Date published:

Synchronous rumblings detrimental to brain performance

Researchers from the Centre for Cognitive Neuroscience have shown that commonly used sound impulses planned to stimulate cognitive processes impair them.

Professor Michał Klichowski, director of the Centre, describes the studies:

'There are thousands of recordings on platforms such as YouTube with acoustic stimuli used to improve cognitive processes. The so-called binaural beats, or synchronous rumblings, are relatively widespread. In simple terms, this form of brain stimulation involves delivering tonal sounds of different frequencies to each ear, interacting to produce the sensation of binaural beats. The frequencies are selected so that their difference mirrors the desired frequency of the brain waves. People all over the globe listen to recordings in their homes when they are studying or doing other cognitive activities.

For two years, Prof. Michał Klichowski and Dr Agnieszka Kruszwick from the Faculty of Educational Studies and Prof. Andrzej Wicher and Prof. Roman Gołębiewski from the Chair of Acoustics experimented with natural conditions, demonstrating that such forms of acoustic brain stimulation are counterproductive - instead of helping people perform cognitive tasks, they dramatically impair cognitive performance.

Within this experiment, 1,000 people performed complex learning tasks in their homes, listening to specific sounds in individual cases. The sounds were various, such as music, noise, but also just binaural beats. It was that listening to binaural beats significantly worsened performance on these tasks.

Since this is the first study on the usage of binaural beats at home, further research is needed. However, it can already be concluded that applying binaural beaters to ourselves may not only be unhelpful, but also harmful. This could be the outcome of poorly chosen frequencies or too much exposure time. It is also possible that there is some neuronal mechanism behind such an inverted effect of binaural beats, which is still unknown.

Researchers at the Centre for Cognitive Neuroscience have put forward several hypotheses. One suggests that binaural beats somehow interfere with brain waves and lower their frequency so that brain activity is mismatched with the task at hand. The second hypothesis refers to the fact that most of our daily cognitive tasks are highly variable and, therefore, it is not advisable to modulate only one frequency when performing them. Binaural beats thus may temporarily block brainwave frequencies specific to performing a particular part of the task.

An article with the results of this project has just been published in the journal Scientific Reports, one of the Nature Portfolio journals.

Photo: A. Wykrota