Pumping up Perception
While Nicolelis and Kipke are boosting the brain’s ability to control external devices, others in the DARPA initiative are aiming to manipulate the brain’s inner workings-specifically those that send, receive, and process sights and sounds. By tapping into the visual and auditory regions of the mind, researchers are testing whether such information can be transmitted between brains and computers to enhance perception and communication. If successful, the projects could lead to astounding new interfaces that enhance humans’ ability to recognize faces, objects, and speech and to make decisions. They might even enable brain-to-brain wireless communication, says DARPA’s Rudolph.Before they can devise such systems, researchers must learn how to “read out” information from the brain, as well as “write in” information, says Tomaso Poggio, an expert on artificial intelligence at MIT. Poggio and MIT neurophysiologist James DiCarlo, both principal investigators in the DARPA program, are working with visual perception and object recognition in rhesus monkeys. The researchers will present objects such as abstract shapes, cars, and animals on a computer screen. One possible experiment is based on previous collaborations with MIT neuroscientist Earl Miller: the researchers could train a monkey to decide whether a computer-generated animal on a screen looks more like a cat or a dog (see “Mind Readout,” sidebar). Software would blur the line, creating, for example, an image that is 60 percent cat and 40 percent dog. While the monkey is making its decision, the researchers would use implanted electrodes to record signals from neurons in the visual cortex: some of these cells fire when the monkey views a cat, others when it sees a dog.