Despite many discoveries in the field of neuroscience over the past several decades, researchers haven’t been able to fully crack the brain’s “neural code,” which explains how the brain’s roughly 100 billion neurons turn raw sensory inputs into information we can use.
But in an article in Nature Neuroscience, biomedical engineering professor Garrett Stanley has detailed his progress toward the elusive goal. He has observed the spiking activity of neurons in response to outside stimuli and made clear predictions about what is being seen, heard or felt.
“The recent development of improved tools for measuring and activating neuronal circuits has finally put us in a position to start writing the neural code and controlling neuronal circuits in a physiological and meaningful way,” he says.
His work dovetails with the BRAIN Initiative, announced by President Obama in April, which seeks to map brain activity. Tech faculty members Robert Guldberg, executive director of the Petit Institute for Bioengineering and Bioscience, and Craig Forest, assistant professor of mechanical engineering, attended a White House ceremony to announce the initiative.
The potential rewards for cracking the neural code are immense. In addition to understanding how brains generate and manage information, neuroscientists may be able to control neurons in individuals with epilepsy and Parkinson’s disease or restore lost function following a brain injury. Researchers also may be able to supply artificial brain signals that provide tactile sensation to amputees wearing a prosthetic device.
A longstanding debate exists over whether the neural code is a “rate code,” where neurons simply spike faster than their background spiking rate when they are coding for something, or a “timing code,” where the pattern of the spikes matters.
Stanley suggested the neural code is a “synchrony code,” where the synchronization of spiking across neurons is important. “Eavesdropping on neurons in the brain is like listening to a bunch of people talk,” Stanley says. “A lot of the noise is just filler, but you still have to determine what the important messages are.”
Twitter