Double Dissociation: Understanding its Role in Cognitive Neuropsychology


  • I am grateful to Anne Aimola Davies, Max Coltheart, Kim Plunkett, Nick Shea, Michael Smithson, and two anonymous referees, for comments on an earlier version of this paper.

    Max Coltheart was one of the founding editors of Mind & Language and has written with distinction and influence on the themes of this paper—the aims and assumptions of cognitive neuropsychology, double dissociation, computational modelling, and the relationship between cognitive psychology and neuroscience. My intellectual debts to him will be evident on every page and the paper is dedicated to him with gratitude.

Corpus Christi College, Merton Street, Oxford OX1 4JF, UK.


The paper makes three points about the role of double dissociation in cognitive neuropsychology. First, arguments from double dissociation to separate modules work by inference to the best, not the only possible, explanation. Second, in the development of computational cognitive neuropsychology, the contribution of connectionist cognitive science has been to broaden the range of potential explanations of double dissociation. As a result, the competition between explanations, and the characteristic features of the assessment of theories against the criteria of probability and explanatory value, are more visible. Third, cognitive neuropsychology is a division of cognitive psychology but the practice of cognitive neuropsychology proceeds on assumptions that go beyond the subject matter of cognitive psychology. Given such assumptions, neuroscientific findings about lesion location may enhance the value of double dissociation in shifting the balance of support between cognitive theories.