Up to the early 1980s neuropsychological assessments of persons with intellectual disability (ID) usually meant an assessment for developmental delay, of intelligence (intelligence quotient testing) or of level of adaptive behavior. Popular tests included the Stanford-Binet, Wechsler Intelligence Scales, Bayley Scales of Infant Development, the Griffin Mental Developmental Scales, and the Vineland Social Maturity Scale. These were assessments of the "overall" level of ability. Arthur Dalton in New York was one of a few pioneering clinicians who at this time, focused on the development of tests for specific areas of cognition in persons with ID. Following his work, sub- quent researchers, in the latter part of the twentieth century, have proposed and dev- oped a number of measures not only to detect the level of cognitive abilities but also to measure decline; a perquisite to the diagnosis of dementia. At the beginning of the twenty-first century as demonstrated in this book, several neuropsychological measures have been developed to aid the clinical diagnosis of dementia/dementia in Alzheimer's disease (AD).
Neuropsychological assessments no longer remain the sole responsibility of psychologists, as psychiatrists, resear- ers, ID nurses, neuroscientists, all now play a part in the development and adm- istration of specific tests.