The answer to the question of whether the brain operates like a computer therefore depends on what kind of a computer one has in mind. Unlike the rationalist idea of computation based on feature extraction and representation according to a series of logical steps, the conception of the brain as a computer is plausible considered as a neural network whose connectivity changes over evolutionary and individual time according to feedback from trial and error. This perspective can be made even more biologically attractive by letting a computational equivalent of natural selection operate on an evolving population of neural networks. By changing the weights of the connections between nodes according to the relative success of autonomous networks competing with each other in a virtual environment and reproducing differentially based on some criteria of "fitness," it should be possible to explore how the structure and function of real brains evolved.
By the mid-1990s, mathematically inclined psychologists joined the fray with yet another perspective about how vision, and brains more generally, might work. Their approach was based on a statistical methodology generally referred to as Bayesian decision theory. Thomas Bayes was an English mathematician and Presbyterian minister who published a paper in 1763 showing formally how conditional probabilities lead to valid inferences. Although Bayes's motivation for studying this issue is unclear, his theorem has been widely applied to statistical problems whose solution depends on an assessment of hypotheses that are only more or less likely to be true because they depend on two or more probabilities. For example, the theorem has been used in medicine to evaluate the likelihood of a diagnosis or a clinical outcome given a set of tests or other data that together contribute to the overall probability of having the disease or responding to therapy. Bayes's theorem is usually written in this form:
Was this article helpful?
The Tabata workout system is a version of the High Intensity Interval Training program developed by Professor Izumi Tabata as training for Olympic speed skaters in 1996. The results studies conducted on the training program confirm that even a four minute cardiovascular exercise routine improves a persons level of fitness.