A POSTSAMPLE CUE TO FORGET DOES INITIATE AN ACTIVE FORGETTING PROCESSIN PIGEONS

Remember (R)- and forget (F)-cued training trials differed in whether the sample stimulus was or was not relevant to predicting trial outcom e. Delayed matching-to-sample (DMTS) accuracy was lower on trials in w hich the F, rather than the R, cue followed sample presentation (F-cue effect). Because both types of training trials involved the same prob ability of end-of-trial reinforcement and pattern of discriminated tes t responding, the F-cue effect could not result from the F cue trigger ing negative affect, indiscriminate responding, failure to attend to t est stimuli, or a pattern of responding incompatible with accurate DMT S performance. Results also revealed that the F-cue effect was not sol ely caused by presentation of an unexpected test stimulus. It was conc luded that reduced accuracy on F-cued DMTS trials reflected the operat ion of an active forgetting process.