The Ancient Origins of Consciousness: How The Brain Created Experience by Todd E. Feinberg and Jon M. Mallatt (review)

Something wonderful happened around half a billion years ago and at least once. Feinberg and Mallatt take us through a methodical and convincing argument that consciousness has its roots in vertebrate evolution, and thus consciousness (defined by American philosopher Thomas Nagel as an experience of what it is like to be) is likely to be ubiquitously represented among all the vertebrates we currently live alongside. The conclusion that all vertebrates have always been conscious is not widely accepted by experts and is seemingly not particularly palatable to a species that considers itself unique (and behaves accordingly) in the ability to think and consider its existence in the context of the world. Feinberg and Mallatt remind us that we are investigating a very basic consciousness but that it is consciousness nevertheless. Some species understand their existence, that they are; others may muse on that existence in itself; and still fewer (perhaps just the one) consider this phenomenon interesting enough to write a book about it. The Ancient Origins of Consciousness is a comprehensive update on the hard problem of consciousness. There are no prizes for guessing why philosopher David Chalmers named the task of objectively explaining the highly subjective nature of experience the Hard Problem. This hard problem is of enormous interest to all who think, and its study has traditionally been the focus of philosophical investigation. As a hard problem, Feinberg and Mallet argue, the study of consciousness requires a multidisciplinary approach.

How does this physical thing, mostly housed in our heads behind our eyes, produce this phenomenal experience of consciousness and an understanding of what is like to be? The subtitle How the Brain Created Experience hints that this study looks back at the evolutionary arrival of consciousness. On the dust jacket, Thurston Lacalli points out that hard problems need to be tackled at a base level, and in this case it seems sensible to ask: What are the rudimentary forms of these phenomena as they emerge in evolution?

This study (and that is what it is—a serious study) approaches the hard problem from philosophical, neurobiological and neuroevolutionary positions. The work is the result of a cross-disciplinary collaboration by Todd Feinberg and Jon Mallatt. Feinberg is a neurologist, a practicing clinical psychiatrist (Icahn School of Medicine, New York) and the author of From Axons to Identity: Neurological Explorations of the Nature of the Self. Mallatt is an evolutionary biologist and associate professor of biology and medical science (Washington State University and University of Washington).

Grounded by the basic philosophical puzzles of consciousness, the authors go about methodically investigating the structures of existing species and what we know of ancestral species using morphological (current and fossil), molecular and functional evidence. In this process, Feinberg and Mallatt ask straightforward questions. What are the basic features that are needed for consciousness? When did these features first appear? Evidence strongly suggests that consciousness first appeared during the Cambrian explosion, when vertebrates first started to visually map their environments.

In a dedicated chapter, Feinberg and Mallatt raise the question, "Does consciousness need a backbone?" Posed another way: Could consciousness have evolved independently more than once? The authors note that invertebrates, despite having different brain and sensory apparatus from vertebrates, have function consistent with consciousness. Octopuses, despite their apparent cleverness, are thought to fail crucial consciousness criteria with their independent neurally controlled arms. Countering this, The Ancient Origins of Consciousness makes the case for mental unity in the octopus brain and therefore the possibility of consciousness defined as an experience of what it is to be. If this is truly the case, it is possible that consciousness emerged in cephalopods' ancestors alongside their post-Cambrian evolution of good vision. Unfortunately, these species are not as well studied as vertebrates, and the authors remain cautious, judging cephalopod molluscs and arthropods to be...