In order to investigate a possible role of visual processing in regulation of adaptive behaviours, two behavioural experiments using colour stimulus were performed in human subjects. In the first experiment, hemispheric asymmetry of colour processing was investigated by measuring reaction time to a stimulus presented either in the left or the right visual field responded by the ipsilateral hand. In the second experiment, a modulatory effect of colour on sensory motor gait was investigated using a prepulse inhibition task. Traditionally, it was though that these two processes are in series, while in the present model, these processes are in parallel, in addition to the serial processing. The authors of this book examine the results of these two models and its implications, as well as other developments in the field.