ESCAPE BEHAVIOR AND SHOCK INTENSITY - WITHIN-SUBJECT VERSUS BETWEEN-GROUPS COMPARISONS

Manipulated shock intensity within Ss (WS) and between groups (BG) to investigate whether WS and BG comparisons would show similar performance levels and similar functional relationships between shock intensity and performance. 40 naive female Holtzman albino rats were trained for 60 trials with either 20, 50 or 80 V. presented on all trials or with these intensities varied from trial to trial. After training, Ss received nonshock-extinction trials to an extinction criterion. For both WS and BG comparisons, acquisition performance was a reliable direct function of shock intensity. At each intensity the WS condition performed better than the BG condition. Resistance to extinction increased reliably with increasing shock intensity for groups trained with 1 intensity alone, but resistance was greatest for the group trained with variations in intensity. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.