New study reveals link between the perception of time and the sense of touch

The perception of time relates to the sense of touch.

A new SISSA study “A sensory integration account for the perception of time” published in Computational Biology PLOS discover this connection.

“The challenge of neuroscience posed by the sense of time lies, above all, in the fact that there are no dedicated receptors – the passage of time is a sensory experience built without sensors”, notes Mathew Diamond, director of the tactile perception. and Learning Lab.

“One could imagine a precise clock in the brain, a kind of stopwatch which records the start and the stop and calculates the time elapsed between these two moments. But decades of research haven’t found a stopwatch-like brain mechanism. We thought that understanding sensory systems may be the key to understanding the meaning of time. “

Lead author of the study, SISSA Ph.D. student Alessandro Toso, explains how the team (also including Arash Fassihi, Luciano Paz and Francesca Pulecchi as co-authors) approached the issue:

“We have trained humans and rats to compare the durations of two tactile vibrations. The main clue leading to the new theory is that the perceived duration of the vibration increases not only in relation to the actual elapsed time, but also in relation to the intensity of the vibration. . In other words, subjects (of both species) feel that a stronger vibration lasts longer. “

The team then proposed a model where the experience of elapsed time accompanying a stimulus is generated when the neural representation of the stimulus itself is collected and summed by a downstream accumulator.

This model would explain the two characteristics of the sense of time: a stimulus is judged as long when it is, in fact, longer, but also when its higher intensity evokes a wider sensory response. They tested the model’s plausibility by simulating the perception of time that would emerge through the integration of neuronal firing of actual peak trains recorded from the sensory cortex of rats receiving the vibratory stimulus.

The close correspondence between the prediction of time perceived by the model and the actual perceived time for the same stimuli supports the model. Now the research continues with the identification and analysis of the accumulator.

For many years, this research group has been interested in tactile perception and memory. Following some unexpected discoveries, our curiosity led to a new line of research, the perception of time. This brings us in synergy with Domenica Bueti, SISSA neuroscientist with exceptional experience in time perception. We are looking forward to working together. “

Mathew Diamond, Director of the Perception and Touch Learning Lab