memory (for recent reviews, see Nyberg & Tulving, 1996; Wheeler, Stuss, & Tulving, 1997). In this paper we use the term “remembering” to refer to the operation of Tulving’s episodic system and its associated state of autonoetic consciousness. The term “knowing” is used to refer to Tulving’s semantic system and its associated state of noetic awareness. Subjective reports of these states of awareness are measured by remember and know responses (Tulving, 1985), which indicate at the time of retrieval from memory which of the two mental states is experienced. In normal adults, the evidence, taken altogether, shows that not only are there systematic functional dissocia- tions in subjective reports of remembering and know- ing, but that remembering and knowing are function- ally independent. Some independent variables, such as deeper levels of processing, increase remembering and do not affect knowing. Others, such as presenting iden- tical versus unrelated test primes, increase knowing and do not affect remembering. Yet other independent vari- ables, such as nonword versus word presentations, in- crease remembering and decrease knowing, and at least one—repeated study trials—under certain conditions, leads to a parallel increase in remembering and know- ing (see Gardiner, Kaminska, Dixon, & Java, 1996; Episodic Memory and Remembering in Adults with Asperger Syndrome Dermot M. Bowler, 1,2 John M. Gardiner, 1 and Sarah J. Grice 1 A group of adults with Asperger syndrome and an IQ-matched control group were compared in remember versus know recognition memory. Word frequency was also manipulated. Both groups showed superior recognition for low-frequency compared with high-frequency words, and in both groups this word frequency effect occurred in remembering, not in knowing. Nor did overall recognition differ between the two groups. However, recognition in the Asperger group was associated with less remembering, and more knowing, than in the control group. Since remembering reflects autonoetic consciousness, which is the hallmark of an episodic memory system, these results show that episodic memory is moderately impaired in individ- uals with Asperger syndrome even when overall recognition performance is not. KEY WORDS: Asperger syndrome; remembering memory; knowing memory. Journal of Autism and Developmental Disorders, Vol. 30, No. 4, 2000 295 0162-3257/00/0800-0295$18.00/0 © 2000 Plenum Publishing Corporation INTRODUCTION A considerable amount of evidence has accumulated to show that individuals can readily distinguish between two mental states that characterize their awareness of memory. One state, that of remembering, involves bring- ing back to mind contextual details of previous events and experiences that include an awareness of one’s self, usually at a particular time, and in a particular place. The other state, that of knowing, involves no such remem- bering, but is rather a more abstract awareness of knowl- edge. This knowledge includes not only general knowledge about the world but also knowledge of pre- vious events and experiences that one cannot remem- ber. In Tulving’s (1983, 1985) theory, these two states of awareness, respectively, reflect autonoetic and noetic consciousness, two types of consciousness which in turn reflect two mind/brain systems, episodic and semantic 1 Department of Psychology, City University, London, United Kingdom. 2 Address all correspondence to Dermot M. Bowler, Department of Psychology, City University, Northampton Square, London EC1V 0HB, United Kingdom; e-mail: d.m.bowler@city.ac.uk