A collaborative study involving Philippe Fossati’s team at the ICM, a team from KU Leuven and a team from Maastricht University has shown that neural bases of emotions vary with time.
Our emotions evolve over time. This can seem obvious, but understanding the variations, dynamics and areas of the brain involved in the process is key for future therapy. Emotional variations are a key component in several mental health disorders, such as depression post-traumatic stress disorder and borderline personality.
What happens when we experience an emotion? How does it evolve over time? Research on emotional dynamics is fairly recent. The various methods developed have highlighted two main phases in emotional dynamics. First is the start of the emotion, either brutal or progressive, referred to as the degree of explosiveness. Next comes the emotional compensation phase, meaning a deepening or mitigation of the emotion with time, assessed with a degree of accumulation.
Neural bases of these two phases and their possible variations over time remain unclear. Recent studies have identified certain areas of the brain involved in the establishment of emotions such as the medial prefrontal cortex, the amygdala and the insula.
HOW DOES THE ACTIVITY OF THE VARIOUS AREAS OF THE BRAIN VARY THROUGHOUT THE DIFFERENT PHASES OF AN EMOTIONAL EXPERIENCE?
To find out, researchers from the ICM, KU Leuven and Maastricht University conducted an experiment on 31 participants.
They asked them to write several short texts on personal topics such as their dreams and aspirations. The texts were then read by a jury who inferred the personality of participants. All participants actually received the same negative or neutral responses regarding their personality independently from their texts. Researchers then asked participants to read and think about the responses during 90 seconds and indicate emotional changes felt over time. Meanwhile, brain activity was recorded using functional MRI for real-time observation brain area activity.
Researchers were therefore able to study brain areas involved in explosiveness and accumulation of emotional response following negative social experiences, known to generate long-lasting emotional response enabling
differentiation of both phases.
Results show that emotional trigger and compensation phases are the two main components of emotional change over time and are associated with distinct areas of the brain. Differences in emotional trigger explosiveness are linked to medial prefrontal cortex activity. This area is supposedly involved in self-perception. In this case, activation may reflect the difference between the jury’s evaluation and the self-perception of participants.
Differences in accumulation are linked to activation of the posterior insula, an area known to play a key role in integration of emotional signals.
This is the first study to show the varying activity in areas of the brain that orchestrate emotional response. It underlines how important it is to take the time component into account to understand underlying neural bases in the evolution of emotions, from initiation to intensification or mitigation, following social exclusion.
These results could have an impact on treatments for mental health disorders.
Source : The neural basis of emotions varies over time: Different regions go with onset- and offset-bound processes underlying emotion intensity. Résibois M, Verduyn P, Delaveau P, Rotgé JY, Kuppens P, Van Mechelen I, Fossati P. Soc Cogn Affect Neurosci. 2017 Apr 11.