Roll tilt self-motion direction discrimination training: First evidence for perceptual learning

Abstract

Perceptual learning, the ability to improve the sensitivity of sensory perception through training, has been shown to exist in all sensory systems but the vestibular system. A previous study found no improvement of passive self-motion thresholds in the dark after intense direction discrimination training of either yaw rotations (stimulating semicircular canals) or y-translation (stimulating otoliths). The goal of the present study was to investigate whether perceptual learning of self-motion in the dark would occur when there is a simultaneous otolith and semicircular canal input, as is the case with roll tilt motion stimuli. Blindfolded subjects (n = 10) trained on a direction discrimination task with 0.2-Hz roll tilt motion stimuli (9 h of training, 1,800 trials). Before and after training, motion thresholds were measured in the dark for the trained motion and for three transfer conditions. We found that roll tilt sensitivity in the 0.2-Hz roll tilt condition was increased (i.e., thresholds decreased) after training but not for controls who were not exposed to training. This is the first demonstration of perceptual learning of passive self-motion direction discrimination in the dark. The results have potential therapeutic relevance as 0.2-Hz roll thresholds have been associated with poor performance on a clinical balance test that has been linked to more than a fivefold increase in falls.

Estimating Vestibular Perceptual Thresholds Using a Six-Degree-Of-Freedom Motion Platform

“…More recently, perceptual thresholds were used to document the first evidence of perceptual learning in the vestibular domain 14 .…”

“…A three-down/one-up staircase targets the intensity where participants correctly respond in 79.4% of the trials. Besides adaptive staircase procedures, other studies 14 have used predefined, fixed intensities for threshold estimations. Using fixed intensities allows for estimating the whole psychometric function, which contains a lot more information than a single threshold value.…”

PlatformCommander — An open source software for an easy integration of motion platforms in research laboratories

“…PlatformCommander will then calculate the necessary steps and amplitudes to reach the end-position, while following a sinusoidal profile. Sinusoidal profiles are the most frequently used stimuli in hexapod experiments [2,4,6,13,16,[23][24][25], but PlatformCommander enables specifying arbitrary motion profiles. Once the requested motion sequence is done the hexapod will remain in its final position and the server is waiting for new instructions.…”

“…Compared to other stimulation techniques such as caloric vestibular stimulation or galvanic vestibular stimulation (GVS), hexapods allow for more naturalistic stimuli and the selective stimulation of all five sub-components of the peripheral vestibular organ [1]. Hexapods have been used by various research groups around the world to study vestibular thresholds [2][3][4][5][6][7], multi-sensory integration [8][9][10][11][12] or perceptual decision making [13][14][15]. Most laboratories [2,14,[16][17][18][19][20] use hardware by the same manufacturer (MOOG) and often even the same model (6DOF2000E).…”

COMPASS: Computations for Orientation and Motion Perception in Altered Sensorimotor States

“…It has previously been suggested that vestibular sensory noise may be a limiting factor for sensorimotor adaptation (Clark and Merfeld, 2017), and this model prediction supports the idea that individuals with greater vestibular sensory noise may be slower to adapt to gravity transitions. Excitingly, there is some evidence that through extensive training, an individual may improve their innate vestibular perceptual thresholds (Klaus et al, 2020), though whether that would in turn improve their capacity to adapt to altered gravity remains untested.…”