Copyright American Psychological Association. Not for distribution. Copyright American Psychological Association. Not for distribution. CONTENTS Acknowledgments ................................................................................... ix Introduction. The Neurocognitive Approach to Dreams ..................... 3 Chapter 1. Toward a Neurocognitive Model of Dreams .................. 9 Chapter 2. Methodological Issues in the Study of Dream Content .......................................................... 39 Chapter 3. The Hall–Van de Castle System .................................. 67 Chapter 4. A New Resource for Content Analysis ........................ 95 Chapter 5. New Ways to Study Meaning in Dreams ................... 107 Chapter 6. A Critique of Traditional Dream Theories ................ 135 References .............................................................................................. 171 Index ...................................................................................................... 197 About the Author ................................................................................. 209 vii Copyright American Psychological Association. Not for distribution. ACKNOWLEDGMENTS Thanks to David Foulkes for two careful readings of the entire manu- script; to Adam Schneider for his superlative work in creating the tables and figures in the book; to Teenie Matlock and Raymond Gibbs, Jr., for their help in developing the ideas about figurative thinking in dreams; to Sarah Dunn, Heidi Block, and Melissa Bowen for their many helpful analyses of the dream series that is discussed in chapter 5; to Thomas Van Rompay for the analyses of the dream series discussed in chapter 4; and to Ryan Harvey for his contributions to the analysis of the Barb Sanders dream series in chapter 5. A special thanks to Robert Stickgold and Richard Zweigenhaft for their many useful comments on parts of chapters 1 and 6; to Linda J. Mealey and Nicholas S. Thompson for comments and suggestions that greatly improved the discussion of the accuracy of dream reports in chapter 2; to Kelly Buckley for his suggestions on chapters 5 and 6; and to Raymond Gibbs, Jr., for his reassurances on the discussion of cognitive theory in chapter 1. I also want to thank Mark Solms for answering many questions about the neural network for dreaming and Lawrence Wichlinski for back- ground information on the role of neurochemicals in dreaming. ix Copyright American Psychological Association. Not for distribution. INTRODUCTION: THE NEUROCOGNITIVE APPROACH TO DREAMS Building on established descriptive findings in three separate areas of dream research, this book attempts to show that it is now possible to take the study of dreaming and dreams to a higher level that can rightly be called scientific. For reasons that become apparent throughout the book, it has not been easy for inquiries into dreams to escape from anecdotal clinical theories, on the one side, and neurophysiological reductionism, on the other. It is only since the 1990s that new neuropsychological and neuroimaging findings can be combined with replications concerning the lack of dreaming in young children and the consistency of adult dream content to suggest the new neurocognitive synthesis that is presented here. In addition to proposing a neurocognitive model of dreaming, the book provides a methodological foundation for testing some aspects of the model and includes new findings on dream content that demonstrate the possibilit- ies of those methods. The model is an open-ended and tentative one; it is meant as a starting point for future research. The work upon which it builds has come to maturity and a possible integration at an ideal moment, because advances in neuroscience, content analysis, cognitive linguistics, statistics, and computer software make it possible to test the new model. The timing may be right for consideration of a new model because the empirical findings from systematic studies do not support any of the best known clinical theories. This point has been made in several reviews of the accumulating research evidence (Domhoff, 1999a; Fisher & Greenberg, 1996; Foulkes, 1996a, 1999). However, the full case against all of these theories is brought together for the first time in chapter 6 of this book. This critique is placed at the end of the book so that much of the empirical evidence on which is it based can be presented first. This approach also differs from the neuropsychological model called activation–synthesis theory, which starts at the level of single-cell firings in the brain stems of lesioned cats and moves to speculations about how 3 Copyright American Psychological Association. Not for distribution. the brain stem may have direct effects on dream content (Hobson, 1988; Hobson & McCarley, 1977; Hobson, Pace-Schott, & Stickgold, 2000b). By way of contrast, the neurocognitive model suggested in this book begins at the phenomenological level with the subjective experience of dreaming and with waking dream reports, then proceeds to a neuropsychological level. The similarities and differences between the two models are explored throughout the book and in chapter 6. The model presented in this book starts with findings from neuropsy- chological assessments of people with brain lesions who report changes in their patterns of dreaming (Solms, 1997). These neuropsychological findings are corroborated and expanded by neuroimaging studies of rapid eye move- ment (REM) sleep, the stage of sleep during which dreaming most vividly occurs (Braun et al., 1997, 1998; Heiss, Pawlik, Herholz, Wagner, & Wien- hard, 1985; Maquet et al., 1996; Nofzinger, Mintun, Wiseman, Kupfer, & Moore, 1997). This work allows the model to explain the origins of dreaming and to glimpse the outlines of the neural network that underlies this form of cognition. Next, the model adds findings on children who were observed over many hundreds of nights in the sleep laboratory (Foulkes, 1982, 1999; Foulkes, Hollifield, Sullivan, Bradley, & Terry, 1990). This work allows the model to explain how dreaming develops in terms of the cognitive processes that make it possible. This work combines with the findings on the neural network to make the model truly neurocognitive. Finally, the model explains the nature of dream content by incorporat- ing insights drawn from quantitative investigations of many thousands of dream reports using a rigorous system of content analysis (Domhoff, 1996; Hall & Van de Castle, 1966). This coding system rests at the nominal level of measurement, uses percentages and rates to correct for differences in the length of dream reports, and has high reliability. It is one of the few coding systems that has been used extensively by investigators other than those who created the system, including researchers from Japan, India, Switzerland, and the Netherlands, and it has proven useful with dreams collected by anthropologists in small traditional societies as well (Domhoff, 1996). The results from these three empirical areas of dream research make it possible to state the following generalizations that lead to a neurocognitive model and many testable hypotheses: I Dreaming occurs when a relatively specific neural network— located primarily in the limbic, paralimbic, and associational areas of the forebrain—is activated in the absence of external input coupled with a letting go of control by the self. If defects occur in this network, dreaming can be lost temporarily or 4 THE SCIENTIFIC STUDY OF DREAMS Copyright American Psychological Association. Not for distribution. permanently, or it can be impaired in some way, such as through the loss of visual dream imagery. I Dreaming is a cognitive achievement that develops gradually over the first 8 or 9 years of life. I The “output” of the conceptual systems in the neural network for dream generation, called dream content and available to scientists through written or transcribed dream reports, is drawn from many of the same schemata and memory systems as waking thought and is generally continuous with waking conceptions; this content includes a great deal of previously unrealized repeti- tion in characters, social interactions, misfortunes, negative emotions, and themes. These generalizations lead to several hypotheses concerning the links between the neuropsychological, developmental, and content analysis findings: I Because specific neural defects can lead to the loss or impairment of dreaming and because dreaming develops gradually in chil- dren, adultlike dreaming may depend on the maturation of the neural network for dreaming. For example, the complete loss of dreaming in adults due to injuries in or near either parieto- temporal-occipital junction, along with the finding that in- creased dream reporting in young children correlates with visuo- spatial skills, together suggest that the ability to dream in chil- dren may depend in part upon the development of the neural network for spatial construction, which is centered in this region. I The importance of limbic structures in dreaming and the repeti- tive nature of dream content suggest that the “emotional brain” mapped out by LeDoux (1996) may be one basis for the repeti- tive nature of much dream content, including the nightmarish dreams accompanying posttraumatic stress disorder and tempo- ral-lobe epileptic seizures. I The fact that dreams can be made more vivid and frightening by drugs affecting the dopaminergic and cholinergic systems suggests that the relationship between the neural network for