Backward conditioning in Pavlovian type studies. Reevaluation and present status

Authors of almost all learning texts have indicated that unconditional/stimulus-conditional stimulus (UCS-CS) trials (backward conditioning) utilized in classical conditioning experiments will not result in establishing a conditional response (CR) (excitation). Recently, it has been proposed that backward conditioning can take place although whether UCS-CS trials results in excitation or inhibition has been left unspecified. It is proposed that the diversity of findings can be attributed to inadequate methodology and the use of a classical-instrumental transfer paradigm. When only traditional Pavlovian conditioning studies are examined, the experimental findings suggest that UCS-CS trials will result in inhibition.