Introduction to Working Memory Deficits in Developmental Language Disorders

Working memory (WM) is the ability to hold and manipulate information. After initial sensory input, we are able to hold and actively process a certain amount of information. By encoding (through repeated exposure, rehearsal strategies, and distributed practice), we can put this information into our long-term memory which can later be retrieved.

Working memory (WM) plays a crucial role in learning, particularly for students with Developmental Language Disorders (DLD). These students often face unique challenges that can hinder their academic performance.

Simple model of working memory definition.

Working Memory within Executive Functions

Executive functions are mental skills that help us plan, organize, and manage daily. WM is a critical executive function that maintains controlled attention (the ability to focus on relevant material), choose what to pay attention to or ignore, and guide attention to important information (Diamond, 2020). A cautionary note is that almost no task requires only one executive function. For example, a child may fail a WM task because of problems with inhibitory control, rather than WM itself.

Difference Between Working Memory & Short-Term Memory.

WM and short-term memory are not equivalent. Short-term memory is defined as holding information in the mind without actively processing it or inhibiting other information. For example, holding a phone number in your head before dialing. Working memory is actively processing and manipulating information.

Why is Working Memory Important?

WM helps hold and use information while performing everyday tasks. It is critical to following instructions, problem-solving, learning new skills, making decisions, reading, writing, math (McLeod, 2025).

Everyday Examples:

• Remembering instructions or steps

• Doing mental math

• Holding directions in mind while navigating a route

• Keeping track of a conversation to respond effectively

• Taking notes during class

Subtypes of Working Memory

The Working Memory Model (Baddeley & Hitch, 1974) describes multiple components:

• Central Executive: Decides on what to focus on, organizes tasks, directs information to the correct places in your mind, helps with mental arithmetic and problem solving.

• Phonological Loop: Deals with spoken and written words.

• Visuospatial Sketchpad: Handles visual images and spatial relationships.

• Episodic Buffer: Brings all information together and links to long-term memory.

Others describe working memory to be verbal or visuospatial.

• Verbal WM: Holds and processes language-based information (words, sentences, digits, etc). Supports tasks like following directions, learning new vocabulary, sentence comprehension, recalling spoken sequences.

• Visuospatial WM: Holds and processes visual and spatial information such as locations, shapes, patterns, movements. Supports tasks like reading maps, copying designs, tracking where objects are in space, visual problem solving.

Development of Working Memory

1. Infancy: Infants of 7-12 months have been observed to hold in mind where desired object has been hidden and reach for it, with progressively longer periods (Diamond, 2020)

2. Primary school: Inhibitory and WM skills in primary school-aged children become increasingly differentiated.

3. School-age: Marked improvements in WM are seen between ages of 5-11 on complex span tasks.

4. Adulthood: Executive functions depend on the prefrontal cortex which is the last brain region to mature in our 20s.

Working Memory & Developmental Language Disorder Impacts

Children with DLD show persistent language difficulties that are unaccounted for by biomedical conditions or restricted opportunities and who are at risk of educational and social problems (Archibald, 2018).

There is well-documented evidence that these children have deficits in WM, especially within verbal WM tasks compared to visuospatial (Archibald, 2018). Specifically, children with DLD perform, on average, 1.27 standard deviations (SDs) below peers for verbal WM, 0.63 SDs for visuospatial WM, 0.56 SDs below for inhibition, and 0.27 SDs below peers in cognitive flexibility tasks (Senter et al., 2022). Classroom activities consist of verbal instruction which requires novel and temporary associations of new and old information. Therefore, children with WM deficits may also show struggles academically.

Several theories have been proposed to explain WM deficits in children with DLD. Some suggest that these children have inherently limited WM capacity, while others argue that language impairments increase the demands on processing resources, thereby overloading their WM (Archibald, 2018). Furthermore, this is a high co-occurence rate (22.3%) between DLD and ADHD which may worsen attention within tasks.

Working Memory Deficits May Present as...

• Difficulty with multi-step directions

• Missing details in instructions

• Difficulty recalling story details

• Failing to self-correct during classroom tasks

• Struggles with literacy (reading & writing) or mathematics

• Find complex problem solving challenging

Working Memory is NOT

• Laziness

• Non-compliance

• Behavioural issues

• "Not paying attention"

• Low intelligence

Overall, children with DLD exhibit WM difficulties which in turn affects school performance. It is essential to enhance WM skills in this population to unlock their full potential to thrive in their education.

References

Archibald, L. M. D. (2018). The reciprocal influences of working memory and linguistic knowledge on language performance: Considerations for the assessment of Children with Developmental Language Disorder. Language Speech and Hearing Services in Schools, 49(3), 424–433. https://doi.org/10.1044/2018_lshss-17-0094

Boudreau, D., & Costanza-Smith, A. (2011). Assessment and Treatment of Working Memory Deficits in School-Age Children: The Role of the Speech-Language Pathologist. Language, Speech & Hearing Services in Schools, 42(2), 152–166. https://web-s-ebscohost-com.proxy1.lib.uwo.ca/ehost/pdfviewer/pdfviewer?vid=0&sid=6042988f-2152-4c44-9798-285dbbe3f07e%40redis

Diamond, A. (2020). Executive functions. In Handbook of clinical neurology (pp. 225–240). https://doi.org/10.1016/b978-0-444-64150-2.00020-4

McLeod, S., PhD. (2025). Working Memory model. Simply Psychology. https://www.simplypsychology.org/working-memory.html

Senter, R., Chow, J. C., & Willis, E. C. (2022). Speech-Language Pathology Interventions for Children with Executive Function Deficits: A Systematic Literature review. Language Speech and Hearing Services in Schools, 54(1), 336–354. https://doi.org/10.1044/2022_lshss-22-00013