To find out what happens in the brain while experiencing feelings, so far we have mostly used very simplified lab experiments. Emotions often had little resemblance to everyday life. Scientists at the Max Planck Institute for Cognitive and Brain Sciences are using virtual reality to evoke emotions as realistically as possible — and have been able to calculate the strength of feelings from brain signals.
As in a roller coaster: using virtual reality glasses, test participants can dynamically and interactively immerse themselves in situations and experience them close to reality. Emotions are evoked in a more natural way than in classic laboratory experiments.
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Scene left and right slowly slide across the rail in front of you. Suddenly a fire. voltage increases. The flight reaches its highest point. And only then: the abyss. Shot runs deep. Scenes of a roller coaster ride as experienced by participants in a current study at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig. Not real, but virtual, with the help of Virtual Reality (VR) glasses. The aim of the investigations was to find out what happens in Borbanden’s brains while they are exposed to emotionally stressful situations.
In order to find out how the human brain processes emotions, simplified experiments have mostly been used so far. For example, researchers showed participants pictures of emotional scenes and recorded their mental activity. As a result, the investigations were conducted under controlled laboratory conditions, so that the results could be easily compared. However, the simulated situations were often not particularly emotionally exciting and far from the situations one would normally experience. Because emotions are constantly created through the interaction of past experiences and the various external influences that we interact with. With regard to emotions, it is especially important to create conditions that he feels are as real as possible. This is the only way to assume that the simultaneously measured brain activation approximates that in real life outside the lab. Virtual reality goggles provide a treat here. Through them, participants can dynamically and interactively immerse themselves in situations and experience close to reality. Emotions are evoked in a more natural way.
The results of the current study showed: How strongly a person is emotionally excited is shown by a special form of rhythmic brain activity, the so-called alpha oscillations. Accordingly, the lower the strength of this oscillation in the measured EEG signal, the greater the excitation. “The results confirm previous studies from classical experiments and demonstrate that the signals also occur under conditions approaching everyday life,” says Simon Hoffman, one of the authors of the primary study, which is now published in the specialist journal. eLife. “Using alpha oscillations, we were able to predict how strongly a person experienced an emotional situation. Our models learned which areas of the brain are particularly important for this prediction. Roughly speaking, the following applies: the less alpha activity you measure here, the more excited the person,” explains author Felix Cloche.
“In the future, it may be possible to use these findings and methods for practical applications beyond basic research,” adds author Alberto Mariola. Virtual reality glasses are increasingly being used in psychological treatments, for example. Neurophysiological information about patients’ emotional state can improve treatment. Therapists, for example, can gain first-hand insight into the current emotional feeling during an exposure situation without having to ask the subject directly and thus interrupt the situation.
The scientists examined these relationships with the help of electroencephalography (EEG), which enabled them to record participants’ brain waves while riding a virtual roller coaster – in order to calculate what happens in the brain during the ride. In addition, participants were asked to rate how excited they were during the VR experience using a video clip. In this way, the researchers wanted to see if subjective sensations while driving were related to the measured data on brain activity. Since people differ in how much they like to ride a roller coaster, it doesn’t matter whether the situation is perceived as positive or negative. Just how strong the sensation is.
For the evaluation, the researchers used three different machine learning models in order to predict subjective sensations as accurately as possible from the EEG data. The authors showed that with the help of these methods, the relationship between EEG signals and emotional perception under realistic conditions can also be demonstrated.
