Modelling Reaction Times
We discuss the simulation of reaction times in connectionist systems. The obvious way to do this involves thinking in terms of neural activations building up towards some threshold in cascaded systems, but it has also been suggested that the output activation error scores in standard back-propagation networks should also be correlated with response times. The idea is that in the more realistic cascaded processing systems, the clearer the outputs (i.e. the lower the errors), the lower the time taken to reach the threshold. If this is correct and we can consider our simple feedforward networks to be reasonable approximations to these cascaded systems, then we have an easy way to simulate reaction times. However, the validity of this has been questioned. I will discuss these issues in some detail, suggest a more principled way of extracting simulated reaction times from back-propagation networks and show how this relates to the corresponding cascaded networks.
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