Do Our Brains Make Choices Before We are Consciously Aware?
We are usually confident to believe that we consciously make choices or decisions and are consciously in control of our thoughts. Research from the University of New South Wales (UNSW) reports that these choices and decisions may be automatic and unconscious.
The study suggests we have less control over our personal choices than we think, and that unconscious brain activity seemingly determines our choices before we are aware of them.
The research was published in the journal Nature, based on an experiment carried out in the Future Minds Lab at UNSW School of Psychology. It showed that free choices about what to think can be predicted from patterns of brain activity 11 seconds before people consciously chose what to think about.
In the experiment the researchers asks participants to freely choose between two visual patterns of red and green stripes — one of them running horizontally, the other vertically — before consciously imagining them while being observed in a functional magnetic resonance imaging (fMRI) machine. The participants were also asked to rate how strongly they felt their visualisations of the patterns were after choosing them, again while researchers recorded their brain activity during the process.
The results: The researchers could not only predict which pattern they would choose, they could also predict how strongly the participants were to rate their visualisations. Using a machine learning program, the researchers were successful at making above-chance predictions of the participants’ volitional choices at an average of 11 seconds before the thoughts became conscious.
The specific brain areas that revealed information about the future choices were located in executive areas of the brain — where our conscious decision-making is made — as well as visual and subcortical structures. This is a network of neural activity that could be responsible for the origin of our thoughts.
UNSW director Professor Joel Pearson believes what could be happening in the brain is that we may have thoughts on what he called “standby,” which are based on previous brain activity, which then subsequently influences the final decision without us being aware.
“We believe that when we are faced with the choice between two or more options of what to think about, non-conscious traces of the thoughts are there already, a bit like unconscious hallucinations,” Professor Pearson says.
“As the decision of what to think about is made, executive areas of the brain choose the thought-trace which is stronger. In, other words, if any pre-existing brain activity matches one of your choices, then your brain will be more likely to pick that option as it gets boosted by the pre-existing brain activity. This would explain, for example, why thinking over and over about something leads to ever more thoughts about it, as it occurs in a positive feedback loop.”
The researchers also found that the subjective strength of the future thoughts was also dependent on activity in the visual cortex, an area in the brain that receives visual information from the outside world. The researchers say this suggests that the current state of activity in perceptual areas has an influence in how strongly we think about things.
From a neuroscience perspective, the results of this research raises questions about our sense of volition for our own private and personal mental visual images. This study is the first to capture the origins and content of involuntary visual thoughts and how they might bias subsequent voluntary conscious imagery.
The insight gained with this experiment may also have implications for mental disorders involving thought intrusions that use mental imagery, such as PTSD, the authors say.
“Our results cannot guarantee that all choices are preceded by involuntary images, but it shows that this mechanism exists, and it potentially biases our everyday choices,” Professor Pearson says.
From a philosophical and behavioral perspective, of course it raises the questions of the nature of our unconscious thoughts being the driver for our actions, and whether that calls into question the concept of “free will.”