When you are caught in a situation where you don’t know whether to laugh or to cry, how does your brain decide what to do? Researchers at the Max Planck Institute for Human Cognitive and Brain Sciences in Germany and the University of Haifa, Israel have identified the neural mechanisms that help our brains decipher complex emotional situations that include both positive and negative elements.
The findings are published in the journal Human Brain Mapping.
“When someone offends you while smiling, should your brain interpret it as a smile or an offense? The mechanism we found includes two areas in the brain that act almost as ‘remote controls’ that together determine what value to attribute to a situation, and accordingly which other brain areas should be on and which should be off,” said study co-leader Dr. Hadas Okon-Singer of the University of Haifa.
While previous research has identified the mechanisms by which the brain determines whether something is positive or negative, most of these studies have focused on dichotomous situations — the participants were exposed either to a completely positive stimulus (a smiling baby or a pair of lovers) or a completely negative one (a dead body).
The new study, led by Okon-Singer and Dr. Christiane Rohr of the Max Planck Institute, sought to examine complex cases involving both positive and negative stimuli. They wanted to find the neural mechanism that “chooses” whether a given situation is positive or negative and classifies different situations that are emotionally unclear.
In order to simulate the lack of emotional clarity, the researchers presented the participants with scenes from emotionally-conflicting movies, such as Quentin Tarantino’s Reservoir Dogs, while inside an MRI machine. This movie involves many complex situations, including one scene where a person is torturing another while smiling, dancing, and talking to his victim in a friendly manner.
The participants later reported whether they felt that each scene included a conflict. For each moment in the movie, the participants also rated the extent to which they felt that the positive elements were dominant, so that the scene was pleasant to watch, or the extent to which negative elements were dominant, so that the scene was unpleasant to watch.
As in previous studies, the researchers identified two active networks — one that operates when we perceive the situation as positive, and another that operates when we perceive it as negative.
For the first time, however, they identified how the brain switches between these two networks.
The findings show that the transition between activity in the positive or negative network is facilitated by two areas in the brain — the superior temporal sulcus (STS) and the inferior parietal lobule (IPL). These areas form part of the negative and positive networks, but also acted when the participants felt that the movie scene embodied an emotional conflict. The STS was found to be tied to the interpretation of positive situations, while the IPL was linked to the interpretation of negative situations.
Okon-Singer explains that these two areas essentially function as “remote controls” that become active when the brain recognizes an emotional conflict. The two areas seem to “speak” to each other and interpret the situation in order to decide which one will be on and which one off, thereby determining which network will be active.
“The study suggests that these areas can influence the value — positive or negative — that will be dominant in an emotional conflict through control of other areas of the brain,” she added.
The findings may help facilitate further research to examine why this mechanism does not work properly in some people.
“We hope that by understanding the neural basis of the interpretation of situations as positive or negative will in the future help us to understand the neural systems of populations that have emotional difficulties. This will enable us to develop therapeutic techniques to make the interpretations among these populations more positive,” the researchers concluded.
Source: University of Haifa