Non-Invasive Brain Stimulation Could Alter Our Emotional Predictions
The human brain is a predictive machine, constantly anticipating sensory input based on past experience. This process, known as predictive processing, involves signals that “travel” as waves through various parts of the cerebral cortex in different frequency bands. Beta oscillations (13-30 Hz) are responsible for predictions, while gamma oscillations (30-90Hz) handle prediction errors. Researchers from the Universitat Autònoma de Barcelona (UAB), the Mayo Clinic and the University of Munich have discovered how non-invasive electrical stimulation can modulate these signals to modify behavior.
The study involved 75 participants who were asked to predict facial expressions in response to different emotional contexts that evoked happiness, sadness or fear. Non-invasive electrical stimulation was applied using an electrode headgear while simultaneously recording brain activity with electroencephalography. The researchers found that stimulation at a frequency of 20 Hz had an effect on predictions of facial expression, making them more stereotyped.
“This result demonstrates that predictive processing is encoded in the brain in specific frequency bands and that it can be non-invasively modulated ‘at will’ to ‘artificially’ modify behavior,” says Lorena Chanes, associate and ICREA Academy professor at UAB. The study provides new insights into the neural basis of predictive processing, which could help develop non-invasive therapies capable of restoring balance when affected by conditions related to mental health.
The authors note that their observations could extend beyond social perception and have implications for other cognitive tasks. “It is possible that modulations similar to those observed in this study could be observed in other cognitive tasks,” they state.
According to authoritative sources, an increasing number of conditions are being described in terms of predictive processing interruptions seen in previous studies related to depression. While the observed effect is small, it opens up possibilities for developing therapies based on this type of modulation. The study’s authors suggest that future research could explore similar modulations in other cognitive tasks.
Reference: Draganov M, Galiano-Landeira J, Doruk Camsari D, Ramírez JE, Robles M, Chanes L. Non-invasive modulation of predictive coding in humans: causal evidence for frequency-specific temporal dynamics. Cerebral cortex. Posted online May 8, 2023: bhad127. doi:10.1093/cercor/bhad127
According to authoritative sources.