Marcus H Heitger | KU Leuven (original) (raw)
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Papers by Marcus H Heitger
Journal of the Neurological Sciences, 2007
Learning & Memory, 2012
The corpus callosum (CC) is the largest white matter tract in the brain. It enables interhemisphe... more The corpus callosum (CC) is the largest white matter tract in the brain. It enables interhemispheric communication, particularly with respect to bimanual coordination. Here, we use diffusion tensor imaging (DTI) in healthy humans to determine the extent to which structural organization of subregions within the CC would predict how well subjects learn a novel bimanual task. A single DTI scan was taken prior to training. Participants then practiced a bimanual visuomotor task over the course of 2 wk, consisting of multiple coordination patterns. Findings revealed that the predictive power of fractional anisotropy (FA) was a function of CC subregion and practice. That is, FA of the anterior CC, which projects to the prefrontal cortex, predicted bimanual learning rather than the middle CC regions, which connect primary motor cortex. This correlation was specific in that FA correlated significantly with performance of the most difficult frequency ratios tested and not the innately preferr...
Journal of Neurophysiology, 2012
Although we are beginning to understand how observed actions performed by conspecifics with a sin... more Although we are beginning to understand how observed actions performed by conspecifics with a single hand are processed and how bimanual actions are controlled by the motor system, we know very little about the processing of observed bimanual actions. We used fMRI to compare the observation of bimanual manipulative actions with their unimanual components, relative to visual control conditions equalized for visual motion. Bimanual action observation did not activate any region specialized for processing visual signals related to this more elaborated action. On the contrary, observation of bimanual and unimanual actions activated similar occipito-temporal, parietal and premotor networks. However, whole-brain as well as region of interest (ROI) analyses revealed that this network functions differently under bimanual and unimanual conditions. Indeed, in bimanual conditions, activity in the network was overall more bilateral, especially in parietal cortex. In addition, ROI analyses indic...
Human Brain Mapping, 2011
Please be patient while the object screen loads. Change Site View : Select a site UCL FUNDP FUSL... more Please be patient while the object screen loads. Change Site View : Select a site UCL FUNDP FUSL FUCaM. ...
Progress in Brain Research, 2002
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2008
Following on from our earlier findings of a close relationship between motor function and outcome... more Following on from our earlier findings of a close relationship between motor function and outcome after mild traumatic brain injury (mTBI), this study examined whether it might be possible to predict poor recovery in the form of postconcussion syndrome (PCS) based upon early eye and arm motor function. Within 1 week post-injury, we assessed 37 mTBI patients on measures of saccades, oculomotor smooth pursuit, upper-limb visuomotor function, neuropsychological status, and self-reported health condition. At 3 months, 8 patients met the criteria for PCS. Using discriminant function analyses, we examined whether this future PCS-group could be identified prospectively based on motor function, neuropsychological status, and self-reported health condition at 1 week post-injury. Early eye movement function was the most effective in distinguishing between PCS and non-PCS patients, achieving a sensitivity and specificity of 100% in the present sample. This was followed by self-reported early h...
PLOS One, 2013
In bimanual coordination, older and younger adults activate a common cerebral network but the eld... more In bimanual coordination, older and younger adults activate a common cerebral network but the elderly also have additional activation in a secondary network of brain areas to master task performance. It remains unclear whether the functional connectivity within these primary and secondary motor networks differs between the old and the young and whether task difficulty modulates connectivity. We applied graph-theoretical network analysis (GTNA) to task-driven fMRI data in 16 elderly and 16 young participants using a bimanual coordination task including in-phase and anti-phase flexion/extension wrist movements. Network nodes for the GTNA comprised task-relevant brain areas as defined by fMRI activation foci. The elderly matched the motor performance of the young but showed an increased functional connectivity in both networks across a wide range of connectivity metrics, i.e., higher mean connectivity degree, connection strength, network density and efficiency, together with shorter mean communication path length between the network nodes and also a lower betweenness centrality. More difficult movements showed an increased connectivity in both groups. The network connectivity of both groups had "small world" character. The present findings indicate (a) that bimanual coordination in the aging brain is associated with a higher functional connectivity even between areas also activated in young adults, independently from task difficulty, and (b) that adequate motor coordination in the context of task-driven bimanual control in older adults may not be solely due to additional neural recruitment but also to aging-related changes of functional relationships between brain regions.
Journal of Magnetic Resonance Imaging, 2006
Journal of the Neurological Sciences, 2007
Learning & Memory, 2012
The corpus callosum (CC) is the largest white matter tract in the brain. It enables interhemisphe... more The corpus callosum (CC) is the largest white matter tract in the brain. It enables interhemispheric communication, particularly with respect to bimanual coordination. Here, we use diffusion tensor imaging (DTI) in healthy humans to determine the extent to which structural organization of subregions within the CC would predict how well subjects learn a novel bimanual task. A single DTI scan was taken prior to training. Participants then practiced a bimanual visuomotor task over the course of 2 wk, consisting of multiple coordination patterns. Findings revealed that the predictive power of fractional anisotropy (FA) was a function of CC subregion and practice. That is, FA of the anterior CC, which projects to the prefrontal cortex, predicted bimanual learning rather than the middle CC regions, which connect primary motor cortex. This correlation was specific in that FA correlated significantly with performance of the most difficult frequency ratios tested and not the innately preferr...
Journal of Neurophysiology, 2012
Although we are beginning to understand how observed actions performed by conspecifics with a sin... more Although we are beginning to understand how observed actions performed by conspecifics with a single hand are processed and how bimanual actions are controlled by the motor system, we know very little about the processing of observed bimanual actions. We used fMRI to compare the observation of bimanual manipulative actions with their unimanual components, relative to visual control conditions equalized for visual motion. Bimanual action observation did not activate any region specialized for processing visual signals related to this more elaborated action. On the contrary, observation of bimanual and unimanual actions activated similar occipito-temporal, parietal and premotor networks. However, whole-brain as well as region of interest (ROI) analyses revealed that this network functions differently under bimanual and unimanual conditions. Indeed, in bimanual conditions, activity in the network was overall more bilateral, especially in parietal cortex. In addition, ROI analyses indic...
Human Brain Mapping, 2011
Please be patient while the object screen loads. Change Site View : Select a site UCL FUNDP FUSL... more Please be patient while the object screen loads. Change Site View : Select a site UCL FUNDP FUSL FUCaM. ...
Progress in Brain Research, 2002
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2008
Following on from our earlier findings of a close relationship between motor function and outcome... more Following on from our earlier findings of a close relationship between motor function and outcome after mild traumatic brain injury (mTBI), this study examined whether it might be possible to predict poor recovery in the form of postconcussion syndrome (PCS) based upon early eye and arm motor function. Within 1 week post-injury, we assessed 37 mTBI patients on measures of saccades, oculomotor smooth pursuit, upper-limb visuomotor function, neuropsychological status, and self-reported health condition. At 3 months, 8 patients met the criteria for PCS. Using discriminant function analyses, we examined whether this future PCS-group could be identified prospectively based on motor function, neuropsychological status, and self-reported health condition at 1 week post-injury. Early eye movement function was the most effective in distinguishing between PCS and non-PCS patients, achieving a sensitivity and specificity of 100% in the present sample. This was followed by self-reported early h...
PLOS One, 2013
In bimanual coordination, older and younger adults activate a common cerebral network but the eld... more In bimanual coordination, older and younger adults activate a common cerebral network but the elderly also have additional activation in a secondary network of brain areas to master task performance. It remains unclear whether the functional connectivity within these primary and secondary motor networks differs between the old and the young and whether task difficulty modulates connectivity. We applied graph-theoretical network analysis (GTNA) to task-driven fMRI data in 16 elderly and 16 young participants using a bimanual coordination task including in-phase and anti-phase flexion/extension wrist movements. Network nodes for the GTNA comprised task-relevant brain areas as defined by fMRI activation foci. The elderly matched the motor performance of the young but showed an increased functional connectivity in both networks across a wide range of connectivity metrics, i.e., higher mean connectivity degree, connection strength, network density and efficiency, together with shorter mean communication path length between the network nodes and also a lower betweenness centrality. More difficult movements showed an increased connectivity in both groups. The network connectivity of both groups had "small world" character. The present findings indicate (a) that bimanual coordination in the aging brain is associated with a higher functional connectivity even between areas also activated in young adults, independently from task difficulty, and (b) that adequate motor coordination in the context of task-driven bimanual control in older adults may not be solely due to additional neural recruitment but also to aging-related changes of functional relationships between brain regions.
Journal of Magnetic Resonance Imaging, 2006