Erjavec, M., Lovett, V.E. & Horne, P.J. (2009).
Do infants show generalized imitation of gestures? II.
The effects of skills training and multiple exemplar matching training.
Journal of the Experimental Analysis of Behavior, 91, 355-376.
The determinants of generalized imitation of manual gestures were
investigated in 1- to 2-year-old infants. Eleven infants were
first trained eight baseline matching relations; then,
four novel gestures that the infants did not match in probe
trials were selected as target behaviors. Next, in a
generalized imitation test in which matching responses
to baseline models were intermittently reinforced, but
matching responses to target models were not eligible
for reinforcement, the infants matched baseline models
but not the majority of their target behaviors. To ensure
their failure to match the target behaviors was not due
to motor constraints, the infants were trained, in a
multiple-baseline procedure, to produce the target responses
under stimulus control that did not include an antecedent model
of the target behavior. There was no evidence of generalized
imitation in subsequent tests. When the infants were next
trained to match each target behavior to criterion (tested
in extinction) in a multiple-baseline-across-behaviors
procedure, only 2 infants continued to match all their targets
in subsequent tests; the remaining infants matched
only some of them. Seven infants were next given mixed
matching training with the target behaviors to criterion
(tested in extinction); they subsequently
matched these targets without reinforcement when
interspersed with trials on which matching responses
to baseline models were intermittently reinforced.
In repeat tests, administered at 3-week intervals,
these 7 children (and 2 that did not take part in
mixed matching training) continued to match most
of their target behaviors. The results support a
trained matching account, but provide no evidence of
generalized imitation, in 1- to 2-year-old infants.
Key words: imitation, generalized imitation, infants, trained matching,
multiple exemplars, manual gestures