalogram (EEG) and eye-tracking data, it is still unclear how this partial level of awareness relates to fMRI BOLD activation. Using EEG, functional magnetic resonance imaging (fMRI), and a change blindness paradigm, we found multi-modal evidence to suggest that sensing a change is distinguishable from being blind to it. Specifically, trials during which participants could detect the presence of a colour change but not identify the location of the change (sense trials), were compared to those where participants could both detect and localise the change (localise or see trials), as well as change blind trials. In EEG, late parietal positivity and N2 amplitudes were larger for localised changes only, when compared to change blindness. However, ERP-informed fMRI analysis found no voxels with activation that significantly co-varied with fluctuations in single-trial late positivity amplitudes. In fMRI, a range of visual (BA17,18), parietal (BA7,40), and midbrain (anterior cingulate, BA24) areas showed increased fMRI BOLD activation when a change was sensed, compared to change blindness. These visual and parietal areas are commonly implicated as the storage sites of visual working memory, and we therefore argue that sensing may not be explained by a lack of stored representation of the visual display. Both seeing and sensing a change were associated with an overlapping occipitoparietal network of activation when compared to blind trials, suggesting that the quality of the visual representation, rather than the lack of one, may result in partial awareness during the change blindness paradigm.
URL:
Data for this project is available at: https://osf.io/w6bh3/
Population prevalence of the post-traumatic stress disorder subtype for young children in nationwide surveys of the British general population and of children-in-care
Authors:
HITCHCOCK, C., GOODALL, B., Sharples, o., Meiser-Stedman, R., WATSON, P., Ford, T., DALGLEISH, T.
Reference:
Journal of the American Academy of Child and Adolescent Psychiatry
Year of publication:
In Press
CBU number:
8710
Abstract:
Objective: Posttraumatic stress disorder (PTSD) is a debilitating condition which when left untreated, can have severe life-long consequences for an individual’s psychological, social and occupational functioning. Initial conceptualizations of PTSD were centered on adult presentations. However, the instantiation of developmentally appropriate PTSD for Young Children (PTSD-YC) criteria, tailored to preschool (aged 6 years old and under) children, represents an important step towards identifying more young children experiencing distress. Here we explore population-level prevalence of PTSD-YC, indexed via the Alternative Algorithm for PTSD (AA-PTSD). Method: We utilize population-representative data to test whether application of AA-PTSD criteria, relative to the DSM-IV PTSD algorithm, increases identification of 5-6 year old children with clinical needs, in both the general population (N=3202), and among looked-after-children (i.e., children-in-care; N=137) where the risk of mental health issues is greater. Results: Notably, no 5-6 year old children in the general population sample were diagnosed with PTSD using adult-based DSM-IV criteria. In contrast, AA-PTSD prevalence was 0.4% overall, rising to 5.4% in trauma-exposed children. In looked-after-children, overall PTSD prevalence rose from 1.2% when applying adult-led DSM-IV criteria to 14% when using AA-PTSD. Of trauma-exposed looked-after-children, 2.7% met criteria for DSM-IV PTSD, compared to 57.0% when applying AA-PTSD. In both samples, use of the Alternative Algorithm to index PTSD-YC criteria markedly increased identification of children experiencing functional impairment due to symptoms. Conclusion: Results demonstrate the utility of the PTSD-YC diagnosis beyond at-risk and treatment-seeking samples. Use of PTSD-YC criteria very substantially improves identification of 5-6 year old children burdened by PTSD at the population-level.
Data for this project is available at: https://ukdataservice.ac.uk/
The limited reach of surprise: evidence against effects of surprise on memory for 1 preceding elements of an event
Authors:
BEN-YAKOV, A., SMITH, V., HENSON, R.
Reference:
Psychonomic Bulletin & Review
Year of publication:
In Press
CBU number:
8709
Abstract:
When reflecting on the past, some of our strongest memories are for experiences that took us by surprise. Extensive research has backed this intuition that we are more likely to remember surprising moments than mundane ones. But what about the moments leading up to the surprise? Are we more likely to remember those as well? While surprise is a well-established modulator of memory, it is unknown whether memory for the entire event will be enhanced, or only for the surprising occurrence itself. We developed a novel paradigm utilising stop-motion films, depicting of a seqeuence of narrative events, in which specific occurrences could be replaced with surprising ones, while keeping the rest of the film unaltered. Using this design, we tested whether surprise exerts retroactive effects on memory, and specifically whether any potential effect would be confined to elements in the same event as the surprising occurrence. In a large cohort of participants (n=340), we found strong evidence that surprise did not retroactively modulate memory, neither when participants were tested immediately after study nor 24 hours later. We suggest two possible accounts for these findings: 1) that the components of an event are encoded as independent episodic elements (not as a cohesive unit), or 2) that surprise segments experience, sectioning off the preceding elements as a separate event. Scripts (including instructions for reproduction): https://github.com/ayaby/stopmotion
Data available, click to request
Impaired sensory evidence accumulation and network function in Lewy body dementia
Authors:
O’Callaghan, C., Firbank, M., TOMASSINI, A., Schumacher ,J, O’Brien, J.T., Taylor J
Reference:
Brain Communications
Year of publication:
In Press
CBU number:
8706
Abstract:
Deficits in attention underpin many of the cognitive and neuropsychiatric features of Lewy body dementia. These attention-related symptoms remain difficult to treat and there are many gaps in our understanding of their neurobiology. An improved understanding of attention-related impairments can be achieved via mathematical modelling approaches, which identify cognitive parameters to provide an intermediate level between observed behavioural data and its underlying neural correlate. Here, we apply this approach to identify the role of impaired sensory evidence accumulation in the attention deficits that characterise Lewy body dementia. In 31 people with Lewy body dementia (including 13 Parkinson’s disease dementia and 18 dementia with Lewy bodies cases), 16 people with Alzheimer’s disease, and 23 healthy controls, we administered an attention task whilst they underwent functional 3 T MRI. Using hierarchical Bayesian estimation of a drift diffusion model, we decomposed task performance into drift rate and decision boundary parameters. We tested the hypothesis that the drift rate—a measure of the quality of sensory evidence accumulation—is specifically impaired in Lewy body dementia, compared to Alzheimer’s disease. We further explored whether trial-by-trial variations in the drift rate related to activity within the default and dorsal attention networks, to determine whether altered activity in these networks was associated with slowed drift rates in Lewy body dementia. Our results revealed slower drift rates in the Lewy body dementia compared to the Alzheimer’s disease group, whereas the patient groups were equivalent for their decision boundaries. The patient groups were reduced relative to controls for both parameters. This highlights sensory evidence accumulation deficits as a key feature that distinguishes attention impairments in Lewy body dementia, consistent with impaired ability to efficiently process information from the environment to guide behaviour. We also found that the drift rate was strongly related to activity in the dorsal attention network across all three groups, whereas the Lewy body dementia group showed a divergent relationship relative to the Alzheimer’s disease and control groups for the default network, consistent with altered default network modulation being associated with impaired evidence accumulation. Together, our findings reveal impaired sensory evidence accumulation as a specific marker of attention problems in Lewy body dementia, which may relate to large-scale network abnormalities. By identifying impairments in a specific sub-process of attention, these findings will inform future exploratory and intervention studies that aim to understand and treat attention-related symptoms that are a key feature of Lewy body dementia.
URL:
Data for this project is held by an external institution. Please contact the authors to request a copy.
Avoiding monetary loss: a human habenula functional MRI ultra-high field study
Authors:
Weidacker, K., Seung-Goo, K, NORD, C., Rua, C., Rogers, C.T., Voona, V.
Reference:
Cortex, 142, 62-73
Year of publication:
2021
CBU number:
8705
Abstract:
A number of convergent human neuroimaging and animal studies suggest that habenula neurons fire in anticipation of non-rewarding outcomes, and suppress their firing in anticipation of rewarding outcomes. This normative function of the habenula appears disrupted in depression, and may be critical to the anti-depressant effects of ketamine. However, studying habenula functionality in humans using standard 3 T MRI is inherently limited by its small size. We employed ultra-high field (7 T) fMRI to investigate habenular activity in eighteen healthy volunteers during a Monetary Incentive Delay Task, focussing on loss avoidance, monetary loss and neutral events. We assessed neural activation in the field of view (FOV) in addition to ROI-based habenula-specific activity and generalized task-dependent functional connectivity. Whole FOV results indicated substantial neural differences between monetary loss and neutral outcomes, as well as between loss avoidance and neutral outcomes. Habenula-specific analyses bilateral deactivation during loss avoidance, compared to other outcomes. This first investigation into the habenula's role during loss avoidance revealed that the left habenula further differentiated between loss avoidance and monetary loss. Functional connectivity between the right habenula and the ipsilateral hippocampus and subcallosal cingulate (regions implicated in memory and depression pathophysiology) was enhanced when anticipating potential losses compared to anticipating neutral outcomes. Our findings suggest that the human habenula responds most strongly to outcomes of loss avoidance when compared to neutral and monetary losses, suggesting a role for the habenula in both reward and aversive processing. This has critical relevance to understanding the pathophysiology of habenula function in mood and other neuropsychiatric disorders, as well as the mechanism of action of habenula-targeting antidepressants such as ketamine.
URL:
Data for this project is available at: https://www.repository.cam.ac.uk/handle/1810/319242
Characterising factors underlying praxis deficits in chronic left hemisphere stroke patients
Authors:
Rounis, E., HALAI, A., Pizzamiglio, G., LAMBON RALPH, M.A.
Reference:
Cortex
Year of publication:
In Press
CBU number:
8702
Abstract:
Limb apraxia, a disorder of skilled action not consequent on primary motor or sensory deficits, has traditionally been defined according to errors patients make on neuropsychological tasks. Previous models of the disorder have failed to provide a unified account of patients’ deficits, due to heterogeneity in the patients and tasks used. In this study we implemented principal component analysis (PCA) to elucidate core factors of the disorder in a cohort of 41 unselected left hemisphere chronic stroke patients who were tested on a comprehensive and validated apraxia screen. Three principal components were identified: posture selection, semantic control and multi-demand sequencing. These were submitted to a lesion symptom mapping (VBCM) analysis in a subset of 24 patients, controlled for lesion volume, age and time post-stroke. Although the first component revealed no significant structural correlates, the second and third components were related to regions in the ‘ventro-dorsal’ and ‘ventral’ and ‘dorsal’ pathways, respectively. These results challenge the previously reported distinction between ideomotor and ideational deficits and highlight a significant role of common cognitive functions in the disorder, which include action selection, semantic retrieval, sequencing and response inhibition. Further research using this technique would help elucidate the cognitive processes underlying limb apraxia and their relationship with other cognitive disorders.
Data for this project is held by an external institution. Please contact the authors to request a copy.
An Efficient, Accurate and Clinically-Applicable Index of Content Word Fluency in Aphasia
Authors:
Alyahy, R.S.W., Conroy, P., HALAI, A.D., LAMBON RALPH, M.A.
Reference:
Aphasiology
Year of publication:
In Press
CBU number:
8648
Abstract:
Background: Despite the clinical importance of assessing the efficiency and accuracy of fluency in terms of content words production during connected speech, assessments based on discourse tasks are very time-consuming and thus not clinically feasible. Aims: (1) Examine the relationship between single-word naming and word retrieval during discourse production. (2) Investigate the relationship between word retrieval and content word fluency derived from a simple versus naturalistic discourse tasks. (3) Develop and validate an efficient and accurate index of content word fluency that is clinically viable. Methods: Two discourse tasks (simple picture description and naturalistic storytelling narrative) were collected from 46 participants with post-stroke aphasia, and 20 age/education matched neuro-typical controls. Each discourse sample was fully transcribed and content analysis was applied on each sample to measure word retrieval and content word fluency. Three single-word naming tasks were also administered to each participant with aphasia. Results: Correlational analyses between single-word naming and word retrieval in connected speech revealed weak/moderate relationships. Conversely, strong correlations were found between measures derived from simple picture description against naturalistic storytelling discourse tasks. Moreover, we derived a novel, transcription-less index of content word fluency from the discourse samples from an independent group (neuro-typical controls), and then we validated this index across two discourse tasks in the tested group (persons with aphasia). Correlation and regression analyses revealed extremely strong relationships between participants’ (neuro-typical controls and persons with aphasia) scores on the novel index and measures of content word fluency derived from the formal transcription and analyses of discourse samples, indicating high accuracy and validity of the new index. Conclusions: Simple picture description rather than picture naming provides a better estimate of word retrieval in naturalistic connected speech. The novel developed index is transcription-less and can be implemented online to provide an accurate and efficient measure of content word fluency. Thus, it is viable during clinical practice for assessment purposes, and possibly as an outcome measure to monitor therapy effectiveness, which can also be used in randomised clinical trials.
URL:
Data for this project is held by an external institution. Please contact the authors to request a copy.


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