As you read this column you are not aware of all the parts of your brain that are working to make a series of squiggly lines into words. Each group of squiggles have associated sounds and are then organized into words, sentences, paragraphs, poems and books. These squiggly lines can communicate all sorts of thoughts, ideas and detailed information.
Reading language is a relatively new skill for humans. The earliest known writing system was found in Sumer, located in southern Mesopotamia, around 3500 BC. The human brain did not evolve to be able to read the same way it did for spoken language. First the human brain learned to make certain sounds to stand for certain objects, names, numbers, etc. Over thousands of years more and more sounds were developed using neural pathways including the use of the tongue and ears. The development of written language required those neural pathways to be restructured now using the visual pathways. This complex process of reading also requires the skill of speaking, the skill of saying the sounds of the squiggly lines. Reading can be silent or spoken. A person can speak a language fluently and not be able to read.
Using brain imaging researchers (Turkeltaub et al) are able to see which parts of the brain are activated when you are reading. Several parts of the brain, primarily on the left side, are activated when reading. The parietal-temporal region (towards the back) does the job of breaking a written word into its sounds. The occipital-temporal region (at the back) of the brain stores the appearance and meaning of words. This is critical for a reader to be able to identify words without having to sound each one out. The frontal region (at the front) allows the person to process the speech sounds as we listen and speak.
The human brain did not evolve to be able to read the same way it developed to speak. In order to read the brain has to re-wire its circuits. Every child’s brain has to change the way it functions as the child learns to read. Beginning readers show more activity in the parietal-temporal area (word analysis) while more experienced readers become more active in the occipital-temporal (word recognition). This means that learning to read evolves the development of new neural pathways. Different regions of the brain are working at the same time and these different regions are all collaborating at the same time.
Rich language experiences such as being read to and looking at pictures and words early in life contribute to making the brain more receptive to acquiring reading skills. With struggling readers brain imaging shows patterns of activity that are different from strong readers. The pathways for language and cognition are not as efficient and established so the work of reading is harder. It is harder for child readers not previously exposed to the squiggly lines and their sounds (phonics) as they have not been able to use the neural pathways needed.
Published 10/09/2024
Sally Robinson, MD Clinical Professor
Keeping Kids Healthy
Also See: UTMB Pediatrics - Pediatric Primary Care