"Cell": Rewriting theories, neuroscientists reveal the mechanism of brain processing speech

The top academic journal "Cell" recently published a research paper led by a well-known Chinese scholar and neuroscientist Professor Edward Chang

When the semantic sound is transmitted to the ear, our cochlea converts the sound wave into an electrical signal and transmits it to the auditory cortex in the temporal lobe of the brain

However, this hypothesis has been lacking direct evidence for decades, that is, neurophysiological recording of the entire auditory cortex with extremely high spatial resolution

The development of this research is inseparable from the support of some patients

▲ Schematic diagram of the location and division of the auditory cortex in the left hemisphere of the human brain (picture source: reference [1])

Then, in the experiment, the researchers began to play phrases and short sentences to the participants, trying to find signs of information flowing from the primary auditory cortex to the superior temporal gyrus

However, this is not the case

▲Directly record signals through electrodes and give stimuli to discover parallel pathways for voice information processing (picture source: reference [1])

In another experiment, the researchers used a weak electric current to stimulate the patient's auditory cortex

In contrast, when the researchers used electrical current to stimulate the superior temporal gyrus of patients, patients reported that they could hear someone speaking, "but could not distinguish words

Based on these evidences, the research team believes that the processing of sound and speech information in the auditory cortex of the brain is parallel, rather than the serial processing considered by traditional models

Note: The original text has been deleted

Reference materials:

[1] Liberty S.

[2] Sounds and words are processed separately and simultaneously in the brain.