When reading or when we talk to ourselves to reflect on something, our brain generates a sound impression which it interprets as a real outside voice, say French researchers. We all know that little inner voice that accompanies us throughout the day and in our thoughts. However, its origin and how it is perceived by the brain were still shrouded in mystery.
A team of experts from “Research Center for Neural Science” in Lyon and the “University Medical Center” in Grenoble raised slightly the “veil” covering this strange phenomenon in a study published in The Journal of Neuroscience. For this experiment, the French scientists, coordinated by Jean-Philippe Lachaux, Head of Research at INSERM, monitored four adults suffering from a severe form of epilepsy.
These patients lived, during the time of treatment and medical monitoring, with electrodes implanted in the brain, and, using this technique, the doctors were able to get an excellent signal for the EKGs.
Once they have spotted in the auditory cortex the area that responds to the sound of outside voices, expressed in real terms, researchers asked volunteers to read, silently, a text on a monitor without provide them with further instructions. The result: the area of the brain that analyzes external voices was activated even during the silent reading, signaling a “verbalized thought.”
“For the first time, thanks to this study, we could ‘see’ in real time the trace left in the brain by this small inner voice,”
said Jean-Philippe Lachaux.
“We did not expect to find it, because it is an intangible phenomenon. The brain creates sound starting from nothing, with every word,” he added.
The most likely of the assumptions made by French scientists is that the combination of sounds and words that we learn to speak when we are children, when we start talking, and then when we begin to read aloud becomes an automatism that persists throughout the live.
“This combination results in an increase in connections between brain areas involved, which are activated spontaneously, one after another,” said Jean-Philippe Lachaux. This occurs even when we don’t read aloud. The researchers further noted that the phenomenon is especially stronger if more attention is required from the reader – for example, if the text is difficult to read or if the person can not read fluently.
The results of this research, which confirm a number of previous studies could be used in rehabilitation and assistance programs for depressive and schizophrenic patients who fail to master always this “little inner voice” when it fills their brains with negative thoughts, says Jean-Philippe Lachaux.
“Using a technique similar to that used in this study, we could show them specifically what happens in their brains. This will help them move away from negative thoughts overwhelming them and regain their control,”
the French professor added.
Reply