Scientists from the UK and Germany found that auditory and visual stimuli and focus attention on the signals of the specific modality regulate the activation of the sensory cortex of a person in different ways. For example, visual signals affect the response of the auditory cortex in its deep layers, and the concentration in the surface. Article published in the journal eLife.
Our senses constantly receives a vast amount of information of different modalities, for example auditory and visual. The brain is necessary to regulate the handling of this stream, and to select important signals from the General noise and respond in a timely manner. Previous studies showedthat information from other senses can cause or modulate a response in the areas of the cortex that are responsible for others.
In addition to the impact zones touch each other, there is also a Central mechanism that regulates information processing in the brain — attention: depending on the current goals and objectives it focuses on certain stimuli. For example, when we read the book, the perception of sounds is suppressed. Two of the described method of regulation closely interact: for example, the appearance of multiple similar stimuli can “take away” attention from other sensory modalities.
The mechanisms of such linkages are not well studied, but some work on primates and rodents say that the attention and emotional effects uses layers of different depth. To test and Refine the correlation of these data with the human brain, the authors work under the guidance of Gau Remy (Remi Gau) from the University of Birmingham investigated the processing of visual, auditory, and mixed information when focusing on one of these modalities. To do this, 13 volunteers were presented with blocks of different stimuli: sound, increasing in frequency and volume, diverging from the center of the screen circles or auditory and visual signals simultaneously.
To direct attention to visual or auditory information, in the experiment, the volunteers reacted to the appearance on the screen of the gray point, or the sounding of tone of a certain frequency. About the signal which modality is to be expected, the subjects were warned before each block. In the end, people’s attention was focused on a specific type of stimulus, while his senses came alternately the signals of different modality.