Working memory, the temporary storage and processing of information long studied in the psychology literature, has important implications for the assessment and treatment of language impairments, according to Donna Boudreau, PhD, CCC-SLP.
"A lot of our language tasks have working memory components in them," said Dr. Boudreau, an associate professor in the Department of Speech and Hearing Sciences at Portland State University in Portland, OR. "When we're asking a child to engage in a task, like telling us if a word or sentence is similar to one they just heard, we think of that as a language task; but in truth it is a compare/contrast task. The child has to hold that information in memory while making a decision about what subsequent sentences are similar or different."
Working memory differs from short-term memory in that it has a processing component in addition to a storage component. Both are limited capacity systems, unlike the theoretically infinite capacity of long-term memory.
"Not only is information stored in working memory, but a mental operation is completed as well," Dr. Boudreau explained. "Information from long-term memory is retrieved and brought into working memory when completing certain kinds of tasks."
Working memory is a major component of connected language tasks and reading comprehension, as both require the storage and processing of data. As new information is received in tasks such as listening to a story or reading a chapter in a history book, modifications to current information in a person's memory are required for comprehension.
"That's very different from short-term memory because you're not asked to actively engage in any kind of thinking or mental processing in short-term memory," Dr. Boudreau told ADVANCE.
She credited the work of James Montgomery, PhD, CCC-SLP, a professor in the School of Hearing, Speech and Language Sciences at Ohio University, in Athens, whose research has found that working memory skills are a strong predictor of sentence comprehension abilities.1,2,3
"Research shows us that children with language impairments have a more limited working memory capacity than typically developing peers, which contributes to language comprehension," Dr. Boudreau said. "The child that has greater working memory limitations is going to have more difficulty with longer sentences, more complex sentences, as well as discourse level tasks, such as narratives and reading comprehension."
Working memory capacity is highly correlated with how well children understand what they read, as their ability to process the information read is restricted by the resources they need for storing that information. This is an important factor in treatment options.
"Research has shown that children with language impairments perform more poorly than their typically developing peers on both phonological and verbal working memory tasks," she said, "so any time we can change the storage and processing demands for the child, we're able to help them be more efficient with the working memory capabilities that they have."
Although working memory often is discussed in psychology, it is a fairly recent concept in the field of language assessment. However, some assessment tools are available to clinicians. The CELF-4, published by Harcourt Assessments, in San Antonio, TX, contains a working memory subtest that focuses on forward and backward digit recall.
"From a clinical perspective I don't think that we've always been looking at working memory in our standard language evaluation," she said. "When we look at some of the subtests that we use for language assessment, some of the tests tax a child's working memory capabilities, so potentially you're seeing a child's actual performance influenced by how good their working memory skills are."
There have been limited studies on whether working memory capacities can be increased or improved. Dr. Boudreau suggests clinicians use other strategies to reduce working memory demands on children and boost their efficiency for managing their working memory capacity.
Speech-language pathologists can help children develop appropriate frameworks for activities that may require increased working memory demands, such as assisting children in developing schemas for narrative and expository text.
"Ensuring the child has well-developed schema for text will allow him or her to be more efficient with what information is most critical to retain, freeing up other resources for other aspects of the task," she explained. This efficiency in managing available resources is particularly important for tasks that significant demands on working memory abilities.
Clinicians also can work with the child to develop an external cuing system to deal with complex instructions. They can write down multiple-step instructions to break down the information into smaller parts more easily.
"Developing some level of metacognition about the memory demands and, subsequently, the challenges inherent in some classroom activities helps a child be more efficient," Dr. Boudreau said.
It is important for speech-language pathologists to make the classroom teacher aware of working memory demands and their potential impact on a child's classroom performance. Multiple-step directions may be a challenge, particularly for activities that are not part of the classroom routine or are delivered without contextual support. Instead, teachers can simplify their language, provide visual contextual support, or ask the child to repeat the instructions.
Clinicians should spend some time observing the child's classroom to identify more easily those tasks that may be challenging for the child, she suggested. Reading, writing and standardized testing all place demands on aspects of short-term, long-term and working memory.
Currently, Dr Boudreau's research focuses on evaluating how the level of working memory demand influences a child's ability to understand and retell stories.4,5 Because the role of working memory in language assessment and intervention may influence standardized test performance, she is collaborating on research in this area with Amy Costanza-Smith, PhD, CCC-SLP, of the Child Development and Rehabilitation Center, Oregon Health & Science University, in Portland.
"Children who have language difficulties often have working memory limitations," Dr. Boudreau explained. "We want to think about that in terms of language assessment from the perspective of making sense of children's performance on standardized tests. Working memory may be influencing how well they're performing on certain tasks that are intended to measure language rather than memory."
1. Montgomery, J., Magimairaj, B., O'Malley, M. (In press). The role of working memory in typically developing children's complex sentence comprehension. Journal of Psycholinguistic Research.
2. Montgomery, J., Windsor, J. (2007). Examining the language performances of children with and without specific language impairment: Contributions of phonological short-term memory and processing speed. Journal of Speech, Language, and Hearing Research, 50: 778-97.
3. Montgomery, J. (2004). Sentence comprehension in children with specific language impairment: Effects of input-rate and phonological working memory. International Journal of Language and Communication Disorders, 39: 115-34.
4. Boudreau, D.M. (2007). Narrative abilities in children with language impairments. In R. Paul (ed.), Language Disorders from a Developmental Perspective. Mahwah, NJ: Lawrence Erlbaum Associates.
5. Boudreau, D.M. (2005). Verbal working memory skills and narrative abilities in children with language impairment. Poster session presented at the American Speech- Language-Hearing Association Annual Convention, San Diego, CA, November.
For More Information
Donna Boudreau, PhD, e-mail: Boudreaud@pdx.edu
Alyssa Banotai is an Associate Editor at ADVANCE. She can be reached at firstname.lastname@example.org.