Tuesday, May 10, 2011

IBM's Watson plays Jeopardy “Unconsciously”

The video above shows Watson, a computer system with artificial intelligence developed by IBM, participating in a televised game show against Jeopardy record holders Brad Rutter and Ken Jennings. The computer uses algorithms (which have been around for a while) to parse out phrases from the jeopardy questions and match them against information in its internal memory. Watson has open access to a memory bank of 200 million pages of text including dictionaries, thesauri, newswire articles, literary works and all of the encyclopedic entries of Wikipedia. This information takes up four terabytes of disk space in its RAM based memory. It is not the first computer to solve these kinds of questions but it is the first to do so in the order of a couple of seconds with very high accuracy. 
Watson parses the clues into different keywords and sentence fragments in order to find statistically related phrases. Through the simultaneous execution of thousands of language analysis algorithms, Watson comes up with a number of potential answers (mostly proper nouns or verbs), that are statistically most likely to match the cues given by Jeopardy's Alex Trebek. Watson chooses the answer that has been found most frequently by different, independently operating, algorithmic searches.  
Watson is not conscious. It has proven that it can best the most skilled human trivia practitioners in the world but it doesn't "understand" the questions that it answers. Watson might be able to narrow its associative search down to a single city but it cannot appreciate why it chose the city, cannot visualize what it would be like to visit this city and has no desire to do so. Although it can come up with a precise list of the most closely semantically related words and concepts, it cannot reflect on these in a creative, insightful or emotional way. In some ways though, Watson's method of processing is very much like our own. Its multiassociative approach is much like the way our unconscious mind can select a single answer when given a set of related cues.
Like Watson we have mental representations of words, perceptions and concepts organized in our head and these are associated to one another in various ways. The associations are determined by our experiences and each concept, is associated with many other concepts. To access the memory of a concept, several other closely related concepts must be activated at the same time. In fact, when a set of concepts are coactivated (like the words twinkle, distant and night sky), sometimes there is only one representation that all of these descriptions sum together to activate. Interestingly, even our brain cells, at a very fundamental level are organized for multiassociativity. Individual neurons must have messages being sent to them by many other neurons, for them to increase their firing rate. In the cognitive, neuroscientific and AI sense, representations made active by a jeopardy question send out outputs to many different dormant representations and the ones that are converged upon the most become active. In other words, multiple cues activate tons of different representations, but only the representations that best match the suite of cues - taken all together - are activated maximally to become conscious.  The important question is, are the associative links in your network of associations wired up in such a way that the representation corresponding to the correct answer will become active?

An answer on Jeopardy a few days ago was: The name of a planet, an element and a Roman god. Within three seconds, the question, "what is mercury," popped into my head. It didn't pop in within a few hundred milliseconds so I must have done some conscious thinking beforehand. But I also know that I did not go sequentially down the list of elements and planets in my head in search for a commonality. The node in my brain (which might correspond to a cluster of neurons or even of cortical minicolumns) that corresponds to the concept of mercury, was converged upon and made active by these other concepts in an automatic and unconscious way. 

Snap judgments are made, unconsciously, in this way. But humans can do more than just make blind, automatic multiassociative guesses. Given time and the motivation to deliberate, humans can contemplate questions from a variety of different perspectives. It seems to me that most Jeopardy questions offer a number of associative cues that will automatically cue up the answer in a contestant’s head if they know it. Some Jeopardy questions seem to offer cues that require additional processing and the use of inferential and deductive thinking. Interestingly, Watson seems to be able to make up for its lack of human logic, on questions like these, with processing power and extensive memory.
To me the important question is, how does one imbue a system like Watson’s with human-like consciousness beyond instantaneous multiassociation? I think that the answer lies in endowing a computing system like Watson with the equivalent of a prefrontal cortex to keep certain representations active through the span of several seconds. Of course, this form of artificial intelligence would have to have a prolonged series of developmental experiences, similar to a childhood, to learn which representations to keep active in which scenarios. By maintaining the activiation of a representation, something that happend moments ago can impact future activity. This may not help much in Jeopardy where each question is meant to stand on its own independent from the other questions. However, in my mind, extended activation is totally responsible for the creativity, insight and emotionality that is necessary for most human activities. 

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