Memory in autistic spectrum disorder.

Behavioral evidence concerning memory in high-functioning forms of autism (HFA) and in moderately low-functioning autism (M-LFA) is reviewed and compared.Findings on M-LFA are sparse.However, it is provisionally concluded that memory profiles in HFA and M-LFA (relative to ability-matched controls) are similar, but that declarative memory impairments are more extensive in M-LFA than in HFA.Specifically, both groups have diminished memory for emotion-or person-related stimuli.Regarding memory for non-social stimuli, both groups probably have mental-age appropriate nondeclarative memory; and within declarative memory, both groups have mental-age appropriate immediate free recall of within-span or supra-span lists of unrelated items, as well as cued recall and paired associate learning.By contrast, recognition is largely unimpaired in HFA but moderately impaired in M-LFA; and free recall of meaningful or structured stimuli is moderately impaired in HFA but more severely impaired in M-LFA.Theoretical explanations of data on declarative memory in HFA identify problems in the integrative processing, or the consolidation and storage, of complex stimuli; or a specific problem of recollection.Proposed neural substrates include the following: disconnectivity of primary sensory and association areas; dysfunctions of medial prefrontal cortex, hippocampus or posterior parietal lobe; or combinations of these associated with neural disconnectivity.Hypothetically, perirhinal dysfunction might explain the more extensive declarative memory impairments in M-LFA.Foreseeable consequences of uneven memory abilities in HFA and M-LFA are outlined, including possible effects on language and learning in M-LFA.Finally, priorities for future research are identified, highlighting the urgent need for research on memory in lower-functioning individuals.