Decision making can be an unconscious activity

Contrary to what we still believe, decision making can be a process due to the fact that mental activities unconsciously control the majority. A group of scientists have discovered how the brain actually prepared for us an unconscious decision. Even just seconds before we consciously make a decision, that result is predictable from unconscious activities in the brain.

This was demonstrated by a work by scientists from the Max Planck Institute - Institute of Brain Science and Awareness at Leipzig, in partnership with University Hospital Charité and Center for Computational Neuroscience Bernstein in Berlin. Scientists belong to the group of Professor John-Dylan Haynes using brain scanners to investigate what happens in the human brain just before people make decisions.

  'Many processes in the brain happen automatically and there is no interference of our consciousness . It prevents the brain from overloading for simple everyday tasks. But when they become decisions, we often assume they are made consciously. This is what our current work suspects. '

In the study, published in Nature Neuroscience, volunteers can freely decide if they want to press the button with their right or left hand. They have the right to decide to do this whenever they want, just need to remember when they decide. The goal of this experiment is to discover what happens in the brain during the period just before the person feels they agree. Often scientists find out what happens when making a decision, not a few seconds before. The fact is that the decision can be predicted before making it quite long is a surprising finding.

The blue brain regions are the places from which a volunteer's decision can be predicted before it is made.The image above shows the three-dimensional image of a brain activity pattern in the information brain region.Computer-based sample sorting tools can be trained to identify typical micro patterns that occur just before volunteers decide left or right.These tools can be used to predict a 7-second decision before individuals believe they have made a conscious decision.(Photo: John-Dylan Haynes)

The unprecedented prediction of this free decision is made possible by complex computer programs designed to identify typical brain activity patterns that precede one of the two options. Micro-samples that work in the frontal cortex can predict the options before volunteers know which side to choose. The decision cannot be perfectly guessed but the predictability is clearly above the random level. This shows that the decision can be unconsciously determined but the final result can be reversed.

'Most researchers investigate what happens when people have to make immediate decisions, typically an immediate response to an event in our situation. Here we focus on more interesting decisions that are made naturally and more autonomously. '

More than 20 years ago, a scientist specializing in American brain named Benjamin Libet discovered a type of brain signal called 'ready potential' that occurred in a very small part of a second before deciding consciousness. given. Libet's experiment was fiercely controversial at the time and sparked a widespread debate. Many scientists believe that if our decisions are unconsciously prepared by the brain, our feeling of 'free will' must be an illusion. In this view, it is the brain that makes the decision, not the human perception. Libet's experiment was particularly controversial because he discovered only a very short period of time between brain activity and conscious decisions.

In contrast, Haynes and colleagues now demonstrate how brain activity predicts how a person will decide in a time span of up to 7 seconds before this happens . But they also recommend that this work does not exclude the concept of free will: 'Our work proves that the decision is unconsciously prepared much longer than people think. But we still don't know where the final decision was born. We need to find out if a decision made by brain regions can still be changed. '

Article references: Chun Siong Soon, Marcel Brass, Hans-Jochen Heinze & John-Dylan Haynes.'The unconscious determinants of free decisions in the human brain.'Nature Neuroscience magazine April 13, 2008.