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Hi everybody, Before I will read your comments on the target paper I will formulate my first and second impressions (I was referee on two drafts of the paper). If you did not understand what I say (my native language is German) please do not hesitate to ask me. General comments: I very much appreciate the work of Raija-Leena Punamäki. Every researcher's heart will beat faster if she/he had the possibility to analyze such data. In general, the studied population is very interesting from a political point of view (a repressed minority). Although I like the paper there are of course a lot of topics I will address that I had handled in a different way. It seems that Popper's rational critizism is crucial for scientific development. If I say everything is okay nothing will happen. The comments will be ordered into sections which are parallel to those in the paper. Introduction I recently published an extensive overview on the dream recall literature (Schredl, M., & Montasser, A. (1996-97). Dream recall: state or trait variable? - Part I and Part II. Imagination, Cognition and Personality, 16, 181-210, 239-261. I found 6 models and hypothesis constructed for explaining intraindividual and/or interindividual diffenrences in dream recall frequency. 1. Repression hypothesis (Freud) 2. Life-style hypothesis (Schonbar) 3. Interference hypothesis (Cohen and Wolfe) 4. Salience hypothesis (Cohen and MacNeilage) 5. Arousal-Retrieval model (Koulack and Goodenough) 6. Functional state-shift hypothesis (Koukkou and Lehmann) The research provide some evidence for each of these models but a model integrating all aspects is lacking. I stress this fact because Punamäki selected only a few hypothesis of the pool. In general, there exist serious problems in evaluating the hypothesis since some of them (repression hypothesis, interference hypothesis, salience hypothesis) are not testable in a direct way. Contrary to classical memory theory the original stimuli (experienced dream) is not measurable. One could only measure the recalled dream. These remarks should be understood as hints to be very careful in interpreting the data of the present study but of all other studies, too. I personally do not like the mood congruency hypothesis since it is not testable. How should it be possible to measure dream emotions independendly from mood after awakening. I would like to name it carry-over effect. It seems more plausible to me that dreams influence morning mood. Maybe research, for example carried out by Domhoff (about 1969) support this hypothesis. He investigated recall of dreams during the day triggered by an experience. Method section In a previous draft Punamäki wrote that the participants were intensively informed about the purpose of the study. Since it was shown that dream recall frequency could be affected easily by instruction I proposed that Punamäki should comment on this possibility. Personally, I think the participants knew very well the aims of the study. Second, the results may be influenced by experimenter effects since the groups were interviewed by two different persons. The researcher himself (highly motivated) obtained the sample with higher dream recall frequency. I think a comment on this should be given. Personally, I like the funny sampling method. If you would do such a thing in Germany, everybody would laugh at you. There is, however, one weakness in this approach shortly addressed by Punamäki. He did not give a response rate or a sample size of all potential participants. This could lead to severe biases in the data. Results I have some problems with figures 3 and 4 since they do not depict raw data but lines computed by the statistic program. Second, I do not understand the formula for deriving correlations between dream emotions and morning mood. Is N ranging from 2 to 7. If so, it may be an artefact that high recallers had higher coefficients since more data enter in the correlation coefficient. Discussion First, I think it would be very interesting not only measuring dream recall freqency per se but also analyze frequency of negative dreams or nightmare frequency (Punamäki elicited it in the composite score sleep difficulties). In view of the continuity hypothesis I would expect a heightened frequency of negatively toned dreams. The above mentioned objections to the testability of the salience hypothesis should lead to very careful conclusion. In a recently conducted study we found that high recallers reported more positive emotions than low recallers whereas negative emotions do not differ. We explained this fact that high recallers are more trained in recalling dream content since research has shown that positive emotions were often not mentioned explicitely (Hall and Van de Castle). I cite this data since I would like to stress the fact that one could not be sure of the direction or of causal relationships. Sleep laboratory data exploring the relationship between physiological and/or cortical arousal and dream recall after awaking lead to contradictory results. I would like to add a possible causal mechanism. Since we have shown that sleep quality and frequency of noctural awakenings correlate substantially with dream recall frequency it may be plausible that stress affected sleep quality and nocturnal awakening and, therefore, dream recall is heightened. This would be fit in the arousal-retrieval model of dream recall. The regression analysis (exept for analysis regarding dream salience) yielded coefficients of explained variance of about 10 %. This should be interpreted in the following way: The elicited measures are only few of a larger pool which may influence dream recall frequency. So the confirmed hypotheses could only explain a small portion of the whole variance and one should give attetion to further factors affecting dream recall. Dipl. Psych. Michael Schredl Sleep laboratory Central Institute of Mental Health P. O. Box 12 21 20 68072 Mannheim Germany Telefon: Germany 0621/1703-602 Fax: Germany 0621/23429 Homepage: http:/www.zi-mannheim.de/schlaflab/abteilung.htm