Brain is strobing, not constant, neuroscience research shows: First sight, now sound: New discoveries show perception is cyclical -- ScienceDaily
The key findings are:
1. auditory perception oscillates over time and peak perception alternates between the ears -- which is important for locating events in the environment; 2. auditory decision-making also oscillates; and 3. oscillations are a general feature of perception, not specific to vision.
The work is the result of an Italian-Australian collaboration, involving Professor David Alais, Johahn Leung and Tam Ho of the schools of Psychology and Medical Science, University of Sydney; Professor David Burr from the Department of Neuroscience, University of Florence; and Professor Maria Concetta Morrone of the Department of Translational Medicine, University of Pisa.
With a simple experiment, they showed that sensitivity for detecting weak sounds is not constant, but fluctuates rhythmically over time.
It has been known for some years that our sight perception is cyclical but this is the first time it has been demonstrated that hearing is as well.
"These findings that auditory perception also goes through peaks and troughs supports the theory that perception is not passive but in fact our understanding of the world goes through cycles," said Professor Alais from the University of Sydney.
"We have suspected for some time that the senses are not constant but are processed via cyclical, or rhythmic functions; these findings lend new weight to that theory."
These auditory cycles happen at the rate of about six per second. This may seem fast, but not in neuroscience, given that brain oscillations can occur at up to 100 times per second.