Latent inhibition in humans from simple stimulus exposure.

Two experiments observed an effect consistent with a latent-inhibition (LI) effect in humans that (a) did not depend on masking or instruction-generated expectations and (b) suggested that the effect results from a change in processing of the predictive cue. Participants viewed a video of a superhero character flying through three different contexts past a different stimulus in each context. In conditioning, The superhero flew past a target cue that was either Novel (Group No Exposure), had been preexposed in the Same context as where conditioning was occurring (Group Same), or was preexposed in a Different context (Group Different). Each time the superhero flew past the target cue his Hands Glowed (outcome). On test (E1), an image of the superhero flying in the context with normal Hands and the target cue was present. Participants were asked if anything was missing. Experiment 2 tested participants with the superhero present and his Hands Glowing to test outcome-cue associations (Test 1) or just the superhero in the context (Test 2, counterbalanced) to assess contextual associations. In E1 fewer people in Group Same reported the outcome missing than Group No Exposure or Group Different. In E2 fewer people in Group Same reported the target cue missing when presented with the outcome than in the other groups, a result inconsistent with interference accounts of LI. When presented only with contextual cues, reports of the stimulus missing showed that the context was associated with the stimuli presented within it. Results are discussed with respect to theories and demonstrations of human LI. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Extinction contexts fail to transfer control: Implications for conditioned inhibition and occasion-setting accounts of renewal.

The renewal effect is often explained as a side effect of the extinction context acting as a negative occasion setter. Four experiments tested whether extinction contexts show the selective-transfer property of occasion setters. Experiments 1-3 used a predictive judgment task where participants rated the probability of certain foods (cues) producing gastric malaise (outcomes) in different restaurants (contexts). Experiment 4 used a behavioral suppression task where sensor lights (cues) served as signals to suppress firing responses in certain galaxies (contexts). All 4 (Experiments 1-4) addressed whether a potentially negative occasion-setting context transferred its modulatory power to an extinguished (presumably occasion set) target in the test phase of an ABC renewal design. Experiments 2-4 further assessed the possibility that the extinction context acts as a conditioned inhibitor by testing a simple excitor on a context where extinction occurred. Neither selective (occasion-setting) nor nonselective transfer (conditioned inhibition) was demonstrated. Implications for theories of renewal and occasion-setting are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Loss of salience as a source of latent inhibition in human associative learning.

Two experiments made use of a procedure known to generate latent inhibition in human associative learning. Participants received training consisting of exposure to a list of actions performed by a fictitious Mr. X. For most of his actions, an outcome was described, but some were not followed by any outcome. The last action performed by Mr. X was novel for participants in the NOVEL condition. For participants in the EXPOSED condition, Mr. X had performed that target action on repeated occasions, without it producing any outcome. After training, all participants were tested on their ability to retrieve what was the last action performed by Mr. X. In both experiments, retrieval of the target action was poorer in the EXPOSED than in the NOVEL condition. Experiment 2 also included a condition in which the target action was followed by a novel outcome and demonstrated a latent inhibition effect-poorer performance in the EXPOSED condition on a test of the association between the target event and its outcome. These results are interpreted in terms of an attention-reducing mechanism, triggered by the repeated preexposure to the target in the absence of a following event. It is argued that the attentional change involves a reduction in the effective salience of the stimulus of the target event, and thus reduces the processing necessary for encoding in memory and the ability of the event to enter into associations.