Cognitive Disabilities

Table of Contents

  1. Demographics
  2. Medical Details
  3. Accommodations

Demographics

Intellectual disability is held by about 200 million people globally.

Dyslexia is the cause of 70%-80% of cases of reading difficulty.

Dyslexia rates are estimated at 5-10%, but sometimes as high as 17%.

Dyscalculia rates are estimated at 3-6%.

ADHD rates in children are between 2-7%.

ADHD rates in adults is at 4%.

Autism has a prevalence of 1 in 100 people.

NVLD has a prevalence of 1 in 100 amongst children in the USA.

Medical Details

A Note on the Category Itself

The IAAP defines cognitive disabilities as those that interfere with the mental functions required for cognitive processing. Separating out cognitive disabilities, speech and language disabilities and psychological disabilities is how the IAAP does it, but different organizations and thinkers make distinctions in different ways. For example, some would consider aphasia to be a cognitive disorder instead of a speech and language disorder. Some would classify anxiety disorders as cognitive disorders instead of psychological disorders. For the purposes of the examination however, stick to what the IAAP tells you. Classifying specific conditions into their appropriate subtypes is one of the areas they explicitly recommend you to study (so I assume it is highly testable).

The disorders presented in this category vary in presentation but deal in impairment in one or multiple of the following areas:

Intellectual Disability

Diagnosis

According to the AAIDD, a linked BoK source, one meets the requirements for intellectual disability if they have impaired intellectual functioning (assessed by a low IQ score, generally lower than 75) and impaired adaptive behaviour existing prior to them being an adult (22 years old). Adaptive behaviour refers to conceptual skills (reading, writing, arithmetic, navigation), social skills, and practical skills (occupational skills, financial skills, personal care, following instructions).

The IQ number changes from jurisdiction to jurisdiction, as does the age that determines adulthood. While it is an official diagnosis in the DSM-V, more relevant to the lives of people with intellectual and developmental disability, these are the criteria that determine eligibility for support.

There are various specific disorders associated with intellectual disability, but many just receive a general 'intellectual disability' label with unknown causes.

According to the American Psychiatric Association, a linked BoK source, intellectual disability may be present alongside other conditions, such as autism spectrum disorder, cerebral palsy, epilepsy, ADHD, anxiety and depression.

The Current Situation

Given the way that society is structured right now, many people with intellectual and developmental disabilities continue to legally not be entitled to many of the rights that the mainstream population is given.

For example, many of them work for subminimum wage or for free. When people abuse them, their cases are handled by a segregated court and not by the normal justice system. Many live in group homes or straight-up prison-like institutions where abuse runs rampant. Those who don't often will not even have keys to their own house or apartment. Many have their rights restricted unfairly by their caregivers and are offered no way to gain their rights back. This treatment (besides abuse) is largely fully legal. Society really, really needs to do better.

As an accessibility professional, you should at least be semi-aware that this is going on in your backyard.

Obligatory note on IQ

Here's a piece from Big Think titled, Is IQ a load of BS? that I recommend you read to understand what IQ is and isn't. The piece neglects to note that IQ testing itself is highly, highly variable. People will get different IQ scores depending on whether they have had a bad day or not, they can train to 'game the test' and get a higher score. There's also multiple versions of IQ testing.

Dyslexia

Dyslexia is not the sole cause for disability related to reading difficulty, but it accounts for a large portion of it (other causes might be things like language processing disorders). The actual mechanism for dyslexia is unclear, but it affects reading, writing, and spelling. Most people think its primary mechanism is difficulty in phonological processing, but it also might interfere with verbal working memory, and rapid naming and sequencing skills.

Dyslexia is not considered to be an intellectual disability. Instead, we can consider it a kind of information processing disorder.

According to the European Dyslexia Association, a linked BoK source, dyscalculia, developmental language disorder, anxiety disorders, depression, and ADHD are commonly diagnosed alongside dyslexia.

Although usually present from childhood, adult-onset dyslexia may occur in the context of dementia or brain injury.

Dyscalculia

According to Understood's article on dyscalculia, a linked BoK source, dyscalculia is known alternatively as mathematics learning disability, mathematics learning disorder, math dyslexia, and number dyslexia. Individuals with dyscalculia might have an impaired ability to think in terms of 'number sense.'

Number sense is composed of a few things, notably

Autism Spectrum Disorder

ASD is a neurological condition characterized by impaired ability to engage in social communication and interaction, and repetitive behaviours.

Symptoms must be severe enough to interfere with daily life, symptoms cannot be explained by the presence of another condition, and symptoms must be present as the autistic person was growing up.

ASD is diagnosed at ASD Level 1, ASD Level 2, and ASD Level 3 to indicate the level of support the autistic person might require on an ongoing basis, but these are not considered separate disorders. The 1-2-3 classification supersedes what used to be a set of different disorders, including Childhood Disintegrative Disorder, Pervasive Developmental Disorder Not Otherwise Specified, Asperger's, and Rett Syndrome. All of these disorders are now considered deprecated within the DSM V, all of them falling under the broad spectrum of ASD.

There is a tendency for people not well-versed in the matter to think of the 'spectrum' as meaning that everyone is "a little bit autistic" in their own way. This is not the case. The 'spectrum' refers to the idea that those that fit the criteria for the disorder are a very heterogeneous population with a wide variety of support needs. The various ways that social impairment and repetitive behaviours manifest themselves are multitudinous. If you've met a person with ASD, you've met one autistic person. There are a lot of autistic people in my life. Trust me when I say that our diversity cannot be understated.

Some autistic people also have an intellectual disability. According to the US Centre for Disease Control, a linked BoK source, other comorbidities may include hyperactivity, impulsivity and inattention, seizure disorders, anxiety disorders, and gastrointestinal issues.

Attention Deficit Hyperactivity Disorder

ADHD is fundamentally a neurological disorder of executive functioning or the ability to sustain attention towards a directed goal. The DSM V criteria for ADHD, as linked in the BoK, sketch out two three types: predominantly inattentive, predominantly hyperactive, and combined type.

The inattentive type is associated with poor listening skills, forgetfulness, carelessness, diminished attention span, and inability to complete assignments.

The hyperactive-impulsive type is associated with restlessness, fidgeting, inability to wait one's own turn, tendency to interrupt another's activities or speech.

According to ADHD Mythbusting, a source linked in the BoK, while everyone may display some of these behaviours at some point or another, ADHDers display them with greater intensity, severity, and chronicity than people without ADHD. To receive a diagnosis, symptoms must be present before the age of 12.

The Mythbusting website also clarifies that ADHD is not just an excuse for laziness, it is not something that is commonly grown out of, it is not overdiagnosed, nor is it caused by 'bad parenting.'

According to the National Resource Center on ADHD, linked in the BoK, ADHD in adulthood is associated with depression, mood disorders, and substance abuse. More than two thirds of children with ADHD have at least one other co-existing condition.

Non-Verbal Learning Disorder

NLD, while not listed in the DSM-V, is a proposed disorder fundamentally characterized by an inability to manage visual-spatial information. This results in struggles with learning (especially mathematics), visualizing concepts, recognizing patterns, executive functioning issues, social impairment (especially when it comes to concepts like 'personal space.'). A child with NLD might struggle to tie their shoes, ride a bike, and tell their left from their right. Classically, NLD children are hyperverbal and have a large vocabulary.

NLD shares a lot of common characteristics with ASD, to the point that they are frequently mistaken for one another, anecdotally highly co-occurring, and some folks even believe that NLD falls within ASD's 'spectrum.' Such speculation is possible because, as a proposed disorder, it remains under-researched, under-funded and consensus for diagnostic criteria remains very, very open.

Accommodations

We've covered a wide range of profiles, so predictably, accommodations will be highly specific to the person.

If I had to identify a common theme, people with cognitive disabilities benefit from guidance. Many people with cognitive disabilities receive guidance from designated support workers, counsellors or therapists. But for the purposes of universal and inclusive design, 'guidance' is a very general heading that boils into making expectations clear and allowing tolerance for error. In what ways may we build guidance and tolerance for error into the system itself?

Supporting Reading Ability

Reading can be hard for anyone, but it can be particularly challenging for people with intellectual disabilities or dyslexia. Providing alternatives to reading, such as audio explanations, videos, or images, may be an option, but it is not always going to be feasible.

When you do provide communication, consider using plain language. The Plain language institute offers this definition, which is formalized into an ISO standard on Plain language.

A communication is in plain language if its wording, structure, and design are so clear that the intended readers can easily find what they need, understand what they find, and use that information.

Let's isolate and point out a few key points in this definition.

Plain language is related to but not synonymous with the concept of 'easy read.' Easy read is a format intended for people with intellectual disabilities or very low literacy. If you're writing in the plain language spirit and your intended reader consists of people with intellectual disabilities, you might reach for 'easy read' as a framework for your text.

Wikipedia boils down the UK Government's easy read guidelines into this concise paragraph:

Easy read advocates sentences of no more than ten to fifteen words, with each sentence having just one idea and one verb. Active sentences are used instead of passive sentences. Easy read is closely edited to express ideas in a small number of simple words. Any difficult word or idea is explained in a separate sentence

Easy read materials are frequently accompanied by illustrations or images to support the deciphering of the text.

Writing in plain language, or creating easy read texts, is more of an art than a science. Whether something is readable is only determined the second that the intended audience reads it. Guideline 3.1 of WCAG, Readable, suggests three techniques for making your text more readable: define unusual words, define abbreviations, and ensure text doesn't surpass lower-secondary education reading level (and if it does, to provide an accessible alternative). These are all Level AAA criteria, and not required to meet what most jurisdictions feel is a basic minimum standard.

The UDL Guidelines for Language and Symbols as well as Building Knowledge also offer some ideas on how to support reading ability.

Supporting Navigation

Offer hints on how to navigate through both physical and digital spaces. Highlight important information or locations, ensure signage or links are large and clear. Use tactile, graphic, architectural cues to support wayfinding in the physical world. Rely on skeuomorphic design and common navigation patterns, breadcrumbs, sitemaps, and search bars in the digital world.

Supporting Task Completion

Instructions should be clear and easy to read. Limit distractions when sustained effort is needed for task completion. And ensure that there is enough time to complete the task. For example, a person with ADHD might fill out half a form and then leave the tab open for four days trying to convince themselves to go back and finish it. It would be heartbreaking if all their progress was lost. Speaking from first-hand experience here.

Supporting Cognitive Functions through Assistive Tech

Assistive tech that support reading ability can include:

Assistive tech that support task completion include:

Accommodating Cognitive Disabilities Benefits Everyone

The CPACC Body of Knowledge really does take time to stress this point. Supporting reading ability, navigation, and task completion bolsters usability.

In my view, it also is beneficial because temporary cognitive dysfunction can literally strike anyone at anytime. This is just human nature. Sometimes we do it to ourselves intentionally, for fun. Sometimes it is out of grief, or because we're overwhelmed or stressed. And I think a non-insignificant portion of the population has various degrees of long COVID-related brain fog.