Discriminative control by gaze-shift cues in children with autism increased was established with exposure to the Delayed Cue training procedure with remote controlled toys. During Delayed Cue training, the experimenter’s gaze shift was a perfect predictor of subsequent toy activation. The increase in unprompted correct responding across Delayed Cue training sessions indicates a transfer of stimulus control from the toy activation cue to the experimenter’s gaze-shift cue as the time delay between the gaze shift and toy activation increased. Training progressed fairly rapidly with Paul and Mark (DQ 58 and 57, respectively), but Jim, the more developmentally limited participant (DQ 29), did not meet the initial accuracy criterion until his second exposure to the Delayed Cue procedure.
The present study included no direct comparison of the Delayed Cue training method with any other methods, but we note that it appears to compare favorably in one respect with the more conventional prompting strategy of Whalen and Schreibman (2003)
. Training was successful with all participants in both studies. Training in Whalen and Schreibman required a total of 270 to 390 trials, and this is comparable to the 252 training trials for participant Jim to meet the initial learning criterion for the Contingent Activation condition in the present study (28 sessions, 9 trials per session). Two participants in the present study, however, required substantially fewer training trials to meet this initial learning criterion, 63 for Mark and 90 for Paul. Although numerous differences between the two studies allow only speculation, these results at least raise the question of whether training with the within-stimulus prompt of toy activation in the present study might be more efficient than training with extra-stimulus prompts as in Whalen and Schreibman (e.g., pointing to target objects; Schreibman, Charlop, & Koegel, 1982
; reviewed in Lancioni, & Smeets, 1986
). Investigation of this possibility will require a formal comparison of training methods.
Another positive feature of the results was the maintenance of correct responding at fairly high levels during the Intermittent Activation condition. It seems reasonable to assume that gaze-following in non-programmed environments may produce reinforcers on an intermittent basis (i.e., adults may not always be looking at something interesting to the child). The results from Intermittent Activation conditions indicate that the trained behavior persisted under conditions that may approximate the reinforcement contingencies of uncontrolled environments.
Limitations of the present study include a relatively restricted setting and time course. Further study will be needed to determine the extent to which gaze-following trained with toy-activation consequences (a) will generalize to novel settings and adults, non-toy target items, and visually complex non-laboratory settings; and (b) will persist with intermittent social reinforcement over longer periods of time.
One possible reaction to this approach concerns the contrived reinforcement contingencies for the child’s behavior in the Contingent Activation condition. That is, were we teaching the child that he or she could activate a toy just by looking at it? In response to this concern, we note that toy activation occurred only if the child followed the adult’s gaze-shift cue. Thus, it seems more accurate to say we were teaching the child that sometimes adults can predict the occurrence of interesting events, and this seems true in many situations for young children.
Finally, we point out that the child’s gaze-following behavior in training sessions need not constitute joint attention responding. On the one hand, gaze-following was always followed by an upbeat verbal comment from the adult about the toy; to the extent that the function of the behavior was to produce this shared social interaction regarding the toy, the behavior could be classified as joint attention responding. On the other hand, on training trials and some of the trials in most Intermittent Activation sessions, gaze-following was also followed by toy activation; to the extent that function of the behavior was limited to producing this non-social sensory reinforcement, then the behavior would not be appropriately classified as joint attention responding. Although this distinction is theoretically interesting and important, the function of the child’s behavior seems independent of the procedure’s value for measuring the child’s ability to detect target locations on the basis of the adult’s gaze-shift cues. We have argued that the ability to make such discriminations is a likely prerequisite for gaze shifts in joint attention initiation and coordination (Dube et al., 2004
). The present results demonstrate the feasibility of the Delayed Cue toy-activation method as a means to accomplish relevant discrimination training.