Working Memory and intellectual disabilities

Abstract

Intellectual disability (ID) is a neurodevelopmental disorder that begins in childhood, characterised by intellectual and adaptive functioning deficits in conceptual (language, reading, maths, reasoning, knowledge, memory), social (empathy, friendships, interpersonal communication skills, social judgement), and practical (personal care, money management, organising school tasks) domains (DSM-5: American Psychiatric Association, 2013). ID has been described as ‘the most common developmental disorder and the most handicapping of the disorders beginning in childhood’ (Harris, 2006, p. 79), and DSM-5 requires three criteria to be met for a diagnosis of ID: Deficits in intellectual functioning (reasoning, problem solving, Working Memory, planning, abstract thinking, judgement, academic learning, learning from experience, practical understanding) in one or more skill domains (conceptual, social, practical) that are confirmed by clinical evaluation and individualised, standardised intelligence testing. This is defined as per formance levels that are two or more standard deviations below the general population (i.e. scores of less than 70) on psychometrically sound and valid, comprehensive and culturally appropriate tests. Deficits in adaptive functioning that significantly hamper the ability to meet developmental and sociocultural standards for personal independence and social responsibility. In practice, the adaptive deficits limit functioning in one or more activities of daily life, such as communication, social participation and independent living, and across multiple environments, such as home, school, work and recreation. Adaptive functioning deficits are assessed using clinical evaluation and individualised, culturally appropriate, psychometrically sound measures. Standardised measures can be used with knowledgeable informants (e.g., parent or other family member, teacher, care provider) and the individual if possible. The onset of these difficulties is during the childhood period.