When we interact with an object, much information about the object is conveyed through signals from the hand. Information about the shape of the object, its texture, its compliance, and its thermal properties is carried in the pattern of activity evoked in a variety of receptors embedded in the skin, the joints, and the muscles. We can often recognize an object simply on the basis of sensory signals emanating from our hands. Without this information, manipulating objects would be slow, clumsy, and effortful.
Our goal is to characterize the sensory information originating from the hand and understand how this information is transformed in successive stages of processing. Our approach involves combining psychophysics, peripheral and cortical neurophysiology, and computational modeling. The goal is to discover the aspect of the neural response that accounts qualitatively and quantitatively for behavior at each stage of perceptual processing.
The scope of our research spans the perceptual chain:
- How are patterns of indentations on the skin converted into trains of action potentials in sensory fibers?
- How is the stimulus represented in the peripheral nerve?
- How are simple stimulus features – e.g., orientation – represented in the early stages of cortical processing?
- How are these representations of simple features integrated into more complex, holistic and invariant representations?
In addition to addressing the fundamental question of neural coding and the neural basis of perception, our research has important practical implications. The near complete absence of somesthetic information provided by current prostheses severely limits their usability. In collaboration with scientists and engineers across the world, we are applying our basic research to develop ways to convey sensory feedback in upper limb neuroprostheses.
-- Sliman Bensmaia, Ph.D.
Principle Investigator
Research opportunities
The somatosensory research lab is seeking graduate students
interested in studying the neural basis of perception. Each
graduate student will have access to state-of-the-art
neurophysiological equipment and to senior research
technicians with extensive experience in neuroscience
research. Graduate students will also have at their disposal
undergraduate research assistants to help with psychophysical
data collection.
On-going projects include:
- Processing of time varying signals in the somatosensory system
- Neural mechanisms of tactile texture perception
- Sensory-motor interactions (in collaboration with Dr. Nicho
Hatsopoulos)
- Conveying tactile and proprioceptive feedback in sensorized
neuroprostheses
Students interested in doing a rotation in the lab can help
analyze unpublished psychophysical and neurophysiological data
to get a sense of the lab’s approach (possibly culminating in
a journal publication).
