DNA Molecules Simulate Neural Net Behaviors Caltech Research Gets DNA NNs to Recall Memories from Patterns

Researchers at the California Institute of Technology (Caltech) have made an artificial neural network (NN) out of DNA, creating a circuit of interacting molecules that can recall memories based on incomplete patterns, just as a brain can. Consisting of four artificial neurons made from 112 distinct DNA strands, the researchers’ NN plays a mind-reading game in which it tries to identify a mystery scientist. The researchers “trained” the NN to “know” four scientists, whose identities are each represented by a specific, unique set of answers to four yes-or-no questions, such as whether the scientist was British.

After thinking of a scientist, a human player provides an incomplete subset of answers that partially identifies the scientist. The player then conveys those clues to the network by dropping DNA strands that correspond to those answers into the test tube. Communicating via fluorescent signals, the network then identifies which scientist the player has in mind. Or, the network can “say” that it has insufficient information to pick just one of the scientists in its memory or that the clues contradict what it has remembered.