Blocking in human causal learning is affected by outcome assumptions manipulated through causal structure
Additivity-related assumptions have been proven to modulate blocking in human causal learning. Typically, these assumptions are manipulated by means of pretraining phases (including exposure to different outcome magnitudes), or through explicit instructions. In two experiments, we used a different approach that involved neither pretraining nor instructional manipulations. Instead, we manipulated the causal structure in which the cues were embedded, thereby appealing directly to the participants’ prior knowledge about causal relations and how causes would add up to yield stronger outcomes. Specifically, in our “different-system” condition, the participants should assume that the outcomes would add up, whereas in our “same-system” condition, a ceiling effect would prevent such an assumption. Consistent with our predictions, Experiment 1 showed that, when two cues from separate causal systems were combined, the participants did expect a stronger outcome on compound trials, and blocking was found, whereas when the cues belonged to the same causal system, the participants did not expect a stronger outcome on compound trials, and blocking was not observed. The results were partially replicated in Experiment 2, in which this pattern was found when the cues were tested for the second time. This evidence supports the claim that prior knowledge about the nature of causal relations can affect human causal learning. In addition, the fact that we did not manipulate causal assumptions through pretraining renders the results hard to account for with associative theories of learning.
KeywordsBlocking Causal learning Cue competition
Support for this research was provided by KU Leuven GOA Grant No. 3H051018. F. Blanco was consecutively supported by a KU Leuven F+ fellowship awarded to F. Baeyens (F+/10/009) and by a postdoctoral contract funded by the University of Deusto. We thank Itsaso Barberia, Yannick Boddez, Mathijs Franssen, Miguel A. Vadillo, and Bram Vervliet for their valuable comments. Special thanks are due Álvaro Ibañez for his help in recruiting the sample for Experiment 2.
- Kamin, L. J. (1968). “Attention-like” processes in classical conditioning. In M. R. Jones (Ed.), Miami Symposium on the Prediction of Behavior: Aversive stimulation (pp. 9–31). Miami, FL: Miami University Press.Google Scholar
- Mitchell, C. J., De Houwer, J., & Lovibond, P. F. (2009). The propositional nature of human associative learning. Behavioral and Brain Sciences, 32, 183–198, disc. 198–246.Google Scholar
- Pavlov, I. P. (1927). Conditioned reflexes: An investigation of the physiological activity of the cerebral cortex (G. V. Anrep, Trans.). London, UK: Oxford University Press.Google Scholar
- Rescorla, R. A., & Wagner, A. R. (1972). A theory of Pavlovian conditioning: Variations in the effectiveness of reinforcement and nonreinforcement. In A. H. Black & W. F. Prokasy (Eds.), Classical conditioning II: Current research and theory (pp. 64–99). New York, NY: Appleton-Century-Crofts.Google Scholar
- Shanks, D. R., & Dickinson, A. (1987). Associative accounts of causality judgement. In G. H. Bower (Ed.), The psychology of learning and motivation (Vol. 21, pp. 229–261). San Diego, CA: Academic Press.Google Scholar
- Widrow, B., & Hoff, M. (1960). Adaptive switching circuits. In Western Electronic Show and Convention Record (Vol. 4, pp. 96–104). New York, NY: Institute of Radio Engineers.Google Scholar