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Exploring the role of stimulus similarity on the summation effect in causal learning

Pérez, Omar D. and San Martín, René and Soto, Fabián A. (2018) Exploring the role of stimulus similarity on the summation effect in causal learning. . (Unpublished)

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Several contemporary models of associative learning anticipate that the higher responding to a compound of two cues separately trained with a common outcome than to each of the cues alone -a summation effect- is modulated by the similarity between the cues forming the compound. Here, we explored this hypothesis in a series of causal learning experiments with humans. Participants were presented with two visual cues that separately predicted a common outcome and later asked for the outcome predicted by the compound of the two cues. Importantly, cue similarity was varied between groups through changes in shape, spatial position, color, configuration and rotation. In variance with the predictions of these models, we observed similar and strong levels of summation in both groups across all manipulations of similarity (Experiments 1-5). The summation effect was significantly reduced by manipulations intended to impact assumptions about the causal independence of the cues forming the compound, but this reduction was independent of stimulus similarity (Experiment 6). These results are problematic for similarity-based models and can be more readily explained by rational approaches to causal learning.

Item Type:Report or Paper (Discussion Paper)
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URLURL TypeDescription Paper
Pérez, Omar D.0000-0002-4168-5435
Soto, Fabián A.0000-0002-1001-679X
Alternate Title:The role of stimulus similarity on the summation effect in human causal learning
Additional Information:The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license. Posted January 31, 2018. We thank Julián Contreras for helping with data collection for some of the experiments reported in this paper.
Record Number:CaltechAUTHORS:20181026-145617029
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:90440
Deposited By: Tony Diaz
Deposited On:26 Oct 2018 22:10
Last Modified:13 Apr 2023 17:40

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