How our brain decides for us...

David Eagleman
Baylor University

The blogposts "Are our lives controlled by our unconscious brain?" and “How our brain creates a usefulversion of reality – latest neuroscience” showed neuroscientist Dr. David Eagleman’s research applied in the PBS series, "The Brain with David Eagleman".  The post is from the episode “How Do I Decide?” and shows how our brain makes our decisions for us in some surprising ways.

Every decision arises from competing networks.

Dr. Eagleman begins with “your brain is constantly making choices, weighing out different options and it’s often in a state of conflict locked in a great power struggle with itself.”

How does a simple choice arise for whether we get mint or lemon frozen yogurt, if we like both?  This choice unleashes “…a whirlwind of activity.  Neurons are wildly getting in touch with one another forming competing networks – one favors the zing of the zesty lemon, the other the freshness of the mint.  

When I finally go for the lemon I have no real idea why I chose it…” It happened “because the lemon network fought harder”. 

    

What happens when two neural networks clash?

The Stroop test involves naming colors that don’t “match” their names, i.e. the word “blue” would be colored “red”.  This causes conflict between the weaker "naming colors" network and the strong "reading words" network to get the correct "red" answer.     

You can feel for yourself how strong this conflict is.  To get the "naming colors" network to win, you have to help it out by actively suppressing the "reading words" network. 

"Emotional" networks can produce "illogical" results 

Decision studies compare different scenarios.  A famous one involves a train trolley whose brakes have failed and is racing out of control towards four workers.  

As they’re too far away to warn, they are going to die, but you see a lever.   If you pull it, the trolley will go on another track and they will be saved.  However, as there is one man working on the other track, he will die.  What do you do? 

In a similar scenario, there are still four workers in the path of the out-of-control trolley but now there’s no lever to divert the trolley, but there is a man standing on a tower next to the track.  If you push him into the trolley’s path, it will stop the trolley and save the four workers, but he’ll die.  What do you do? 

Interestingly, everyone makes the same choices – they’ll pull the lever, but they won’t push the man.  So what’s the difference?  In both cases, it's trading one life for four.  

Obviously the difference is that you have to physically, personally, push the man to his death.  That recruits "emotional" neural circuits which override logic to cause four men to die instead of one. 

How nonconscious "hunches" create "conscious" choices 

Most folk trust decisions based on intellect and doubt those based on feelings.  But what if "unconscious" feelings generate "conscious" intellectual decisions?  Dr. Richard Tunney at the University of Nottingham studies how "unconscious" decisions arise using the "Iowa Gambling Task" (IGT) which simulates "real life" decision making.

The IGT has a volunteer draw a card from one of four decks.  Each time (s)he draws a card (s)he wins some amount of money and (s)he loses some.  The goal is to earn as much as possible.

Dr. Tunney connects her to a machine similar to a lie detector that monitors changes in the sweat glands in the skin.
 

The decks are rigged so that if she keeps choosing from decks A and C she’ll make the most money.  The question is “How many cards will she have to draw to figure that out?”

Tunney found that participants consciously choose the good decks after “20 to 30 cards.”   

However, the "lie detector" shows that the nonconscious brain figures it out much earlier.  After only 10 cards there is a spike as the nonconscious brain generates a warning "feeling" whenever a “bad" deck is reached for - a “hunch” that the body registers before her conscious mind does. 

Tunney sees this “...physiological response prior to making the decision.  This spike here, in effect predicts the choice the participant is going to make."   As more cards are drawn, her hunch grows stronger and she eventually consciously “knows” which decks to draw from and which to avoid.   It feels like a logical deduction but it’s built on a nonconscious foundation.  

How the brain’s energy level changes decisions

Is justice rational and impartial?   If two men come up for parole on the same day three hours apart, who’ve committed the same offense and served the same sentence, the first prisoner is paroled and the second isn't…why?  What changed the decision?   

  

In studies of over a thousand rulings from different judges, they found that prisoners were 3X more likely to be given parole just after lunch, when board members were well fed, than just before lunch when they were hungry.  

Making decisions is mentally taxing.  If brains are low on energy it directly affects the prefrontal cortex, the core of decision making.   Humans can be rational decision makers, but only when they’re well fed.  Even the court system can be hijacked by the basic chemistry of our bodies.

"Willpower" depends on the energy you've got

“Willpower” allows you to pass on that second cookie, or to hit that deadline.  In one study, folk watch a wildlife film showing animals in distress.  Half are told to react normally, the other half are instructed to use their willpower to suppress their emotions.

Afterwards, folk squeezed a hand exerciser as long as they could.  Those who curbed their emotions give up squeezing sooner as they exerted so much mental effort that they actually reduced their physical strength.  

Self-control, resisting temptation, making hard decisions or taking initiative - all draw from the same energy source.  It can be a vicious cycle if you're continuously exercising "self-control" and suppressing emotions.  Willpower goes down so you have less remaining to resist temptations.  Willpower isn’t something that we exercise, it’s something that we use up, like a tank of gas.



FYI, Rich Doyle's and my "Into the Stillness: Dialogues on Awakening Beyond Thought" was originally published by NonDuality Press (NDP) near London.   In Sept/Oct, NDP was acquired by New Harbinger Press (NHP) in San Francisco, but the key NDP folk were retained.  we met the NHP folk in San Jose at the Science and NonDuality gathering.

This has already resulted in our book being "picked up" by Barnes and Noble.  you may have seen that the Kindle version vanished from amazon, in the switch.  This will be fixed shortly.