05/12/2021 at 12:24 PM CEST
A new study conducted at Canada’s McGill University shows that the brain has a specific mechanism for synchronizing vision and hearing: to make sense of complex environments, brain waves are permanently aligned and compensate for sound processing speeds and vision, which are noticeably different.
This brain integration makes it possible for an image and a sound created at the same time to be perceived synchronously in order to understand reality, although both stimuli reach the brain and are processed by different neural circuits and at different speeds. The research was published in the journal Communications Biology.
According to a press release, scientists maintain that there is a process called “temporary recalibration.” Through this mechanism, the brain in a certain way deceives us: modifies our perception of time so that we can perceive sound and visual stimuli in an integrated way, when in fact we should receive them separately.
How does this system work? A series of brain signals permanently adapt to the environment to monitor the sensory information received. They detect and order each stimulus, associating those that may be in divergence.
As a result, we obtain a comprehensive understanding of reality and we can take advantage of the different types of information that our senses give us.
The process in action
The discovery was made after various tests with volunteers, which were carried out inside a magnetoencephalography (MEG) machine. This technology enables images of brain waves to be obtained with millisecond precision.
The participants were stimulated with light signals and different sounds, which were delivered with a certain temporal disparity. They were asked to report whether they could receive them at the same time.
The experiment grew in complexity: the visual stimuli were modified and offered at different distances, while the temporal difference in terms of sounds increased, which also varied randomly.
In the results, the researchers found that the volunteers were able to perceive the different types of stimuli as a whole in most cases, even in the face of the pitfalls or difficulties that had been induced.
This demonstrates that the brain constantly works to align both sensory inputs, in order to avoid a distorted perception of reality. In this way, we can relate the images and sounds that we perceive, acquiring tools to understand the world and our environment with greater precision.
Related topic: Vision and movement are related in the brain.
Perception of reality
In general terms, the scientists concluded that their study confirms the existence of a brain system that aims at a better adaptation of the individual to the “bombardment” of stimuli received permanently.
Thanks to the possibility of associating the different signals beyond temporal or physiological differences, integrated brain circuits offer a clearer and more orderly perception of reality.
Finally, the specialists highlighted that in the case of diseases such as autism or schizophrenia, there are anomalies in this process of integration and recalibration, leading to multiple problems in adapting to the environment. In addition, the reception of the different signals in a disintegrated way produces psychological and behavioral inconveniences at the same time.
Consequently, this discovery can function as a gateway to new strategies to mitigate the negative effects of these pathologies.
Coupled oscillations enable rapid temporal recalibration to audiovisual asynchrony. Lennert, T., Samiee, S. & Baillet, S. Communications Biology (2021) .DOI: https: //doi.org/10.1038/s42003-021-02087-0
The researchers confirmed a unique interaction between fast and slow brain waves in the auditory and visual regions of the brain: both systems integrate to facilitate understanding of reality. Credit: Baillet, S. et al / McGill University.