The Brain As Expectation Machine: Understanding Placebos, False Memories, and More

 

BOOK REVIEW

Suggestible You: The Curious Science of Your Brain’s Ability to Deceive, Transform, and Heal
Erik Vance (National Geographic Partners, 2016)

 

BY NATHAN CURLAND

I was first introduced to Erik Vance when he was interviewed about his book by Steve Mirsky on a "Science Talk" podcast on Scientific American Online in November. That interview motivated me to borrow a volume from the library. It is quite a find.

Vance is a science journalist who has a long career in the field. He was brought up in a Christian Science environment and believed in faith healing until, at age 18, he had an epiphany while rock climbing that caused him to reject the god-based premise of the religion. However, he had seen vivid cases and heard stories where people had recovered from what appeared to be serious diseases, so he became interested in science and exploring valid real-world explanations for them. 

This led him to scientists who were studying the placebo effect and were starting to uncover physiological bases for how the body’s own internal chemistry will respond to signals from the unconscious brain to help fight illnesses. However, to find where these brain signals originated, he had to turn to more fundamental work coming out of modern understandings in the field of neuroscience as to how the brain constructs our individual view of reality. 

What he found is that our brains are expectation machines. The flood of information that they receive at any instant of time is so overwhelming that we cannot process it all. So we pick out the important features and then fill in the rest based on our past experiences. This creates an expectation of what is to come, which (along with the body’s own pharmaceutical factory) is the basis of the placebo effect. 

But that’s not all. This expectation property makes our brains very malleable and can be used to explain a wide range of effects, including why people can be hypnotized or develop false and implanted memories.

Vance takes us down all these avenues. He describes interviews he has had with numerous scientists specializing in this field, hypnotists, Chinese medicine practitioners, homoeopathics, etc. Along the way he discovers how this ability of the brain to “trick itself” can be used to help people who suffer from certain ailments such as chronic pain, insomnia, depression, and even Parkinson’s. 

The most interesting part of this the discovery is that there appears to be a genetic component as to how suggestible any particular individual is. This helps explain why bringing a new drug to market to fight these type of ailments is so expensive. The presence of people prone to the placebo effect will mean that many more people must be enrolled in trials so that the benefit of a particular drug can be ascertained.

The most disturbing part of the book is the section on false memories. Vance takes us back to 1980s when a secret cult of child molesters was “discovered” in a small town in Florida, creating mass hysteria.. Ten years later, children from this school, under hypnosis, “revealed” details of the debauchery that occurred. 

Many people were arrested and sent to jail. It wasn’t until many years later that scientists were able to show that these memories were false, a result of how the mind does not really remember things well. In fact, it remembers only “the last time the memory was accessed” and then fills in the blanks based on a person’s current perceptions and attitudes. It can also be influenced by other factors, such as how questions are asked or current societal mores.

Vance has the ability to tell a good story (or this case, many stories) and make them interesting and entertaining. There is even a “Hypnotic Induction Script” in the appendix if you wish to try out your hypnosis skills! The book is 246 pages long, not counting the long list of sources at the back, and is a fast and easy read. I highly recommend it.