Functional integration of cutaneous and proprioceptive senses and its clinical application

Somatosensation, including cutaneous sense and proprioception (joint position), is fundamental for successful locomotion and object manipulation. The dichotomy of cutaneous sensation and proprioception was recently challenged by a novel hypothesis of tactile submodalities convergence as evidenced by the fact that hand joint position is mainly determined by the signals originated from cutaneous stretch receptor of the dorsum hand. Also, most parts of primary somatosensory and posterior parietal cortexes receive convergent inputs from cutaneous and proprioceptive afferents, suggesting that submodality convergence is universal in somatosensation. In the present grant, we will first explore the functional implication of these convergences in human psychophysical experiments and then characterize the neural coding of submodality integration in the somatosensory cortex in macaque monkey. Patients with neurological disorders suffer from a variety of impairment of cutaneous and proprioceptive senses, respectively. In the second part of the present grant, we will perform lesion studies by applying neuropsychological experiments in patients with sensory loss to reconfirm the submodality integration model we have established. Finally, we seek to apply the knowledge we obtained for submodality integration to develop clinically plausible rehabilitation strategies or orthotics to compensate for the loss of proprioception. The lines of inquiry of present project will provide substantial breakthrough in the functional implication of submodality convergence among cutaneous sense and proprioception, the neuronal modeling of submodality integration, and clinical rehabilitation measures for patients with sensory impairment.

Project ID:PG10301-0180
External Project ID:NHRI-EX103-10113EC