Conceptual Differences between Speech Therapy and Verbal Behavior Therapy

Written by Blair Jacobsen, M.A., BCBA

Children diagnosed with Autism Spectrum Disorder are often eligible for several types of therapy. Here at BCOTB we utilize Verbal Behavior therapy techniques to teach children to communicate and excel in their environment. Verbal Behavior therapy and speech therapy are sometimes confused because they both focus on teaching effective communication. While there are several conceptual differences between the two disciplines, this blog will focus on what we consider to be the most important difference: the behavior analysis functional view of Verbal Behavior.

Speech therapy often focuses on increasing expressive and receptive language skills, with a focus on increasing the mean length of utterance (MLU). The mean length of utterance refers to the average number of morphemes (words or parts of words) that a child uses to communicate. The mean length of utterance is regarded as a reliable index of language development. In a study in 1973, Brown described different stages of language development by breaking these stages down by typical age and typical mean length of utterance.

Skinner’s (1957) account of Verbal Behavior examines both the motivation behind the words we use as well as the contexts in which we use them. This view is radically different than Brown’s (1975) because it does not focus on a structural view of language (i.e., how many words one uses) but rather on a functional view of language (why we use the words we do). Skinner divided language into a taxonomy of operants that we teach at BCOTB.

·  Echoic-repeating a spoken word

·  Mand-requesting

·  Tact-labeling

·  Intraverbal-having a conversation

The echoic, mand, tact, and intraverbal are regarded as primary or elementary verbal operants because a child needs to have a strong repertoire in each of these operants before secondary verbal operants develop. Secondary verbal operants are called autoclitics. Autoclitics refer to words that we use to help convey meaning (think verb tenses, plurals, articles, prepositions, and other grammatical devices). If we were to track the mean length of utterance, autoclitics would contribute greatly to the overall average. However, autoclitics are secondary operants and should only be taught when the primary operants are already strong.

Carbone (2012) recommends waiting to teach autoclitics (e.g., “I want,” “I need,” etc.) until a child uses 300-400 untaught words. Carbone also recommends teaching two word phrases as a prerequisite to more complex sentences. This recommendation is partly based on Brown’s (1973) study, which suggests that children do not begin to use two word phrases to communicate until they have acquired 50-60 words. Furthermore, Brown outlines that it is not until a child is around the age of five that he or she uses a mean length of utterance of around 4 morphemes. Since this learning process develops over several years, attempts to produce a high mean length of utterance when a child only uses a few words to request things often prove artificial, with the child not learning the meaning of the words he or she is using.

At BCOTB we follow Carbone’s (2012) recommendations when it comes to increasing the mean length of utterance and teaching children to use complete sentences. We want language to be meaningful to children and not just “look” meaningful. For example, if a child is taught to add too many words to his or her single word requests too soon, the following language patterns typically arise:

·  “I want more up please.”

·  “I want stop.”

·  “I need more help go.”

None of these requests sound typical and do not benefit the child any more than simply saying “up” or “stop.” Indeed saying “up” or “stop” sounds more natural than using inappropriate syntax. Following Carbone’s recommendations is one way that we help guard against an artificially high mean length of utterance that is not truly functional for the child.

BCOTB believes that teaching language within context, with the appropriate motivation in place is the most effective way to establish lasting changes in a child's verbal repertoire. If you are interested in reading research to this effect or have any questions about our therapy and how it differs from other therapies, feel free to email us at info@bcotb.com or to contact your therapist for more information.

References

Brown, R. (1973). A first language: The early stages. London: George Allen & Unwin

Carbone, V. (March 9, 2012). Lecture . Advanced Topics in Behavior Analysis and an Application of a Natural Science Approach to Teaching Language to Children with Disabilities. Consultant Workshop. Lecture conducted from Behavioral Consulting, Tampa.

Skinner, B. F. (1957). Verbal behavior. Acton, MA: Copley Publishing Group.