Recognition Memory for High and Low Associative Stimuli in Autistic Individuals with Outstanding Memory Skill

Individuals with autism exhibit typical recognition memory performance, but they show a reduced use of context and relational processing in more complex memory tasks. It is unclear whether the same is true for autistic individuals with exceptional memory skill for whom superior rote memory skill has been assumed.

In this study, we investigated recognition memory for high and low associative stimuli in autistic memory experts. In accord with the rote memory notion, we expected an equal recognition performance for high and low associative stimuli and superior memorizing of nonsense material compared to control participants.

Seven autistic memory experts and seven typically developed control subjects, matched according to age, sex, handedness, and full-scale intelligence quotient (IQ), were examined on a continuous old-new recognition paradigm, including high or low associative pseudowords and shapes. Memory expertise was characterized as a currently present outstanding memory skill above the subject's general level of ability and above the general population and was validated through direct clinical observation or some form of credible evidence.

Our hypotheses were partially corroborated with autistic memory experts recognizing high and low associative shapes equally well in contrast to control participants who showed superior recognition of high associative shapes. However, memory experts did not outperform control participants in the recognition of low associative shapes. There were no differences for the recognition of pseudowords.

Findings do not indicate enhanced memory for nonsense material, but a failure to make use of semantic features of abstract stimuli as assumed for autism as a whole.