Enhancing the flow of information through the brain could be crucial to making neuroprosthetics practical.
The abilities to learn, remember, evaluate, and decide are central to who we are and how we live. Damage to or dysfunction of the brain circuitry that supports these functions can be devastating, leading to Alzheimer’s, schizophrenia, PTSD, or many other disorders. Current treatments, which are drug-based or behavioral, have limited efficacy in treating these problems. There is a pressing need for something more effective.
One promising approach is to build an interactive device to help the brain learn, remember, evaluate, and decide. One might, for example, construct a system that would identify patterns of brain activity tied to particular experiences and then, when called upon, impose those patterns on the brain. Ted Berger, Sam Deadwyler, Robert Hampsom, and colleagues have used this approach (see “Memory Implants”). They are able to identify and then impose, via electrical stimulation, specific patterns of brain activity that improve a rat’s performance in a memory task. They have also shown that in monkeys stimulation can help the animal perform a task where it must remember a particular item.
Their ability to improve performance is impressive. However, there are fundamental limitations to an approach where the desired neural pattern must be known and then imposed. The animals used in their studies were trained to do a single task for weeks or months and the stimulation was customized to produce the right outcome for that task. This is only feasible for a few well-learned experiences in a predictable and constrained environment.