By Mylène Gorissen
One thing I remember from my childhood is being bruised, scratched, and wounded all the time from playing wildly in the garden. Sometimes I would end up crying on my mother’s lap with a bleeding and injured knee. She would give me a hug, a kiss on my forehead and stick a colourful band-aid on my knee and the pain would vanish. At that time, it was like magic. As I grew older into young adulthood, the bruises and scratches slowly disappeared over time, just like the magic of my mother’s hugs and kisses. After all, hugging is overrated being an adult, isn’t it?
In the modern world, we have developed many online ways to communicate and thus interpersonal interactions are disappearing from the stage of communication. In fact, touching each other is often being discouraged, despite that it really provides us with an extra channel of communication. Kissing in public is frequently perceived as disturbing and provocative, and one of the first things you are being trained in as a medical intern is to touch your patients as little as possible. Touch is used to intensify (non)verbal communication, for example, a firm handshake when greeting someone you want to impress or a gentle kiss to express dedication to a loved one. Also, touch plays a significant role in our emotional well-being. It contributes to the development of premature infants, regulates their stress-response, and has an analgesic effect .
This analgesic effect of touch caught my interest because it could be the explanation of the magic of my mum’s hugs. The mechanisms underlying touch-related analgesia are not entirely clear. In 1965 Ronald Melzack and Patrick Wall already proposed the Gate Control Theory of pain . This theory was used for many years to explain how pain perception can be altered. When you fall on the street as a kid and hurt your knee, a pain stimulus will go via the small nerve fibres through the gate of pain and will eventually arrive in the brain. According to the theory, touching the knee by putting the colourful band-aid on it will produce a stimulus in the bigger nerve fibres. The gate of pain closes, a signal of normal touch goes to the brain and the pain will disappear. Your own nervous system is thus capable of cheating you!
Recent research has shown that love couples who are holding hands when administered pain show correlated analgesia magnitude and synchronised brain waves. These findings indicated that brainwaves were more physiologically synchronised, and less pain was felt when holding hands . The mechanism of the pain gate control theory is also used in treating patients with chronic pain with motor cortex stimulation. Directly stimulating the motor cortex with electricity creates the same effect as the touch on the hurting knee: by administering a signal of normal touch, the pain relieves. This treatment is sometimes used in patients with trigeminal neuropathic pain and post-stroke pain.
With growing older, the magic of hugging as a child might have disappeared, but hugging and interpersonal touching are certainly not overrated, even as an adult.
 Gallace, A., Spence, C. The science of interpersonal touch: an overview. Neuroscience & Biobehavioral Reviews February 34; 246-259 (2010).
 Melzack R, Wall PD. Pain Mechanisms: A New Theory. Science. November 19;150 (3699):971-9 (1965).
 Pavel Goldstein, Irit Weissman-Fogel, Simone G. Shamay-Tsoory. The role of touch in regulating inter-partner physiological coupling during empathy for pain. Scientific Reports 7 (1) (2017).
 Henssen DJHA et al. Long-term effect of motor cortex stimulation in patients suffering from chronic neuropathic pain: An observational study. PLoS One. Jan 30;13(1) (2018).