For example, a patient with right hemisphere damage, when looking at a friend, has a very difficult time comprehending that what is in front of them is their friend, but instead sees only arm, foot, brown hair, pant leg, male, etc. The left is very poor at seeing the whole, and only sees parts. The left hemisphere can only think in logic, systems, abstractions, utility, control. But as we all know, once a joke is explained it is no longer funny.

The left hemisphere is very bad at humor, and requires jokes to be explained. By contrast the left hemisphere is almost incapable of understanding context - to the extent that if the right hemisphere is damaged the person cannot even understand that some of their body parts belong to them - their arm is not 'their arm' because that requires too much context, their arm is just 'an arm', disembodied. The right hemisphere knows context, knows what is implicit - for example, the right hemisphere is very good at understanding stories, which are usually filled with context and implied content. The right hemisphere directly perceives life and meaning. The left hemisphere then re-presents the world in abstract categories, which are quite lifeless and devoid of any meaning. The left hemisphere is not very good at directly perceiving the world, and largely relies on what the right hemisphere perceives. For example, the right hemisphere sees the world as it is, as the impressions come in, and perceives things as a whole.

His distinctions are so varied and nuanced (and did I say constantly backed by experimental evidence.), that now that I am trying to write about it I realize how much this book could use a second read. The first part of the book puts forth some of the more nuanced ways the brain left & right hemispheres are different (beyond the cocktail discussion level of right-brain-emotional/left-brain-verbal). The First Half of the Book - the two hemispheres perceive reality differently This is hands-down one of my favorite books in quite a while.

Great book if you want to sink your teeth into the newest neuroscience about the human brain hemispheres. He clearly acknowledges the gaps between data, interpretation, and outright speculation, but even his speculation is firmly rooted in data.

Weighing in at 616 pages, and absolutely packed with research results, this is not a light read. The Master and His Emissary, by Iain McGilchrist, book review

The master and his emissary book