Fig 1.
Schematic representation of the delayed nonmatching-to-position procedure, showing the state of the three panel lights during each period of a trial in which the left side-hole was randomly selected as the sample, making the right side-hole the correct (nonmatching) hole during the choice period. The Intertrial period (a) precedes each trial. The Sample period (b) requires two responses in the sample hole to proceed to the Delay Period. During the Delay period (c), responding in the center hole is required to enter the Choice period. During the Choice Period (d), a nonmatching response produces food and turns off all lights, or a matching response turns off the hole lights and produces 5 seconds of flashing houselight. After food delivery or flashing of the houselight, the next Intertrial Period (e) begins.