CONDITIONED-RESPONSE TIMING AND INTEGRATION IN THE CEREBELLUM

Classical, conditioning procedures instill knowledge about the tempora l relationships between events, The unconditioned stimulus (US) is the event tit be timed, The conditioned response (CR) is viewed as a pred iction of the imminence of the US, Knowledge of the elapsed time betwe en conditioned stimuli (CSs) and US delivery is expressed in the topol ogical features of the CR The peak amplitude of the CR coincides with the timing of the US. A simple connectionist network based on Sutton a nd Barto's Time Derivative (TD) Model of Pavlovian Reinforcement provi des a mechanism that can account for and simulate CR timing in a varie ty of protocols, This article describes extensions of the model to pre dictive timing under temporal uncertainty, The model is expressed in t erms of equations that operate in real time according to a competitive learning rule, The unfolding of time from the onsets and offsets of e vents such as CSs is represented by the propagation of activity along a sequence of time-tagged elements, The model can be aligned with anat omical circuits of the cerebellum and brain stem that are essential fo r learning and performance of conditioned eye-blink responses.