In 1980 PBS broadcast the great Carl Sagan’s Cosmos, a landmark series, which did a masterful job of popularising science. Now, 35 years later, neuroscientist David Eagleman transports us to another mysterious place. This time the destination is the inner cosmos – the brain. Sagan is tough act to follow, but Eagleman will also make you see yourself in a new way. The Brain: The Story of You, a new six-part series, also made by PBS, is crammed with fascinating insights and unusual perspectives.
One typical example is how our senses work. We think that we have direct access to the world through our senses. But this is an illusion. In the outside world there is no colour, no sound, no smell; everything is taking place in our brain. The brain has no access to the external world. Our sensory organs – eyes, ears, nose, mouth, and skin –collect information from a whole range of disparate sources such as electromagnetic radiation, air compression waves, and aromatic molecules. Our senses then translate this data into the language the brain understands: electrochemical signals. The idea that seeing isn’t happening in your eyes, hearing isn’t taking place in your ears and smell isn’t happening in your nose takes some getting used to. The electrochemical rendition may not be 100% faithful, but it is sufficient for us to navigate successfully through the world.
All this is brought to life by some wonderful visual effects. Here are some of the fascinating cases and experiments that Eagleman shows in the series. They are accompanied by short videos that you can find on YouTube.
The shows have a number of case studies. In 1971 Ian Waterman was a butcher on Jersey. Then the 19-year old came down with a severe case of gastric flu, which destroyed half his nervous system. He had no sense of touch below the neck and he lost the sense of proprioception, which tells the brain about the position of our limbs. Waterman was told he would be confined to a wheelchair for the rest of his life. But with sheer determination he has made himself get up and walk. But it is a struggle as he has to think consciously about every movement his body makes.
The Trolley problem
In a post from 2009, Some philosophical thought experiments #1, I looked at the Trolley problem:
A trolley is running out of control down a track. In its path are 5 people who have been tied to the track. Fortunately, you can flip a switch, which will lead the trolley down a different track to safety. Unfortunately, there is a single person tied to that track. Should you flip the switch? Consider another, similar dilemma. You’re walking along the track again, you notice the trolley is out of control, although this time there is no auxiliary track. But there is a man within arm’s reach, between you and the track. He’s large enough to stop the runaway trolley. You can save the five people on the trolley by pushing him onto the tracks, stopping the out-of-control vehicle, but you’ll kill the man by using him to stop the trolley. Again, what do you do?
This is a staple of ethics debates, but neuroimaging provides an interesting perspective. In the first scenario, which involves pulling a lever, activates the regions involved in solving logical problems; it is like solving a mathematical problem. In the second scenario, in which you have to push the man onto the track, activates additional networks into the decision: brain regions involved in emotion. This doesn’t necessarily help us resolve the ethical dilemma, but it does help why people often say yes to pulling the lever, but reject pushing the man onto the track, even though the calculation of lives lost is exactly the same.
The effects of Botox on facial muscles are well known. What is surprising is that people who have used are Botox worse at identifying the emotions shown in pictures correctly. The reason is apparently that we will often subconsciously mirror other people’s emotions when we are with them. Botox impedes this imitation, making users proved worse at interpreting emotions.
Eagleman recreated an experiment by Paul Bloom et al. which tested the ability of 100 babies to judge social behaviour of a puppet that had previously helped or harmed another puppet in a short show without dialogue. When asked after the show to choose a bear to play with almost all the babies choose the bear that had been kind. Even though they can’t walk or talk, they already have the tools to make judgments about others.
What is Empathy?
Eagleman shows how watching someone else in pain activates one’s own pain matrix, the pain processing areas of the brain. This is the foundation of empathy. But not all empathy is created equal. With collaborator Don Vaughn, he wanted to carry out a study using brain scans to determine how empathetic we are to people who are different from us. The 135 participants saw videos of a hand, which was labelled “Christian,” “Jewish,” “Hindu,” “Muslim,” “Scientologist” or “Atheist”, being touched by a cotton swab or stabbed by a syringe. While this was happening, the blood flow to their brain was being measured. The idea was to look at the regions of the brain that respond when viewing another person in pain. The results were sobering. Some people were equally empathetic to all hands, but many did care more about “their team”, including the atheists. We really are influenced by the in-group / out-group dynamic. And remember the only difference was a label.
There are many themes in the book – how the brain can distort time, its plasticity, the fallibility of memory, the feeling of free will, the unconscious, the power of now, the mechanisms of decision making and the quest for immortality. It’s a series I can highly recommend.