Scientists at the Max Planck Institute for Cognitive and Brain Sciences have found that reading aloud and reading silently engage different parts of the brain involved in movement, hearing, and information processing. The results of the study were published in the medical journal Neuroscience & Biobehavioral Reviews (NBR).
Scientists analyzed data from more than 150 studies in which participants read letters, words, misspellings (meaningless letter combinations), sentences, and texts in various languages. The volunteers’ brain activity was monitored using magnetic resonance imaging (MRI).
The study found that reading individual letters primarily engaged a specific region of the left cerebral cortex, whereas reading words and full sentences activated broader areas, including the left temporal gyrus and the inferior frontal gyrus. These regions responded differently to real words and misspellings, indicating specialized roles in processing written language.
In addition, scientists found significant differences between overt (aloud) and covert (silent) reading. Reading aloud activates brain regions associated with movement and hearing, whereas silent reading engages different cognitive systems.
Researchers paid special attention to how the brain distinguishes between explicit and implicit reading. For example, silent reading of words and misspellings activated the left prefrontal cortex, cerebellum, and temporal cortex. Meanwhile, lexical decisions—the process of determining whether a set of letters forms a real word—involved both the inferior frontal and insular regions.
The authors emphasized that the findings enhance our understanding of the neurobiological basis of reading and may aid in developing methods for diagnosing and treating speech and cognitive disorders.
