Emergent identity matching after successive matching training. II: Reflexivity or transitivity

Abstract

Three experiments evaluated whether the apparent reflexivity effect reported by Sweeney and Urcuioli (2010) for pigeons might, in fact, be transitivity. In Experiment 1, pigeons learned symmetrically reinforced hue-form (A-B) and form-hue (B-A) successive matching. Those also trained on form-form (B-B) matching responded more to hue comparisons that matched their preceding samples on subsequent hue-hue (A-A) probe trials. By contrast, most pigeons trained on just A-B and B-A matching did not show this effect; but some did--a finding consistent with transitivity. Experiment 2 showed that the latter pigeons also responded more to form comparisons that matched their preceding samples on form-form (B-B) probe trials. Experiment 3 tested the prediction that hue-hue matching versus hue-hue oddity, respectively, should emerge after symmetrically versus asymmetrically reinforced arbitrary matching relations if those relations are truly transitive. For the few pigeons showing an emergent effect, comparison response rates were higher when a probe-trial comparison matched its preceding sample independently of the baseline contingencies. These results indicate neither a reflexivity nor a transitivity effect but, rather, a possible identity bias.

Keywords: identity bias; key peck; pigeons; reflexivity; stimulus classes; stimulus equivalence; successive matching; symmetrical versus asymmetrical training; transitivity.

Fig 1

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced hue–hue probe trials (filled circles) averaged over the eight test sessions for each Group REFL pigeon in Experiment 1. Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.

Fig 2

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced hue–hue probe trials (filled circles) averaged over the eight test sessions for the 4 Group TRANS pigeons in Experiment 1 that did not exhibit emergent A–A matching. Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.

Fig 3

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced hue–hue probe trials (filled circles) averaged over the eight test sessions for the 3 Group TRANS pigeons in Experiment 1 that did exhibit emergent A–A matching. Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.

Fig 4

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the eight form–form (B–B) test sessions in Experiment 2 for the 4 Group TRANS pigeons that did not exhibit emergent A–A matching in Experiment 1. Positive  =  reinforced arbitrary baseline trials and test trials on which the form comparison matched the preceding form sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the form comparison did not match the preceding form sample. Note that ordinates differ across pigeons.

Fig 5

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the eight form–form (B–B) test sessions in Experiment 2 for the 3 Group TRANS pigeons that did exhibit emergent A–A matching in Experiment 1. Positive  =  reinforced arbitrary baseline trials and test trials on which the form comparison matched the preceding form sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the form comparison did not match the preceding form sample. Note that ordinates differ across pigeons.

Fig 6

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the eight hue–hue (A–A) test sessions in Experiment 2 for the 4 Group TRANS pigeons that did not exhibit emergent A–A matching in Experiment 1. Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.

Fig 7

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the eight hue–hue (A–A) test sessions in Experiment 2 for the 3 Group TRANS pigeons that did exhibit emergent A–A matching in Experiment 1. Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.

Fig 8

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the first eight hue identity (A–A) test sessions for each Group S pigeon in Experiment 3. Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.

Fig 9

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the first eight hue identity (A–A) test sessions for each Group A pigeon in Experiment 3 (first six sessions for pigeon A2). Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.

Fig 10

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the eight form identity (B–B) test sessions for each Group S pigeon in Experiment 3. Positive  =  reinforced arbitrary baseline trials and test trials on which the form comparison matched the preceding form sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the form comparison did not match the preceding form sample. Note that ordinates differ across pigeons.

Fig 11

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the eight form identity (B–B) test sessions for each Group A pigeon in Experiment 3. Positive  =  reinforced arbitrary baseline trials and test trials on which the form comparison matched the preceding form sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the form comparison did not match the preceding form sample. Note that ordinates differ across pigeons.

Fig 12

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the second eight hue identity (A–A) test sessions for each Group S pigeon in Experiment 3. Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.

Fig 13

Comparison pecks/sec (± 1 SEM) on the baseline arbitrary matching trials (open circles) and nonreinforced probe trials (filled circles) averaged over the second eight hue identity (A–A) test sessions for each Group A pigeon in Experiment 3. Positive  =  reinforced arbitrary baseline trials and test trials on which the hue comparison matched the preceding hue sample. Negative  =  nonreinforced arbitrary baseline trials and test trials on which the hue comparison did not match the preceding hue sample. Note that ordinates differ across pigeons.