Tickling someone has a strange effect on the body and as researchers have been trying to better understand its causes, they have been researching on mice.
The Humboldt University of Berlin researchers have been studying the effects of tickling in a study led by Michael Brecht and have released their findings in the Science journal.
The mechanisms behind the action of tickling have been quite a mystery as researchers could not explain why some people are more ticklish than other, or why we cannot tickle ourselves.
They also sought to determine why some areas are more sensitive to the action than others and the general question of why do we laugh when tickled.
As the aforementioned Brecht went to explain, their research analyzed the inner workings of the brain when someone is being tickled by studying mice and their reaction to the action.
Previous studies have shown that mice emit ultrasonic vocalizations when they are tickled, which can be described as their form of laughing.
Their ticklish spots are another similarity to humans as they were determined to be more sensitive to tickling in their feet and belly areas and also their backs but showed no effect when being tickled on their tails.
As these areas were established as being more prone to react, the researchers turned their attention to the brain area known as the somatosensory cortex.
This is the brain region which processes the various types of physical simulations the likes of touch, temperature, pressure, and pain.
A map of the whole body can be found in the somatosensory cortex and as they expected, tickling a certain specific area led to a lit up of the corresponding part in the cortex.
As the somatosensory area was also seen to light up according to the mice’s activities, the scientists also determined that the effects of tickling depend on the previous mood of the person and on their activities.
Studies showed that a relaxed mouse was more likely to be ticklish than a mouse that had been stressed or that was anxious.
To further test the relation between tickling and its effects on the brain and detect if ticklishness is, in fact, all in your head, the team proceeded to experiment on the somatosensory cortex by stimulating it.
As the cortex areas’ corresponding to their most ticklish point were simulated, the mice emitted their high-frequency laugh although the action in itself was not being carried out.
This went to show that the somatosensory cortex, a brain area which was believed to be purely tactile, has a larger domain of activity.
According to Brecht, the results of the last stimulation tests came as surprise for the scientists as that specific cortex area seems to be even more involved in generating laughter than it was known before.
As such, the researchers came to the possible conclusion that tickling may be a brain trick which rewards playing, pleasant activities and positive interactions.
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