Contiguity and overshadowing interactions in the rapid-streaming procedure

Abstract

When multiple cues are associated with the same outcome, organisms tend to select between the cues, with one revealing greater behavioral control at the expense of the others (i.e., cue competition). However, non-human and human studies have not always observed this competition, creating a puzzling scenario in which the interaction between cues can result in competition, no interaction, or facilitation as a function of several learning parameters. In five experiments, we assessed whether temporal contiguity and overshadowing effects are reliably observed in the streamed-trial procedure, and whether there was an interaction between them. We anticipated that weakening temporal contiguity (ranging from 500 to 1,000 ms) should attenuate competition. Using within-subject designs, participants experienced independent series of rapid streams in which they had to learn the relationship between visual cues (presented either alone or with another cue) and an outcome, with the cue-outcome pairings being presented with either a delay or trace relationship. Across experiments, we observed overshadowing (Experiments 1, 2, 4, and 5) and temporal contiguity effects (Experiments 2, 3, and 4). Despite the frequent occurrence of both effects, we did not find that trace conditioning abolished competition between cues. Overall, these results suggest that the extent to which contiguity determines cue interactions depends on multiple variables, some of which we address in the General discussion.

Cue duration and trial spacing effects in contingency assessment in the streaming procedure with humans.

“…As the streaming procedure is, relatively speaking, a more recent paradigm for the study of human associative learning, one might view this lack of the effect of temporal variables as indicating that, perhaps, because of the fast rate of stimulus presentation in it, the streaming procedure is “special”: Learning does not follow the same rules as in more established procedures which, contrary to the streaming, would tap genuine associative learning. We do not think so, as, on one hand, many canonical conditioning phenomena have been demonstrated in the streaming procedure (contingency effect: Crump et al, 2007; Hannah et al, 2009; Jozefowiez, 2021; Laux et al, 2010; Maia et al, 2018; counterconditioning: Jozefowiez et al, 2020; cue density effect: Jozefowiez, 2021; latent inhibition, partial reinforcement, and extinction: Jozefowiez, Witnauer, et al, 2023; overshadowing: Alcalà et al, 2023; proactive, interspersed, and retroactive interference: Jozefowiez, Witnauer, et al, 2023; renewal: Jozefowiez, Moschchenko, et al, 2023; in unpublished studies, we also have observed blocking and outcome density effects) and, on the other hand, as we already pointed out, the insensitivity of performance to temporal variables in human studies of associative learning is more the norm than the exception. Understanding why the effect of temporal variables is so ubiquitous in animal studies while it is so difficult to obtain in human studies might require a reevaluation of the role of time in associative learning.…”

Further evidence for the role of temporal contiguity as a determinant of overshadowing

“…A growing body of evidence is now available across species, experimental protocols and learning parameters that support the key role of temporal and spatial contiguity in the outcome of compound conditioning. However, weakening of temporal contiguity not always yielded a visible attenuation of cue competition (see Alcalá, Miller, et al, 2023 ). This suggests that other variables, in addition to temporal contiguity, can also determine the outcome of compound conditioning experiment.…”

Category relevance attenuates overshadowing in human predictive learning.

“…Their mean age was 36.26, SD = 11.88 (range 21–67). We used similar studies conducted online and exploring overshadowing as a reference to estimate the sample size ( n = 40; Alcalá, Miller, et al, 2023). All participants were fluent in English language and had completed more than 200 prior approved tasks in Prolific with a mean approval equal to or greater than 98%.…”

“…However, all these studies mentioned above were conducted with nonhuman animals and little evidence is available on the importance of relative salience in human studies. At their best, studies using human participants have identified the specific conditions of temporal and spatial contiguity under which competition or facilitation is more likely to be observed (Alcalá, Kirkden, et al, 2023; Alcalá, Miller, et al, 2023; Glautier, 2002; Herrera et al, 2022). This advises that more research is needed to achieve a better understanding of the specific factors underpinning cue interaction phenomena in human participants.…”