Every day we are faced with situations where we need to instantly decide what to do. In particular, to suppress the impulse to act in the usual way and act differently. For example, if a traffic light turns green, we immediately start walking. However, if a car rushes along the street, breaking the rules, you need to stay in place.
A team of researchers from two German universities, led by neuroscientist Nikolai Axmacher, conducted an experiment to elucidate the neurophysiological mechanisms of making such instant decisions. The subjects heard the words “high tone” and “low tone” pronounced in high and low voices, and they were asked to indicate in what tone the words were pronounced. When the meaning of the word did not coincide with the timbre of the voice (“high tone” was pronounced in bass and vice versa), the participants in the experiment thought longer before answering and were more likely to make mistakes.
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Two groups participated in the experiment. In the first group (healthy people), data on brain activity were collected using MRI. The second group consisted of patients with epilepsy, in whom electrodes were implanted in the hippocampus to plan future surgical treatment. Using these electrodes, the researchers were able to obtain EEG data directly from the hippocampus (a procedure called electrocorticography). Both measurement methods confirmed the activation of the hippocampus during decision making to resolve the internal contradiction.
The hippocampus is essential for memory, and researchers are trying to understand how this relates to other functions.
“Perhaps the successful resolution of the internal contradiction activates the memory system. No useful lessons can be learned from a contradiction left unresolved. According to our model, the brain works like a filter. He actively reacts to resolved contradictions, but does not show such activity when faced with unresolved contradictions or standard situations. However, this hypothesis has yet to be clarified,” Nikolai Axmacher explains.
Подробнее см. С. Oehrn et al. «Human hippocampal dynamics during response conflict», Current Biology, August 2015.