Comment on Otgaar et al. ‘The neuroscience of dissociative amnesia and repressed memory: Premature conclusions and unanswered questions’

Like Markowitsch and Staniloiu (this issue), Otgaar et al. do not directly deal with issues associated with the concept of recovered memories. Their paper consists of a critical review of neuroimaging studies on dissociative amnesia, or memory repression. A finding of positive correlations between symptoms of dissociative amnesia and specific electrophysiological processes in the brain might have suggested a biological substrate for repression, which is a key concept in debate regarding the validity of recovered memories.

However, analysis of the data reviewed by the authors shows that the correlations between the functions of given brain areas and dissociative amnesia are both, weak and inconsistent. Furthermore, they are conceivable in terms of malingering, intentional suppression, metamemory beliefs, organic amnesia, and the like—without invoking the concept of repression. Many studies also suffer from methodological shortcomings, including misdiagnosis of dissociative amnesia. The authors therefore conclude that ‘conceptual and methodological issues strongly limit the interpretation of neuroscientific investigations of dissociative amnesia and repressed memory… [they] tell us little about whether traumatic memories can be unconsciously blocked… [and therefore] none of the proposed biomarkers are sufficiently reliable for diagnosis in clinics or legal arenas’. Consequently, they suggest that the term ‘dissociative amnesia’ be replaced by ‘amnesia of uncertain etiology’.

Since biological correlates of dissociative amnesia are discussed in two papers, the present one and the one written by Markowitsch and Staniloiu, it seems desirable to compare the two. Clearly, they lead to opposite views concerning the validity of the concept of repression. Since the two reviews are based on differential data bases, they do not factually contradict each other. Nonetheless, the implications of their reviews are contradictory in the sense that according to Markowitsch and Staniloiu the psychological concepts of repression and recovery of traumatic memories have a solid biological underpinning, whereas according to Otgaar et al. no biological foundation for these concepts has been found. Thus, Markowitsch and Staniloiu, but not Otgaar et al., consider repression biologically feasible.

Taken together, it is quite possible, of course, that some biological processes (such as those reviewed by the former) are correlated with specific behavioural manifestations, while others (such as those reviewed by the latter) are not. However, this concluding remark sounds more like a mediation between the two groups of reviewers, rather than between those arguing for or against the ‘recovered memory hypothesis’.