HUMAN

One grand search engine for all the qualities that make Homo sapiens different from other species.

Cognitive neuroscientist Gazzaniga (Psychology/Univ. of California, Santa Barbara; The Ethical Brain, 2005, etc.) knows his stuff—and a lot of other people’s stuff too. The elegant popularizer trots out study after study in brain science, emphasizing evolutionary and developmental psychology as well as his own research on split-brain patients and others with neurological lesions. No surprise, then, to find him weighing human traits for their adaptive value in terms of safety, survival and reproduction, especially qualities that promote socializing and cooperation. Indeed, he sometimes argues too much for an adaptive value for well nigh every human feature he discusses. Gazzaniga describes how lesions reveal the brain’s organization into myriad modules specialized for, say, recognizing faces (located in the right hemisphere). He argues for a left hemisphere “interpreter” who’s in charge—making sense of all the inputs, but ready to make up stories if need be. This seems to put him in the camp of dualism, which supposes there is something else behind the physical substance of brain tissue that accounts for the mind; though the idea’s been around since Descartes, it remains debatable. The author celebrates the unique richness of the human neocortex, more complex than in any other animal. By inference, the cortex and its extensive connectivity account for art, music, analytical thinking (and thus science), self-awareness, imagination and our ability to pretend and to evoke the past and future. Gazzaniga also declares that humans are unique in their ability to project the mental states of others: to understand that behind their behavior are minds like ours that have desires and beliefs. To his credit, he discusses controversies and conflicting studies in all these areas, as well as in the origin of language, consciousness, morality and religion. Credit him too with a wonderful final section on current research on robotics and gene manipulation.

A savvy, witty guide to neuroscience today.