Motivationally-based learning mechanisms and the dynamics of saccade initiation

Saccadic eye movements are controlled by a simple system that can be investigated experimentally and computationally to help to elucidate mechanisms of neural information processing. Proper initiation of saccadic eye movements depends on an intricate balance between reflexive and voluntary or goal directed control mechanisms. The superior colliculus is a major site of signal integration that has been shown to drive the initiation of saccades in the brainstem. Previous work has shown that a winner-take-all mechanism implemented with a continuous attractor neural network can explain and reproduce a multitude of behavioural findings. This investigation advances the model of saccade initiation in order to account for trial-by-trial adaptation of reaction times in a biologically plausible manner. Simulations of various behavioural paradigms reproduced experimental data, supporting the idea that there is a mechanism in place that produces short term, motivationally-based modulation of inputs driving saccade initiation.