Illusion
Tactile illusions are found when the perception of a quality of an object through the sense of touch does not seem to be in agreement with the physical stimulus. They can arise in numerous circumstances and can provide insights into the mechanisms subserving haptic sensations. Many of them can be exploited, or avoided, in order to create efficient haptic display systems or to study the nervous
tactile illusions are illusions that exploit the sense of touch. Some touch illusions require active touch (e.g., movement of the fingers or hands), whereas others can be evoked passively (e.g., with external stimuli that press against the skin).
Examples
One of the best known passive tactile illusions is the cutaneous rabbit illusion, in which a sequence of taps at two separated skin locations results in the perception that intervening skin regions were also tapped.[1]
The tau effect is an illusion in which equally spaced taps to the skin are perceived as unequally spaced, depending on the timing between the taps.
The kappa effect is a complementary illusion to the tau effect: taps separated by equal temporal intervals are perceived to be separated by unequal temporal interval, depending on the spatial intervals between the taps.
If a person exposes their forearm and closes their eyes or turns their head in the opposite direction while a second person slowly traces a finger from the wrist upward to the crook of the elbow, many people are unable to say when the crease of their elbow is being touched.
When eating, if a person holds food with one texture and another texture is presented to the mouth, many people perceive the perceived freshness and crispiness of the food to be between the two textures.[2]
New Scientist has got a nice feature online where they explain seven touch illusions you can try yourself, with the explanations for how they’re tricking your brain.
My favourite is probably the most simple, the ‘Aristotle illusion':
One of the oldest tactile
tactile illusions are illusions that exploit the sense of touch. Some touch illusions require active touch (e.g., movement of the fingers or hands), whereas others can be evoked passively (e.g., with external stimuli that press against the skin).
Examples
One of the best known passive tactile illusions is the cutaneous rabbit illusion, in which a sequence of taps at two separated skin locations results in the perception that intervening skin regions were also tapped.[1]
The tau effect is an illusion in which equally spaced taps to the skin are perceived as unequally spaced, depending on the timing between the taps.
The kappa effect is a complementary illusion to the tau effect: taps separated by equal temporal intervals are perceived to be separated by unequal temporal interval, depending on the spatial intervals between the taps.
If a person exposes their forearm and closes their eyes or turns their head in the opposite direction while a second person slowly traces a finger from the wrist upward to the crook of the elbow, many people are unable to say when the crease of their elbow is being touched.
When eating, if a person holds food with one texture and another texture is presented to the mouth, many people perceive the perceived freshness and crispiness of the food to be between the two textures.[2]
New Scientist has got a nice feature online where they explain seven touch illusions you can try yourself, with the explanations for how they’re tricking your brain.
My favourite is probably the most simple, the ‘Aristotle illusion':
One of the oldest tactile