Grant: Operating Grant

We are studying the central neural mechanisms that underlie the ability to perceive surface roughness using touch. Project 1 will examine the neuronal coding of roughness in somatosensory cortex. Project 2 will investigate the role of voluntary attention in enhancing neuronal responsiveness to touch at the level of the gateway for sensory inputs to the cortex, the sensory thalamus. Both projects examine neuronal discharge in relation to perception & action (sensory decision signaled by movement). Project 1 tests our hypothesis that roughness is encoded by the activity of small groups of specialized cortical neurones. The results will provide important insights into how the brain works & how it generalizes to form an invariant representation of tactile inputs. The results will have direct applications in the development of sensorimotor neural prosthetics: where to implant electrodes in the brain & what "language" to use. Project 2 is based on our pilot work showing for the 1st time that voluntary attention exerts substantial controls over neuronal sensitivity to tactile stimuli in the sensory thalamus. We will confirm & extend these observations. Attention improves perception, focusing the brain's processing capacities on stimuli relevant to one's goals in the context of a CNS that is inundated with a steady stream of sensory inputs - information overload in our multi-tasking society. An example is using tactile search to quickly locate the car key, not the house key, at the bottom of a deep & cluttered purse. Our work challenges the old view that voluntary attention acts only at high levels of the CNS. Showing that attention is a global controller will provide new insights for interventions to re-educate attention, a major health issue affecting all ages. Moreover, we suggest - based on our previous work & that of others - that targeted strategies to rehabilitate tactile perception must include directed attention combined with sensory training + active movement.