Associative Symmetry, Antisymmetry, and a Theory of Pigeons' Equivalence‐class Formation

Abstract

Five experiments assessed associative symmetry in pigeons. In Experiments 1A, 1B and 2, pigeons learned two-alternative symbolic matching with identical sample- and comparison-response requirements and with matching stimuli appearing in all possible locations. Despite controlling for the nature of the functional stimuli and insuring all requisite discriminations, there was little or no evidence for symmetry. By contrast, Experiment 3 demonstrated symmetry in successive (go/no-go) matching, replicating the findings of Frank and Wasserman (2005). In view of these results, I propose that in successive matching, (1) the functional stimuli are stimulus-temporal location compounds, (2) continual nonreinforcement of some sample-comparison combinationsjuxtaposed with reinforcement of other combinations throughout training facilitates stimulus class formation, (3) classes consist of the elements of the reinforced combinations, and (4) common elements produce class merger. The theory predicts that particular sets of training relations should yield "antisymmetry": Pigeons should respond more to a reversal of the nonreinforced symbolic baseline relations than to a reversal of the reinforced relations. Experiment 4 confirmed this counterintuitive prediction. These results and other theoretical implications support the idea that equivalence relations are a natural consequence of reinforcement contingencies.

Assessing Symmetry by Comparing the Acquisition of Symmetric and Nonsymmetric Conditional Relations in a Capuchin Monkey

“…Symmetry has also been successfully demonstrated in pigeons using successive (Go/No-Go) matching procedures, in which identity matching was trained together with arbitrary relations (e.g., Frank, 2007;Frank & Wasserman, 2005;Urcuioli, 2008;Vasconcelos & Urcuioli, 2011). The present study also extends the findings of Picanço and Barros (2015), with symmetry-compatible performance in a capuchin monkey in a successive (Go/No-Go) procedure.…”

“…Recently, some studies that used a successive (Go/No-Go) matching procedure (e.g., Frank, 2007, Frank & Wasserman, 2005Urcuioli, 2008;Vasconcelos & Urcuioli, 2011) reported the property of symmetry in pigeons, supporting the argument that procedural issues may be responsible for several of the prior failures to document symmetry in nonhumans. Following Sidman's proposition (Sidman, 1994(Sidman, , 2000, Urcuioli argued that such difficulties in demonstrating equivalence class formation in nonhuman subjects may be attributable to inappropriate control by stimulus and reflexivity (e.g., Sweeney & Urcuioli, 2010;Urcuioli & Swisher, 2012).…”

“…9 (Special Issue) PP. 30 -39 locations during training and testing and thus may reflect more of a procedural issue than dependency on any direct multiple exemplar (or language) training (Urcuioli, 2008;Vasconcelos & Urcuioli, 2011). In addition to issues concerning adventitious control by stimulus locations, another procedural issue that may be partially responsible for negative results with nonhuman subjects is the presentation of probe trials without programmed reinforcement (Brino, Galvão, & Barros, 2009;Galvão, Calcagno, & Sidman, 1992;Schusterman & Kastak, 1993).…”

“…If any learning-set effect occurred, then acquisition should have been faster as successive training conditions were implemented. As mentioned above, some studies reported positive results of symmetry assessment by controlling the stimulus location during training and restricting the stimuli to only one possible location during testing using a successive Go/No-Go procedure (e.g., Frank, 2007;Frank & Wasserman, 2005;Urcuioli, 2008;Vasconcelos & Urcuioli, 2011). The present study implemented such stimulus-location control using multiple sample and comparison locations in a 3 x 3 matrix (as used by Brino et al, 2009;Barros et al, 2002;Barros, Galvão, & McIlvane, 2002;Galvão et al, 2005).…”

Emergent relations in pigeons following training with temporal samples

“…Nonhuman subjects, however, have yielded mostly negative results (e.g., Hogan & Zentall, 1977;Lionello-DeNolf & Urcuioli, 2002;Lipkens, Kop, & Matthijs, 1988;Tomonaga, Matsuzawa, Fujita, & Yamamoto, 1991;Yamamoto & Asano, 1995). Reflexivity (Sweeney & Urcuioli, 2010), symmetry (Frank & Wasserman, 2005;Garcia & Benjumea 2006;Urcuioli, 2008;Vasconcelos & Urcuioli, 2011;Velasco, Huziwara, Machado, & Tomanari, 2010;Yamamoto & Asano, 1995), and transitivity (D'Amato, Salmon, Loukas, & Tomie, 1985;Kuno, Kitadate, & Iwamoto, 1994) have been reported in separate experiments with nonhuman animals. However, only one study with a California sea lion has obtained positive results with combined tests (Schusterman & Kastak, 1993).…”