REINFORCEMENT DIFFERENCE LIMEN (RDL) FOR DELAY IN SHOCK ESCAPE

280 female albino Sprague-Dawley rats pressed 1 of 2 retracting levers to terminate shock. Pressing 1 lever produced a standard delay of shock offset, the other, a comparison delay. 3-5 comparison levels were paired with standard delays of 0, 1, 2, 4, 8, or 16 sec. The reinforcement difference limen (RDL) was defined as the minimal difference between delays producing a 75% preference for response followed by the shorter delay. RDL size increased as a function of the standard delay with a log-log slope of about 1, indicating that the relative function, DELTAD/D, is invariant over the range of delays tested (Weber's law). (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.