One cannot tickle oneself because our brain anticipates our own movements and cancels out unexpected sensations. Thus, the surprise effect necessary for tickling disappears when we tickle ourselves.
Tickling activates several regions of the brain, notably the somatosensory cortex, responsible for the perception of touch, and the anterior cingulate cortex, linked to emotional and social aspects. When someone else tickles you, these two areas communicate and then trigger the particular sensation you know well: an irresistible urge to laugh accompanied by a slight feeling of discomfort. The interesting fact is that the brain clearly distinguishes whether it is you or someone else performing the action, which completely changes the way it processes the received nerve information. This brain distinction partly explains why you laugh when someone else tickles you, but not when you try to do it yourself.
The cerebellum, located at the back and base of the brain, functions as a kind of predictive center. When we decide to perform a movement, it creates a sort of copy called an efference copy, which allows it to precisely anticipate the sensations that this movement will produce. This anticipation means that our brain "knows" what to expect in terms of sensations. As a result, the element of surprise disappears, and the tickling sensation you might cause yourself becomes very weak or even nonexistent. Your cerebellum basically acts like a filter, automatically distinguishing what comes from you from what comes from an unexpected external stimulus, such as another person tickling you by surprise.
When you touch your own skin, your brain knows exactly what to expect, since you are the one initiating the action. An external stimulation, on the other hand, escapes your direct control: your brain cannot precisely anticipate the intensity or location of the touch, so it is experienced as more intense and surprising. It is precisely this unpredictability that makes the sensation of tickling possible. This difference lies in the way your brain processes these two stimulations: it strongly dampens the expected sensations, meaning those you produce yourself, while remaining highly alert to any touch coming from outside, potentially more important for your survival. That is why a caress or a tickle from another person will always be felt differently and more intensely than if you try yourself.
Our brain constantly manages a lot of sensory information. To avoid being overwhelmed, it applies a kind of internal filter called sensory inhibition. In simple terms, it suppresses sensations resulting from our own movements or actions because it already knows what to expect. For example, when you brush your teeth or write, you barely feel these stimulations because your brain anticipates what your body will do. But if it receives an unexpected contact from another person, it is surprised and reacts strongly. When you try to tickle yourself, your brain predicts exactly what sensation your fingers will produce. As a result, it automatically reduces the intensity of this expected sensation, and you hardly feel anything. This mechanism actually serves to save your attention resources so you can more effectively detect unexpected external sensations that might be important or dangerous.
Did you know that people with schizophrenia can sometimes tickle themselves? This is thought to be due to a disruption in the neural process of sensory anticipation, which alters their perception of self-generated stimuli.
Did you know that the areas of the body sensitive to tickling, such as the ribs or feet, often correspond to parts of the body that are particularly vulnerable or sensitive? This could be linked to an ancestral alert mechanism aimed at protecting these sensitive areas from potential dangers.
Did you know that laughter triggered by tickling is not the same as laughter caused by humor? In fact, laughter associated with tickling is a reflex activated by specific sensory stimulation; it does not necessarily depend on our emotional or cognitive state.
Did you know that some animals, like rats, also respond to tickling with vocalizations similar to ultrasonic laughter? This suggests that the phenomenon of laughter associated with tickling might be older and more widespread in the animal kingdom than previously thought.
Sensitivity to tickling varies based on numerous individual factors such as the density of nerve endings, sensory perception, emotional state, and social context. Thus, some people may be very sensitive while others are much less so.
Here’s the translation: "Even though there is generally not a complete loss of sensitivity to tickling, habituation can occur. In fact, repeated exposure to identical stimuli often reduces the brain's response. This explains why the sensation of tickling may diminish in some people as they age or when a particular stimulus becomes predictable."
The laughter triggered by tickling is linked to a reflexive response in the brain to unexpected and light stimulation, activating brain regions associated with both sensory reaction and emotion. This involuntary response is also believed to be associated with a social function, helping to strengthen emotional and social bonds between individuals.
Sure! Here’s the translation: "Yes, some animals, including great apes and rats, show responses similar to those of humans when tickled. For example, the rat emits ultrasound that is interpreted as an equivalent of human laughter when it is tickled by a researcher. These observations indicate that the phenomenon of tickling affects several animal species with sufficiently complex nervous systems."
Yes, to date, research indicates that the inability to tickle oneself is common across all studied cultures. This phenomenon is attributed to the way the central nervous system automatically anticipates our own movements, which leads to the inhibition of the sensory response when attempting to tickle oneself.
In some exceptional cases, particularly related to brain injuries or certain psychiatric conditions such as schizophrenia, a disruption of the normal mechanism of sensory anticipation may allow a person to experience self-generated sensations of tickling. However, these cases remain very rare and are the subject of specific studies to precisely understand their neurological origin.
100% of respondents passed this quiz completely!
Question 1/5
