At Verbal Beginnings, intervention focuses on increasing a variety of areas within each learner’s repertoire, including verbal behavior, social skills, functional life skills, and group instruction skills. Within this blog, we will focus on the development of speech and language, or verbal behavior as we, as behavior analysts, refer to it.
Both children and adults can have difficulties with speech as a result of issues with physical development or injury. Speech refers to the output of the words that we speak. Language refers to the content words that we use and combine in order to convey our communicative intent in an effective manner. Development of ‘language’ can, at times, be impaired by difficulty with speech or sensory and information processing issues. Development of language hinges upon our ability to discriminate the meaning of words, and integrate them in ways that that allow us to communicate effectively with others.
Speech and language each display different yet overlapping developmental courses. Examination of a child’s behavior as it fits in relation to their age and learning history allows us to understand, and improve, a child’s speech and language. Below, we will describe milestones in early speech and phonology (sound) development and briefly describe how simple behaviors like babbling are key to later sophisticated communication behaviors.
Infants of 0-2 months of age tend to babble simply as a response to their environment. This ‘vegetative’ babbling is spontaneously emitted, just like crying, in response to their environment.
From 2-4 months, infants develop the ability to ‘coo’ which is distinguished by a tendency to move the tongue back and forth in the mouth and produce a higher frequency of vowel-like sounds.
From 3-6 months infants begin to display ‘marginal’ babbling which includes emitting less vowel-like sounds more frequently. These sounds also become more complex as they begin to be paired with each other to form syllables.
From 6-10 months-of-age, infants then begin to display ‘canonical’ babbling. Canonical babbling involves the production of higher complexity combinations of vowel and consonant sound combinations, often reduplicated (e.g., “mama”, “dada”). As the sophistication of a child’s vocal- verbal abilities rises speech and language development becomes deeply influenced by the child’s ability to achieve parity, or a match between the child’s emitted behavior and his/her experience of the outside world (Palmer, 1996).
The achievement of parity, also helps promote a rise in both the complexity of speech and language skills and the accuracy of matching between the child’s emitted behavior and that of others. In a sense, the ability to ‘match’ behaviors observed in the environment becomes itself reinforcing. Through this process small units of speech become strung together in ever more complex ways. Behaviors that were initially purely vocal and reflexive (e.g., emitting sound in response to fear or hunger) become vocal verbal behaviors under the control of a child’s history of learning, resulting in access to food, social approval, or removal of unpleasant stimuli. Over time, direct responses from the environment control less of the child’s behavior and begins to exert a higher degree of control on the child’s verbal behavior.
The clinical implications of these developmental pathways, along with the importance of social control and achieving parity, for children with autism and developmental disorders are numerous. Key among these is that the complex collection of behaviors needed to successfully produce an effect on the environment. For children with developmental disorders, we start by assessing the child’s ability to produce sound and then examining whether the sounds emitted are under the control of social contingencies, rather than echoic or self-stimulating control. If a child is able to produce a wide variety of sounds and we can start to bring these sounds under stimulus control of natural environmental contingencies thus shaping the child’s verbal behavior and regain developmental momentum. This makes addressing delays in vocal verbal behavior (e.g., when variation or parity in babbling does not match developmental milestones) a key step in addressing your child’s future functioning.
If you would like to learn more about speech, language, and verbal development check our early intervention page.
By Angela Cathey, M.A. & Todd A. Ward, PhD, BCBA-D, President and Founder of bSci21Media, LLC