The Brain As a Decision Making Tool
The brain is confronted with around 11 000 000 bits of information coming from our senses every second. It is constantly gathering, filtering, processing and categorising loads and loads of data. The perfect decision making tool, one might think.
From deciding to hit the snooze button just one last time in the morning or what pair of shoes to buy to deciding what university to go to or whether to propose or not, our life is full of decisions. However, according to the British newspaper Mirror an average person will come to regret 19% of their decisions over their lifetime. What happens in the brain when we make a decision and why are we so bad at it?
Active Brain Regions During Decision Making
Ventromedial prefrontal cortex
In 1848, a railworker from Vermont named Phineas Gage had a tragic accident but also a big portion of luck. When the gunpowder he was packing into a rock with an iron bar accidentally exploded and sent the bar directly though his skull, it missed any vital areas. Not only did he survive, but he seemed to be of sound mind after the incident and quickly recovered to turn back to his job. However, as his friends stated, he was “no longer Gage” (Harlow, 1868, p. 327). From a distinguished, polite and reliable man he turned into a capricious child, unable to make plans and hold onto them, learn from mistakes and and unwilling to follow instructions when hey interfered with his one wishes.
Why am I telling you this story? Gage suffered from a lesion of his ventromedial prefrontal cortex, a region very central to vision making, because it plays a role in social sensitivity and motivational balance.
Particularly this region integrates somatic states, emotions and feelings linked to an experience that we made before, with the information at hand to make a decision that is most likely to have a positive outcome. People like Gage, who have lesion in this brain area, often lack the ability to use emotions and feelings to estimate what’s best for them.
Interestingly, the right prefrontal region is activated by punishment and the left part by reward. Thus the right side is active when we decide to avoid something that might turn out bad for us. A lesion in the right part leads to risky decisions, because negative aspects of the outcome are underestimated and positive ones are overestimated.
Amygdala
The amygdala gets activated every time, you look at the ground from a very high diving board or walk through a dark lane and hear a crackling noise behind you. It senses that there might be danger and lets you know by triggering the release of stress hormones and neurotransmitters that result in you being scared.
In decision making, the amygdala throws in emotional responses that are related to the options that we are choosing from. Remember when you just could not bring yourself to ride the roller coaster with your friends because you were to scared? That is your amygdala communicating with you.
Anterior cingulate cortex
The anterior cingulate cortex is part of the paralympic system and I like to think of it as the control centre of suitable behaviour. It’s job is to evaluate risks and rewards to select the best possible way to go and it is most active in situations of inner conflicts.
Say, you think about calling in sick because you really don’t want to miss out a big event your friend spontaneously invited you to, but also you feel bad about lying and you’re short of cash anyways. While the ventromedial prefrontal cortex is busy collecting emotional data like how uncomfortable you felt the last time, you had to tell your boss you can’t go to work or how much fun you previously had with that same friend, the anterior cingulate cortex estimates the probability of getting caught outside by a colleague or the chance of being invited by your friend another time.
Why do we suck at decision making?
The cause of bad decisions can be put in just one word: heuristics.
Heuristics are shortcuts in problem solving and decision making, that help finding a solution that is good enough to serve a problem quickly. Especially when we do not have much information about different options or are under time pressure, we use heuristics to skip the effort of engaging in complex though processes that take up too many resources in our brain. In some cases this “cognitive laziness” can be really useful, but it can also comes with the cost of jumping to conclusions that are not actually true.
A well-known decision making shortcut is the recognition heuristics, where you overestimate the importance or the value of something that you are familiar when directly compared to something you don’t really know much about.
Which german city is bigger? Heidelberg or Bamberg? While Bamberg is a very laid back city (one of the most beautiful ones in Germany in my opinion) with not much recognition in international media, Heidelberg is quite known for its old campus and its renowned research institutes. Because you have already heard about Heidelberg, but not about Bamberg, it is reasonable to think that Heidelberg is the bigger city and your right!
If I ask you the same question but change the cities to Munich and Berlin, you might have more difficulties making a choice, because both are well known german cities.
In this case the recognition heuristics come to your advantage. In another scenario, for example when I ask you “Are there more giant pandas or mottled umbers?” they can trick you into thinking that there are more giant pandas, because you never heard of mottled umbers (a moth) before, although you also know that giant pandas are an endangered species.
Next to recognition heuristics, there are many more quirks that often mislead us in our rational thinking, so called cognitive biases. For example, when you wake up hungover after a club night and decide to never drink again but then two month later you end up doing shots again, that’s the recency effect!
Wanna know more about biases and why we keep making wrong choices? I’m working on a series of articles to cover you up, so make sure to follow!
References
Anderson, John R. (2015). Cognitive psychology and its implications. Eighth edition. New York, N.Y.: Worth Publishers. Chapter 11: Decision Making, 260–280.
Martínez Selva, José & Sánchez-Navarro, Juan & Bechara, A & Román, F. (2006). Brain mechanisms involved in decision-making. Revista de neurologia. 42. 411–8.
