Miller Shettleworth Essay - 21273 Words

Journal of Experimental Psychology: Animal Behavior Processes 2007, Vol. 33, No. 3, 191–212 Copyright 2007 by the American Psychological Association 0097-7403/07/$12.00 DOI: 10.1037/0097-7403.33.3.191 Learning About Environmental Geometry: An Associative Model Noam Y. Miller and Sara J. Shettleworth University of Toronto K. Cheng (1986) suggested that learning the geometry of enclosing surfaces takes place in a geometric module blind to other spatial information. Failures to find blocking or overshadowing of geometry learning by features near a goal seem consistent with this view. The authors present an operant model in which learning spatial features competes with geometry learning, as in the Rescorla–Wagner model. Relative total†¦show more content†¦The signature phenomena of cue competition in conditioning are overshadowing and blocking. In overshadowing (Pavlov, 1927), when two cues are redundant predictors of the same outcome, less is learned about either than when it is the sole predictor of the outcome. In blocking (Kamin, 1969), training with a single cue reduces (blocks) learning about a second, redundant cue added later. Several studies have looked for blocking or overshadowing of geometric information by features (for a review, see Cheng Newcombe, 2005). Most studies have concluded that a predictive feature near a goal does not block learning about the shape of an enclosure (e.g., Hayward, Good, Pearce, 2004; Pearce et al., 2001; Wall et al., 2004). Moreover, in contrast with the expected competition between cues, geometry is sometimes learned better in the presence than in the absence of informative features. Pearce et al. (2001), for example, found that a beacon improved learning about the geometry of a triangular water tank. Other researchers have come across hints of this same phenomenon (e.g., Hayward et al., 2004; Hayward, McGregor, Good, Pearce, 2003). Using a geometrically unambiguous kite-shaped water tank, Graham, Good, McGregor, and Pearce (2006) demonstrated in rats substantial potentiation of geometry learning by a feature. Kelly and Spetch (2004a, 2004b) also found clear evidence of potentiation of geometry learning by a feature in an operant task in which people and pigeons were