2025 Theses Doctoral

From Screen to Reality: Turning Faces into Reinforcers

Yeo, Yoojin

Attending to a person’s face is a significant developmental milestone for young children’s social and communication development. Across two experiments, the researcher evaluated whether a screen-based intervention could establish faces as reinforcers across different settings and contexts.

In Experiment 1, the researcher developed and conceptually validated a virtual face conditioning program by answering whether conditioned reinforcement to adult faces can be established through reinforcing attention to virtual faces and, if so, whether the stimulus control transfers to in-person faces and other real-life situations. The dependent variables of Experiment 1 were attention to virtual faces (faces presented on a screen), attention to live faces, and generalized observing probes for faces and voices in naturalistic settings. A seven-phased screen-based intervention, which gradually faded from the filters with three changes to the face down to no filter, was used as an intervention for six young children with disabilities. During the intervention, participants’ observing responses for virtual faces were synchronously reinforced using a reinforcement package that included preferred snacks, praise, and tactile reinforcement. The results showed that following the intervention, although the degree of increase varied, all participants showed an increase in all three dependent variables.

In Experiment 2, the researcher further investigated the effectiveness of the virtual face conditioning intervention by systematically replicating Experiment 1 with another six young children with disabilities. The researcher aimed to demonstrate further implications of conditioned reinforcement for faces in early social behaviors and daily instructions.

More specifically, Experiment 2 incorporated two additional dependent variables, the Early Social Communication Scales (ESCS; Mundy et al., 2013) - a tool designed to assess joint attention, behavioral requests, and social interaction behaviors in young children - and learning rate. The results replicated the effectiveness of virtual face conditioning intervention by showing similar increases for the same three dependent variables from Experiment 1. The results showed the greatest increase in initiating social interaction and initiating behavior request skills compared to the other domains. However, limited gains were observed in joint attention, suggesting that conditioned reinforcement for faces may be necessary for establishing joint attention, but it is not sufficient. Additionally, the participants showed an increased learning rate in the five-week period following the intervention. This suggests that virtual face conditioning was effective in establishing a crucial preverbal foundational cusp that influences the participants’ daily learning.