Procedure
The Institutional Review Board at [details omitted for
double-anonymized peer review] approved all study procedures and all
parents provided written consent for their children to participate.
Table 1 provides demographic and measure characteristics, respectively.
Prior to study visits, families were provided with a social story and
habituation protocol to familiarize children with the physiological
recording equipment. Caregivers and their children completed two visits
to the lab separated by 4-6 weeks. During both visits children completed
the MacArthur Reactivity protocol (MRP; Bush et al. 2011). If children
were comfortable, ECG was recorded during the MRP. Parents completed the
Behavior Assessment System for Children (BASC) Parent Rating Scale –
Preschool or Child (PRS-P or PRS-C, respectively).