Why children's brains need physical and social interaction in real time and space.

As the debate about the age at which children should be exposed to social media gathers pace, an understanding of how children's brains develop should be at the forefront of the conversation. Social media is only one aspect of the influence of screen time on the developing human brain.

An abridged excerpt from the book Reflexes Movement Learning and Behaviour below explains how and why physical interaction and social engagement in the real world are crucial to the development of neural circuits involved in language, emotional expression and self-regulation.

The impact of screentime on the developing brain is twofold:

1.      What it prevents a child from doing

2.      What it does

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What screen time prevents

Physical activity:

While children are using electronic media they are not engaged in large physical movements, physical interaction with another human being or free, spontaneous and self-generated creative play. Physical activity is necessary to entrain body awareness, control, balance, coordination, non-verbal language (involved in the ability to read and respond appropriately to the intentions of others) and learning "how" - through trial and error - to do new things.

All mammals naturally engage in rough and tumble play. It is through this activity that life skills are learned (chasing, fleeing, catching etc), social bonds are formed, regulation and control of strength and force are practised and challenged and physical boundaries are established. Young mammals who do not engage in this type of play tend to be rejected by the pack when they reach adulthood.

Sensory experience of content:

Relating and integrating multi-sensory experiences with images is limited in the milieu of screentime so the physical and biochemical changes that occur in response to real sensory experiences are different. 

A photo of children playing in a field of lavender, exploring the feel of the flowers with their fingers, releasing the aroma by brushing up against the plants, helps to illustrate this point.  The combination of colours constantly changing in the light, touch, smell and the chemical effect of scent on the brain will become associated with the scent of lavender for life.    A screen image of a lavender field will only conjure up those physical changes if the feel and scent of fresh lavender is already known.

A similar dulling of sensory and emotional involvement may also develop when exposed to images of violence.  The revulsion that naturally occurs when forced to be an unwilling witness to violent scenes does not necessarily have the same impact or intensity when viewed remotely where there is a physical shield between reality and its consequences. Potentially, this can result in a person becoming detached from the real effects of violence, inured to the suffering of others and reduce instinctive empathic responses. Conversely, children can be traumatised by exposure to horrific images on screen.

Social skills:

Unlike an adult's brain, a child's brain is still developing, and as a result, is more malleable.

Too much time in front of a screen not interacting with other people can lead to difficulties with social interaction. Lack of opportunity or practise in picking up on nonverbal cues, which include facial expressions, postural changes, speed and quality of movements, tone of voice, and eye contact all provide important insights into the feelings and intentions of others and how to respond to them. Even the sense of smell can provide subliminal messages about a person’s state of arousal.

If used at the expense of real inter-personal relationships, excessive screen time can result in deficit in sensing and understanding social nuances and lead to relationship problems later in life.  Sympathy or “common feeling” begins with the ability to feel as another.

Screen time, if not being used for social interaction potentially reduces time engaged in conversation.  Conversation is key to language development through the exchange of thoughts and ideas and listening to each other. Early elements of conversation are physical as well as verbal involving, listening, processing, reflecting, mirroring and mimicking the actions of another.   Conversation is not just about exchange of information but sharing thoughts, expression of feelings, understanding, interpretation and seeing situations in new ways. It is spontaneous, free flowing and exploratory in direct response to the Conversation connects us, forms bonds, enables us to articulate feelings and anxieties that may have become locked in the self, as well as providing a melting pot for the generation of new ideas.  Conversation is the alchemy through which the raw materials of random thoughts and observations can be turned into creative gold.  It can challenge our accepted view of the world, introducing us to new ideas and perspectives and motivate the flagging will. 

Sleep:

Sleep is essential for physical growth (growth hormone is secreted during sleep), development, learning, memory, emotions, behaviours, and overall mental health. Electronic devices emit blue light from their screens. When exposed to this before bedtime, a child’s body may interpret blue light as daylight, causing their brain to signal the body to stay awake even after the screen has been turned off. Long-term exposure to blue light can result in disturbed sleep patterns and imbalances in a child’s biological clock.

What screen time does

Attention:

Prolonged screen activity has greater impact on brain wave states in children decreasing vigilance to external stimuli and increasing passive attention. When children are exposed to technology at high rates, their brain may adopt an internet approach to thinking – quickly scanning and processing multiple sources of information involving rapid shifts of visual attention.  While this type of processing is useful for scanning novel environments, it is not good for developing listening skills, retaining information in short term memory or for developing the specific eye movements needed for reading.  This type of processing has many features in common with aspects of attention deficit disorder.

Thinking styles:

Computer programmes are pre-set often developed by a particular type of mind and therefore lead the child to explore or follow a designated programme as opposed to responding in innovative creative ways.  If a child spends long periods of time engaged in activity through a single medium, the developing brain starts to “think” in a similar way. 

A study carried out in Japan in 2022 indicated that boys who watch screens at the age of one are more likely to show signs of autism at the age of three.  Boys who used screens for one to two hours a day were twice as likely to be diagnosed as having autism, while two to four hours per day increased the risk by 3.5 times (Kushima et al. 2022).  The reason was uncertain as it is possible that children with autistic tendencies seek out and demand more screen time, but screen time also affects the brain wave state of children differently from adults and this may play a part in children’s difficulty in shifting attention away from screen activity. Difficulty in shifting attention between different sensory modalities is also a feature of autistic spectrum disorder.

Mood regulation:

Excessive screen time has been linked to issues with attention, frustration,  aggression and other behaviour. Children who have more than two hours a day of screen time are more likely to have angry outbursts or be irritable when asked to stop using their devices, or when they are not using them.  The latter is thought to be related to the potentially addictive properties linked to screen time including how screen time affects brain wave states and increase in the neurotransmitter dopamine, which is linked to the sense of reward.

Brain waves:

More than 50 years ago, Krugman (1971) discovered that TV screen time dampens the activity of the critical left brain within 30 seconds of starting to view.  Brain wave activity switches from an alert waking state, associated with increased beta activity to predominant alpha waves, indicating an unfocused, dream like state in which adults and children alike are more receptive to images and feelings.  “Both advertisers and politicians intuitively know how powerful the TV/Brain effect is!” (Large M, 2006)

The brain constantly generates electrical activity in both sleep and waking states and can be recorded using an electroencephalograph or EEG machine.  German psychiatrist Hans Berger (1873 – 1941) was the first to record brain waves from the scalp and discover that there was a change in activity when subjects became drowsy or fell asleep.  Other scientists subsequently confirmed Berger’s observations and the technology for detecting and analyzing brain waves states has advanced considerably.  The two fundamental aspects of brain activity measured using as EEG are frequency and amplitude of the waves.  The specific frequencies of different bands of brain wave and their associated mental states in relation to arousal are listed in Table 6.1 above.

Exposure to screens has been shown to reduce attention span in children. Increased slow-wave (theta band) and decreased fast-wave (beta and gamma bands) generated from EEG, as well as increased theta/beta ratio, have been observed in children with Attention-Deficit-Hyperactivity-Disorder (ADHD).  Results support the negative relationship between screen exposure and attention-related patterns generated from EEG in typically developing preschool children. (Zivan et al 2019).

In a study carried out to investigate associations between screen-based media use and brain white matter integrity in preschool-aged children researchers reported,

"In this cross-sectional study of 47 healthy prekindergarten children, screen use greater than that recommended by the American Academy of Pediatrics guidelines (Table 6.2) was associated with lower measures of microstructural organization and myelination of brain white matter tracts that support language and emergent literacy skills and corresponding cognitive assessments.

These findings suggest a need for further study into the association between screen-based media use and the developing brain, particularly during early childhood." (Hutton et al. 2019)

Research carried out at the Australian National University in Canberra found that television viewing reduced the quantity of the highest frequency brain waves involved in alert attention and decision making and increased theta activity.  Whereas alpha activity is associated with relaxed waking states, theta is associated with drowsiness and a generalized dampening down of the brain’s ability to send or receive information by decreasing vigilance and linked to states of passive inattention.  Merrelyn Emery, one of the researchers in the Australian study concluded that the abundant constant theta activity, which approaches a drowsy or hypnogogic pattern when watching television for example, affects the way that knowledge is processed and acquired.

We can confidently predict that as theta activity increases during viewing, there will be at the ontogenetic level, a corresponding increase only in “knowing of” and not “knowing” (Emery 2006).

Theta activity is also associated with a different kind of perception.

An increase in theta represents a breakdown between person and environment in the sense that environmental vigilance is neglected (Ibid 2006).

This type of secondhand knowledge derived from passive observation rather than experience is not integrated in the same way as information learned from direct experience, which roots knowledge into the self. Krugman (2000) described this type of knowledge as being, recognition without recall, exposure without perception.

Addictive properties:

Researchers have found that screen time is not just habit forming, but that dopamine, strongly connected with addiction, is implicated.

Screen use releases dopamine in the brain, which can negatively affect impulse control. Studies have shown screen time affects the frontal cortex of the brain, similar to the effect of cocaine. Similar to drugs, screen time sets off a pleasure/reward cycle that can have a negative impact (Lorenz K, 2018)

Dopamine is a neurotransmitter[S1]  involved in pleasure and reward systems in the brain, as well as the inhibition of involuntary movement when at rest. It is one of three neurotransmitters collectively known as monoamines, of which the other two are norepinepherine (noradrenaline) and seratonin.  Norephinepherine acts as a key chemical in mediating the physical changes involved in arousal and it is important in the regulation of hunger and alertness.  Seratonin is important in the regulation of sleep, particularly the onset of sleep.  Dopamine plays many roles in the body and is involved in reward, motivation, memory attention and body movements.  Low levels may negatively affect mood, motivation and memory All of the monoamines are closely linked to mood states and if poorly regulated, emotional disorders.

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In a book Healing ADD:  The Breakthrough Program That Allows you to See and heal the 6 Types of ADD the author (Amen 2001), said that children with Attention Deficit Hyperactive Disorder (ADHD) are particularly susceptible to the addictive properties of electronic games.   In a study published in the journal Nature in which researchers carried out PET scans on subjects playing action video games, they discovered that the basal ganglia, where dopamine is produced, were more active when playing the game than at rest.  Amen goes on to say that,

"both cocaine and Ritalin (a stimulant drug used to treat the symptoms of ADHD) work in this part of the brain as well.

One of the properties of Ritalin is to make more dopamine available to the brain. 

Video games bring pleasure and focus by increasing dopamine release.  The problem with them is that the more dopamine is released, the less neurotransmitter is available later to do schoolwork, homework, chores and so on.  While the brainwave theory partly explains the dulling effect of television on the brain, the neuro-chemical theory explains some of its addictive properties with the let down or withdrawal symptoms that follow (Amen 2001).

Visual skills:

Over-use of computers and computer games may also affect the developing visual skills of young children.  Whereas concentration on near-point activities too soon (such as early reading before the necessary supporting postural and visual skills are in place) may be associated with visual near point stress, (Skeffington,1947)  possibly leading to the development of non-hereditary short sight, computer use requires intensive periods of focus at extended near distance – a focusing distance just beyond the ideal reading distance – with a tendency to develop convergence and focusing problems at reading distance. A significant number of children assessed at INPP in recent years appear to have difficulty with near-point (reading distance) convergence and can benefit from a small, temporary plus prescription, easing near-point stress at reading distance until reflex status has matured and accommodative and convergent skills have become more flexible.  This is a symptom which has become increasingly evident in the last 10+ years.  Whether it is related to increased use of screen time is not yet known.

While many hand-held computer games help to train accommodation between field vision and central vision, they do not train the eye tracking skills needed for reading. Children become good at rapid shifts of visual attention within their field of vision, but hand-held computer games do not develop the smooth sequential eye movements needed to follow a line of print without the eyes jumping further along the line, to the line above or the line below.  Children become good at rapidly decoding individual symbols, shapes or “pictures” on a screen, but are not as good at following a series of symbols from left to right and decoding them in an accurate sequence.  This is important for spelling.

Prolonged screen time can also result in symptoms of digital eye strain that may include burning, itchy, or tired eyes. As with sleep, blue light is also damaging to the retinal cells and can speed up macular degeneration.  Depending on the type of device in habitual use – for example, hand held devices tend to be used at near distance while laptops involve extended near distance - this can also lead to the development of myopia or near sightedness in children.

Posture:

Being hunched over smartphones or tablets for long periods of time can affect posture and the developing spine. This can lead to harmful physical effects that can last for the rest of their lives, such as back pain and headaches. 

Weight:

As mentioned above, screen time is a sedentary activity. This, coupled with eating high-calorie junk foods and reduced physical exercise, can lead to childhood obesity and poor muscle tone. When children and adults have meals or snacks while watching sitting in front of a screen, they have less conscious control over what or how much they eat.

Fast foods are exactly what they say they are: instantly available, eaten fast, often "on the hoof", and they generally have a high fat sugar and refined carbohydrate content. When food is eaten at speed, the  satiety centre in the brain does not have time to recognise signals sent from the gut that the body has had enough and respond by switching off the hunger signals before more food is eaten (Goddard Blythe 2001).

The gut-brain axis normally controls appetite and satiety via neuronal and hormonal signals when entry of nutrients into the small intestine stimulates the release of peptides which act as negative feedback signals to reduce meal size and terminate feeding, but it takes at least twenty minutes for this feedback system to be recognised in the brain.  “Fast” food can overtake this system.  Satiety also occurs in relation to the ratio of nutrients to calories, protein and fibre content and the insulin response.

In this context, children who have a habit of eating during screen time are at increased risk of becoming overweight.  The combination of increased weight and less physical activity can affect the development of muscle tone making the taking of regular exercise more difficult and less appealing.

In Balance:

While mindful (and regulated) use of digital devices is linked with well-being, conditions imposed on societies by the Covid 19 Pandemic in 2020 resulted in a significant increase in the use of screen time for children and adults.  Pandya and Lodha (2021) carried out a review of screen use in an attempt to understand the virtual social connectedness, excessive use of digital technology, its consequences and suggest strategies to maintain healthy use of digital technology.  They reported,

"excessive screen time to be associated with a range of negative mental health outcomes such as psychological problems, low emotional stability, and greater risk for depression or anxiety (Allen et al., 2019; Aziz Rahman et al., 2020; Ministry of Human Resource Development, 2020). Negative consequences often result when digital use is impulsive, compulsive, unregulated or addictive". (Kuss and Lopez-Fernandez, 2016).

How much is too much?

Electronic media is not all bad.  During the Covid 19 pandemic it enabled communities in isolation to remain connected, families to see one another online, essential items to be delivered, businesses to survive and technological advances to be made.   Before the pandemic it provided a source of education and entertainment, access to images and knowledge and data way beyond the scope of individual physical proximity and will continue to do so, but like medication the difference between benefit and harm or the emergence of side effects is dose dependent, which raises the question, how do we ensure that children’s exposure to screen time is age appropriate?

The American Academy of Pediatrics (2022) recommended that in children under 18 months of age, screen time should be avoided other than for chatting. Between and 18 and 24 months children should only watch high quality programming with an adult to help them understand what they are seeing. Screen time for children aged 2 - 5 years should be limited to one hour per day. Parents should co-view with children to help them understand content. Between 6 and 12 years of age consistent limits should be set on the time spent using media and parents should ensure media does not take the place of adequate sleep, physical activity and other activities essential to health. From 12 years of age, recommendations are to designate media-free times together (parents should also adhere to this), such as mealtimes, walks, driving etc. as well as having media-free zones at home such as bedrooms.

While the current political debate is focused on use of social media in children under 16 years of age, electronic media influences the development of neural circuits that affect physical, linguistic, emotional and social development from birth. A new generation of parents, who have grown up with electronic media may not be aware of the social sculptor hidden within their own and their children's devices. Humans evolved to live in the context of the physical world. Despite rapid technological advances, this fundamental aspect of human development has not changed. Electronic media should be a tool for life, not a way of life.

Source: All references referred to in the above article may be found in Chapter 6 of Reflexes, Movement, Learning and Behaviour.