Does dyslexia affect working memory?

Dyslexia can be associated with working-memory differences, but not for everyone and not in one fixed way. The clearest pattern in research with children concerns tasks that involve holding speech sounds or spoken information in mind while doing something else.

Working-memory difficulty is not required for a diagnosis of dyslexia, and it should not be treated as a single cause of reading and spelling difficulties. However, it may be relevant when a learner finds particular reading, spelling or spoken-information tasks especially demanding.

What do short-term memory and working memory mean?

Short-term memory is the ability to hold a small amount of information in mind briefly. For example, remembering a telephone number for long enough to write it down uses short-term memory.

Working memory involves holding information in mind while also using it. If a teacher says, “Get your maths book, turn to page 16 and answer questions one to three,” the learner needs to remember the instruction, keep the order of the steps in mind and act on them.

Some working-memory tasks involve spoken words and speech sounds. Researchers may describe this as phonological memory: briefly holding sound-based language information in mind. This may be involved when someone repeats an unfamiliar word to themselves, remembers the sounds in a word, or holds information from the beginning of a sentence while reading the rest.

Other tasks involve visual or spatial information, such as remembering the position of shapes in a pattern. These are not the same as verbal tasks, and research does not suggest that every person with dyslexia has difficulty in both areas.

What does the research suggest?

Research with children who have dyslexia, and with children described more broadly as having reading difficulties, has identified average differences on short-term-memory and working-memory tasks. The clearest differences are usually found on verbal tasks: for example, recalling digit sequences, holding speech sounds in mind, or remembering spoken information while processing other information.

Research across the wider reading literature also shows a moderate association between working memory and reading. This does not establish cause and effect. It cannot tell us whether working-memory differences contribute to reading difficulty, whether reading experience affects memory-task scores, or whether other factors are involved.

The findings also do not predict an individual learner’s experience. Some children with dyslexia may find working-memory tasks demanding, while others may not. A child who struggles to remember spoken instructions does not necessarily have dyslexia, and a child with dyslexia will not necessarily find this difficult.

Current expert consensus describes dyslexia as a difficulty in reading and spelling associated with multiple factors. Phonological processing — noticing, storing and working with the sounds in spoken language — is particularly commonly associated with dyslexia. Working memory can contribute to how dyslexia presents for some learners, but it is not a stand-alone explanation.

Why spoken information and speech sounds are especially relevant

The most consistent finding is not simply that children with dyslexia have “memory problems”. Rather, the strongest pattern involves tasks that require spoken language or speech sounds to be held in mind.

This may be relevant to reading and spelling because both involve speech sounds. When reading an unfamiliar word, a learner may need to identify its sounds, blend them together and connect them with letters. When spelling, they may need to hold a sequence of sounds in mind while recalling suitable letters or spelling patterns.

Phonological awareness is closely related to this area. It means recognising and working with the sound structure of spoken words. For example, it includes hearing that cat and hat rhyme, identifying the first sound in ship, or separating stamp into individual sounds.

Evidence with children with dyslexia suggests that working memory, phonological awareness and efficient word reading are associated. This should not be read as a fixed sequence in which one factor causes the next. It does suggest that speech-sound tasks may be useful to consider when trying to understand why reading or spelling is demanding for a particular learner.

In everyday learning, spoken instructions can place similar demands on memory. A pupil may understand each part of an instruction but forget a step before beginning. They may also find it demanding to hold a word in mind while analysing its sounds. These experiences can have many causes, including unfamiliar vocabulary, tiredness, distraction, anxiety or a task that is too difficult. They do not establish dyslexia or a working-memory difficulty by themselves.

What about visual and spatial working memory?

Research has also identified average differences on some visual-spatial working-memory tasks in children with dyslexia or broader reading difficulties. These tasks may involve remembering patterns or the locations of items.

However, this pattern is less consistent and the differences reported are generally smaller than those found for verbal working-memory tasks. Studies have also used different definitions of dyslexia and reading difficulty, different age groups, languages and memory tasks.

For this reason, it would be inaccurate to assume that dyslexia involves a general visual-memory difficulty. A score on a visual-spatial task tells us about that task; it does not automatically tell us how a learner will manage diagrams, copying, page layout or other classroom activities.

Can working memory be used to identify dyslexia?

No. A working-memory assessment may provide useful information about how a learner approaches particular tasks, but it cannot diagnose dyslexia on its own.

Dyslexia assessment needs to consider reading and spelling, development, teaching opportunities and the learner’s wider pattern of needs. A result from one memory task cannot provide that full picture. Dyslexia is varied, so two learners with dyslexia may need different forms of support.

Most research in this area has involved children, so the same patterns should not automatically be assumed in adults with dyslexia.

Reducing unnecessary memory demands

Many ordinary learning activities require information to be held in mind. This can include remembering several spoken instructions, listening while taking notes, keeping track of information across a sentence, or holding sounds in mind while blending or segmenting a word.

When the learning aim is not to test memory, one practical approach is to make key information available rather than expecting it all to be remembered. For example, instructions can be given in short, clearly separated steps and also written down. A checklist can allow a learner to tick off each stage. A worked example can show what the finished task should look like.

A learner may also find it useful to repeat the first instruction back, ask for key points in writing, or refer to notes while completing a task. These approaches reduce the amount that needs to be held in mind so that attention can stay on the learning goal.

Computerised working-memory training should be approached carefully. Evidence from a trial involving children with dyslexia and identified working-memory difficulties found a small improvement on working-memory measures, but no added progress in decoding or spelling beyond a reading and spelling programme. It should not be presented as an established route to improved literacy.

The bottom line

Dyslexia may affect working memory for some people, especially on tasks involving speech sounds and spoken information. The research does not point to one working-memory profile for everyone with dyslexia, and it does not show that working memory is the sole cause of dyslexia.

The useful question is often practical: what does this task ask the learner to hold in mind, and would presenting information more clearly help them focus on the task itself?