Previous research involving visual attention between parents and toddlers has focused more on the ability of each person to follow the gaze of the other person’s eyes. In recent years, many studies have found a link between eye contact, gaze and autism spectrum disorder (ASD).
The Indiana researchers realized that hand-eye coordination is much more common throughout the day, and that when the parent and toddler both focus their hands and eyes on an object they interact as equals, rather than one or the other taking the lead.
"Currently, interventions consist of training children to look at the other's face and gaze," said Chen Yu, associate professor in the Department of Psychological and Brain Sciences at Indiana University, Bloomington. "Now we know that typically developing children achieve joint attention with caregivers less through gaze following and more often through following the other's hands."
The researchers understand that, "The daily lives of toddlers are filled with social contexts in which objects are handled, such as mealtime, toy play and getting dressed. In those contexts, it appears we need to look more at another's hands to follow the other's lead, not just gaze."
The findings open up exciting questions about language learning and the teaching of language. They could also have major implications for the treatment of children with early social-communication impairment, such as autism, where joint caregiver-child attention with respect to objects and events is a key issue. The researchers believe these findings solve some of the problems and inadequacies of the classic unified “gaze-following” theory.
The researchers found that gaze-following theory tends to be imprecise in the real and chaotic world outside the sterility of a laboratory. It can be hard to tell precisely what someone is looking at when there are several objects together. It is easier and more precise to follow someone's hands. In other situations, it may be more useful to follow the other's gaze, according to the researchers. "Each of these pathways can be useful," Yu said. "A multi-pathway solution creates more options and gives us more robust solutions."
Researchers used innovative head-mounted eye-tracking technology that records the views of those wearing it, like Google Glass, which has never been used before with young children. While recording moment-to-moment data of what both parent and child visually attend to as they play together in the lab, the researchers also applied advanced data-mining techniques to discover fine-grained eye, head and hand movement patterns from a rich dataset they obtained from multimodal digital data.
"This really offers a new way to understand and teach joint attention skills," said co-author Linda Smith, Distinguished Professor in the Department of Psychological and Brain Sciences at Indiana University. Smith has done pioneering research and theoretical work in the development of human cognition, particularly as it relates to children ages 1 to 3 acquiring their first language. "We know that although young children can follow eye gaze, it is not precise, cueing attention only generally to the left or right. Hand actions are spatially precise, so hand-following might actually teach more precise gaze-following."
The Cerebellum Coordinates Eye and Hand Tracking Movements
I have written extensively in The Athlete’s Way
about the possible role the cerebellum plays in cognitive function and well-being throughout a lifespan. This research from Indiana University offers more proof of the connection between the cerebellum and cerebral functions linked to learning and social behavior.
The mysterious and powerful cerebellum (Latin: Little Brain) is only 10% of brain volume but holds over 50% of your brain’s neurons. My father, who was a neurosurgeon and neuroscientist always said, “whatever the cerebellum is doing, it’s doing a lot of it.”
In another study from March 2013, a research team honed in on the gene Tsc2 in Purkinje cells of the cerebellum and found that loss of Tsc2 in Purkinje cells lead to autistic-like behavioral deficits. These studies provide compelling evidence that Purkinje cell loss in the cerebellum and/or dysfunction may be an important link between ASD as well as a "general anatomic phenomenon that contributes to the ASD phenotype," according to researchers.
A 2001 study published in the journal Nature Neuroscience confirmed that the cerebellum coordinates eye and hand tracking movements. The researchers used functional magnetic resonance imaging (fMRI) during visually guided tracking tasks that required varying degrees of hand-eye coordination.
The researchers found that the cerebellum was more active during independent rather than coordinated eye and hand tracking. However, in three further tasks, they also found increases in cerebellar blood oxygenation as hand-eye coordination increased.
This proves that the cerebellum has a direct relationship to tracking performance, with high activity seen during both coordinated and independent conditions of hand and eye tracking. This data provides the most direct evidence that the cerebellum not only supports motor coordination but plays a significant role in learning to coordinate eye and hand movement.
Could the Vestibulo-Ocular Reflex be Linked to Autism?
The cerebellum also controls the vestibulo-ocular reflex (VOR) which is a reflex eye movement that stabilizes images during head movement by producing an eye movement in the direction opposite to head movement, which keeps the image in the center of your visual field. VOR is used for tracking a target and for helping to coordinate hand-eye movement. For example, when the head moves to the right, the eyes move to the left, and vice versa. Since slight head movement is present all the time, the VOR is very important for stabilizing vision.
The vestibulo-ocular reflex needs to work very quickly to maintain clear vision and focus. Head movements must be compensated for almost immediately—otherwise, your vision would look like a video taken with a shaky hand or in motion. VOR is used to play most sports
and is key for hitting a tennis ball, hockey puck, baseball, catching a football... and for striking any moving target.
My father—who was a nationally ranked tennis player in his youth—always said, "Of this I am absolutely positive, becoming a neurosurgeon was the direct consequence of my eye for the ball." When people say 'keep-your-eye-on-the-ball,' they are literally describing the importance of a finely tuned vestibulo-ocular reflex.
To achieve clear vision, signals from the inner ear are sent as directly as possible to the eye muscles: the connection involves only three neurons, and is correspondingly called the three neuron arc. Using these direct connections, eye movements lag the head movements by less than 10 milliseconds. A well functioning vestibulo-ocular reflex is one of the fastest reflexes in the human body.
My fascination with the cerebellum and VOR is something my father passed on to me. I've yet to find research that connects the VOR to brain connectivity, autism, or learning disabilities. To my knowledge, the role of VOR in autism spectrum disorder and other learning disabilities is still an educated guess.
Brain Connectivity Between Hemispheres is Key to Learning
Another study from August 2013 found that atypical visual orientation in 7-month-olds could be a sign of risk for autism. The study titled “White Matter Microstructure and Atypical Visual Orienting in 7-Month-Olds at Risk for Autism” was published in American Journal of Psychiatry. White matter in the corpus callosum connects the left and right hemispheres of your cerebrum.
The researchers from Philadelphia found that children who are later diagnosed with autism have subtle but measurable differences in attention as early as 7 months of age. Researchers found that infants who went on to be diagnosed with autism are slower to shift their gaze from one object to another (by approximately 50 milliseconds), compared to peers who did not receive the diagnosis.
The scientists identified specific brain circuits in the corpus callosum were responsible for causing the slower response. The findings point to a problem they called "sticky attention," which is a phenomenon observed in preschool and older children with autism, but not yet well studied before in babies at risk for autism.
They were slower than both high-risk-negative and low-risk infants to orient or shift their gaze to objects that appeared outside their direct gaze. Results also implicate a specific neural circuit (the splenium of the corpus callosum), which may develop differently in those at risk for ASD compared to typically developing infants, who show more rapid orienting to visual stimuli.
"This is a very exciting study, because the impairments in shifting gaze and attention that we found in 7-month-olds may be a fundamental problem in autism," said Robert T. Schultz, Ph.D. Director of the Center for Autism Research and a co-author on the study. "These results are another piece of the puzzle in pinpointing the earliest signs of autism. Understanding how autism begins and unfolds in the first years of life will pave the way for more effective interventions and better long-term outcomes for individuals with autism and their families."
Other research on the benefits of playing an instrument before age 7 and the importance of hand gesticulation early in life imply that the neural scaffolding that connects brain hemispheres needs to be laid down early for the neural connections to have an infrastructure to build upon.
Conclusion: Scaffolding for Brain Connectivity is Built in Toddlers via Hand-Eye Coordination
Research is mounting that creating strong connectivity between both hemispheres of the cerebrum and both hemispheres of the cerebellum holds the key for optimizing brain function throughout a lifespan.
This new research on the role of hand-eye coordination in the early development of toddlers is another clue for practical ways that we can give toddlers and children the best odds for learning, creating social connectivity and lay the neural groundwork for maximizing their potential.
Just like a baby chick who has a patch put over one eye throughout early development would not have the scaffolding to build the neural connections needed for vision in that eye ... it makes sense that daily activities in early life are important for laying down an initial neural scaffolding between brain hemispheres that serves as an infrastructure to fortify well-connected brain hemispheres in childhood and beyond.
As I put the pieces of this puzzle together, my hypothesis (and advice) is that parents, teachers and caregivers should strive to include daily activities that strenghten brain connectivity between all four brain hemispheres—starting from the first day of a person’s life. These initial neural connections will play a crucial role in optimizing a child's human potential for a lifespan.
If you’d like to read more on this topic please check out my Psychology Today blogs: “How Is the Cerebellum Linked to Autism Spectrum Disorders?”, “Musical Training Optimizes Brain Function”, “Decoding the Secrets of Brain Connectivity”, “Better Motor Skills Linked to Higher Academic Scores”, “Childhood Creativity Leads to Innovation in Adulthood”, “Can Mindfulness Backfire?”, “Loving Touch Is Key to Healthy Brain Development”, “Einstein’s Genius Linked to Well-Connected Brain Hemispheres”, “Why is Dancing So Good for Your Brain?”, “Human Babies Rely on Primitive Reflexes to Learn Language”, “Hand Gesturing Engages All Four Brain Hemispheres” and "The Neuroscience of Calming a Baby."