Since its discovery, our understanding of the primary motor cortex has continued to evolve. The presentations of rare, isolated, motor palsies of small muscle groups have heavily contributed to the characterization of the somatotopic representation of the human body on the cortex. We present a case of localized, left shoulder small muscle group weakness secondary to ischemic cerebral infarction...

When humans perform movements and receive on-line visual feedback about their performance, the spatial qualities of the visual information alter performance. The spatial qualities of visual information can be altered via the manipulation of visual gain and changes in visual gain lead to changes in force error. The current study used functional magnetic resonance imaging during a steady-state pr...

Whenever the visual stream is abruptly disturbed by eye movements, blinks, masks, or flashes of light, the visual system needs to retrieve the new locations of current targets and to reconstruct the timing of events to straddle the interruption. This process may introduce position and timing errors. We here report that very similar errors are seen in human subjects across three different paradi...

The increase in older adults over the coming decades will be accompanied by a greater burden of chronic neurological diseases affecting the motor system. The motor system adapts to maintain motor performance with the primary motor cortex (BA4) emerging as a pivotal node within this neuroplastic process. Studies of ageing often consider BA4 a homogenous area but cytoarchitectonic studies have re...

UNLABELLED PET activation studies employing the autoradiographic technique and 15O-water or 15O-butanol use the difference between images acquired under baseline conditions and during activation to detect focal changes in cerebral blood flow which occur upon stimulus presentation. Typically, the activating task or baseline conditions are maintained throughout the entire imaging period. Simulati...

Aging and dual-task paradigms often degrade fine motor performance, but the effects of aging on correlated neural activity between motor cortex and contracting muscle are unknown during dual tasks requiring fine motor performance. The purpose of this study was to compare corticomuscular coherence between young and elderly adults during the performance of a unilateral fine motor task and concurr...

Environmental enrichment (EE) is an experimental protocol based on a complex sensorimotor stimulation that dramatically affects brain development. While it is widely believed that the effects of EE result from the unique combination of different sensory and motor stimuli, it is not known whether and how cortico-cortical interactions are shaped by EE. Since the primary visual cortex (V1) is one ...

4 List of papers 5 Aim 6 Spatial alignment of visual and proprioceptive feedback 7 Real-life conditions with a novel visuoproprioceptive alignment 7 The neurophysiological substrate for aligning the visual and proprioceptive spaces 8 Is proprioception an obstacle for motor performance in conditions with a new visuoproprioceptive alignment ? 9 Contribution of visual and proprioceptive feedback t...

Optimal behavior and survival result from integration of information across sensory systems. Modulation of network activity at the level of primary sensory cortices has been identified as a mechanism of cross-modal integration, yet its cellular substrate is still poorly understood. Here, we uncover the mechanisms by which individual neurons in primary somatosensory (S1) and visual (V1) cortices...

Cross education is the process whereby training of one limb gives rise to increases in the subsequent performance of its opposite counterpart. The execution of many unilateral tasks is associated with increased excitability of corticospinal projections from primary motor cortex (M1) to the opposite limb. It has been proposed that these effects are causally related. Our aim was to establish whet...