International Journal of Behavior Analysis & Autism Spectrum Disorders
2015, 1
Number 1
Preliminary Evaluation of an Echoic Response Requirement Following Errors during Auditory-Visual Conditional Discrimination Training
Charlotte L. Carp, Sean P. Peterson, and Anna Ingeborg Petursdottir Texas Christian University
Einar T. Ingvarsson University of North Texas and Child Study Center, Fort Worth
Two experiments were conducted to provide a preliminary evaluation of requiring an echoic response following errors during auditory-visual conditional discrimination training. Two children diagnosed with autism spectrum disorder participated in Experiment 1, and four typically developing 4- to 6-year-old children participated in Experiment 2. The echoic response requirement was combined with a model prompt and compared to a condition that included a model prompt without an echoic requirement, as well as a differential reinforcement condition (Experiment 1) and a picture prompt condition (Experiment 2). Acquisition was fastest in the echoic + model prompt condition for one of two participants in Experiment 1 and three of four participants in Experiment 2. Although these data may provide preliminary support for the procedure, additional research is needed to establish the reliability of these findings and identify the behavioral mechanisms involved. Key words: autism; conditional discriminations; echoic; error correction; receptive language
Auditory-visual matching-to-sample (MTS) training procedures are commonly used in early intensive behavioral intervention (EIBI) curricula for children diagnosed with autism spectrum disorder (ASD). For example, the procedures are used extensively in early vocabulary-building and as components of instruction in more complex verbal, pre-academic, and academic skills (Leaf & McEachin, 1999; Lovaas, 2003; Sundberg & Partington, 1998; Taylor & McDonough, 1996). An auditory-visual MTS training trial includes presentation of an auditory sample stimulus (e.g., a spoken word) and an array of visual comparison stimuli. The array includes one positive comparison (e.g., a picture of a ball), the selection of which produces a reinforcing consequence in the presence of the sample (e.g., the spoken word “ball”), and one or more negative comparisons (e.g., pictures of a cup and a block), responses to which are not reinforced. The stimuli that serve as negative comparisons in a trial that
includes a particular sample ideally serve as positive comparisons in other trials that include other samples (e.g., “cup” and “block”; Green, 2001). The goal of training is to establish conditional discriminations, in which the control that each visual comparison exerts over the selection response is dependent upon the presence of a particular auditory sample (Catania, 2007). Much is known about the conditions under which MTS training successfully produces conditional discriminations, including the selection of stimuli and reinforcing consequences, the structure of training, and appropriate prompting and prompt-fading procedures (for reviews, see Green, 2001; Grow & LeBlanc, 2013). However, additional research may be warranted on procedural modifications that have been proposed to enhance conditional stimulus control. Grow and LeBlanc (2013) suggested that for learners with histories of faulty stimulus control, instructors might consider requiring a differential observing response on each trial. In MTS, a differential observing response is a response to the sample stimulus that is extraneous to the target conditional discrimination and differs depending on which sample stimulus is presented (Dube & McIlvane, 1999). For example, in visualvisual MTS, a differential observing response may
Anna Ingeborg Petursdottir, Department of Psychology, Texas Christian University; Charlotte L. Carp, Department of Psychology, Texas Christian University Charlotte L. Carp is now at McNeese State University and Sean P. Peterson is now at the University of Nebraska Medical Center. Address correspondence to Anna Ingeborg Petursdottir, Department of Psychology, TCU Box 298920, Fort Worth, Texas 76129. Email:
[email protected]
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ECHOIC RESPONSE REQUIREMENT
consist of naming the visual sample stimulus (Constantine & Sidman, 1975; Geren, Stromer, & Mackay, 1997) or matching the visual sample to an identical comparison before having an opportunity to match it to a target, nonidentical comparison (Dube & McIlvane, 1999). In auditory-visual MTS, as Grow and LeBlanc (2013) pointed out, a potential differential observing response consists of an echoic response to the auditory sample. A few studies have assessed the effects of an echoic response to the sample on the acquisition of auditory-visual conditional discriminations. Two studies (Charlop, 1983; Leung & Wu, 1997) have reported positive results with participants who were diagnosed with ASD. By contrast, Petursdottir, Lepper, and Peterson (2014; Experiment 2) found no facilitative effect on typically developing children’s acquisition of auditory-visual discriminations involving foreignlanguage nouns and corresponding pictures. Charlop’s (1983) study included two experiments. Five children who exhibited echolalia participated in the first experiment. Baseline consisted of auditory-visual MTS trials involving auditory stimuli and corresponding objects. Correct object selections were reinforced, whereas incorrect selections resulted in the experimenter saying “no” and removing the stimuli. Each participant was then exposed to two conditions that included an echoic response requirement on each trial. In the echo relevant word condition, the participant was required to echo the auditory sample prior to selecting a comparison; in the echo irrelevant word condition, the participant was required to echo a different word prior to being presented with the auditory sample (the irrelevant words were not correlated with the auditory samples and thus cannot be conceptualized as DORs). Two participants also were exposed to a condition in which the experimenter presented the auditory sample twice without asking for an echoic response, which controlled for increased exposure to the auditory sample in the relevant word condition. All participants’ accuracy increased relative to baseline in the relevant word condition, but not in the irrelevant word condition or in the control condition. Experiment 2, conducted with six other children, suggested that children who exhibited
echolalia not only displayed faster acquisition when an echoic response requirement was included in MTS trials, but also enhanced generalization to novel experimenters and settings, relative to a condition that included prompting and promptfading procedures but no echoic response requirement. These effects, however, did not extend to children who did not exhibit echolalia. Leung and Wu (1997) replicated the findings from Charlop’s (1983) Experiment 1 in the context of teaching receptive naming of Chinese characters. As in Charlop (1983), their participants consistently responded with higher accuracy when required to echo the auditory sample than when an echoic response was not required. A limitation of both studies (Charlop, 1983; Leung & Wu, 1997) was that the increase in accuracy observed when participants echoed the auditory sample in each trial did not maintain when the echoic response requirement was withdrawn. Even though the participants responded with high accuracy when they echoed the sample in each trial, performance deteriorated immediately in a reversal to baseline phase that was included in one experiment of each study. This aspect of the data raises questions about the practicality of the effect, as speakers in the natural environment typically do not require echoic responses of their listeners. Thus, additional research is needed to determine if the echoic response requirement can be faded successfully while maintaining accurate MTS responding. In this paper, we report two pilot experiments that were conducted to explore the effects of requiring an echoic response to the sample only as an error correction event (Rodgers & Iwata, 1991) following incorrect responses in auditory-visual MTS trials. This strategy was chosen because it would automatically result in the gradual elimination of the echoic response requirement as accuracy in the MTS task increased. The experiments were run concurrently but independently, so their designation as Experiment 1 and Experiment 2 here is arbitrary. Experiment 1 was conducted with children diagnosed with autism who had histories of slow acquisition in auditory-visual conditional 2
Carp, Peterson, Petursdottir & Ingvarsson discrimination training, and Experiment 2 was conducted with typically developing children.
Stimuli. Visual stimuli consisted of laminated 8.2 cm x 6.4 cm cards that contained photographs of objects (see Table 1). Vocal sample stimuli consisted of the conventional names of the objects spoken by the experimenter. Small bites of preferred food items were presented contingent on correct, unprompted responses. Prior to each session, seven food items (selected based on consultation with the intervention center) were arranged horizontally on the table in front of the participant, who was instructed to select an item. The first item the participant placed in his or her mouth was used in the subsequent session.
EXPERIMENT 1 Experiment 1 evaluated the effects of requiring an echoic response to the auditory sample following each incorrect response, immediately prior to providing a modeling prompt to select the positive comparison. This condition was compared to two control conditions in which (a) an incorrect response resulted in a modeling prompt without an echoic response requirement, and (b) an incorrect response resulted in no consequence other than the presentation of the next trial. Method Participants and setting. Participants were two children diagnosed with autism who attended a center-based program that provided behavioranalytic treatment. Sherri was a 5-year-old girl of Asian descent who had been attending the program four days per week for five months. Her receptive skills consisted of following one-step instructions and a few auditory-visual conditional discriminations that involved identifying common items in pictures. Her expressive skills consisted of vocal imitation and vocal mands. Three months prior to the study, Sherri’s IQ was measured at 47 using the Wechsler Preschool and Primary Scale of Intelligence – Second Edition (WPPSI-II), and at the same time her age equivalent score on the Peabody Picture Vocabulary Test – Fourth Edition (PPTV-4) was
