How does touch affect our mental and physical health? | DW Documentary

[Music] [Music] no words can make feelings as palpable as a gentle touch but a touch can also relieve pain strengthen our immune system and even make us live longer [Music] long mainly ignored by science gentle touch is finally getting the attention it deserves [Music] touch is a fundamental i would say it's an absolute necessity as much as the air we breathe and the food that we eat and it can calm your whole world it can make your body feel better you become less stressed [Music] touching stimuli change the biochemistry of our brain in a dramatic

and positive way and now we can't do it as much we start to notice how incredibly important it is [Music] the first touch [Music] one of the most important moments in our lives this baby cannot see further than 30 centimeters yet and our sense of hearing does not fully develop until we are four weeks old [Music] we first experience the world through touch it seems we're so reliant on our sense of touch that it is even essential to our survival we can't do without it because it's the easiest way for us to interact with our

environment [Music] when a baby cries it wants to feel its parents touch words are not yet enough to soothe it without the gentle pressure of the womb babies find a sense of security through caress and body heat they are reassured that someone is there and cares for them touching strengthens the bond between child and parents from the very first moment we mentioned yeah we humans are heard animals in this way i think that we actually use touch to learn and feel that we are now part of our group and our community also protects us i

think that this is especially important at the beginning of life that we know we are not alone that there is someone who will take care of us and we now somehow belong to this community with these other people we as humans need relationships no one can exist on their own we evolved to live together in a small group because it offers us protection from the elements and our enemies and we express belonging through touch it makes us feel secure close gives us comfort or pleasure it is how we express joy and connection [Music] humans have

a highly differentiated system for perceiving and classifying touch because a touch can also mean power and violence it can frighten and threaten us in fractions of a second the receptors in our skin tell us just what kind of touch it is [Music] whether we should relax or spring to action to escape danger recognizing and classifying touch is the very first language we learn science has only recently begun to research how subtle and nuanced this language really is rebecca buma and her colleague in ling cooping sweden are investigating the role that touch plays in our communication

this one now look at this yeah just how good is it at expressing our emotions the two test subjects cannot see each other they try to convey different messages by just using their arm or hand i love you i'm sad watch out electrodes register the slightest movements of the facial muscles an objective method to measure emotions [Music] the information she is supposed to communicate to him appears on a screen and he can recognize her messages of course you can also try to convey emotions with words but i think what comes across and what you actually

feel is something else it's entirely different if i say to someone hey i love you or if i show it by touching hugging kissing or cuddling with them above all we are better able to convey love and compassion through touch than through words facial expressions or gestures touch creates a much deeper emotional connection how has the fact that we now have to keep our distance affected us and our relationships it just creates barriers it creates barriers between people and so if you cannot reach out and touch someone it means you lack that interaction with them

and it means that we can't reinforce our social bonds and this is especially true at the moment for younger people who are learning how to interact and so in a normal world we would shake hands or hug or kiss especially children and now we have to tell them no no you can't do it and so not only does it have an impact on social relationships that we make for the moment but it could have bigger implications for the future as well just reaching your hand out to another person creates a kind of relationship with them

but how does that happen this is one of the questions that neuroscientist rochelle ackerly is investigating at the university of ex marseille although the pandemic has forced her to take a break from her research her findings are generating an ever greater interest because many of us are acutely aware of what we are missing in our lives right now gentle touch can be both calming it can be relaxing but it's also something that we need it's essential for life because if we didn't have reward in touch if we didn't find it pleasurable we wouldn't do it

and if we didn't do it we wouldn't be here [Music] touch is especially important at the beginning of life after birth it stabilizes breathing body temperature and even blood sugar levels through contact babies sense their physical boundaries that helps them to learn the difference between themselves and others it is essential for certain developmental milestones and then you can still see the effects of it even 10 years later that there are cognitive differences between babies who had experienced a lot of touch and those who had experienced very little a basic biological need and yet for many

years cuddling stroking and hugging children was frowned upon as late as the 1950s and 1960s physical closeness was considered unnecessary or even harmful but research and experience has changed all this especially among our closest relatives [Music] they clearly demonstrate what happens when newborns do not experience closeness and touch if animals only received basic care for months after birth many of them died and those that survived suffered irreparable psychological and physical damage they showed reduced body growth underdeveloped immune systems and an inability to perform even the simplest memory functions central areas in the brain were impaired

and showed reduced volume [Music] because touch has a very direct effect on our brains it is essential for us to develop a sense of self physical contact sets important developmental processes in motion and also stimulates growth when a baby is touched millions of receptors in the skin react and produce very small currents these microcurrents reach different regions of the brain via a dense network of nerve fibers when the electrical impulses connect with specialized nerve cells there their memory gates open signal molecules are released they trigger growth-promoting processes directly in the other nerve cells or they

can reach cells via the blood and trigger growth processes there in the famine this is how touch always produces a reaction throughout the body it changes our organism we see this not only in babies but also in adults so we cannot ignore it because it affects all aspects of our biology and physiology an experiment in the leipzig haptics lab brain waves are recorded before during and after a massage martin grunvald has been interested in gentle touch since the early 1990s back then the topic was basically still uncharted territory for the scientific community how does a

massage change brain activity the eeg measurements show that brain waves slow down the result is a profound state of relaxation similar to when a person is fast asleep however the brain not only becomes less active it also releases a cocktail of messenger signals [Music] when hormones and neurotransmitters are released certain messenger chemicals go on to reach the other areas of the body through the bloodstream this process leads to among other things muscle relaxation a decrease in heart rate and shallower breathing there is a whole host of physical changes every single touch literally goes under our

skin [Music] we often overlook visual or acoustic stimuli but this is never the case with touch because recognizing someone's touch and analyzing it is essential for our survival in a millisecond our brains can determine whether or not a touch poses a threat millions of receptors in our skin react they register pressure vibration heat cold and pain passing on the information via nerve fibers scientists only recently discovered a very special type of nerve fiber it specializes exclusively in gentle pleasant touch these fibers do not provide us with information about our external world but they are able

to register whether we liked the touch or not the discovery of these so-called sea tactile afferents gives insight into exactly how significant it touches for our social lives francis mcglone is one of the best known researchers when it comes to these stroking fibers this discovery filled him with excitement [Music] and i can remember the moment i was reading a paper by what i would say my one of my heroes in neuroscience a professor aqua valbo and orca valvo in this paper had discovered a nerve fiber in the skin of humans called the c tactile afferent

that responded to gentle touch and when i was reading that paper i was on a aeroplane flying out of washington i could see washington memorial on my through my window and i was reading that paper and i just at that moment a penny dropped i thought i know exactly what that nerve fiber is basically responding to from that was 1995 or 96 and since then i've been fortunate enough to pursue my passion in characterizing and understanding just what this nerdfighter does and how vital it is to our well-being this finding led to the discovery of

a totally new sensory system when we are gently touched information about the type and location of the touch is sent to the brain in a matter of milliseconds at the same time c-tactile afferents also react their signals only reach the brain after one to two seconds to be more exact to areas of the brain that are responsible for processing positive feelings how we think about others and self-perception i think it's what glues social groups together so this touch is playing a fundamental role in in regulating the the reward of social contact in groups and when

you're together you're far more able to deal with stresses from the outside environment it's like the missing particle that's allowed us to understand just what the social brain really fuels off and that is this touch nerve that brings everything together perhaps the sea tactile afferents were discovered so late because they are difficult to find a discovery of this magnitude requires real specialists like here in ling coop in sweden a paper-thin needle pierces through the skin into a nerve in the arm the problem is that there are many different fibers in the nerve which can be

connected to very different receptors so it's a matter of finding the right one but what is the fiber reacting to exactly the needle is corrected until a fiber finally responds to the gentle stroking stimuli it is a time-consuming procedure usually taking hours but it pays off the researcher can finally determine to what the sea tactile afferents respond best when you press gently with low force with a slow stroking velocity like this they are tuned to respond optimally to this kind of stroke over the skin and so we think that these see tactile fibers give us

a sense of positive effective touch and so it's pleasant touch and so when we if we stroke the skin too fast or too slowly it's not optimal but if we stroke it like a gentle caress of the skin it optimally activates these fibers and we think that this is how you gain pleasure out of touch the so-called stroking robot experiments demonstrate this it can be used to test different touches in exactly the same way on each test subject the more signals received via the c tactile afferents the more pleasant the test subjects perceive the touch

the effect is strongest at 34 degrees celsius the same temperature as our fingertips and interestingly there's more of these nerve fibers here on the back than there are in the forearm so why do people like having their back massage well they like having their back massage because there's more of these nerve fibers there in evolutionary terms why would you put a reward touch system on the back well you can't get to your back to groom it so you need to get somebody else another primate needs to come along and groom your back [Music] another indication

that touch plays a social role [Music] this highly complex system of receptors and nerve fibers connects us with our environment and other people but see tactile afferents alone cannot explain why we find touch so pleasant because the same stimulus the gentle touch of the skin can trigger completely different reactions depending on the situation and who is touching us [Music] that's why the first thing our brain has to learn is to distinguish whether we or someone else is touching us because that makes a huge difference to our brain [Music] when i stroke my arm my brain

can sort of predict what's going to happen how it's going to feel when i stroke my arm and what happens is that the brain then blocks out this information so it's as if the brain suppresses the feeling that occurs when i stroke my own arm and it does that by knowing what's going to happen and so it actually doesn't even matter to us so we don't consciously perceive the touches nevertheless we touch ourselves constantly mostly on the face between 400 and 800 times a day why to answer this question martin gruenvald's research group in leipzig

came up with an intriguing study the hypothesis was if this is all just biologically speaking irrelevant if this is an unnecessary touch then physiological changes in the brain will not show up but if this is a touch stimulus which is important for us on a physical level then there should be corresponding neurophysiological changes in the brain and this is exactly what we have shown now the test subjects are given the task to feel different patterns on small plates remember the structures and record them later they do not know that they are being filmed while doing

this so that their brain waves can be evaluated in parallel with their self touching when they try to remember what they have felt they suddenly hear some disturbing noises the eeg reveals just how stressed the test subjects are [Music] [Applause] this gives researchers their first chance to see in a laboratory setting how the organism regulates itself in this way the annoying sounds disrupt their concentration all of the information stored in their memory gets lost they feel overwhelmed and it is exactly at such a moment that self-touching frequently occurs the evaluation of brain waves shows how

short touch regulates brain activity it goes back to a medium level of arousal as a result the test subjects can better focus on the task at hand and i think that's the first step but when it comes to the processes behind it which parts of the brain trigger other areas in the brain to make your hands touch your face so you can feel better it's all a bit unclear now but the question where does that impulse to touch ourselves come from is a very interesting philosophical question touch comes from outside and works deep within us

it keeps us emotionally balanced [Music] and yet self-touch cannot replace the touch of another person [Music] but why is it different when we are touched [Music] and why does the same stimulus trigger so many different reactions in our brain from the greatest feelings of joy to deep aversion a caress can comfort calm and lower the heart rate for example if your best friend is in distress and a caress can also trigger us in different ways for example when we're in love then our pulse rises we're aroused because every single touch sends lots of different information

to our brain [Music] for example vibration pressure the duration of touch so the qualities of the touch but then it's also evaluated and so it's also how did that touch make me feel did i like it do i want more of the touch and so the brain actually puts together all this information to deliver a whole a rounded experience for touch rebecca buma is investigating exactly how and where this happens at the center for medical image science and visualization in lean cooping today she wants to see not only the brain but also the spinal cord

at work her theory the spinal cord might play a much bigger role in processing touch stimuli than previously thought i think what is particularly exciting about this is that we are now focusing a little less on the brain for a very long time neuroscience revolved exclusively around everything happening in the brain and we completely disregarded the whole interaction between brain and body and the physiology of the body before the signals from the sea tactile afferents even reach the brain they must first arrive in the spinal cord in the dorsal horn here the information i am

being touched is conveyed to other nerve cells mainly interneurons which transmit and process the information only a few nerve cells then send messages up to the brain what is interesting here is that the interneurons in the spinal cord receive information from the brain and this could impact our perception of touch in the spinal cord depending on the situation we are in and who is touching us everything is finally ready for the mri measurements the spinal cord activity also change when the subject touches himself or is touched [Music] the brain scans show that when the subject

touches himself activity in some areas is significantly reduced compared to the resting state but it's quite a different story when someone is touching us many brain regions are clearly activated especially regions in which we recognize the intentions thoughts and plans of others and which are responsible for that feeling of reward a major difference does it also show up in the spinal cord measurements alternating between the brain and the spinal cord are now taken which area becomes activated first and how do they influence each other so if the touch stimuli enter the spinal cord via the

nerves it is already differentiated here between me and others the brain knows that i'm touching myself maybe then we'll have less activation in the spinal cord the brain knows someone else is touching me maybe if it is someone i particularly like then it may be that the brain actually increases the activity in the spinal cord so that we react more sensitively to it now the data from the many test subjects must be evaluated the results could help us develop innovative approaches to treating mental illnesses or developing new types of prostheses anyone who feels a pleasant

touch wants more of it the reward system in our brain is responsible for this hormones are released the brain creates its own drugs so to speak mixing together a different cocktail depending on the type of touch [Music] these include for example endorphins the so-called happiness hormones that give us a high and also oxytocin the bonding hormone that makes us feel close and connected to the other person [Music] this explains why a hug can be so much more comforting than words [Music] because oxytocin plays a very important role in how we form social bonds it is

popularly known as the cuddle hormone and associated with birth and sex [Music] but studies carried out on primates show that oxytocin determines all of our long-term social bonds regardless of whether we are related or have sexual interests a friendship between primates is expressed primarily through mutual grooming particularly high levels of oxytocin are released when the two animals also have intense contact with each other in other ways [Music] the closer the primates are to each other the more touching positively affects them this makes evolutionary sense because oxytocin strengthens the need for closeness and promotes appropriate social

behavior and not only in the one who is receiving loving attention somebody who's giving touch also has to be rewarded and that reward i think is the building of the social relationship that we discuss with primates grooming the back of another primate you need to build a relationship for that to happen you scratch my back i'll scratch yours at a basic level and that's reciprocity and human behavior [Music] being in love only deepens our desire to be touched [Music] oxytocin not only ensures this but also feelings of reliability fidelity and security in a relationship and

it even improves our health [Music] also has calming and growth inducing effects it also influences our immune system it really is a versatile and useful hormone substance [Music] couples with long-term elevated oxytocin levels actually live longer they are less susceptible to stress their blood pressure is lower their pain tolerance level is higher and they are even better learners [Music] the more that couples parents children and loved ones touch each other the more loving they feel about the relationship oxytocin binds us together deepening our feeling of belonging however the bonding hormone can also have side effects

oxytocin doesn't just have these wonderful positive effects making you feel close to everyone around you otherwise you could say that we should give oxytocin to everyone and that will make us all love each other which makes for a conflict-free society but oxytocin just reinforces the fact that we only feel connected to the people we are already close to you so when it comes to people who we feel do not belong to our group we are even more distanced [Music] oxytocin reinforces the feeling of having to defend our group against others [Music] what does this mean

in times like these when we are supposed to keep our distance when we are supposed to limit physical contact to our innermost circle so far we can only speculate but one thing is for sure it is not good for us rights physical contact is absolutely essential to the existence of our species if it's missing for too long physical and above all psychological damage can occur this is the first time in evolution that primates have been told not to touch each other it's a precedent that's never happened before and the cost and consequences we don't know

i mean you see the data of mental health rising although the exact figures are not yet available health insurers have noticed that as social distancing measures have increased so too has mental health-related sick leave anxiety disorders depression and even addictions quite a few of us are looking for a substitute to replace what we are missing [Music] and brains are very clever now that could mean eating more drinking more yeah what people may be doing is finding a substitute for that reward that wasn't there mediated through gentle touch not that they were necessarily aware that that

was the cause of it but there's a reward state missing i need to get back to feeling good i'll have a smoke i'll have a cigarette i'll have a drink you know i'll have a cream cake that's possible that these behaviors that we're seeing now may well be a consequence of the fact that we're not socially touching anymore bayata dietsen launched her own study at the beginning of the lockdown in 2020. how does social distancing impact us is there a direct connection between our lack of contact and our stress levels the whole thesis that we

say touch can buffer this could now really be investigated and with a really relevant stressor compared to laboratory stress tests that we used before 250 households from all over germany participated in the study families singles all age groups before starting all test subjects were sent saliva sample tests to their homes then they had to answer questions on different days they received these questions as text messages on their cell phone do you feel lonely are you in pain do you have physical contact how nervous and stressed do you feel the answers were then directly related to

stress hormones they took saliva samples while they were answering these questions and this gave us the opportunity to combine the individual measurements the psychobiological information with the subject information in this everyday survey and because we had a relatively large number of test subjects which in turn produced a lot of measurements we can then go on to compare these individual measurements with each other and achieve a statistically significant result so we don't just have these average values how much touch or proximity or social contact per day they report but we have it moment by moment the

saliva samples are now cooled and stored at the institute the evaluation begins what are the cortisol levels like and how high are the oxytocin levels the assumption is that stress hormones decrease more rapidly in people who experience pleasant touch and that is exactly what is so important for us [Music] because stress is not inherently harmful to our bodies our evolutionary history already shows this in stressful situations it's usually a matter of survival for example when an attack is imminent the body adapts to fight or flight at lightning speed it activates the cardiovascular system lungs and

muscles at the same time the immune system kicks in it prepares itself to be able to quickly heal from any impending injury our defense against individual pathogens or substances on the other hand shuts down our autonomic nervous system and stress hormones are responsible for this adrenaline noradrenaline and cortisol as soon as the situation has been dealt with these hormone levels drop again and the mind and body can recover pleasant touches dramatically decrease stress hormones making for a perfect buffer against permanent stress that is harmful to our health and more [Music] the sea tactile afferents that

register every gentle touch could also influence how we perceive acute pain [Music] we've all done it when we hurt ourselves we automatically touch and caress the painful area we don't even think about it and science says that makes perfect sense studies show that touch has a very positive influence on us it can even inhibit acute pain for example when test subjects are confronted with electrical stimuli or thermal stimuli such as heat stimuli and pain is triggered as a result then touch can directly alleviate their pain response if something suddenly hurts the pain sensors in the

skin are the first to sound the alarm [Music] these lightning speed nerve fibers ensure that we notice the injury immediately for example we can immediately pull our hand away from a hot stove top and automatically rub our hand over the painful area at the same time however the pain signal is also sent out via the slower c-tactile afferent if we now rub our hand over the painful area the positive caress signals are sent at the same time our brain therefore receives a negative and a positive signal simultaneously and what happens is that when we are

stroked the brain sends the signal down to lower levels of processing so maybe in the thalamus or maybe already in the spinal cord and tells the neurons there okay calm down we are being stroked it's all good someone is there and so everything can be taken down a notch [Music] we still don't know exactly how pain is relieved but it works and not only for physical pain touch also helps with emotional pain often more effectively than words [Music] it communicates important information between two people it creates a deep emotional connection that transcends words [Music] and

yet as the world becomes increasingly digitized we have less and less physical contact with one another and the pandemic has only further reinforced this tendency for most of us not by choice if you don't see people in person you can't touch them and so i i do believe that our interactions on the internet and for example the rise of people working from home it does decrease the amount of touch that we receive on a daily basis and if we do have decreased touch it really could impact on our well-being today most of us touch our

smartphones or tablets far more than we touch other people we are in constant contact across thousands of miles but still very much alone loneliness has become a mass phenomenon with serious consequences for our health because when we are on our own and lose the protection of the group the body goes on alert cortisol levels rise and the risk of heart attacks strokes and depression increases with wise man godzilla does we know this already thank god we know that loneliness can have such serious consequences just like smoking and alcohol nicotine consumption and alcohol consumption loneliness is

just as big of a health threat from smoking diabetes pollution etc is maybe 35 40 the other race of an early death from loneliness is something like 45 percent and that's almost a that's almost a global pandemic in its own right but nobody's really woken up to the fact that what lonely people don't get is touch hello video calls can give us a sense of closeness to family and friends but they cannot replace physical proximity many of us have now become aware of this [Laughter] before the pandemic commercials were full of happy people in front

of tablets in front of cameras waving to each other greeting their loved ones around the globe everyone was content and happy since the pandemic we've all had to rely on our digital devices peering into some little camera doing our best to balance our work while still keeping our social lives going and the majority of us almost 90 percent are incredibly unhappy with this type of communication what would it be like if in the future we could also touch each other in the virtual world until now our sense of touch has always been considered too complex

to be technically replicated touching over the internet in this video it seems to work a mother is touching the screen and her child feels her touch remotely [Music] john rogers of northwestern university helped develop the system he and his team want to make long distance touch possible [Music] what we've tried to do is to develop technologies that are compatible with the human body soft flexible skin interface platforms that you can almost think of as a as like a second skin that can laminate onto different parts of the body that might be of interest they connect

the artificial skin wirelessly to the computer when the screen is touched the small integrated electronic elements react [Music] they convert the electrical currents into pressure and vibrations but the artificial skin cannot simulate gentle touching but it is a step in the right direction that i think replicates the kind of touch that can serve as you know a deeply sort of emotional and personal uh you know connection with with other other people so so we think about it uh you know in terms of um you know adding to the uh social media experience that that maybe

we're engaging in right now which is currently dominated only by visual and auditory cues if you were wearing a device i would be able to pat your shoulder for example and you would be able to to feel that you know in in real time two of his employees show just how noticeable these touches are one draws letters on the screen his colleague can feel and reproduce them on his arm this artificial skin is not yet ready for the market but there are a number of potential applications video games feeling prosthesis and internet communication social media

is one application that's that's sort of obvious to think about i think especially in the context of what we're living through right now with with the pandemic and sort of remote safe engagement uh that still retains that um you know that that that interaction based on touch and and it's really hard to replicate that and you can't really replicate it just with video and audio touches sent online from a distance could they provide a solution for those in need of physical contact for example for older people living alone or those in long distance relationships at

the very least it might be better than no touching at all but could this ever replace the feeling we experienced during a face-to-face encounter you may be able to apply a jacket and somebody can give you a virtual hug which is quite a fun concept however i still don't think it takes the place of actual touch and the reinforcement that you get from somebody hugging you and both you enjoying it and them they enjoy it as well when it's hard of heart when things get tough like during the pandemic it becomes clear that what we

are truly longing for isn't technology we want a real person who goes out for a beer with us or reads us poetry [Music] touch always has a direct and immediate effect it evokes emotions [Music] we all need it it's a basic component of our biological makeup we are all equipped with receptors for gentle touch [Music] and yet everyone experiences touch differently experiences our cultural background how we perceive ourselves and our current situation all this influences whether and when we like it [Music] but habit also shapes how we feel our cuddle sensors need to be trained

regularly throughout our lives people who are not touched or do not want to be touched find gentle caressing less pleasant over time [Music] and we think that if you get touched less and less in your life you miss it so much that you actually you probably feel sad about it you may become depressed about it and that's not good because you actually appreciate the touch less and less and so you seek touch less and less so really for touch you have to have touch on a on a on a basis which is very regular otherwise

we tend to lose these these signals these interactions and it takes effort to to reinforce them again [Music] fortunately our sense of touch can return at any time it stays with us throughout our lives even into old age a caress can still reach a person even when they are barely connected to the physical world it conveys emotions that we so urgently need especially towards the end of life reliability safety and security [Music] rochelle ackerly has made a remarkable discovery the case of touch is very interesting because it's true that for the other senses they diminish

with time and so as we get older you see less well you hear less well however for touch it seems to have two layers so the touch that you have which is what we call discriminative touch it's the touch for example when you reach out and touch something with your hands that does decrease with age so um it's every for example every ten years or so in your life you will lose about five percent of all the touch fibers in your nerves however what we find is that when people get older they appreciate touch more

and they actually find touch more pleasurable [Music] we often don't realize how strongly touch affects our mood our health and our relationships but we are becoming more and more aware of it touch makes us happy throughout our lives [Music] you