The scientists' findings about how the brain regulates sensory inputs and motor outputs to accomplish those tasks are detailed in the June 13 issue of the journal Neuron. Their discovery could have a direct application to future efforts to help victims of stroke or spinal injury with "neuroprosthetics" that might move artificial limbs or other procedures that might lead to the reestablishment of motor control in stroke victims.
According to the researchers, how we filter out much of the of sensory inputs we're not interested in to focus on a specific smell, taste or sound is a consequence of the way the sensory and motor cortices of our brain are hardwired to handle sensory inputs. This subconscious mechanism enables us to immediately send motor signals to our eyes, ears, nose and hands to enhance our perception of the sensory information that we are interested in.
"The act of sensation is inexplicably tied to that of motor control," says David Kleinfeld, a professor of physics at UCSD and one of the leaders of the research collaboration. "If we spot a friend in the distance, our eyes move to track him or her. If we caress an object with our fingers, our hand moves to optimize the sense of texture. If a new odor permeates a room, we sniff to sample and identify the smell. In all of these processes, we separate the sensory input from the motor component that directs and defines the sensation."
In their experiments, the scientists discovered the specific mechanisms by which sensory signals are converted into motor
Contact: Kim McDonald
University of California - San Diego