A microgyrus is an area of the

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of ...

that includes only four

cortical layers The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consisting of a ...

instead of six. Microgyria are believed by some to be part of the genetic lack of prenatal development which is a cause of, or one of the causes of,

dyslexia Dyslexia, also known until the 1960s as word blindness, is a disorder characterized by reading below the expected level for one's age. Different people are affected to different degrees. Problems may include difficulties in spelling words, r ...

Albert Galaburda Albert Mark Galaburda (born 20 July 1948 Santiago, Chile) is a cognitive and behavioral neurologist with a special focus on the biologic bases of developmental cognitive disorders. He is the Emily Fisher Landau Professor of Neurology and Neuroscien ...

Harvard Medical School Harvard Medical School (HMS) is the graduate medical school of Harvard University and is located in the Longwood Medical Area of Boston, Massachusetts. Founded in 1782, HMS is one of the oldest medical schools in the United States and is consi ...

noticed that

language center In neuroscience and psychology, the term language center refers collectively to the areas of the brain which serve a particular function for speech processing and production. Language is a core system, which gives humans the capacity to solve dif ...

s in dyslexic brains showed microscopic flaws known as ectopias and microgyria (Galaburda ''et al.'', 2006, ''Nature Neuroscience'' 9(10): 1213–1217). Both affect the normal six-layer structure of the

cortex Cortex or cortical may refer to: Biology * Cortex (anatomy), the outermost layer of an organ ** Cerebral cortex, the outer layer of the vertebrate cerebrum, part of which is the ''forebrain'' *** Motor cortex, the regions of the cerebral cortex i ...

. These flaws affect connectivity and functionality of the cortex in critical areas related to sound and

visual processing Visual processing is a term that is used to refer to the brain's ability to use and interpret visual information from the world around us. The process of converting light energy into a meaningful image is a complex process that is facilitated by ...

. These and similar structural abnormalities may be the basis of the inevitable and hard to overcome difficulty in reading.

References

External links

The neurological basis of developmental dyslexia

Cerebrum Congenital disorders of nervous system Dyslexia {{neuroanatomy-stub