Language of a fly proves surprising

March 10, 2008 | Source: PhysOrg.com

Los Alamos, Princeton University, and Indiana University research fundamentally alters earlier beliefs about how neural networks function and could provide the basis for intelligent computers that mimic biological processes.

The researchers developed a novel way to view the world through the eyes of a common fly and partially decode the insect’s reactions to changes in the world around it.

They used electrodes to tap into motion-sensitive neurons in the visual system. The team harnessed the wired fly into an elaborate turntable-like mechanism that mimics the kind of acrobatic flight a fly might undergo while evading a predator or chasing another fly. The mechanism can spin extremely fast and change velocities quickly. A fly in the mechanism sees changes in the world around it and its motion-sensitive neurons react much in the same way as they would if the insect were actually flying.

Under complex flight scenarios, the fly’s neurons fired very quickly. The researchers looked at the firing patterns and mapped them with a binary code of ones and zeroes. The motion-sensitive neurons emitted spikes very often and very precisely, contradicting earlier research findings that the precise timing of the impulses was largely irrelevant.

The research is significant because it re-examines fundamental assumptions that became the basis of neuromimetic approaches to artificial intelligence, such as artificial neural networks. These assumptions have developed networks based on reacting to a number of impulses within a given time period rather than the precise timing of those impulses.

New understanding of neural function in the design of computers could assist in analyses of satellite images and facial-pattern recognition in high-security environments, and could help solve other national and global security problems.