The effects of stimulus pairings on autistic children's vocalizations: Comparing forward and backward pairings.

In a procedure known as stimulus-stimulus pairing (Yoon and Bennett, 2000), the experimenter pairs a target sound (e.g., "bah") with a child's preferred item (e.g., a toy). Even though the stimulus pairings proceed independently of the child's behavior, this procedure has proved capable of increasing imitation of the target sound in developmentally delayed children (Shillingsburg et al., 2015). The underlying behavioral processes remain poorly known, however, and few systematic variations of the basic procedure have been published. In the present experiment, with autistic children as participants, (a) we compared the effects of forward versus backward pairings on the imitation of target sounds, and (b) we evaluated formally the relation between the children's preexisting verbal repertoires and the efficacy of the pairing procedure. As is often reported in the Pavlovian literature, backward pairings promoted lower levels of conditional responding than forward pairings. Also, we found a negative relation between a child's verbal level and pairing efficacy: children with the lower scores on the Behavioral Language Assessment Form (Sundberg and Partington, 1998) exhibited more conditioning. These findings confirm in a single study what has been so far only suspected informally.