The category of cognitive disabilities covers a broad and loosely defined set of conditions that create greater difficulty for people to perform one or more types of mental tasks than the average person. Most cognitive disabilities have a foundation in biology or physiology. Causes can range from traumatic brain injury to genetic disorders and subtle nuances based upon the structure or chemistry of the brain.

The impact on people affected with cognitive disabilities spans a wide range. People with minor learning disabilities may be able to perform at such a high level that their disability is never even discovered. At the opposite extreme, people with profound cognitive disabilities may need assistance with nearly every aspect of daily living.

For accessibility purposes, it is useful to focus on functional disabilities rather than attempting to determine root cause. The six main categories of functional disabilities are memory, problem-solving, attention, reading a verbal comprehension, math comprehension and visual comprehension. Each requires different accessibility adaptations. Focusing on functions rather than causes makes it easier for accessibility professionals ranging from website designers to space planners to address specific solution areas.