Transposition in pigeons: reassessing spence (1937) with multiple discrimination training

Abstract

We studied transposition in pigeons, using multiple-pair discrimination training. Four birds discriminated two pairs of circles: 1+ 2- and 5+ 6- or 1 - 2 + and 5- 6 + (digits denote circle diameters and plus and minus signs denote reward and nonreward, respectively). Four other birds discriminated four pairs of circles: 1+ 2-, 1+ 3-, 4+ 6-, and 5+ 6- or 1- 2 +, 1- 3 +, 4- 6+, and 5- 6+. Finally, 4 birds discriminated only one pair of circles: 1+ 2-, 1- 2+, 5+ 6-, or 5- 6+. Testing included five new pairs--1/5, 2/3,2/6,3/4, and 4/5--that distinguished absolute from relational accounts of transposition. The pigeons' relational responding rose from one- to two- to four-pair training. The similarity of the testing stimuli to one another also affected relational responding: Transposition increased with highly dissimilar stimuli. Neither Spence's (1937) theory nor existing relational accounts could predict the obtained pattern of relational responding.

Multiple-pair training enhances transposition in pigeons

“…Testing included two stimulus pairs for which, according to theoretical postdiscrimination generalization gradients, transposition should decrease from one-pair to two-pair to three-pair training. On the basis of the results of our earlier study (Lazareva, Wasserman, & Young, 2005) and contrary to these predictions, we expected that transposition should increase from one-pair to two-pair to three-pair training. We found that multiple-pair discrimination training enhanced transposition, which, on average, rose from 47% (one-pair training) to 52% (two-pair training) to 64% (three-pair training).…”

“…Beyond these results, Lazareva et al (2005) found in subsequent experiments that pigeons' transposition responses rose from one-to two-to four-pair discrimination training along the size dimension, thus replicating and extending the findings of Johnson and Zara (1960). Can an increase in transposition after an increase in the number of training pairs be predicted from excitatory and inhibitory stimulus generalization gradients?…”

“…Can an increase in transposition after an increase in the number of training pairs be predicted from excitatory and inhibitory stimulus generalization gradients? Figure 1 (top panel) illustrates the obtained and predicted results from Lazareva et al (2005). The pigeons' mean level of transposition responses increased from 64% after onepair training to 75% after two-pair training to 84% after fourpair training.…”

“…For example, when the training stimuli are widely spaced along the sensory dimension (in other words, when the training stimuli are highly dissimilar), a summation of excitatory and inhibitory gradients does not produce a peak shift, a result that has been Multiple-pair training enhances transposition in pigeons (Mackintosh, 1974;Riley, 1968;Rilling, 1977), perhaps because neither study formally explored the predictions of Spence's (1937) theory. In our own recent study (Lazareva et al, 2005), we further explored the effects of multiple-pair training on transposition behavior by exposing pigeons to multiple training pairs separated by untrained testing stimuli. In one such test, we concurrently trained pigeons on two discriminations: S1 versus S2 and S5 versus S6 , where the different numerals represent the diameters of different circles (Experiment 1).…”

Concept Learning in Animals

“…For this reason, any test involving stimuli that are not too far removed from the S+ or the S-may produce what can be interpreted as relational responding, so-called transposition. This associative account is problematic for the development of a relational class, because the generalization of absolute values may pro-vide a more parsimonious interpretation of such responding than a relational interpretation (see Lazareva, Wasserman, & Young, 2005 for a critical discussion of these issues and new data which challenge Spence's classical account).…”