Absolute localization of vibrotactile stimuli on the torso

Absolute localization of vibrotactile stimuli on the torso

van Erp, J.B.F.
TNO Defensie en Veiligheid

2008

Vibrotactile mobility systems present spatial information such as the direction of a waypoint through a localized vibration on the torso. Using these systems requires the ability to determine the absolute location of the stimulus. Because data are available only on the ability to determine the relative location of stimuli on the torso, we developed a novel method for measuring absolute localization on the basis of triangulation. For 15 observers, we calculated the subjective location of visual and tactile stimuli on the frontal half of the torso. The size of the 95% confidence intervals around the subjective tactile locations is about the size of the stimuli (1.66 cm) and is slightly larger than that around the subjective visual locations (mean difference, 0.17 cm). The error in tactile judgments over and above that in the visual judgments is present only for locations near the body midline. When the subjective visual and tactile locations are not co-located, the difference can best be described by a shift along the radius from the body midaxis. The same holds for the differences between the veridical and the subjective locations. Therefore, the difference between the veridical and the subjective directions of a stimulus is small. The results make us believe that stimulus locations on the torso are coded in polar coordinates of which the angle is perceptual invariant and the distance is less important, probably because it varies with changes in, among other things, posture and breathing.

adult
article
human
male
physiology
skin
touch
vibration
vision
Adult
Humans
Male
Skin
Touch
Vibration
Visual Perception
tactile displays
time

http://resolver.tudelft.nl/uuid:403c1d18-4835-4746-ab6b-12337086ba48

https://doi.org/10.3758/pp.70.6.1016

23063

Perception & Psychophysics, 70 (6), 1016-1023

article