28 October 2010

BCI Eavesdrops on a Daydream

New research points to the ability to snoop on people’s visual imagination—although it’s still a long way away from the full-fledged dream-reading technologies popularized in this summer’s blockbuster movie Inception. Scientists from Germany, Israel, Korea, the United Kingdom, and the United States have performed experiments in which they were able to monitor individual neurons in a human brain associated with specific visual memories. They then taught people to will one visual memory onto a television monitor to replace another. The results suggest that scientists have found a neural mechanism equivalent to imagination and daydreaming, in which the mental creation of images overrides visual input. And, if technology someday advances to enable reading the electrical activity of many thousands or millions of individual neurons (as opposed to the dozens typically available by hard-wiring methods today), scientists might begin to access snippets of real daydreams or actual dreams. The researchers inserted microwires into the brains of patients with severe epilepsy as part of a presurgery evaluation to treat their seizures.

The microwires threaded into the medial temporal lobe (MTL), a region of the brain associated with both visual processing and visual memory. A typical patient might have 64 microwires cast into his MTL, like fishing lines into the ocean, researchers at Caltech mentioned. Soon after the patients’ surgery, researchers interviewed the subjects about places they’d recently visited or movies or television shows they’d recently seen. Then, on a display, he’d show images of the actors or visual landmarks the subjects had described. Slides of the Eiffel Tower, for instance, or Michael Jackson—who had recently died at the time of the experiment—would appear on a screen. Any image that reliably caused voltage spikes in one or more of the microwires would become one of the subject’s go-to images. There are about 5 million neurons in our brain that encode for the same concept. There are many neurons that fire all together when you think of Michael Jackson. But, he adds, each neuron also codes for numerous other people, ideas, or images, which is partly how we associate one memory with another thought, place, idea, or person.

More information:

http://www.youtube.com/user/NatureVideoChannel?feature=mhump/a/u/0/bqkUbiUkR5k

http://spectrum.ieee.org/biomedical/bionics/braincomputer-interface-eavesdrops-on-a-daydream/?utm_source=techalert&utm_medium=email&utm_campaign=102810