Vo An Nguyen

Publications (2)11.78 Total impact

• Source

  Available from: Aymeric Guillot

  Article: Brain activity during visual versus kinesthetic imagery: an fMRI study.

  Aymeric Guillot, Christian Collet, Vo An Nguyen, Francine Malouin, Carol Richards, Julien Doyon
  [show abstract] [hide abstract]
  ABSTRACT: Although there is ample evidence that motor imagery activates similar cerebral regions to those solicited during actual movements, it is still unknown whether visual (VI) and kinesthetic imagery (KI) recruit comparable or distinct neural networks. The present study was thus designed to identify, through functional magnetic resonance imaging at 3.0 Tesla in 13 skilled imagers, the cerebral structures implicated in VI and KI. Participants were scanned in a perceptual control condition and while physically executing or focusing during motor imagery on either the visual or kinesthetic components of an explicitly known sequence of finger movements. Subjects' imagery abilities were assessed using well-established psychological, chronometric, and new physiological measures from the autonomic nervous system. Compared with the perceptual condition, physical executing, VI, and KI resulted in overlapping (albeit non-identical) brain activations, including motor-related regions and the inferior and superior parietal lobules. By contrast, a divergent pattern of increased activity was observed when VI and KI were compared directly: VI activated predominantly the occipital regions and the superior parietal lobules, whereas KI yielded more activity in motor-associated structures and the inferior parietal lobule. These results suggest that VI and KI are mediated through separate neural systems, which contribute differently during processes of motor learning and neurological rehabilitation.
  Human Brain Mapping 10/2008; 30(7):2157-72. · 5.88 Impact Factor
• Source

  Available from: Aymeric Guillot

  Article: Functional neuroanatomical networks associated with expertise in motor imagery.

  Aymeric Guillot, Christian Collet, Vo An Nguyen, Francine Malouin, Carol Richards, Julien Doyon
  [show abstract] [hide abstract]
  ABSTRACT: Although numerous behavioural studies provide evidence that there exist wide differences within individual motor imagery (MI) abilities, little is known with regards to the functional neuroanatomical networks that dissociate someone with good versus poor MI capacities. For the first time, we thus compared, through functional magnetic resonance imaging (fMRI), the pattern of cerebral activations in 13 skilled and 15 unskilled imagers during both physical execution and MI of a sequence of finger movements. Differences in MI abilities were assessed using well-established questionnaire and chronometric measures, as well as a new index based upon the subject's peripheral responses from the autonomic nervous system. As expected, both good and poor imagers activated the inferior and superior parietal lobules, as well as motor-related regions including the lateral and medial premotor cortex, the cerebellum and putamen. Inter-group comparisons revealed that good imagers activated more the parietal and ventrolateral premotor regions, which are known to play a critical role in the generation of mental images. By contrast, poor imagers recruited the cerebellum, orbito-frontal and posterior cingulate cortices. Consistent with findings from the motor sequence learning literature and Doyon and Ungerleider's model of motor learning [Doyon, J., Ungerleider, L.G., 2002. Functional anatomy of motor skill learning. In: Squire, L.R., Schacter, D.L. (Eds.), Neuropsychology of memory, Guilford Press, pp. 225-238], our results demonstrate that compared to skilled imagers, poor imagers not only need to recruit the cortico-striatal system, but to compensate with the cortico-cerebellar system during MI of sequential movements.
  NeuroImage 08/2008; 41(4):1471-83. · 5.89 Impact Factor