Review - The Ravenous Brain
How the New Science of Consciousness Explains Our Insatiable Search for Meaning
by Daniel Bor
Basic Books, 2012
Review by Gustav Jahoda, Ph.D.
Mar 26th 2013 (Volume 17, Issue 13)
This book deals with a topic that has long remained shrouded in mystery, namely consciousness. As the author shows, philosophers have attempted to grapple with it over the centuries, to no avail. It is only now, thanks to a combination of evolutionary theory and the resources of modern technology, that remarkable advances in understanding have become possible. Bor lucidly describes how this has been achieved, melding scientific rigour with intimate personal touches. For example he begins with an account of how the experience of his father' stroke and the ensuing personality change set him on his quest. The work is densely packed with -- often challenging -- ideas, so that only broad themes and particular highlights can be sketched. The general message, persuasively argued, is that consciousness (or awareness) is an emergent from complex information processing.
This is not to say that it is something which suddenly appeared in humans, but is deeply rooted in evolutionary history. Even the simplest organic forms have built-in devices which guide them in their interactions with external world, which means that they process information, albeit very crudely. Nature proceeds by trial and error through replication with modification, and the small minority of species that survived acquired increasingly complex means of dealing with useful information and eventually, through learning, were able to acquire an ever more sophisticated internal map of their world. Although the human brain, with its billions of neurons capable of forming an incredibly large number of connections is unique, it is merely the endpoint of a chain that goes back to the origins of life on earth. While the main emphasis is on information, early on animals acquire what Bor calls a 'value system', which begins with representations of what is good or bad for the organism and extends into more differentiated emotions. It is mainly in this connection that Bor refers to the human need to adapt to their social/cultural environment.
The evolutionary history is reflected in the several levels of the human brain from the primitive brain stem to the neocortex. Not just illustrations of the effects of damage to various parts are offered, which throws light on their functions, but a wide range of ingenious new experimental evidence is presented. While the cortex processes complex information, Bor claims that the unconscious is severely limited in this respect. He effectively demolishes a widely reported experiment that sought to prove the opposite, and dismisses so-called 'eureka' experiences. However, there is suggestive anecdotal evidence, e.g. by the famous mathematician Poincaré. Moreover, Bor himself mentions in several places intricate tasks performed unconsciously, of which the following is an example: 'an active, ever-changing, yet unconscious statistical machine is in force, transforming the basic information we receive into a detailed model of the immediate world, including how it is likely to change . . .' -- that is surely no mean feat ! In the context of experiments showing that the brain arrives at decisions seconds before they become conscious, the author discusses the vexed issue of 'free will'. The question is how such results are to be interpreted. He fails to make his own position entirely clear, but reading between the lines it seems that at least in one sense he regards it as an illusion.
Given the vast amount of information impinging on us every second some filtering and focusing device is essential and that is the attentional system. It responds to emotional and instinctive signals, and in humans extends to abstract objectives. Its mechanism consists of ' the electrical activity of vast collections of neurons' competing with each other for dominance and 'Those with most powerful voice recruit others to their cause, and suppress any dissenters' until the strongest win and gain access to consciousness. It is worth noting that an analogous concept was put forward some two centuries ago, when Herbart postulated a struggle between Vorstellungen (which may be glossed as 'ideas') with the stronger pushing the weaker ones into the unconscious. There follows a discussion of theories of the special case of self-awareness, which Bor regards as a by-product of 'a deep intellect and a rich conscious life'. Returning to attention, he introduces the concept of short-term 'working memory' , the conscious outcome of attentional filtering which is confined to a severely limited capacity of about four objects -- about the same as a monkey's. This raises the question as to how, in these circumstances, humans have been able to reach such intellectual heights. The answer given is that while there are few discrete compartments, each can deal with immensely complex objects through a process of 'chunking', the compression of data, and the elimination of anything irrelevant. There is also a search for structure, coherent patterns and meaning, a process involves the integration of past experiences. It is what Bartlett, ignorant at the time of the neural story, dubbed the 'fundamental "effort after meaning" '.Language is also said to be closely linked to chunking, and Bor does not believe in the often postulated 'language instinct' .
The next chapter, poetically named 'The brain's experience of a rose', reviews the evidence of the manner in which various parts of the brain contribute to awareness. For instance, the pre-frontal parietal network is activated when one faces any kind of novel or complex task. At the same the notion of a fixed division of labour between various parts of the brain is abandoned in favour of a dichotomy of flexible, dynamic conscious processes versus automatic ones in the unconscious. Experiments demonstrate the transition from deliberate chunking and pattern-seeking to, once having found them, their use in an automatic fashion. The issue of the subjectivity of conscious experience is tackled and, surprisingly, a daring mathematical model that requires such subjectivity is outlined. Given that subjectivity, what can one find out about consciousness in infants and animals? Quite a lot it seems. Many animal species are, like humans, 'ravenous for information', and if placed in an impoverished environment display signs of stress. Some birds are capable of planning a novel use of tools for getting food. Other experiments show that the performance of monkeys on a difficult gambling task implied a meta-awareness of the same kind as that displayed by humans. Bor's general conclusion is that there is indeed likely to be a stepwise continuum of degrees of consciousness down to rather simple creatures, a fact which raises ethical issues.
The rest of the book deals with the effects of brain damage, where scanning can be used to identify conscious mental activity in patients classified by traditional diagnoses as being in a persistent vegetative state. Various forms of mental illness are also considered in the light of the ideas developed in the earlier part of the work. As the author's wife suffers from bipolar disorder, this is clearly a very personal matter as well as a theoretical one for him. Since much mental illness is to a considerable extent associated with stress, he advocates meditation shown to have beneficial physiological effects. He muses that mental illness is perhaps the price we pay for our rich conscious life, many of whose foundations are brilliantly expounded
There are of course problems that remain. At various points there are references to instinct, emotion and values, and it is sometimes suggested that these act as driving forces, but it is not really explained how these intermesh with the activities of the vast mass of neurons. When 'war' breaks out among conflicting groups of neurons, what determines the outcome? Do not emotions and values play some part? One is reminded of the pithy saying by Hume that 'Reason is . . . the slave of the passions', which is no doubt exaggerated but embodies an important truth. This also relates to Bor's view that \a sufficiently complex computer might come to display consciousness. One has certainly to take that seriously, and in fact there is currently an ambitious undertaking in Lausanne, known as 'The Human brain project' which seeks to explore this issue. The question that arises is whether it is just the astronomical number of connections that are sufficient by themselves to create consciousness.
There comments are themselves a tribute to the clarity of this book, which stimulates readers to think for themselves. It is also very well written, which makes it a pleasure to read. In sum, it can be recommended without reservation to anyone who wants to be informed about recent advances in our knowledge about how that extraordinary organ, our brain, came to be, and how it functions.
© 2013 Gustav Jahoda
Gustav Jahoda, Ph.D. is Emeritus Professor of Psychology at the University of Strathclyde, Glasgow. His main fields of interest are cross-cultural and social psychology, especially the development of social cognition. He is the author of A History of Social Psychology (Cambridge University Press).