Psychometric Features of the Pictorial Infant Communication Scales (PICS) in Preschool-Aged Children with ASD

Background: Joint attention, commonly referred to as the ability to coordinate social attention, is a crucial milestone in the development of communication (Bakeman & Adamson, 1984; Mundy et al., 2007). It is also a significant area of skill deficit in children with ASD (Diagnostic & Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV-TR) 2000; Kasari, Freeman, & Paparella, 2006). While reliable and valid parent-report measures of communication abilities are available (e.g., MacArthur-Bates Communicative Development Inventory; Fenson et al., 2002), assessment of joint attention has largely been limited to semi-structured, examiner-led interactions (e.g., Early Social Communication Scales; Mundy et al., 2003), which are time consuming and laborious to score. The Pictorial Infant Communication Scales (PICS; Delgado, Mundy, Venezia, & Block, 2003) was designed to address the need for an efficient parent-report measure of joint attention.

Objectives: To investigate the validity and underlying structure of the PICS for parent report of joint attention behavior in preschool-aged children with ASD.

Methods: The sample consisted of 197 preschool-aged children with ASD who were part of a completed multi-site study comparing comprehensive preschool programs for children with ASD. Children were between the ages of 3 and 5 years during enrollment, and were followed throughout the school year. Parents completed the PICS at the PRE-assessment time point. 

The PICS is a brief, 16-item parent report questionnaire in which parents are asked to rate how frequently their child has displayed joint attention behaviors during the past two-week period using a 4-point Likert scale (i.e., ‘not sure’, ‘never’, ‘sometimes’ and ‘frequently’). Each item is accompanied by pictures depicting the behaviors that parents are asked to rate. The PICS yields subscale scores for Initiates Joint Attention (IJA), Initiates Behavior Requests (IBR), and Responds to Joint Attention (RJA), as well as a Total Score. Correlations between the subscale scores were calculated, and internal consistency was examined for the total and subscale scores. The structure of the PICS was examined using confirmatory factor analyses (CFA).

Results: Construct validity was supported by intercorrelations among subscale scores. Specifically, the IBR and IJA scales were correlated at r = 0.93, while RJA and IJA were correlated at r = 0.78 and RJA and IBR were correlated at r = 0.60. The total score and subscales of the PICS were found to have a high degree of internal consistency (alpha coefficients ranging from 0.72 to 0.89). Results from the CFA provided support for the established three-factor model, broadly representing IJA, IBR, and RJA, χ²(101) = 230.06, p < .0001, CFI = 0.96, RMSEA = 0.082 (95% CI [0.07, 0.10], WRMR = 0.99. This model was preferred over a two-factor solution where IJA and IBR were collapsed, χ²(2) = 22.91, p < .0001.

Conclusions: Overall, the psychometric properties of the PICS appear promising, suggesting that it is a valid tool for measuring joint attention skills in preschool-aged children with ASD. Future research examining the concurrent and predictive relationships between the PICS and direct observation measures of joint attention and language would be beneficial.