Marcos J L, Redondo J
Departamento de Psicología, Campus de Elviña, Universidad de La Coruña, Spain.
Biol Psychol. 1999 Jun;50(2):89-102. doi: 10.1016/s0301-0511(99)00007-1.
The purpose of this experiment was to study whether conditioned diminution of the unconditioned response (UR) is a phenomenon with an associative basis. Discriminative electrodermal conditioning was used with an interval between the conditioned stimulus (CS) and unconditioned stimulus (US; aversive white-noise) of 8 s. Fifty-nine volunteer subjects received discrimination training in which one CS was reinforced (CS+ /US) and a second CS was non-reinforced (CS-). After this discriminative training phase, participants were tested using intermixed trials in which a US was preceded by either a CS+, a CS-, or a neutral stimulus (NS). The results indicated that the skin conductance response amplitude of the UR was lower when the US was preceded by the CS+ than when the US was preceded by the CS- or the NS. However, NS/US presentations elicited URs of greater amplitude than those of the CS- /US presentations. The results can be explained in terms of orienting reflex reinstatement. In addition, it is argued that conditioned diminution has an associative basis.
