Urcuioli, P.J. & Vasconcelos, M. (2008).
On the origins of emergent differential sample behavior.
Journal of the Experimental Analysis of Behavior, 90, 61-80.
Two experiments evaluated the source(s) of emergent differential
sample behavior in pigeons. Initially, pigeons learned two-sample,
two-alternative symbolic matching in which different patterns of sample
responding were required to produce the comparisons. Afterwards, two
other samples nominally identical to the comparisons were added to the
matching task. On new-sample trials, completion of either sampleĞresponse
requirement produced comparison alternatives which were either the same
as or different from the alternatives on the familiar-sample trials.
Differential responding to the new samples developed only when the comparisons
were the same as the familiar samples. The results are consistent with
acquired sample equivalence and adventitious reinforcement accounts of
emergent sample behavior and are inconsistent with bidirectional transfer
(symmetry) between the response patterns explicitly required to
the originally trained (familiar) samples and the subsequently
reinforced comparisons.
Key words: emergent sample behavior, differential sample responding,
bidirectional transfer, symmetry, acquired equivalence, adventitious
reinforcement, pigeons, pecking