Letter to the Editor: Causes and correlates of intrusive memory: a response to Clark, MacKay, Holmes and Bourne

(ProQuest: ... denotes formulae and/or non-US-ASCII text omitted; see image) Correspondence No reader of Psychological Medicine needs to be reminded that correlation does not imply causation, but there are two attitudes that might be taken to that fact, and between them a spectrum of positions. Just as we need to avoid the cognitive illusions that lead us to ignore the base rate when assessing posterior probabilities, or to treat as most likely that which is most typical (Kahneman & Tversky, 1973, 1974), so we must avoid succumbing to our tendency for treating correlations as causal (Matute et al. 2011). If the study of psychological medicine is to take a properly scientific approach to its causal hypotheses then it must, on this view, concern itself with mechanisms. (p. 1787, emphasis added, here and in the two following quotations) They summarize this position by saying that: the main aim of the original paper (and our subsequent replication) was to investigate whether the occurrence of an intrusive memory is determined by the neural activity during the original encoding of experimental trauma.