Antonio Damasio takes exception
to Descates’ observation, “I think, therefore I am” in his 1994 book
‘Descartes’ Error’. The overarching theme of the book is exploration of the
concept of self, and identifying the physiological processes that underlie
decision making of individuals.
Rather than a simple exploration
of an idea, Damasio methodically takes his readers through the scientific
process involved in addressing any problem. We start the book with
identification of the issue at hand, introduction of the various players,
development of a hypothesis, designing of experiments to test it and finally
interpret the results to inform the greater community of the inferences.
The first third of the book
concentrates on case studies. We are introduced to various patients and the
brain lesions that have impaired their emotional and decision making
capabilities.
Without lowering the level of
discourse or easing up on the use of scientific jargon, Damasio provides a
platform for teaching his audience about the overall anatomy of the brain, the difference
between the cortical and sub-cortical structures. He then dwells into the
structure, function and connectivity of the neurons, their biochemistry about
the neurons, their parts, roles and finally the neurochemistry of the brain.
As we go from one patient to
another, we learn about different brain structures and how lesions or injury to
these parts are associated with different symptoms.
Damasio spends a decent amount of
time explaining the molecular basis of behavior. Not only do we learn about the
influence of the brain on the body and that of the body to the brain.
Additionally, he explains how human control over our instincts as being a
possible outcome the brain circuits that have evolved to learn acquired social
rules.
Where Damasio shines the best in
his book is the distinction that he draws between emotion and feeling. While
emotion is the body state, representing the electrical and chemical make up of
the body at a given time, feeling refers to the cognitive juxtaposition of the
body images with context.
With these ideas in mind, we are
next introduced to the concepts that underlie Somatic Marker Hypothesis, the
theory of mind that analyzes the decision-making processes of our brain.
Briefly, when presented with a stimulus, a thought or a future scenario, images
are created in our brains, which result in somatic (body) changes manifested as
something as simple as rising of the blood pressure. Presentation of any
stimulus or a real life situation with social consequences thus leads to a
possible physical change that can show our emotions.
He finally concludes the second
portion of his book explaining how the somatic markers lead to inherent biases
within the brain, which explains the different behaviors and risks that people
are ready to undertake.
The third and final part of the
book deals with experimentation to test the somatic marker hypothesis that was
developed in the previous chapter. We learn of experiments designed to simulate
real world complex decision making process. The results from these show how
brain injury can lead to an impediment to sound decisions. This is used as a
proxy for the bad social and economical decisions that patients of brain damage
have shown in their lives.
All of this sets the stage for
Damasio to explain his choice of the title. Descartes’s observation was based
on his belief that the idea of self originates from the existence of a working
brain and that it is the brain that distinguishes us from other animals. However,
Damasio through his somatic marker hypothesis lays shows the opposite, thus
correcting Descartes’ to “I am, therefore I think”. We learn of the constant
feedback loop between the body and the brain that underlies our perception of
self and that of others. Any breakdown within this loop leads to an altered,
incomplete view of what it means to be a human being.
Sitting at the intersection of
psychology, neuroscience and philosophy, I find this book highly enjoyable and recommend
it book to anyone who wishes to explore what it means to be a human and if we
can ascribe certain aspects of humanity to other species.
