Using brain imaging, scientists have discovered that the way different brain regions communicate with each other is dependent on a person’s underlying motive.
To understand human behavior, it is crucial to understand the motives behind them, according to researchers at the University of Zurich. Observing behavior or asking people to explain their actions do not give reliable results, as people can be unwilling to reveal — or even be aware of — their own motives.
For the study, psychologist and neuroscientist Drs. Grit Hein and Ernst Fehr from the Department of Economics, University of Zurich, teamed with Yosuke Morishima, Susanne Leiberg, and Sunhae Sul, and found that the way relevant brain regions communicate with each other changes depending on the motives driving a specific behavioral choice.
The interplay between brain regions allowed the researchers to identify the underlying motives. These motives could not be uncovered by observing the person’s choices, or based on the brain regions that are activated during the decision-making, the researchers note.
For the study, participants were placed in an fMRI scanner and made altruistic decisions driven by an empathy motive (the desire to help a person) or a reciprocity motive (the desire to reciprocate an individual’s previous kindness).
Simply looking at the functional activity of specific regions of the brain couldn’t reveal the motive underlying the decisions, according to the scientists, as the same areas in the brain lit up in both settings.
“However, using Dynamic Causal Modeling (DCM) analyses, we could investigate the interplay between these brain regions and found marked differences between empathy-based and reciprocity-based decisions,” said Hein.
“The impact of the motives on the interplay between different brain regions was so fundamentally different that it could be used to classify the motive of a person with high accuracy.”
The study also found that motives are processed differently in selfish and prosocial people. In selfish people, the empathy motive increased the number of altruistic decisions, but not the reciprocity motive.
After activating the empathy motive, selfish individuals resembled people with prosocial preferences in terms of brain connectivity and altruistic behavior, the study found.
In contrast, prosocial people behaved even more altruistically after activating the reciprocity, but not the empathy motive, according to the researchers.