George Christos

MEMORY AND DREAMS

The Creative Human Mind

George Christos is a physicist by training who now teaches mathematics at Curtin University of Technology in Perth, Australia. For the past decade he has been interested in how human memory works, and in this book he offers his ideas about this, especially in relation to dreaming.

The book has six chapters, which are intended to be partly independent of one another, so that there is deliberately some repetition. The first chapter is introductory, with an overview of the territory. The second is intended for readers with little knowledge of how the brain works; it gives a brief account of neurons and how they are connected, of the synaptic gap, and of some neurotransmitters; the main parts of the brain thought to be involved in memory formation. especially the hippocampus, are also described.

Chapter 3 presents an account of memory and relates this to models derived from neural networks. This leads to an important idea for Christos, which reappears in Chapter 4: that is, that the brain produces "spurious memories". One current theory about memory is that it depends on "strange attractors" which can emerge in dynamic systems like neural networks. According to some theorists these attractors constitute the basic building blocks of memory. In certain circumstances memories occur in neural networks which were not stored there intentionally; these are called spurious memories and Christos believes that they can also occur in the brain. However, he does not provide much in the way of psychological evidence for this, though he suggests that they may explain curious experiences such as déjà vu and jamais vu.

One might think that spurious memories would be something to avoid as far as possible, but Christos thinks that they are essential for creativity because they provide the input for new ideas. They seem to be the seed from which originality arises. This is the theme of Chapter 4, and it is developed further in Chapter 5 where the role of dreaming is considered. Some scientists, notably Francis Crick, have proposed that the function of dreaming is to erase unwanted memories and so to make the brain more efficient, a process described as "unlearning". Christos agrees with this up to a point, but he thinks that dreaming also generates more spurious memories in order to enhance creativity. He has little sympathy with Freudian or Jungian notions of dream symbolism but regards dreaming as serving to "roughen up" the memory landscape to generate new patterns and new linkages among memories.

The final chapter proposes a theory about sudden infant death syndrome (SIDS). Approximately one in a thousand live births results in a death whose cause is unknown, when an apparently healthy infant dies suddenly and unexpectedly while asleep. This is a diagnosis of exclusion: it is made when no cause for the death can be found. Numerous explanations have been suggested but there is no firm agreement about the mechanism of death in these cases. Christos's hypothesis is that the infant dreams it is back in the womb, and because it did not need to breathe at that time it stops breathing. He claims that this theory can explain all the known facts about SIDS. But is it testable?`

As Christos acknowledges, it is not enough just to account for the known facts. A would-be scientific theory should also make predictions by which it can be tested. This is difficult to do in the case of SIDS but Christos offers some suggestions. The most useful (and potentially beneficial) test, he believes, would be to make the environment as unlike the womb as possible so as not to encourage the infant to dream of being back in the womb and to remind it that it has been born. If the theory is right, it follows that attempts to recreate a womblike environment for infants by wrapping them up firmly or using apparatus intended to make sounds like those of the mother's heartbeat are misguided and potentially dangerous. Giving the baby a dummy (comforter) to suck might be helpful because this would not happen in the womb, but thumb-sucking is undesirable because fetuses do suck their thumbs before birth. (In fact, they also breathe in the womb, although obviously they inhale amniotic fluid, not air.)

Though the book is short it is quite ambitious and tackles a number of somewhat disparate subjects: memory, dreaming (including lucid dreams), creativity, and SIDS. It is well written and fairly jargon-free and provides a useful overview of current thinking about the questions it deals with, which is interesting whether or not one agrees with the author's conclusions. I doubt that the SIDS theory will gain widespread acceptance. I think the "spurious memory" theme ought to have been developed at greater length than it is here; for example, it would be interesting to know whether Christos believes that it is relevant to the contentious matter of "recovered memories".

14 November 2003