Locomotor capture and multisensory integration in the perception of linear self-motion
Single Paper Presentation

Frank Durgin
Psychology, Swarthmore College

     Abstract ID Number: 182
     Full text: Not available
     Last modified: March 19, 2006
     Presentation date: 06/18/2006 8:30 AM in Hamilton Building, McNeil Theatre
     (View Schedule)

Abstract
Normal walking begins with a strong vestibular signal during initial acceleration that is absent on a treadmill. During walking without visual feedback, automatic spatial updating of self-position along a linear trajectory is quite accurate. On a treadmill, such updating seems not to be automatic, but when tested using optic flow, locomotor speed can be shown to be overestimated. Conversely, supplying normal (for walking) acceleration profiles to a passive passenger on a cart produces a gross overestimation of the peak speed of self-motion. That is, locomotor signals and inertal signals presented in isolation both provide overestimates of the rate of self-motion, though they are well-calibrated when they co-occur. Because these signals normally do co-occur, it is likely that they share a joint coding space that intercalibrates the signals based on sensory and motor prediction. Here we report on some consequences of providing mismatched vestibular and motor signals using a treadmill on a cart with synchronized acceleration phases. Under these conditions, vivid locomotor capture (like visual capture of vestibular signals – Lishman & Lee, 1973) can occur, so that perceived speed of travel is determined primarily by perceived treadmill speed. Aftereffects will also be described.