Human Babies Rely on Primitive Reflexes to Learn Language
Learning a language requires primitive brain areas to be rewired and fine tuned.
Posted Sep 04, 2013
A new study released on September 3, 2013 found that infants up to 6 months old respond strongly to nonhuman primate vocalization as if it were coming from a human voice and sheds light on the developmental origin between speech and cognition.
The human process of unlearning innate reflexes and then relearning them through practice and the process of creating fine tuned motor skills is a fundamental part of healthy development and self-expression.
The biological connection between language acquisition and being able to use our hands to create things sets us apart from our primate cousins. Interestingly, another study also released on September 3, 2013 found that the same brain region used for language is also used when humans make complex tools, supporting the theory that language and tool making evolved in tandem.
The newest research suggests that the advancement of hand-held axe production may have coincided with the development of language, as these functions overlap in the same regions of the human brain. Language and tool making is another example of how the cerebrum (up brain) and cerebellum (down brain) work together.
A bird that is hatched and reared in isolation from other birds is still capable of building a perfect nest. Spiders know how to weave intricate spider webs based on implicit memories in their genes. Human beings are the same. The day we are born we know a lot of things that help us survive for the first six months of our lives. But these reflexes must be unlearned as toddlers, and often relearned by incorporating more advanced cognitive functions as children and adults.
Our implicit memories stored deep in our primitive brain areas are what Carl Jung referred to as the collective unconscious. These are ancient memories (or archetypes) passed on through our genes. The human brain is built like an archeological dig with our most recent humanness being stored near the top in the prefrontal cortex and as you head down towards the brainstem, you tap the more primal and reptilian implicit memories that have been embedded into your DNA over eons.
Human Babies Respond to Calls from Primates
Human infants' responses to the vocalizations of nonhuman primates sheds light on the developmental origin of a crucial link between human language and cognitive abilities. A new study titled, “Non-Human Primate Vocalizations Support Categorizations in Very Young Human Infants” was published on September 3, 2013 in the Proceedings of the National Academy of Sciences.
The new findings document that for young infants, listening to either the vocalizations of humans or nonhuman primates both support fundamental cognitive processes. Alissa Ferry, lead author and currently a postdoctoral fellow in the Language, Cognition and Development Lab at the Scuola Internationale Superiore di Studi Avanzati in Trieste, Italy, together with Northwestern University colleagues, documented the link between vocalizations of nonhuman primates using lemur calls.
When considering the deep roots of our collective unconscious, it is fascinating that young infants respond to the vocalization of a lemur as if it were a human. Ferry says, "We found that for 3- and 4-month-old infants, non-human primate vocalizations promoted object categorization, mirroring exactly the effects of human speech, but that by six months, non-human primate vocalizations no longer had this effect -- the link to cognition had been tuned specifically to human language." This is in keeping with many other primitive reflexes that infants must unlearn in the first six months of life.
Furthermore, the researchers found that infants' response to nonhuman primate vocalizations at three and four months was not just due to the sounds' acoustic complexity. Infants who heard backward human speech segments failed to form object categories at any age.
Susan Hespos, co-author and associate professor of psychology at Northwestern said, "For me, the most stunning aspect of these findings is that an unfamiliar sound like a lemur call confers precisely the same effect as human language for 3- and 4-month-old infants. More broadly, this finding implies that the origins of the link between language and categorization cannot be derived from learning alone."
"These results reveal that the link between language and object categories, evident as early as three months, derives from a broader template that initially encompasses vocalizations of human and nonhuman primates and is rapidly tuned specifically to human vocalizations," said Sandra Waxman, co-author and Louis W. Menk Professor of Psychology at Northwestern.
Waxman said these new results open the door to new research questions. Such as, "Is this link sufficiently broad to include vocalizations beyond those of our closest genealogical cousins," asks Waxman," or is it restricted to primates, whose vocalizations may be perceptually just close enough to our own to serve as early candidates for the platform on which human language is launched?"
Language and Tool-Making Evolved in Tandem
Language and stone tool-making are unique features of humankind that evolved over millions of years. Dr Natalie Uomini from the University of Liverpool Department of Archaeology, Classics & Egyptology, said: "Nobody has been able to measure brain activity in real time while making a stone tool. This is a first for both archaeology and psychology. Our study found correlated blood-flow patterns in the first 10 seconds of undertaking both tasks. This suggests that both tasks depend on common brain areas and is consistent with theories that tool-use and language co-evolved and share common processing networks in the brain."
The researchers say that their study released on September 3, 2013 is the first-ever to look at how brain activation correlates to Acheulean tool-making and language. Using functional transcranial Doppler ultrasonography (fTCD), the researchers measured brain blood flow lateralization patterns (hemodynamics) in subjects who performed two tasks designed to isolate the planning component of Acheulean stone tool-making and cued word generation as a language task.
This finding is consistent with a shared brain region for both prehistoric stone tool-making and language, and ‘is compatible with language evolution theories that posit a co-evolution of language and manual praxis,’ according to researchers. The findings support the hypothesis that advanced aspects of language probably emerged as early as 1.75 million years ago, with the start of Acheulean technology.
Charles Darwin was one of the first to suggest that tool-use and language may have co-evolved, because both depend on complex planning and the coordination of actions. The combination of high level cognitive (cerebral) skills with fine-tuned muscle (cerebellar) actions makes it possible for humans to create masterpieces of art, literature, science and just about every advancement of modern civilization.
It took early humans almost two million years to move from razor-sharp stones to a hand-held stone axe. Humans didn’t leave the Stone Age until they had the cognitive function combined with physical dexterity to create tools. Stone tool-making and cued word generation caused common cerebral blood flow lateralization signatures in the studies’ participants.
There has been a wave of new research linking the use of hand gestures and healthy childhood development. Researchers hypothesize that the axe-tool required a high level of brain processing from regions of the brain that are also responsible for a range of different functions including the vocal cords and hand gestures.
It make sense that speaking with your hands (gesticulation) and creating a tool with your hands would be directly linked to the same part of your brain that controls language. Recently, there have been interesting reports that link being right or left handed and left brain-right brain thinking.
As I type this, I realize that it’s no coincidence that the keyboard is clearly designed to be an ambidextrous tool that allows humans to express language effortless through the written word while maintaining brain symmetry of thought and action.
Conclusion: Balancing Primitive and Modern Brain Areas is Key
In terms of the architecture of your brain, you can think of your conscious mind as being held in the cerebrum and your unconscious mind being south of the midbrain in the cerebellum and brainstem.
Flexing the strength of your conscious mind, while simultaneously allowing your more primitive unconscious mind to cross the midbrain and enter the realm of conscious thought allows you to have the best of both worlds. With practice, you can learn to engage all four of your brain’s hemispheres which is the key to mastery, the creative process and using either your hands or language to express yourself.