The effects of intensive tact instruction on three verbal operants in non-instructional settings for two children with autism.

Abstract

Introduction It is estimated that only one half of children with autism and related disorders will acquire any speech as a mode of communication (Lord & Paul, 1997). Thus, a frequent need among children with autism is assistance in acquiring and developing effective communication skills (Scheips, Reid, Behrmenn, & Sutton, 1998). Typically, a child with autism in the presence of a nonverbal cue will rarely emit a spontaneous initiation. The child will remain silent and speak only when verbally prompted by another person providing a question or a command (Ingenmey & Van Houten, 1991). However, much of daily communication is not verbally prompted. Thus, it is important to teach children to tact (label) objects or events under non-verbal antecedent control (Greer, & Ross, 2008; Matson, Sevin, Box, Francis, & Sevin, 1993; Williams, Carnerero, & Perez-Gonzalez, 2006) to support the emergence of unprompted speech and spontaneous initiation. Research conducted by Hart & Risley (1995) found that deficits in the development of a speaker repertoire may be the product of nature or environmental factors. Their research found that children from low socioeconomic families frequently displayed deficits in verbal repertoires on entering school. The authors noted that there were significantly fewer verbal interactions emitted among children and parents in families with low levels of socioeconomic status as compared to professional families with high levels of socioeconomic status, and that verbal interactions in families that were defined as working class fell somewhere in the middle. Additionally, professional families had far more positive verbal interactions than families in either of the two other categories. The results of the study suggest that young children who have significantly fewer verbal interactions with their parents are more likely to have language delays and vocabu laries that increase at a much slower rate than children who have high numbers of positive verbal interactions with their parents. We propose that children with native language disabilities have infrequent language experiences as well, and as a result lack certain verbal developmental capabilities that are foundational to the development of language (Keohane, Pereira-Delgado & Greer, in press). Intensive language experiences are necessary to remediate such deficits whatever the underlying cause (Greer, & Keohane, 2005; Greer, & Ross, 2008; Pistoljevic & Greer, 2006). Communication training using intensive behavioral interventions has been a key focus of instruction for children with autism who present with deficits in their listener and speaker repertoires. Communication training involves teaching the vocal operants--mands and tacts, with a view to increasing spontaneous speech emitted by the child (Pereira-Delgado, & Oblak, 2007; Pistoljevic & Greer, 2006; Schauffler & Greer, 2006). A tact is evoked by a nonverbal discriminative stimulus such as an object or event, or the relation between objects or events, and is maintained by generalised or social reinforcers (Skinner, 1957). In contrast, a mand specifies its reinforcer, is evoked by an establishing operation (EO), such as deprivation or aversive stimulation, and is maintained by specific consequences relevant to that EO (Michael, 1988). According to Skinner (1957), each verbal operant is acquired independently and serves a different function. Establishing one operant will not automatically result in the appearance of another. For example, when an utterance is established as a tact it does not automatically follow that the utterance emergences as a mand. Skinner's theoretical analysis is supported by numerous research studies on the topic (Hall & Sundberg, 1987; Lamarre & Holland, 1985; Nuzzolo-Gomez & Greer, 2004; Sundberg, San Juan, Dawdy, & Arguelles, 1990; Twyman, 1995). Skinner characterised spontaneous verbal initiations as pure mands and pure tacts (i. …