Autonomic nervous system (ANS)

A self-regulating division of the nervous system that controls involuntary functions having to do with the cardiovascular, digestive, reproductive and respiratory systems of the body.  It is sub-divided into the parasympathetic and sympathetic nervous systems.  The origin of the term ‘autonomic nervous system’ is credited to John Newport Langley (1852-1925) who coined it in 1898 …

Auto-regressive models

Anauto-regressive model is an approach to statistical analysis used inlongitudinal research. These models involve regressing an outcome variable ofinterest onto measures of that variable at previous time points. The resultingresidual variance provides an estimate of change in the variable.Auto-regressive models can be used to examine the longitudinal relationshipsbetween variables as well as the rank-order stability …

Autobiographical memory

Succinctly defined, it is memory for events and issues related to oneself that includes memories for specific experiences and memory for the personal facts of one’s life (e.g., remembering buying your first house).  Accordingly, we remember more about events occurring at particular periods in time that define us individuals.  What is involved in this type …

Autism

A neurodevelopmental condition nowadays conceptualized as a spectrum, involving difficulties in social development, verbal and non-verbal communication, absence of imaginative play, and a focus on unusually strong and narrow interests.  In classic autism, about half of all afflicted individuals are mute or speak intelligibly only once or twice in their lifetimes, and about 80 percent …

Autism Diagnostic Observation Schedule (ADOS)

Used to assess autistic symptoms and diagnose autism, as well as other pervasive developmental disorders.  It consists of four modules administered in a series of semi-structured tasks involving social interaction between examiner and subject, and designed to be appropriate for differing developmental and language levels.  It has been validated forindividuals from early childhood to adulthood.y. …

Attrition

Drop-out or loss to follow-up of participants in a study because of refusal to continue, failure to locate, or other problems.  The concern is that non-random drop-out may make the sample no longer representative of the original population.  In studies concerned with evaluating the effects of a particular treatment, attrition can be a major problem. The …