Phase 2: Approach and avoidance conditioning, part 1.
If participants failed to make 19 correct responses out of 20, they were reexposed to the avoidance conditioning block.
Phase 7: Approach and avoidance conditioning, Part 2.
That is, 3 of 8 and 5 of 10 research volunteers were dropped from Experiments 1 and 2, respectively, due to a failure to satisfy avoidance conditioning or stimulus equivalence training and testing criteria.
Each animal was allowed to become accustomed to the shuttle-box apparatus for 5 min before every session; the animal was then subjected to 25 daily trials/session of avoidance conditioning
in four consecutive sessions (acquisition test).
Subjects were then exposed to an avoidance conditioning procedure in which one member from each relation was established as a discriminative stimulus for avoidance and nonavoidance, respectively.
Finally, aversive and aesthetically pleasing pictures used for avoidance conditioning were taken from the International Affective Picture System (IAPS: Lang, Bradley, & Cuthbert, 2001).
Each subject signed a consent form, acknowledging the distasteful nature of the aversive pictures to be used during the avoidance conditioning phase, at least 24 hr before the experiment.
Next, an avoidance conditioning procedure was used to establish one member of the relational network (B1) as a discriminative stimulus ([S.
That is, because of the instruction to cancel certain upcoming pictures and sounds, participants may, at the outset of avoidance conditioning, simply have viewed all stimulus presentations (i.
Visual and auditory stimuli were selected from the International Affective Picture System (IAPS; Lang, Bradley, & Cuthbert, 2005) and the International Affective Digitized Sounds (IADS; Bradley & Lang, 1999) for use as aversive and nonaversive stimuli during the avoidance conditioning and transformation testing phases.
On arrival at the laboratory, participants signed a consent form, acknowledging the distasteful nature of some of the stimuli to be used during the avoidance conditioning phase and indicating that they did not have a history of psychopathology.