neuroanatomy Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defi ...

, 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. It is the largest site of Neuron, neural integration in the central nervous system, and plays ...

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. It is the largest site of neural integration in the central nervous system, and plays a key ...

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 (), previously known as word blindness, is a learning disability that affects either reading or writing. Different people are affected to different degrees. Problems may include difficulties in spelling words, reading quickly, wri ...

. Albert Galaburda of

Harvard Medical School Harvard Medical School (HMS) is the medical school of Harvard University and is located in the Longwood Medical and Academic Area, Longwood Medical Area in Boston, Massachusetts. Founded in 1782, HMS is the third oldest medical school in the Un ...

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 that gives humans the capacity to solve diff ...

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 the brain's ability to use and interpret visual information from the world. The process of converting light into a meaningful image is a complex process that is facilitated by numerous brain structures and higher level cogni ...

. 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 {{neuroanatomy-stub