Declarative memory and structural language in children with high and low functioning autism and intellectual disability without autism
My current research is investigating the possible causes of the structural language impairment in children with low functioning autism (LFA), high functioning autism (HFA) and intellectual disability (ID) - an area of research that is highly neglected due to its complexity at theoretical, practical and economic levels.
I am testing the hypothesis that the language impairment in LFA is caused by a declarative memory impairment (Ullman, 2004). To test this I have two paradigms within which to test both familiarity and recollection, including one that I have developed to be specifically used with children (Bigham, Boucher, Mayes & Anns), 2010). A non-verbal test of semantic ability (Pyramids and Palm Trees Test) is being used as the clinical outcome measure for language.
In addition, other variables that are associated with language are being tested. These variables are weak central coherence (measured using the Children's Embedded Features Test), non-verbal IQ (Ravens matrices), Social Economic Status and implicit mindreading (an eye tracking study that is based on an implicit theory of mind task) and using the Social Responsiveness Scale as a diagnostic filter.
Not only is the research investigating the hypothesis that declarative memory is linked to the language impairment in LFA but also more specifically that recollection is impaired across the autistic spectrum whilst familiarity is only impaired at the lower functioning end. In addition, one of the clinical groups comprises 'intellectually disabled' children without autism and possible links of their language impairment will be explored by testing for social economic status of parents, as well as verbal and non-verbal IQs.
I have recruited four groups of 20+ children (3 clinical, 1 control) to be included in all my tests and they are matched on chronological age and verbal IQ. Preliminary results show support for the hypothesis but more analysis is needed. These findings are essential to our understanding of how children learn and will be extremely useful at an international level.