Scientists at the California Institute of Technology (Caltech) have successfully created an artificial neural network using DNA molecules that is capable of brain-like behavior. Hailing it as a “major step toward creating artificial intelligence,” the scientists report that, similar to a brain, the network can retrieve memories based on incomplete patterns.
Potential applications of such artificially intelligent biochemical networks with decision-making skills include medicine and biological research. The researchers predict that, eventually, neural networks could be developed that operate within cells to gather information for disease diagnosis.
More details from Caltech:
Consisting of four artificial neurons made from 112 distinct DNA strands, the researchers’ neural network plays a mind-reading game in which it tries to identify a mystery scientist. The researchers “trained” the neural network 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. The researchers played this game with the network using 27 different ways of answering the questions (out of 81 total combinations), and it responded correctly each time.
This DNA-based neural network demonstrates the ability to take an incomplete pattern and figure out what it might represent—one of the brain’s unique features. “What we are good at is recognizing things,” says [Nature article] coauthor Jehoshua “Shuki” Bruck, [a Caltech computer science professor]. “We can recognize things based on looking only at a subset of features.” The DNA neural network does just that, albeit in a rudimentary way.
Check out these YouTube videos describing the research:
Full story: Caltech researchers create the first artificial neural network out of DNA…
Abstract in Nature: Neural network computation with DNA strand displacement cascades
Building a tiny “DNA brain” (Part I: design), Building a tiny “DNA brain” (Part II: experiments)