Figure 1.

The dDNMTP task has a modular design that allows comparison of neuronal activity associated with comparable behavioural elements during each trial, including: four lever press responses, three movements between adjacent levers, and two reinforcement events. The location of the base lever used for start and delay presses was randomly selected for each trial so that behavioural elements were not consistently confounded with spatial location. To promote stable responding rats received a minimum of 60 pre-surgical training sessions to a criterion of completing 60 trials within a 60 m session with 70% correct for two of three consecutive sessions. Electrophysiological data were analysed only when rats completed a minimum of 40 trials in a 60 m recording session.