scholarly journals Individual susceptibility to TMS affirms the precuneual role in metamemory upon recollection

2018 ◽  
Author(s):  
Qun Ye ◽  
Futing Zou ◽  
Michael Dayan ◽  
Hakwan Lau ◽  
Yi Hu ◽  
...  
Keyword(s):  
Grey Matter ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Memory Performance ◽  
Perceptual Task ◽  
Grey Matter Volume ◽  
List Type ◽  
Resting State Functional Connectivity ◽  
Memory Ability ◽  
Matter Volume ◽  
The Impact

AbstractBackgroundA recent virtual-lesion study using inhibitory repetitive transcranial magnetic stimulation (rTMS) confirmed the causal behavioral relevance of the precuneus in the evaluation of one’s own memory performance (aka mnemonic metacognition).ObjectiveThis study’s goal is to elucidate how these TMS-induced neuromodulatory effects might relate to the neural correlates and be modulated by individual anatomical profiles in relation to meta-memory.MethodsIn a within-subjects design, we assessed the impact of 20-min rTMS over the precuneus, compared to the vertex, across three magnetic resonance imaging (MRI) neuro-profiles on 18 healthy subjects during a memory versus a perceptual task.ResultsTask-based functional MRI revealed that BOLD signal magnitude in the precuneus is associated with variation in individual meta-memory efficiency, and such correlation diminished significantly following TMS targeted at the precuneus. Moreover, individuals with higher resting-state functional connectivity (rs-fcMRI) between the precuneus and the hippocampus, or smaller grey matter volume in the stimulated precuneal region exhibit considerably higher vulnerability to the TMS effect. These effects were not observed in the perceptual domain.ConclusionWe provide compelling evidence in outlining a possible circuit encompassing the precuneus and its mnemonic midbrain neighbor the hippocampus at the service of realizing our meta-awareness during memory recollection of episodic details.HighlightsTMS on precuneus reduces meta-memory ability during memory retrieval.TMS disrupts the correlation between BOLD activity and meta-memory ability.TMS effect is modulated by rs-fcMRI between precuneus and hippocampus.Individuals with greater precuneal grey matter volume more immune to TMS effect.

scholarly journals Motor learning decline with age is related to differences in the explicit memory system

2018 ◽  
Author(s):  
Noham Wolpe ◽  
James N. Ingram ◽  
Kamen A. Tsvetanov ◽  
Richard N. Henson ◽  
Rogier A. Kievit ◽  
...  
Keyword(s):  
Older Adults ◽  
Motor Learning ◽  
Motor Skills ◽  
Explicit Memory ◽  
Grey Matter ◽  
Memory Performance ◽  
Motor Adaptation ◽  
Memory System ◽  
Grey Matter Volume ◽  
Matter Volume

ABSTRACTThe ability to adapt one’s movements to changes in the environment is fundamental in everyday life, but this ability changes across the lifespan. Although often regarded as an ‘implicit’ process, recent research has also linked motor adaptation with ‘explicit’ learning processes. To understand how these processes contribute to differences in motor adaptation with age, we combined a visuomotor learning paradigm with cognitive tasks that measure implicit and explicit processes, and structural brain imaging. In a large population-based cohort from the Cambridge Centre for Ageing and Neuroscience (n=322, aged 18-89 years) we first confirmed that the degree of adaptation to an angular perturbation of visual feedback declined with age. There were no associations between adaptation and sensory attenuation, which has been previously hypothesised to contribute to implicit motor learning. However, interactions between age and scores on two independent memory tasks showed that explicit memory performance was a progressively stronger determinant of motor learning with age. Similarly, interactions between age and grey matter volume in the medial temporal lobe, amygdala and hippocampus showed that grey matter volume in these regions became a stronger determinant of adaptation in older adults. The convergent behavioural and structural imaging results suggest that age-related differences in the explicit memory system is a contributor to the decline in motor adaptation in older age. These results may reflect the more general compensatory reliance on cognitive strategies to maintain motor performance with age.SIGNIFICANCE STATEMENTThe central nervous system has a remarkable capacity to learn new motor skills and adapt to new environmental dynamics. This capacity is impaired with age, and in many brain disorders. We find that explicit memory performance and its associated medial temporal brain regions deteriorate with age, but the association between this brain system and individual differences in motor learning becomes stronger in older adults. We propose that these results reflect an increased reliance on cognition in order to maintain adaptive motor skill performance. This difference in learning strategy has implications for interventions to improve motor skills in older adults.

The impact of deep grey matter volume on cognition in multiple sclerosis

2020 ◽  
Vol 45 ◽  
pp. 102351
Author(s):  
L. Lorefice ◽  
E. Carta ◽  
J. Frau ◽  
F. Contu ◽  
E. Casaglia ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Grey Matter ◽  
Grey Matter Volume ◽  
Matter Volume ◽  
Deep Grey Matter ◽  
The Impact

scholarly journals Higher VO2max is associated with thicker cortex and lower grey matter blood flow in older adults

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gaia Olivo ◽  
Jonna Nilsson ◽  
Benjamín Garzón ◽  
Alexander Lebedev ◽  
Anders Wåhlin ◽  
...  
Keyword(s):  
Older Adults ◽  
Blood Flow ◽  
Physical Exercise ◽  
Cortical Thickness ◽  
Grey Matter ◽  
Brain Activity ◽  
Moderate Intensity ◽  
Grey Matter Volume ◽  
Matter Volume ◽  
The Impact

AbstractVO2max (maximal oxygen consumption), a validated measure of aerobic fitness, has been associated with better cerebral artery compliance and measures of brain morphology, such as higher cortical thickness (CT) in frontal, temporal and cingular cortices, and larger grey matter volume (GMV) of the middle temporal gyrus, hippocampus, orbitofrontal cortex and cingulate cortex. Single sessions of physical exercise can promptly enhance cognitive performance and brain activity during executive tasks. However, the immediate effects of exercise on macro-scale properties of the brain’s grey matter remain unclear. We investigated the impact of one session of moderate-intensity physical exercise, compared with rest, on grey matter volume, cortical thickness, working memory performance, and task-related brain activity in older adults. Cross-sectional associations between brain measures and VO2max were also tested. Exercise did not induce statistically significant changes in brain activity, grey matter volume, or cortical thickness. Cardiovascular fitness, measured by VO2max, was associated with lower grey matter blood flow in the left hippocampus and thicker cortex in the left superior temporal gyrus. Cortical thickness was reduced at post-test independent of exercise/rest. Our findings support that (1) fitter individuals may need lower grey matter blood flow to meet metabolic oxygen demand, and (2) have thicker cortex.

scholarly journals Functional Connectivity Between Somatosensory and Motor Brain Areas Predicts Individual Differences in Motor Learning by Observing

2017 ◽  
Author(s):  
Heather R. McGregor ◽  
Paul L. Gribble
Keyword(s):  
Individual Differences ◽  
Functional Connectivity ◽  
Motor Learning ◽  
Resting State ◽  
Brain Function ◽  
Grey Matter ◽  
Grey Matter Volume ◽  
Resting State Functional Connectivity ◽  
Matter Volume ◽  
Sensory Motor

AbstractAction observation can facilitate the acquisition of novel motor skills, however, there is considerable individual variability in the extent to which observation promotes motor learning. Here we tested the hypothesis that individual differences in brain function or structure can predict subsequent observation-related gains in motor learning. Subjects underwent an anatomical MRI scan and resting-state fMRI scans to assess pre-observation grey matter volume and pre-observation resting-state functional connectivity (FC), respectively. On the following day, subjects observed a video of a tutor adapting her reaches to a novel force field. After observation, subjects performed reaches in a force field as a behavioral assessment of gains in motor learning resulting from observation. We found that individual differences in resting-state FC, but not grey matter volume, predicted post-observation gains in motor learning. Pre-observation resting-state FC between left S1 and bilateral PMd, M1, S1 and left SPL was positively correlated with behavioral measures of post-observation motor learning. Sensory-motor resting-state FC can thus predict the extent to which observation will promote subsequent motor learning.New & NoteworthyWe show that individual differences in pre-observation brain function can predict subsequent observation-related gains in motor learning. Pre-observation resting-state functional connectivity within a sensory-motor network may be used as a biomarker for the extent to which observation promotes motor learning. This kind of information may be useful if observation is to be used as a way to boost neuroplasticity and sensory motor recovery for patients undergoing rehabilitation for diseases that impair movement such as stroke.

Alterations in brain structure in adults with anorexia nervosa and the impact of illness duration

2013 ◽  
Vol 44 (9) ◽  
pp. 1965-1975 ◽  
Author(s):  
L. Fonville ◽  
V. Giampietro ◽  
S. C. R. Williams ◽  
A. Simmons ◽  
K. Tchanturia
Keyword(s):  
Anorexia Nervosa ◽  
Brain Structure ◽  
Grey Matter ◽  
Magnetic Resonance Images ◽  
Grey Matter Volume ◽  
Voxel Based Morphometry ◽  
Matter Volume ◽  
Duration Of Illness ◽  
Inadequate Sample Size ◽  
The Impact

BackgroundBrain structure alterations have been reported in anorexia nervosa, but findings have been inconsistent. This may be due to inadequate sample size, sample heterogeneity or differences in methodology.MethodHigh resolution magnetic resonance images were acquired of 33 adult participants with anorexia nervosa and 33 healthy participants, the largest study sample to date, in order to assess whole-brain volume, ventricular cerebrospinal fluid, white matter and grey matter volume. Voxel-based morphometry was conducted to assess regional grey matter volume. Levels of depression, anxiety, obsessionality and eating disorder-related symptoms were measured and used to explore correlations with brain structure.ResultsParticipants with anorexia nervosa had smaller brain volumes as well as a global decrease in grey matter volume with ventricular enlargement. Voxel-based morphometry revealed a decrease in grey matter volume spanning across the cerebellum, temporal, frontal and occipital lobes. A correlation was found between grey matter volume loss and duration of illness in the cerebellum and mesencephalon. No correlations were found with clinical measures.ConclusionsFindings are in accordance with several previous studies on brain structure and match functional studies that have assessed the symptomatology of anorexia nervosa, such as body image distortion and cognitive bias to food. The correlation with duration of illness supports the implication of cerebellar atrophy in the maintenance of low weight and disrupted eating behaviour and illustrates its role in the chronic phase of anorexia nervosa. The lack of other correlations suggests that these findings are not related to the presence of co-morbid disorders.

Social cognition and brain organization in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus)

2018 ◽  
Author(s):  
William D. Hopkins ◽  
Cheryl D. Stimpson ◽  
Chet C. Sherwood
Keyword(s):  
Social Cognition ◽  
Social Behaviour ◽  
Grey Matter ◽  
Species Differences ◽  
Pan Paniscus ◽  
Grey Matter Volume ◽  
Evolutionary Models ◽  
Brain Organization ◽  
Matter Volume ◽  
Cognition Sociale

Bonobos and chimpanzees are two closely relates species of the genus Pan, yet they exhibit marked differences in anatomy, behaviour and cognition. For this reason, comparative studies on social behaviour, cognition and brain organization between these two species provide important insights into evolutionary models of human origins. This chapter summarizes studies on socio-communicative competencies and social cognition in chimpanzees and bonobos from the authors’ laboratory in comparison to previous reports. Additionally, recent data on species differences and similarities in brain organization in grey matter volume and distribution is presented. Some preliminary findings on microstructural brain organization such as neuropil space and cellular distribution in key neurotransmitters and neuropeptides involved in social behaviour and cognition is presented. Though these studies are in their infancy, the findings point to potentially important differences in brain organization that may underlie bonobo and chimpanzees’ differences in social behaviour, communication and cognition. Les bonobos et les chimpanzés sont deux espèces du genus Pan prochement liées, néanmoins ils montrent des différences anatomiques, comportementales et cognitives marquées. Pour cette raison, les études comparatives sur le comportement social, la cognition et l’organisation corticale entre ces deux espèces fournissent des idées sur les modèles évolutionnaires des origines humaines. Dans ce chapitre, nous résumons des études sur les compétences socio-communicatives et la cognition sociale chez les chimpanzés et les bonobos de notre laboratoire en comparaison avec des rapports précédents. En plus, nous présentons des données récentes sur les différences et similarités d’organisation corticale du volume et distribution de la matière grise entre espèces. Nous présentons plus de résultats préliminaires sur l’organisation corticale microstructurale comme l’espace neuropile et la division cellulaire dans des neurotransmetteurs clés et les neuropeptides impliqués dans le comportement social et la cognition. Bien que ces études sont dans leur enfance, les résultats montrent des différences d’organisation corticale importantes qui sont à la base des différences de comportement social, la communication et la cognition entre les bonobos et les chimpanzés.

scholarly journals Modelling the cascade of biomarker changes in GRN-related frontotemporal dementia

2021 ◽  
pp. jnnp-2020-323541
Author(s):  
Jessica L Panman ◽  
Vikram Venkatraghavan ◽  
Emma L van der Ende ◽  
Rebecca M E Steketee ◽  
Lize C Jiskoot ◽  
...  
Keyword(s):  
White Matter ◽  
Frontotemporal Dementia ◽  
Disease Severity ◽  
Grey Matter ◽  
Clinical Stage ◽  
Data Driven ◽  
Grey Matter Volume ◽  
Matter Volume ◽  
Mutation Carriers ◽  
Individual Disease

ObjectiveProgranulin-related frontotemporal dementia (FTD-GRN) is a fast progressive disease. Modelling the cascade of multimodal biomarker changes aids in understanding the aetiology of this disease and enables monitoring of individual mutation carriers. In this cross-sectional study, we estimated the temporal cascade of biomarker changes for FTD-GRN, in a data-driven way.MethodsWe included 56 presymptomatic and 35 symptomatic GRN mutation carriers, and 35 healthy non-carriers. Selected biomarkers were neurofilament light chain (NfL), grey matter volume, white matter microstructure and cognitive domains. We used discriminative event-based modelling to infer the cascade of biomarker changes in FTD-GRN and estimated individual disease severity through cross-validation. We derived the biomarker cascades in non-fluent variant primary progressive aphasia (nfvPPA) and behavioural variant FTD (bvFTD) to understand the differences between these phenotypes.ResultsLanguage functioning and NfL were the earliest abnormal biomarkers in FTD-GRN. White matter tracts were affected before grey matter volume, and the left hemisphere degenerated before the right. Based on individual disease severities, presymptomatic carriers could be delineated from symptomatic carriers with a sensitivity of 100% and specificity of 96.1%. The estimated disease severity strongly correlated with functional severity in nfvPPA, but not in bvFTD. In addition, the biomarker cascade in bvFTD showed more uncertainty than nfvPPA.ConclusionDegeneration of axons and language deficits are indicated to be the earliest biomarkers in FTD-GRN, with bvFTD being more heterogeneous in disease progression than nfvPPA. Our data-driven model could help identify presymptomatic GRN mutation carriers at risk of conversion to the clinical stage.

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