Humans Hard-Wired for Speech but not for Reading and Writing

Humans communicate naturally by speech – that is to say, without any special training besides hearing individuals speak to each other. The reason is the structure of our brains. Researchers have shown that there are two specific centers in the human brain that oversee and control language acquisition; both are in the brain’s left hemisphere. Even when babies are only a few days old, scientists can measure brain activity in these areas as the children learn the pitches and rhythms of the language they hear.

Broca’s area is the part of the brain that interprets sentence structure. When this area is not functioning properly, people are unable to piece ideas together using rules of grammar. Wernicke’s area is important for the understanding of words that make up both spoken and written language.

Spoken language, then, is hard-wired into the human brain. Any child, unless neurologically or hearing-impaired – or are sensory-deprived – will learn to speak at some point. By the time he reaches 10 months, he has already learned how to recognize the phonemes (speech sounds) of the language spoken by those around him, and most generate simple sentences by the time they are 16 to 24 months old. Even one-year-olds understand a great deal of what is said by others. At the same time, though, they lose some of the capacity to distinguish and produce the phonemes of other languages.[1]

Reading is a critical part of life in the 21st  century, and students must learn to read properly so that they can, later on, read to learn. Written language, though, is a fairly recent invention that consists of symbols approximating the sounds of our oral language; our brains are not yet hard-wired to process it. And not all societies have achieved a written language. While all humans have an oral language, of the approximately 6,000 spoken languages that exist around the world, only about 200 have been codified into a written form.[2]

Learning to read entails what French cognitive neuroscientist Stanislas Dehaene calls “neuronal recycling.” This is a process through which vast areas of neurons in our brain begin to perform functions for which they were not initially developed. When we are born, our brains have no areas or neuronal connections especially set aside for the reading process; however, when we learn to read, the theory goes, the brain alters its architecture and generates new connections in areas which, before learning this new skill, did not communicate with each other.

A new study, published in the August 2016 Nature Neuroscience, adds support for this hypothesis. Specifically, researchers at MIT scanned the brains of kids before and after they learned to read; they discovered that they could pinpoint how the area responsible for the reading task would develop based on neuronal connectivity patterns. In other words, the neural circuitry laid down prior to reading determined where and how the brain region responsible for reading, otherwise known as the “visual word form area” (VWFA) formed.[3]

“Long-range connections that allow this region to talk to other areas of the brain seem to drive function,” Zeynep Saygin, lead study author and researcher at MIT’s McGovern Institute for Brain Research, said in a news release.

Prior to learning to read, the area that would later become the VWFA didn’t respond any differently when the kids looked at words versus other objects. Based on the study’s data, though, that area had distinct connection patterns from the surrounding brain regions. Those patterns were enough for the researchers to precisely predict how the VWFA would form by the time the kids were eight.

The authors conclude that “These findings powerfully support the idea that earlier-developing patterns of connectivity instruct the development of cortical regions into functionally distinct regions.” How “distinctive connectivity arises before distinctive function” is a question that demands more research.[3]

The authors speculate that at one time the VWFA may have been “involved in higher-level perception of objects before being co-opted to reading.” There is an intriguing side note to this – knowing that a region will be restructured when kids learn to read may give researchers a way to look ahead at their development. By studying the brain connections prior to the formation of the VWFA, doctors may be able to anticipate early on if kids will have reading difficulties or disorders such as dyslexia. Early knowledge can lead to early intervention and a much more successful outcome to the process of learning to read effectively.

 

Citations:

[1] Kuhl, Williams, Lacerda, Stevens, & Lindblom, 1992, in Moats, Louisa, and Tolman, Carol. (nd). Speaking is Natural; Reading and Writing are Not. Retrieved from http://www.readingrockets.org/article/speaking-natural-reading-and-writing-are-not

[2] Álvarez, Horacio. (March 14, 2014). How Our Brains Learn to Read. Retrieved from http://blogs.iadb.org/education/2014/03/14/how-our-brain-learns-to-read/

[3] Saygin, et. al. (August 2016). in Mole, Beth. (August 11, 2016). Brain wiring needed for reading isn’t learned—it’s in place prior to reading. Retrieved from https://arstechnica.com/science/2016/08/brain-wiring-needed-for-reading-isnt-learned-but-in-place-prior-to-reading/

Author: AceReader Blogger

The AceReader blogging team is made up of specialists in a number of different areas: literacy, general education, content development, and educational software. For questions about posts, please submit them in the form below. For suggestions about blog topics, please email them to blogger@acereader.com.

Leave a Reply