Touch

Aye-Aye Lemur, Madagascar

Aye-Aye Lemur hunting for grubs at night, in Madagascar.

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Somatosensation, which is another word for our sense of touch, occurs in a number of forms, like feeling texture, temperature, pressure, pain or vibration. It’s responsible for proprioception, which helps us know where we are within our environment. It tells us if our feet are firmly planted on the floor, or if we’re holding a paper cup tightly enough that it won’t slip out of our hand, but loosely enough that we don’t crush the cup. Scientists know a good deal about the molecular receptors that mediate the different types of somatosensation, but they know little about how touch is represented in the brain.

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Feeling small: Fingers can detect nano-scale wrinkles even on a seemingly smooth surface (2013)  The smallest pattern that could be distinguished from the non-patterned surface had grooves with a wavelength of 760 nanometres and an amplitude of only 13 nanometres.

“This means that, if your finger was the size of the Earth, you could feel the difference between houses from cars,” Rutland says. “That is one of the most enjoyable aspects of this research. We discovered that a human being can feel a bump corresponding to the size of a very large molecule.”

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Touch can produce detailed, lasting memories (2018)   Exploring objects through touch can generate detailed, durable memories for those objects, even when we don’t intend to memorize the object’s details, according to findings published in Psychological Science, a journal of the Association for Psychological Science.

“An especially interesting finding was that participants were able to visually identify an object they had never seen but only touched one week before without the intention of memorization,” says researcher Fabian Hutmacher of the University of Regensburg. “This is even more remarkable as the competing objects in the recognition test belonged to the same basic-level category – that is, the previously presented object was only identifiable based on subtle touch-based details but not on much more salient visual details.”

“The study challenges existing cognitive and neural models of memory storage and retrieval, as these models seem to be unable to account for the large amount of stored information,” Hutmacher adds.

Compared with visual information, relatively little is known about long-term memory for information sensed through other modalities. Hutmacher and coauthor Christof Kuhbandner decided to focus specifically on haptic, or touch-based, experiences.

In one experiment, participants wore a blindfold as they explored 168 everyday objects, such as a pen, for 10 seconds each. The researchers told the participants they would be tested on the objects later, so they should pay close attention to the texture, shape, and weight of each object. The participants, still blindfolded, completed a haptic memory test for half of the objects immediately after exploring them. They held each object they had explored and a similar novel object that was distinguishable only by subtle details – their task was to indicate which object they had explored before. They completed the same test with the other half of the objects 1 week later.

Participants showed almost perfect recall on the test that followed the exploration period, correctly identifying the object they had explored 94% of the time. Remarkably, participants still showed robust memory for the original objects 1 week later, with 84% accuracy.

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Sensorama Machine, 1957

Forgotten genius: the man who made a working VR machine in 1957 … Wind, scent, vibration – Morton Heilig’s Sensorama had everything but success.

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Virtual Reality Parachute Simulator, 2010

U.S. Navy medic demonstrating a VR parachute simulator at the Naval Survival Training Institute in 2010.

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  1. The Neurobiology Shaping Affective Touch: Expectation, Motivation, and Meaning in the Multisensory Context (2015)
  2. Study identifies gene that makes gentle touch feel painful after injury (2018)
  3. Study: Technology helps upper-limb amputees regain a sense of touch (2019)
  4. A Brief History of Multi-Touch Computer Control (2009)
  5. Assessing skin sensitivity-touch discrimination
  6. Touch Sensitivity Apps

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Touch the Sky (Black Pumas)

Touch the Sky:  Guitar Tutorial, with Eric Burton of the Black Pumas

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