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Review: Human, by Michael Gazzaniga
WE’RE SPECIAL AND YOU KNOW IT Something in the human brain sets us apart from other animals. Ivan Semeniuk follows an expert guide as he attempts to pin it down Human: The science behind what makes us unique by Michael S. Gazzaniga, HarperCollins, $27.50, ISBN 9780060892883
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JESSE MARLOW/OCULI/AGENCE VU
WHY do religious fundamentalists oppose the theory of evolution, despite the weight of evidence supporting it? The answer may lie with a deepseated intuition that humans are qualitatively different from other animals – a difference so great that, for some, descent from a common ancestor is harder to imagine than the alternative. As director of the University of California’s SAGE Center for the Study of Mind in Santa Barbara, Michael Gazzaniga is no creationist. His confidence in our biological ties with the great apes is resolute. Yet, unlike many of his peers, Gazzaniga is not shy about trumpeting our special status in the animal kingdom. “We are a big deal and we are a little scared
www.newscientist.com
about it,” he writes at the outset of Human. What follows is a detailed excursion into Gazzaniga’s lifelong passion – the human brain – and his attempts to figure out exactly what makes it human. Gazzaniga’s studies of splitbrain patients – people with the connections between their left and right cerebral hemispheres severed to alleviate the symptoms of severe epilepsy – have helped to show that the hemispheres of human brains tend to be more specialised than those of other primates, and also that the left hemisphere of a typical righthanded person is where the inner narrative of subjective experience is generated. Human revisits these findings and explores recent research that shows that human brain structure, from gross anatomy down to the Is the need to navigate complex social lives at the root of our humanness?
molecular scale, is significantly different from that of other species. Structural differences, in turn, reflect different cognitive functions, Gazzaniga says, often related to the demands of interacting with larger and more complex social groups. These differences have led to our ability to construct alternate realities which can be played out as simulations in the mind’s eye. This is a useful cognitive tool for forward planning, and it may also underlie the uniquely human impulses to create art and engage in scientific inquiry. Readers interested in an overview of current research will find much of it conveniently packaged here. Those looking for answers will instead find ample reminders of how far brain science has to go before speculation and metaphor can be replaced with concrete models. Gazzaniga does not offer any grand conclusions. Despite all we have learned about the brain, we cannot yet explain how it makes us who we are. What Human resembles most is a voyage through Gazzaniga’s own left hemisphere, which has amassed a wealth of information to be digested and pondered. Finding yourself in such a rich setting, you may well agree with Gazzaniga’s closing sentiment: “Am I ever glad I am not a chimp!” ●
Digging deeper Prehistory by Colin Renfrew, Random House, $23, ISBN 9780679640974 Reviewed by Sarah Hoffman
COLIN RENFREW, a towering influence in archaeology for decades, sums up how the field has endeavoured to reconstruct our human past, before examining the unsolved problems that remain. For example, archaeologists do not fully understand why cultures and civilisations developed in the ways that they did, nor how the human mind developed. Renfrew argues that we need a new theory of cognitive and developmental archaeology. Prehistory is a remarkably useful text in that it will generate lively, thoughtful and passionate discussion and inspire new ways of examining existing evidence.
My day was worse The Undercover Scientist by Peter J. Bentley, Random House, £12.99, ISBN 9781847945235 Reviewed by Sam Kean
PRAY you never have a day as hellish as this. Within 16 hours, the hero of this book gets a computer virus, squirts raw chilli juice in his eye and breaks his toe, little finger and front tooth, among other mishaps. The consolation for us is that every calamity illustrates more science, such as why milk goes putrid, or why diesel ruins petrol cars. None of the science is groundbreaking – everyday wonders get preference – but it makes for novel reading. It’s stream-of-consciousness science, as if Leopold Bloom from James Joyce’s Ulysses was a clumsy but observant engineer.
16 August 2008 | NewScientist | 45
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JESSE MARLOW/OCULI/AGENCE VU
WHY do religious fundamentalists oppose the theory of evolution, despite the weight of evidence supporting it? The answer may lie with a deepseated intuition that humans are qualitatively different from other animals – a difference so great that, for some, descent from a common ancestor is harder to imagine than the alternative. As director of the University of California’s SAGE Center for the Study of Mind in Santa Barbara, Michael Gazzaniga is no creationist. His confidence in our biological ties with the great apes is resolute. Yet, unlike many of his peers, Gazzaniga is not shy about trumpeting our special status in the animal kingdom. “We are a big deal and we are a little scared
www.newscientist.com
about it,” he writes at the outset of Human. What follows is a detailed excursion into Gazzaniga’s lifelong passion – the human brain – and his attempts to figure out exactly what makes it human. Gazzaniga’s studies of splitbrain patients – people with the connections between their left and right cerebral hemispheres severed to alleviate the symptoms of severe epilepsy – have helped to show that the hemispheres of human brains tend to be more specialised than those of other primates, and also that the left hemisphere of a typical righthanded person is where the inner narrative of subjective experience is generated. Human revisits these findings and explores recent research that shows that human brain structure, from gross anatomy down to the Is the need to navigate complex social lives at the root of our humanness?
molecular scale, is significantly different from that of other species. Structural differences, in turn, reflect different cognitive functions, Gazzaniga says, often related to the demands of interacting with larger and more complex social groups. These differences have led to our ability to construct alternate realities which can be played out as simulations in the mind’s eye. This is a useful cognitive tool for forward planning, and it may also underlie the uniquely human impulses to create art and engage in scientific inquiry. Readers interested in an overview of current research will find much of it conveniently packaged here. Those looking for answers will instead find ample reminders of how far brain science has to go before speculation and metaphor can be replaced with concrete models. Gazzaniga does not offer any grand conclusions. Despite all we have learned about the brain, we cannot yet explain how it makes us who we are. What Human resembles most is a voyage through Gazzaniga’s own left hemisphere, which has amassed a wealth of information to be digested and pondered. Finding yourself in such a rich setting, you may well agree with Gazzaniga’s closing sentiment: “Am I ever glad I am not a chimp!” ●
Digging deeper Prehistory by Colin Renfrew, Random House, $23, ISBN 9780679640974 Reviewed by Sarah Hoffman
COLIN RENFREW, a towering influence in archaeology for decades, sums up how the field has endeavoured to reconstruct our human past, before examining the unsolved problems that remain. For example, archaeologists do not fully understand why cultures and civilisations developed in the ways that they did, nor how the human mind developed. Renfrew argues that we need a new theory of cognitive and developmental archaeology. Prehistory is a remarkably useful text in that it will generate lively, thoughtful and passionate discussion and inspire new ways of examining existing evidence.
My day was worse The Undercover Scientist by Peter J. Bentley, Random House, £12.99, ISBN 9781847945235 Reviewed by Sam Kean
PRAY you never have a day as hellish as this. Within 16 hours, the hero of this book gets a computer virus, squirts raw chilli juice in his eye and breaks his toe, little finger and front tooth, among other mishaps. The consolation for us is that every calamity illustrates more science, such as why milk goes putrid, or why diesel ruins petrol cars. None of the science is groundbreaking – everyday wonders get preference – but it makes for novel reading. It’s stream-of-consciousness science, as if Leopold Bloom from James Joyce’s Ulysses was a clumsy but observant engineer.
16 August 2008 | NewScientist | 45