This is a valuable volume but it doesn't quite fulfil my criteria for an interdisciplinary work. No representative for a clinical, medical perspective -- specifically, no psychiatrist and no neurologist -- is among the contributors although one of the three subsections is named Memory, Emotion and Psychopathology. That is probably the main explanation why one very basic aspect of the relations between memory and emotion is not paid attention to: the syndrome (traditionally but misleadingly called "the frontal lobe syndrome") that often results from lesions in frontolimbic structures and that is characterized by the most deep-going emotional disturbances known. If a section about this syndrome had been included, it had also been natural to give more space to a discussion of the relation between motivation, memory and emotion. Also, although affective disorders and depression are mentioned several times in the book, clinical depression and its relevance for memory, emotion and motivation is never treated at depth.
This being said, I found the book very readable, especially because of its high theoretical ambitions. It is based on a meeting in 2005 but unlike many conference-based books, it does not consist of a bunch of more or less unrelated reports of single studies. Instead, it contains a carefully selected set of reviews and theoretical discussions of some central topics concerning memory and emotion. The center of gravity lies on the issue whether, and why, emotions enhance remembering, and whether they sometimes rather prevent or block remembering.
There is a consensus among most of the contributors that emotions usually improves memory. In the first two chapters Daniel Reisberg and Linda Levine & David Pizarro, respectively, emphasize that the explanation of this fact must involve cognitive processes and not only general arousal. I found their reviews and arguments plausible but one question remained after reading. Scientific common sense says that emotions tend to signal biologically important situations and it would indeed be surprising if the human brain did not use its information-processing resources to remember such situations better than others. However, is it true that the processes that code the relevant information are "cognitive" in the sense that they involve conscious or at least consciously accessible judgments? I don't think so, because the nervous system uses a hierarchy of intelligent coding principles of which only the evolutionary most recent deserve the name "cognition" in the mentioned sense. I would have welcomed a systematic discussion of these different levels of processing instead of -- or as a complement to -- the simple dichotomy between "arousal" and "cognitive" theories.
In the third paper, Sven Å. Christianson & Elisabeth Engelberg discuss emotional memory from a forensic point of view. Among other things, they describe a new paradigm for experimental and clinical work, namely, memory for emotions. It is suggested that a practical focus on memory for emotions may have a beneficiary effect in situations where witnesses, victims or offenders have difficulties remembering the crime or its details.
I will not go through all the remaining nine chapters, which does not mean that I find them inferior to the first three ones. Among other things, they contain several informative reviews and discussions of the evidence from neuroimaging about the relations between memory and emotion. But I cannot end this review without specifically mentioning the last chapter, which is a critical review by John F. Kihlstrom of the whole idea of traumatic amnesia. This is surely a highly emotional topic in itself and it is not difficult to agree with Kihlstrom that conclusions about traumatic amnesia have too often been drawn on insufficient evidence. However, I have two reasons to be sceptical to his wholehearted rebuttal of the concept. First, there is the evidence (reviewed by Christianson & Engelberg in the same volume but not mentioned by Kihlstrom) that amnesia is very common among criminal offenders and their victims. Kihlstrom would undoubtedly reply to this challenge by saying that it is not proven that these amnesias are traumatic in nature, but if they are not, what is traumatic? Second, a few years ago -- as a result of widespread Kihlstrom-type criticism -- the idea of lifting of childhood amnesia started to be replaced by talk about implantation of childhood memories. However, the alleged fact that it is so easy to implant false memories about your childhood has never received a satisfactory explanation. Moreover, it seems to me that such an explanation must itself presuppose a very strong negative effect of emotions on remembering processes. If emotions can produce false memories, why can't they block access to the veridical ones?
© 2008 Helge Malmgren
Helge Malmgren, PhD, MD, Department of Philosophy, Göteborg University, Sweden