Acquisition of matching to sample via mediated transfer.

Two severely retarded Down's-syndrome boys learned a matching-to-sample performance through mediated transfer. The transfer paradigm involved three sets of stimuli, one auditory set (A) and two visual sets (B and C). The subjects were taught directly to do B-A and C-B matching, but experienced no direct association between C and A. They acquired the ability to do C-A matching without having been taught that performance directly. They also learned indirectly to name some of the visual stimuli, but naming was apparently not the mediator in the emergent C-A matching. The use of words and letters as stimuli highlighted the possible relevance of mediated associations in the indirect acquisition of elementary reading comprehension and oral reading. The acquisition of matching via mediated transfer also raised some new considerations concerning the role of coding responses in arbitrary matching to sample.