Short-term retention of location within a homogeneous behavior sequence in rats

Fed 8 male Sprague-Dawley rats for entering a food tray following 12 or more consecutive lever presses. Short-term retention of location within the 12-press requirement was then tested by interrupting the press sequence with time-outs (TOs) after various numbers of presses. Each sequence contained 1 TO, and the duration of the TO was varied (0-16 sec) across phases of the experiment. As TO duration increased, the number of presses per trial went from being independent of TO location to being directly related to it. Derived retention scores showed a very rapid negatively accelerated, decreasing relationship to TO duration. Limitations on the interpretation of these retention functions are discussed.