Association for Behavior Analysis International

Shape descriptors are mathematical functions applied to a polygonal profile that produce numerical values representing different characteristics of the profile. Commonly used in image processing applications, shape descriptors are useful discriminative stimuli for certain machine learning algorithms. Here we demonstrate the use of a verbal operant experimental (VOX) analysis for developing polygonal language profiles for children with autism spectrum disorder. The frequency of responses under verbal and nonverbal sources of control are plotted on a multi-axial radar chart to produce a closed polygonal profile for each participant. These language profiles are then subject to a variety of shape descriptors for quantitative comparisons over time, and in relation to the language profiles of neurotypical peers. We describe the characteristics of each shape descriptor, and explain their use in interpreting the results of the VOX analysis. Finally, we discuss the use of shape descriptors for both practitioners and researchers who seek to better understand language development, assessment, and intervention for individuals with autism and other disorders of verbal behavior.

Audio–visual conditional discriminations (AVCD) often come naturally for typically developing children through everyday interactions. However, children with autism may struggle to acquire AVCDs unless they are directly taught. These children often benefit from empirically validated treatments explicitly designed to facilitate the acquisition of this critical skill. Even with high-quality instruction, a subsection of children with autism continue to struggle. The purpose of the current study is to assess the previously cited prerequisite skills (Kodak et al. 2015, 2022; Saunders & Spradlin 1989; Fisher et al. 2019) to determine if they are correlated with the acquisition of AVCD targets, including scanning a picture array (visual discrimination), matching pictures (conditional discrimination; identity matching), responding differentially to different words (auditory discrimination), and touching a portion of the screen that reliably leads to preferred items (reinforcement tracking). We extended the existing AVCD literature by assessing the utility, efficiency, and validity of a technology-assisted battery named READI (Rapid Empirical Assessment of Discrimination Indices). Results showed that the assessment battery correlated with children’s ability to learn AVCDs efficiently. Children who demonstrated all prerequisite skills acquired new AVCD targets quickly, whereas children who failed one or more prerequisite assessments also failed to acquire new targets.

Stimulus overselectivity remains an ill-defined concept within behavior analysis, because it can be difficult to distinguish truly restrictive stimulus control from random variation. Quantitative models of bias are useful, though perhaps limited in application. Over the last 50 years, research on stimulus overselectivity has developed a pattern of assessment and intervention repeatedly marred by methodological flaws. A molecular view of overselectivity, under which restricted stimulus control has heretofore been examined, is fundamentally insufficient for analyzing this phenomenon. Instead, we propose the use of the term “overselectivity” to define temporally extended patterns of restrictive stimulus control that have resulted in disproportionate populations of responding that cannot be attributed to chance alone, and highlight examples of overselectivity within the verbal behavior of children with autism spectrum disorder. Viewed as such, stimulus overselectivity lends itself to direct observation and measurement through the statistical analysis of single-subject data. In particular, we demonstrate the use of the Cochran Q test as a means of precisely quantifying stimulus overselectivity.

Despite advances in evidence-based treatment for autism, disparities in service access, difficulties with customized training support, time constraints, and family stressors remain primary concerns for many caregivers across the globe. Current treatment models may not be accessible, individually tailored, or feasible for families experiencing such hardships or having limited resources. Caregiver-implemented intervention, often facilitated via coaching, is an increasingly widespread solution to early intervention for children with or at risk for autism (Tomeny et al., 2019). This study investigates the effects of a parent-mediated Natural Environment Training (NET) package, based explicitly on a functional analysis of learners' language (i.e., Parent-Mediated Referent-Based Instruction (PM-RBI); Mason & Andrews, 2014; 2020) on parents' fidelity in implementing these procedures. A single-subject, concurrent, multiple-baseline, across-participants design was used across three caregiver-child dyads participating in PM-RBI over 13 weeks via videoconferencing.We describe components of PM-RBI, capitalizing on NET and caregiver coaching principles, and highlight the potential PM-RBI provides to support customized, family-focused, empirically based intervention for caregivers. Potential barriers, benefits, and implications for practice and research will be discussed