Cognitive and neurological disabilities involve disorders of any part of the nervous system, including the brain and the peripheral nervous system. This can impact how well people hear, move, see, speak, and understand information. Cognitive and neurological disabilities do not necessarily affect the intelligence of a person.

More about cognitive and neurological disabilities

Computer technologies and the Web provide many opportunities for people with cognitive and neurological disabilities to interact with content and to process information in ways that are more usable to them. For instance, people can navigate web content using different strategies, access information in text, audio, or other formats, and change the presentation of the content according to their individual needs or preferences.

Depending on the particular needs of an individual, people with cognitive and neurological disabilities need:

• Clearly structured content that facilitates overview and orientation
• Consistent labeling of forms, buttons, and other content parts
• Predictable link targets, functionality, and overall behavior
• Different ways of navigating websites, such as through a hierarchical menu or search option
• Options to suppress blinking, flickering, flashing, or otherwise distracting content
• Simpler text that is supplemented by images, graphs, and other illustrations

People with cognitive and neurological disabilities use different types of web browsing methods, depending on their particular needs. For instance, some people use text-to-speech software to hear the information while reading it visually, or use captions to read the information while hearing it. Some people use tools that resize text and spacing, and customize colors to assist reading, and grammar and spelling tools to assist writing. For these web browsing methods to work, developers need to consider web accessibility requirements which are often shared bAy people with hearing,AC physical, speech, or visual disabilities.

Examples of cognitive and neurological disabilities

• Attention deficit hyperactivity disorder (ADHD) (formerly "attention deficit disorder (ADD)") - involves difficulty focusing on a single task, difficulty focusing for longer periods, or may be easily distracted
• Autism spectrum disorder (ASD) (includes "autism", "Asperger syndrome", and "pervasive developmental disorder (PDD)) - involves impairments of social communication and interaction abilities, and sometimes restricted habits and interests
• Memory impairments - involves limited short-term memory, missing long-term memory, or limited ability to recall language. Dementia is one among many different causes of memory impairments
• Multiple sclerosis - causes damage to nerve cells in the brain and spinal cord, and can affect auditory, cognitive, physical, or visual abilities, in particular during relapses
• Seizure disorders - includes different types of epilepsy and migraines, which may be in reaction to visual flickering or audio signals at certain frequencies or patterns

Learning Disabilities

Learning disabilities is a functional term rather than a medical condition, and is not uniformly defined. In Europe and some other countries it refers to intellectual disabilities, while in Australia, Canada, the U.S., and some other countries it refers to perceptual disabilities.

Intellectual disabilities are sometimes called "learning disabilities" in Europe and some other countries, and "developmental disabilities" in other regions. These involve impairments of intelligence, learning more slowly, or difficulty understanding complex concepts. Down syndrome is one among many different causes of intellectual disabilities

Perceptual disabilities are sometimes called "learning disabilities" in Australia, Canada, the U.S., and some other countries. These involve difficulty processing auditory, tactile, visual, or other sensory information. This can impact reading (dyslexia), writing (dysgraphia), processing numbers (dyscalculia), or spatial and temporal orientation.

A Learning Disability (LD) is a permanent neurological disorder that affects the manner information is received, organized, remembered, and then retrieved or expressed. Users with LD possess average to above average intelligence. The disability is demonstrated by a significant discrepancy between expected and actual performance in one or more of the basic functions: memory, oral expression, listening comprehension, written expression, basic reading skills, reading comprehension, mathematical calculation, or mathematical reasoning. Keep in mind that each user with LD has his/her own set of characteristics and that he/she may not be affected in all areas. In fact, it is not unusual for a person with LD to be gifted in some areas or subjects while experiencing the disability in other areas or subjects.

Common Learning Disabilities:

• Auditory Figure-Group Perception – inability to hear one sound among others
• Auditory Sequencing – inability to hear sounds in the right order.
• Dyslexia – inability to read fluently. Often characterized by transposition of letters and words or skipping words and phrases altogether. Causes slow reading and takes tremendous energy to focus on comprehension.
• Dyscalculia – inability to do mathematics. Inability to grasp and remember math concepts, rules, formulas, sequence (order of operations), and basic addition, subtraction, multiplication and division facts. Poor long term memory (retention & retrieval) of concept mastery.
• Dysgraphia – inability to write words with appropriate syntax. Written work appears careless and childlike, often illegible. Writing is inconsistent in spelling (even the same word spelled differently every time it is used), mixtures of cursive and manuscript, and upper/lower case misuse.
• Dysphasia – inability to speak fluently or sometimes to understand others. The student may be unable to distinguish between sounds, understand lengthy sentences, or complex sentence structure. He/she may have difficulty in thinking of correct words, forming grammatically correct sentences, or make clear explanations.
• Figure-Ground Perception – inability to see an object from a background of other objects.
• Visual Discrimination – inability to see differences in objects

Emotional/Psychological Disorders

Emotional/Psychological disorders cover a wide range of disorders such as neuroses, psychoses, and personality disorders. The majority of psychological disorders are controlled using a combination of medications and psychotherapy. Some conditions are cyclical in nature yet do not follow regular patterns. 

Psychiatric disabilities include anxiety, delirium, depression, paranoia, schizophrenia, and many other disorders. These conditions may cause difficulty focusing on information, processing information, or understanding it. In particular, medication for these disorders may have side effects including blurred vision, hand tremors, and other impairments.

Some specific psychiatric disorders include:

• Anxiety Disorders - disruptions in ability to concentrate and may cause hyperventilation, dizziness, chest pains and fear.
• Bipolar Disorder - periods of mania and depression, manifested by disruptive sleep patterns, increased or decreased self-esteem, and periods of lethargy or euphoria
• Depression - a major disorder characterized by depressed mood, a lack of pleasure in most activities and feelings of worthlessness and guilt.
• Schizophrenia - possible experiences of delusions and hallucinations

Examples of barriers for people with cognitive and neurological disabilities

• Complex navigation mechanisms and page layouts that are difficult to understand and use
• Complex sentences that are difficult to read and unusual words that are difficult to understand
• Long passages of text without images, graphs, or other illustrations to highlight the context
• Moving, blinking, or flickering content, and background audio that cannot be turned off
• Web browsers and media players that do not provide mechanisms to suppress animations and audio
• Visual page designs that cannot be adapted using web browser controls or custom style sheets