A neuroimaging study on how experience shapes the investor's brain

Resumen

Background: Economics have failed to create theories of choice that allow us to accurately predict human behavior under all circumstances. To answer the question on how investors decide, we need to go beyond abstract models based on what is rational given that our rationality is computationally bounded. For this reason, studies in Neuroeconomics have begun to gain knowledge into what are the underlying neurobiological processes of decision-making that guide a person to make some economic decisions and not others. In most cases, these researches have been based on regions of interest, ruling out all the information that whole-brain analyses can bring. This thesis tries to approach the understanding of investment decision-making from a slightly different perspective. As our brain is plastic and it can change according to our experiences, we are going to analyze the investor’s brain to find differences in their decision-making process and if there are any, determine which brain areas are responsible for their investment behaviors. Methods: In order to determine the brain structures specialized in responding to investments, the following methods have been used. For the first study, an activation likelihood estimation meta-analysis using GingerALE software has allowed us to establish which brain areas tend to be activated when an investment decision is made. For the second study, an electroencephalography along with a recording of the motor response, has enabled us to analyze anticipatory processes in terms of the decision preceding negativity latencies, brain activations, response times and gambling decisions between investment bankers and a control group. And for the third study, a magnetic resonance imaging, whole-brain transcriptome data from Allen Human Brain Bank and functional annotations from PANTHER pathways, has made it possible to detect those areas of the brain with an increase in volume, a strengthening in their connections and their associated gene expression. Results: We found that, in the first study, the ventral striatum, the anterior insula, the amygdala, the anterior cingulate cortex and the occipital cortex are activated when we make an investment decision. For the second study, the prefrontal and orbitofrontal cortex under risky conditions and the prefrontal cortex under ambiguous conditions were activated streamlining anticipatory processes, while decreasing their response times and the number of gambling decisions. And for the third study, dopaminergic-related areas increased in volume and strengthened their connections with a higher gene expression of SLC6A3, TH and SLC18A2, whose pathways have been associated with the biosynthesis of catecholamines (dopamine, adrenaline and noradrenaline). Conclusions: In conclusion, investors have shaped their brains to survive in the financial markets by training the areas responsible for investment decision-making through their daily experience playing the market. They have higher gray matter volume and increased structural brain connectivity in dopaminergic-related pathways, which has led to a decrease in the anticipatory processes that precede a risky decision while regulating cognitive and emotional functions on the basis of the amount of available information. This plastic change has been mediated by catecholamines in brain areas previously identified with investment behaviors in the scientific literature.