A group of young physicists from the Cavendish Laboratory in Cambridge have solved both parts of a double puzzle posed to neuroscientists worldwide . The puzzle was set by two researchers in America, John Hopfield and Carlos Brody. The first part of the challenge was to explain how a simulated `mouse brain' made up of about a thousand neurons performed speech recognition; the second part of the contest required entrants to construct their own simulated brain, capable of speech recognition on a ten-word vocabulary, like Hopfield and Brody's.
David MacKay and his research group heard about this competition in September 2000, and they cracked the computational principles underlying the `mouse' after a one-hour brain-storming meeting on 18 October. `I knew we had solved it', said MacKay, `when our tentative explanation started predicting curious details in the recordings from the "brain"'.
MacKay, who is a firm believer in the value of openness in research, immediately published a webpage - http://wol.ra.phy.cam.ac.uk/mackay/HBMouse.html - describing his group's deductions, including a three-minute movie in which he explained how the `brain' works with the aid of two slices of pizza. However, to encourage others to continue thinking about the problem posed in the competition, the authors of the puzzle asked MacKay to keep the explanation secret until the closing date for the competition. Hopfield and Brody will publish the correct solution and announce the winners on 14 December. Each part of the competition carries a $500 cash prize.
The winning entry to the second part of the competition, the search for the best simulated brain, was developed by Seb Wills, a PhD student in the research group, using the principles deduced for the first competition.
The team that cracked the brain puzzle is led by David MacKay, 33, who is a Reader in Natural Philosophy, and also a co-founder of the internet company Transversal.com. The other members of his group are postdoctoral researcher Sanjoy Mahajan, 31, and graduate students James Miskin, 25, David Ward, 24, Seb Wills, 23, and Ed Ratzer, 22. MacKay and Mahajan have PhDs from the California Institute of Technology, where they worked with Hopfield.
While all members of the inference group have physics degrees, the group works on a wide range of topics including the development of human-computer interfaces for disabled users, the development of error-correcting codes for communication systems, the search for gene expression patterns in data from cancer patients, and research into effective physics teaching methods.
David MacKay says, "the boundaries between departments are outdated. I've always been interested in the whole of science - I have collaborations with engineers, computer scientists, materials scientists, psychologists statisticians, pathologists and physiologists. To be a good scientist, you need to be curious and to have an urge to get to the bottom of things. I would find it impossible to be curious about physics alone. I'm grateful to the Physics Department for giving my group a home where we can pursue research without frontiers."
1. For details of the puzzle, and why Hopfield and Brody chose to describe their ideas in the form of a competition, see: http://shadrach.cns.nyu.edu/~carlos/Organism/ and motivation.html, or contact them directly.
2. The inference group is supported by the Gatsby Foundation, by a partnership award from IBM Zurich Research Laboratory, and by studentships from EPSRC, British Telecom and Schlumberger.
3. The group will donate the prize money to the campaign to free Sally Clark, a mother who lost two babies to cot death and was then convicted of murdering them, on the grounds that it is highly improbable that two cot deaths should strike a single family.
Stuart Hogarth On-line Press Officer Cambridge University The Old Schools Email: sh339@cam.ac.uk Trinity Lane Tel: 01223 765234 Cambridge CB2 1TN Fax: 01223 330262
The team that cracked the brain puzzle is led by David MacKay, 33, who is a Reader in Natural Philosophy, and also a co-founder of the internet company Transversal.com. The other members of his group are postdoctoral researcher Sanjoy Mahajan, 31, and graduate students James Miskin, 25, David Ward, 24, Seb Wills, 23, and Ed Ratzer, 22. MacKay and Mahajan have PhDs from the California Institute of Technology, where they worked with Hopfield.
While all members of the inference group have Physics degrees, the group works on a wide range of topics including the development of human-computer interfaces for disabled users, the development of error-correcting codes for communication systems, the search for gene expression patterns in data from cancer patients, and research into effective Physics teaching methods.
The inference group is supported by the Gatsby Foundation, by a partnership award from IBM Zurich Research Laboratory, and by studentships from EPSRC, British Telecom and Schlumberger.
Stuart Hogarth On-line Press Officer Cambridge University The Old Schools Email: sh339@cam.ac.uk Trinity Lane Tel: 01223 765234 Cambridge CB2 1TN Fax: 01223 330262
David MacKay (left) and Seb Wills (right) 1024x512 512x384 256x192 |