Urcuioli, P. J., Pierce, J. N., Lionello-DeNolf, K. M., Friedrich, A., Fetterman, J. G., & Green, C. (2002).
The development of emergent differential sample behavior in pigeons.
Journal of the Experimental Analysis of Behavior,
78, 409-432.
Three experiments attempted to replicate Manabe, Kawashima, and
Staddon's (1995) finding of emergent differential sample behavior
in budgerigars that has been interpreted as evidence of
functional equivalence class formation. In Experiments 1 and 2,
pigeons initially learned two-sample/two-alternative matching to
sample in which comparison presentation was contingent on pecking
one sample on a differential-reinforcement-of-low-rate (DRL)
schedule and the other on a fixed-ratio (FR) schedule. Later, two
new samples were added to the task. Comparison presentation on
these trials occurred after the first sample peck following a
predetermined interval (Experiment 1) or after completion of
either the DRL or FR requirement, whichever occurred first
(Experiment 2). Experiment 1 found no evidence for emergent
spaced versus rapid responding to the new samples as they
established conditional control over the familiar choices. By
contrast, differential responding did emerge for some pigeons in
Experiment 2, with responding to each new sample coinciding with
the pattern explicitly conditioned to the original sample
occasioning the same comparison choice. This emergent effect,
however, disappeared for most pigeons with continued training.
Experiment 3 systematically replicated Experiment 2 using
differential peck location as the sample behavior. Differential
location pecking emerged to the new samples for most pigeons and
remained intact throughout training. Our findings demonstrate a
viable pigeon analogue to the budgerigar emergent calling
paradigm and are discussed in terms of equivalence- and
non-equivalence-based processes.
Key words: emergent behavior, differential sample responding,
acquired equivalence, adventitious reinforcement, key peck,
pigeons