THE IMPACT OF AUTOBIOGRAPHICAL EXPERIENCE ON MEANING: REPLY TO GRAHAM, LAMBON RALPH, AND HODGES.

We have shown that in semantic dementia (Snowden, Griffiths, & Neary, 1994, 1995, 1996) patients' knowledge is significantly influenced by its relevance to their autobiographical experience. Graham, Lambon Ralph, and Hodges (1997), in an investigation of the autobiographical effect, found that general knowledge of sports in which their semantic dementia patients participated was no better than that for other sports and inferred that their data contradict the hypothesis that experience helps to preserve meaning. The purpose of this paper is to address the apparent conflict of views. First, we show that the hypothesis under investigation in the Graham et al. study, that experience maintains all the knowledge about a concept, is not one to which we subscribe and that much of their data is in fact consistent with our own findings. We highlight similarities in our interpretation of the autobiographical effect. We then examine those areas in which our opinions appear to diverge. We argue that autobiographically relevant knowledge can be explicit and is not merely implicit and is semantic and not merely procedural. We argue, moreover, that it is truly semantic and not merely semantic-like. We reconsider the nature of semantic knowledge and the relationship between medial temporal and temporal neocortical memory systems. [ABSTRACT FROM AUTHOR]