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John E Desmond - One of the best experts on this subject based on the ideXlab platform.
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Functional MRI of Human Eyeblink Classical Conditioning in Children with Fetal Alcohol Spectrum Disorders.
Cerebral Cortex, 2016Co-Authors: Dominic T Cheng, John E Desmond, Ernesta M Meintjes, Neil C Dodge, Christopher Warton, Christopher D Molteno, Mark E. Stanton, Mariska Pienaar, Bradley S. Peterson, Joseph L JacobsonAbstract:: Prenatal alcohol exposure has been linked to a broad range of developmental deficits, with eyeblink classical conditioning (EBC) among the most sensitive endpoints. This fMRI study compared EBC-related brain activity in 47 children with fetal alcohol syndrome (FAS), partial FAS (PFAS), heavily exposed (HE) non-syndromal children, and healthy controls. All of the children had previously participated in two EBC studies conducted as part of our longitudinal study of fetal alcohol spectrum disorders. Although learning-related behavioral differences were seen in all groups during the scans, controls showed more conditioned responses (CR) than the alcohol-exposed groups. Despite lower conditioning levels relative to controls, the exposed groups exhibited extensive Cerebellar Activations. Specifically, children with FAS/PFAS showed increased Activation of Cerebellar lobule VI in session 2, while HE children showed increased Activation in session 1. Continuous measures of prenatal alcohol use correlated with learning-related Activations in cerebellum and frontal cortices. Only controls showed significant Cerebellar Activation-CR correlations in the deep nuclei and lateral lobule VI, suggesting that these key regions supporting EBC may be functionally disorganized in alcohol-exposed children. These findings are the first to characterize abnormalities in brain function associated with the behavioral conditioning deficits seen in children with prenatal alcohol exposure.
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the association between eye movements and Cerebellar Activation in a verbal working memory task
Cerebral Cortex, 2016Co-Authors: Dominic T Cheng, Jutta Peterburs, John E DesmondAbstract:: It has been argued that Cerebellar Activations during cognitive tasks may masquerade as cognition, while actually reflecting processes related to movement planning or motor learning. The present study investigated whether the Cerebellar load effect for verbal working memory, that is, increased Activations in lobule VI/Crus I and lobule VIIB/VIIIA, is related to eye movements and oculomotor processing. Fifteen participants performed an fMRI-based Sternberg verbal working memory task. Oculomotor and cognitive task demands were manipulated by using closely and widely spaced stimuli, and high and low cognitive load. Trial-based quantitative eye movement parameters were obtained from concurrent eye tracking. Conventional MRI analysis replicated the Cerebellar load effect in lobules VI and VIIB/VIIIa. With quantitative eye movement parameters as regressors, analysis yielded very similar Activation patterns. While load effect and eye regressor generally recruited spatially distinct neocortical and Cerebellar regions, conjunction analysis showed that a small subset of prefrontal areas implicated in the load effect also responded to the eye regressor. The present results indicate that cognitive load-dependent Activations in lateral superior and posteroinferior Cerebellar regions in the Sternberg task are independent of eye movements occurring during stimulus encoding. This is inconsistent with the notion that cognitive load-dependent Cerebellar Activations merely reflect oculomotor processing.
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load and practice dependent increases in cerebro Cerebellar Activation in verbal working memory an fmri study
NeuroImage, 2005Co-Authors: Matthew P Kirschen, S Annabel H Chen, Pamela Schraedleydesmond, John E DesmondAbstract:Abstract Load-dependent and practice-related changes in neocortical and Cerebellar structures involved in verbal working memory (VWM) were investigated using functional MRI (fMRI) and a two alternative forced choice Sternberg paradigm. Using working memory loads ranging from 2 to 6 letters, regions exhibiting linear and quadratic trends in load-dependent Activations were identified. Behaviorally, reaction time measurements revealed significant linear increases with increasing memory load, and significant decreases with increased task practice. Brain Activations indicated a preponderance of linear load-dependent responses in both superior (lobule VI/Crus I) and inferior (lobule VIIB/VIIIA) Cerebellar hemispheres, as well as in areas of neocortex including left precentral (BA 6), inferior frontal (BA 47), parahippocampal (BA 35), inferior parietal (BA 40), cingulate (BA 32), and right inferior and middle frontal (BA 46/47) regions. Fewer voxels exhibited quadratic without linear trends with the most prominent of these Activations located in left inferior parietal (BA 40), precuneus, and parahippocampal regions. Analysis of load × session interactions revealed that right inferior Cerebellar and left inferior parietal Activations increased with practice, as did the correlations between Activation in each region with reaction time, suggesting that changes in this cerebro-Cerebellar network underlie practice-related increases in efficiency of VWM performance. These results replicate and extend our previous findings of fMRI Activation in the cerebellum during VWM, and demonstrate predominately linear increases in cerebro-Cerebellar Activation with increasing memory load as well as changes in network function with increased task proficiency.
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Cerebellar involvement in cognitive function evidence from neuroimaging
International Review of Psychiatry, 2001Co-Authors: John E DesmondAbstract:A variety of evidence derived from functional neuroimaging suggests that the cerebellum participates in cognitive function, a conclusion consistent with the results of studies of patients with Cerebellar damage and with recent advances in the understanding of cortioCerebellar pathways. This review focuses on the importance of cerebro-Cerebellar interactions in understanding Cerebellar influences on neocortical function. First, the phenomenon of crossed-Cerebellar diaschisis, and the converse occurrence of neocortical hypometabolism following Cerebellar damage, is discussed in light of imaging studies demonstrating the coupling between these structures during specific cognitive tasks. Then, using the pattern of Cerebellar Activation in verbal working memory as a model, experiments are reviewed that demonstrate a specific topology of the functional connectivity of the cerebellum and the neocortex, leading to the hypothesis that the articulatory control system may be mediated by a frontal cortex-superior cer...
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lobular patterns of Cerebellar Activation in verbal working memory and finger tapping tasks as revealed by functional mri
The Journal of Neuroscience, 1997Co-Authors: John E Desmond, John D E Gabrieli, Anthony D Wagner, Bruce L Ginier, Gary H GloverAbstract:The lobular distributions of functional Activation of the cerebellum during verbal working-memory and finger movement tasks were investigated using functional magnetic resonance imaging (fMRI). Relative to a rest control, finger tapping of the right hand produced ipsilateral-increased Activation in HIV/HV [Roman numeral designations based on Larsell’s (Larsell and Jansen, 1972) nomenclature] and HVI and weaker Activation in HVIII that was stronger on the ipsilateral side. For a working-memory task, subjects were asked to remember six (high load) or one (low load) visually presented letters across a brief delay. To assess the motoric aspects of rehearsal in the absence of working memory, we asked the subjects to repeatedly read subvocally six or one letters at a rate that approximated the internally generated rehearsal of working memory (motoric rehearsal task). For both tasks, bilateral regions of the superior Cerebellar hemispheres (left superior HVIIA and right HVI) and portions of posterior vermis (VI and superior VIIA) exhibited increased Activation during high relative to low load conditions. In contrast, the right inferior Cerebellar hemisphere (HVIIB) exhibited this load effect only during the working-memory task. We hypothesize that HVI and superior HVIIA Activation represents input from the articulatory control system of working memory from the frontal lobes and that HVIIB Activation is derived from the phonological store in temporal and parietal regions. From these inputs, the cerebellum could compute the discrepancy between actual and intended phonological rehearsal and use this information to update a feedforward command to the frontal lobes, thereby facilitating the phonological loop.
David J Brooks - One of the best experts on this subject based on the ideXlab platform.
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association of abnormal Cerebellar Activation with motor learning difficulties in dyslexic adults
The Lancet, 1999Co-Authors: Roderick I Nicolson, Angela J Fawcett, Emma L Berry, Harri I Jenkins, Paul Dean, David J BrooksAbstract:BACKGROUND: In addition to their impairments in literacy-related skills, dyslexic children show characteristic difficulties in phonological skill, motor skill, and balance. There is behavioural and biochemical evidence that these difficulties may be attributable to mild Cerebellar dysfunction. We wanted to find out whether there was abnormal brain Activation when dyslexic adults undertook tasks known normally to involve Cerebellar Activation. METHODS: Brain Activation was monitored by positron emission tomography in matched groups of six dyslexic adults and six control adults as they carried out either a prelearned sequence or learned a novel sequence of finger movements. FINDINGS: Brain Activation was significantly lower (p<0.01) for the dyslexic adults than for the controls in the right Cerebellar cortex and the left cingulate gyrus when executing the prelearned sequence, and in the right Cerebellar cortex when learning the new sequence. INTERPRETATION: The results provided direct evidence that, for this group of dyslexic adults, the behavioural signs of Cerebellar abnormality reflect underlying abnormalities in Cerebellar Activation.
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Association of abnormal Cerebellar Activation with motor learning difficulties in dyslexic adults
The Lancet, 1999Co-Authors: Roderick I Nicolson, Angela J Fawcett, Emma L Berry, Paul Dean, I Harri Jenkins, David J BrooksAbstract:BACKGROUND: In addition to their impairments in literacy-related skills, dyslexic children show characteristic difficulties in phonological skill, motor skill, and balance. There is behavioural and biochemical evidence that these difficulties may be attributable to mild Cerebellar dysfunction. We wanted to find out whether there was abnormal brain Activation when dyslexic adults undertook tasks known normally to involve Cerebellar Activation. METHODS: Brain Activation was monitored by positron emission tomography in matched groups of six dyslexic adults and six control adults as they carried out either a prelearned sequence or learned a novel sequence of finger movements. FINDINGS: Brain Activation was significantly lower (p
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The effect of ethanol on alcohol-responsive essential tremor: a positron emission tomography study.
Annals of Neurology, 1996Co-Authors: H. Boecker, L. J. Findley, Adrian J. Wills, A. O. Ceballos-baumann, M. Samuel, Philip D. Thompson, David J BrooksAbstract:: We used H2 15O positron emission tomography (PET) to investigate the effect of ethyl alcohol on regional cerebral blood flow in 6 patients with alcohol-responsive essential tremor and 6 age-matched control subjects. The patients were scanned while at rest and during involuntary postural tremor of the extended right arm. Normal control subjects were scanned at rest and during passive wrist oscillation of the right arm at tremor frequency. Regional cerebral blood flow associated with these conditions was measured before and after oral administration of 2 to 3 units of alcohol. The mean blood alcohol level was 35.3 +/- 20.0 mg/dl in the patient group and caused marked suppression of tremor; it was 33.9 +/- 12.9 mg/dl in the control group. Similar to previous PET studies on essential tremor patients, tremor compared with rest was associated with bilateral Cerebellar Activation including the Cerebellar vermis. This pattern of Activation differed from passive wrist oscillation where ipsilateral Cerebellar Activation was observed. Ethanol ingestion led to bilateral decreases of Cerebellar blood flow in both tremor patients and normal subjects, and this was associated with suppression of tremor in the patients. Alcohol-associated increases of regional cerebral blood flow were observed in the inferior olivary nuclei in the patients but not in the control subjects. We conclude that alcohol-induced suppression of essential tremor is mediated via a reduction of Cerebellar synaptic overactivity resulting in increased afferent input to the inferior olivary nuclei.
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A positron emission tomography study of cerebral Activation associated with essential and writing tremor.
JAMA Neurology, 1995Co-Authors: Adrian J. Wills, Pd Thompson, I. H. Jenkins, L. J. Findley, David J BrooksAbstract:Objective: To compare the abnormal patterns of cerebral Activation associated with essential and writing tremors. Design: Positron emission tomography using oxygen 15—labeled water was utilized to determine regional cerebral blood flow. Positron emission tomography images that were taken of the brain in individual patients were coregistered with magnetic resonance images of the same brain to ascertain accurate localization of cerebral Activation in single patients. Patients with essential tremor underwent scanning at rest, during involuntary postural tremor, and during passive wrist oscillation. Normal control subjects underwent scanning at rest and during voluntary and passive wrist oscillation. Patients with writing tremor underwent scanning while they were holding a pen to paper with consequent involuntary tremor and again while they were holding a pen in the same supinated arm without tremor. Setting: Research hospital. Patients or Other Participants: Seven patients with essential tremor, six patients with writing tremor, and six matched control subjects. Interventions: None. Main Outcome Measures: Regional cerebral blood flow. Results: Essential tremor was associated with abnormal bilateral Cerebellar, red nuclear, and thalamic Activation. Writing tremor was also associated with abnormal bilateral Cerebellar Activation. Voluntary wrist oscillation in control subjects caused only ipsilateral Cerebellar Activation. These findings were evident in single patients, when positron emission tomography images were coregistered with magnetic resonance images and on group analysis of the pooled positron emission tomography data after transformation into stereotaxic space. Conclusion: These results indicate that both essential and writing tremors are associated with abnormal bilateral overactivity of Cerebellar connections.
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red nuclear and Cerebellar but no olivary Activation associated with essential tremor a positron emission tomographic study
Annals of Neurology, 1994Co-Authors: Adrian J. Wills, Pd Thompson, I. H. Jenkins, L. J. Findley, David J BrooksAbstract:: There has been debate as to whether essential tremor has a central origin and over the possible role of the inferior olivary nucleus in its genesis. We used positron emission tomography with radioactive water (H2(15)O) to detect abnormal patterns of cerebral activity associated with this condition, at rest, without tremor, and on posture when the tremor was present. At rest, Cerebellar blood flow was significantly increased bilaterally in the group with essential tremor (30-40%) but no increased olivary activity was evident. Essential tremor during arm extension was associated with further abnormal increases in bilateral Cerebellar and abnormal red nuclear Activation. Again, no olivary overactivity was evident. Voluntary wrist oscillation in control subjects caused only ipsilateral Cerebellar Activation. We conclude that essential tremor is associated with abnormal bilateral overactivity of Cerebellar and red nuclear connections but found no evidence of intrinsic overactivity of the inferior olivary nucleus, as evidenced by raised blood flow.
Jutta Peterburs - One of the best experts on this subject based on the ideXlab platform.
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the association between eye movements and Cerebellar Activation in a verbal working memory task
Cerebral Cortex, 2016Co-Authors: Dominic T Cheng, Jutta Peterburs, John E DesmondAbstract:: It has been argued that Cerebellar Activations during cognitive tasks may masquerade as cognition, while actually reflecting processes related to movement planning or motor learning. The present study investigated whether the Cerebellar load effect for verbal working memory, that is, increased Activations in lobule VI/Crus I and lobule VIIB/VIIIA, is related to eye movements and oculomotor processing. Fifteen participants performed an fMRI-based Sternberg verbal working memory task. Oculomotor and cognitive task demands were manipulated by using closely and widely spaced stimuli, and high and low cognitive load. Trial-based quantitative eye movement parameters were obtained from concurrent eye tracking. Conventional MRI analysis replicated the Cerebellar load effect in lobules VI and VIIB/VIIIa. With quantitative eye movement parameters as regressors, analysis yielded very similar Activation patterns. While load effect and eye regressor generally recruited spatially distinct neocortical and Cerebellar regions, conjunction analysis showed that a small subset of prefrontal areas implicated in the load effect also responded to the eye regressor. The present results indicate that cognitive load-dependent Activations in lateral superior and posteroinferior Cerebellar regions in the Sternberg task are independent of eye movements occurring during stimulus encoding. This is inconsistent with the notion that cognitive load-dependent Cerebellar Activations merely reflect oculomotor processing.
Gary H Glover - One of the best experts on this subject based on the ideXlab platform.
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lobular patterns of Cerebellar Activation in verbal working memory and finger tapping tasks as revealed by functional mri
The Journal of Neuroscience, 1997Co-Authors: John E Desmond, John D E Gabrieli, Anthony D Wagner, Bruce L Ginier, Gary H GloverAbstract:The lobular distributions of functional Activation of the cerebellum during verbal working-memory and finger movement tasks were investigated using functional magnetic resonance imaging (fMRI). Relative to a rest control, finger tapping of the right hand produced ipsilateral-increased Activation in HIV/HV [Roman numeral designations based on Larsell’s (Larsell and Jansen, 1972) nomenclature] and HVI and weaker Activation in HVIII that was stronger on the ipsilateral side. For a working-memory task, subjects were asked to remember six (high load) or one (low load) visually presented letters across a brief delay. To assess the motoric aspects of rehearsal in the absence of working memory, we asked the subjects to repeatedly read subvocally six or one letters at a rate that approximated the internally generated rehearsal of working memory (motoric rehearsal task). For both tasks, bilateral regions of the superior Cerebellar hemispheres (left superior HVIIA and right HVI) and portions of posterior vermis (VI and superior VIIA) exhibited increased Activation during high relative to low load conditions. In contrast, the right inferior Cerebellar hemisphere (HVIIB) exhibited this load effect only during the working-memory task. We hypothesize that HVI and superior HVIIA Activation represents input from the articulatory control system of working memory from the frontal lobes and that HVIIB Activation is derived from the phonological store in temporal and parietal regions. From these inputs, the cerebellum could compute the discrepancy between actual and intended phonological rehearsal and use this information to update a feedforward command to the frontal lobes, thereby facilitating the phonological loop.
C Erdmann - One of the best experts on this subject based on the ideXlab platform.
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The role of the fastigial nucleus in saccadic eye oscillations.
Annals of the New York Academy of Sciences, 2020Co-Authors: C Helmchen, C Mohr, C Erdmann, H Rambold, Andreas Sprenger, Ferdinand BinkofskiAbstract:For the first time, we provide functional magnetic resonance imaging evidence for a recent hypothesis that saccadic oscillations in opsoclonus may result from a disinhibition of the Cerebellar fastigial nuclei. Two patients with severe opsoclonus were examined during fixation in the light and during eye closure and in darkness where opsoclonus disappeared. Their Activation during opsoclonus was compared with 10 healthy subjects performing visually guided and self-paced saccades in the light and darkness. In contrast to the control subjects, the patients showed a strong bilateral midline Cerebellar Activation that involved the deep Cerebellar nuclei. This is probably not just a secondary finding in the fastigial nuclei due to the high frequent saccadic activity because there was, concomitantly, no oculomotor vermal Activation, which is normally seen in healthy subjects. We propose that Cerebellar Activation of the fastigial nuclei may cause opsoclonus via their projections to the brainstem saccadic generator.
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Cerebellar neural responses related to actively and passively applied noxious thermal stimulation in human subjects: a parametric fMRI study.
Neuroscience letters, 2004Co-Authors: C Helmchen, C Mohr, C Erdmann, F BinkofskiAbstract:Cerebellar Activation is consistently found during noxious stimulation but little is known about its pain-related specificity. Under natural circumstances noxious stimuli are actively or passively delivered with concomitant tactile sensory stimulation. Using fMRI we therefore studied pain-related Cerebellar Activation with innocuous and noxious thermal stimuli in a parametric design taking motor execution as confounding factor into account. With respect to psychophysical pain ratings anterior vermal and ipsilateral hemispheric lobule VI Activation was parametrically modulated for stimulus intensity in actively but not in passively elicited thermal stimulation. The cerebellum seems to be capable of distinguishing active from passive painful stimuli.
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Modulation of Cerebellar Activation by predictive and non-predictive sequential finger movements.
The Cerebellum, 2003Co-Authors: M F Nitschke, C Erdmann, D Petersen, Gregor Stavrou, U. Melchert, Karl Wessel, Wolfgang HeideAbstract:We investigated the modulation of Cerebellar Activation by predictive and non-predictive sequential finger movements. It is hypothesized that the prediction of desired movement sequences and adaptation to new movement parameters is mediated by the cerebellum. Using functional MRI at 1.5T, seven normal subjects performed sequential finger to thumb opposition movements, either in predictive (repeatedly 2,3,4,5) or non-predictive (randomized) fashion at a constant frequency of 1 Hz. Performance and error rates were monitored by simultaneous recording of the finger movements. Predictive sequential finger opposition movements activated a Cerebellar network including the lobuli IV–VI ipsilateral to the movements, the contralateral lobuli IV–VI, the vermis, and lobuli VIIB–VIII ipsilaterally. Non-predictive compared to predictive finger opposition movements activated a broader area within the ipsi- and contralateral anterior cerebellum, lobuli IV–VI, the vermis, and the ipsilateral lobuli VIIB–VIII. Additional Activation foci were found in the contralateral lobuli VIIA and VIIB–VIII. Our study demonstrates a modulated information processing within the Cerebellar network dependent on the predictability of movement sequences.
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Cerebellar Activation in opsoclonus an fmri study
Neurology, 2003Co-Authors: C Helmchen, C Erdmann, H Rambold, Andreas Sprenger, Ferdinand BinkofskiAbstract:It is controversial whether opsoclonus is a Cerebellar or brainstem disorder. Two patients whose opsoclonus largely disappeared on eye closure underwent fMRI. A comparison of these two states revealed neither vermal nor brainstem Activation but rather a bilateral Activation in the deep Cerebellar nuclei in excess of what the authors found in healthy subjects. The results support a crucial role of the fastigial nucleus in opsoclonus.
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differential Cerebellar Activation related to perceived pain intensity during noxious thermal stimulation in humans a functional magnetic resonance imaging study
Neuroscience Letters, 2003Co-Authors: C Helmchen, C Mohr, C Erdmann, D Petersen, M F NitschkeAbstract:Abstract Little is known about the Cerebellar involvement in pain processing in spite of the fact that the cerebellum probably plays a crucial role in pain-related behavior. Using functional magnetic resonance imaging we examined the differential Cerebellar Activation in 18 healthy subjects in relation to their perceived pain-intensity of noxious and non-noxious thermal stimuli. In contrast to non-noxious (40°C) stimuli, noxious (48.5°C) stimuli revealed Activation in the deep Cerebellar nuclei, anterior vermis and bilaterally in the Cerebellar hemispheric lobule VI. With the same noxious stimulus (48.5°C) there was differential Cerebellar Activation depending on the perceived pain intensity: high pain intensity ratings were associated with Activation in ipsilateral hemispheric lobule III–VI, deep Cerebellar nuclei and in the anterior vermis (lobule III). This differential Cerebellar Activation pattern probably reflects not only somatosensory processing but also perceived pain intensity that may be important for Cerebellar modulation of nociceptive circuits.