Roll aftereffects: influence of tilt and inter-stimulus interval
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A theme in sensory perception is that exposure to a stimulus causes perception of subsequent stimuli to be shifted in the opposite direction. Such phenomenon is known as aftereffect and has been extensively described in the visual system as well as recently described for the vestibular system during translation. It is known from aviation studies that after a maneuver in roll, pilots can experience a false perception of roll in the opposite direction. The magnitude and duration of this effect as well as the potential influence of the gravity vector have not previously been defined. In the current paper this roll aftereffect (RAE) is examined in response to whole-body roll about an earth-horizontal axis in eight healthy human subjects. The peak velocity of a 0.5-s-duration roll was varied based on previous responses to find the point where subjects perceived no motion. Without a preceding stimulus, the starting position (upright, 9° left, or 9° right) did not influence roll perception. The RAE was measured in a completely dark room using an adapting (first interval) stimulus consisting of 9° of roll over 1.5 s (peak velocity, 12°/s), delivered 0.5, 3, or 6 s prior to test (second interval) stimulus. A significant RAE was seen in all subjects. Half a second after the adapting stimulus, a test stimulus had to be on average 1.5 ± 0.4°/s in the opposite direction to be perceived as stationary. When the subject remained upright after the adapting stimulus, the RAE diminished with time, although it remained significantly larger at 3 and 6 s when the subject remained tilted after the adapting stimulus. These data demonstrate that roll perception can be influenced by small preceding stimuli and tilt causes a persistence of the RAE.
KeywordsGillingham illusion Post-roll illusion Aftereffects
This work was funded by a grant from the National Institute on Deafness and Other Communication Disorders K23 DC011298. Additional support was provided by a clinician-scientist grant from the Triological Society. Technical support was provided by Shawn Olmstead-Leahey. Thanks to my former mentor, Dr. Joseph L. Demer, for reviewing a pre-publication version of this manuscript.
- Addams R (1834) An account of a peculiar optical phenomenon seen after having looked at a moving body etc. Mag J Sci, 3rd series 5:373–374Google Scholar
- Barlow HB (1990) A theory about the functional role and synaptic mechanism of visual aftereffects. In: Blakemore C (ed) Vision: coding and efficiency. Cambridge University Press, Cambridge, pp 363–375Google Scholar
- Guedry FE Jr (1974) Psychophysics of vestibular sensation. In: Kornhuber HH (ed) Handbook of sensory physiology. Springer, New York, pp 3–154Google Scholar
- Heinle TE, Ercoline WR (2002) Spatial disorientation: Causes consequences, and countermeasures for the USAF. Paper presented at the RTO HFM symposium on spatial disorientation in military vehicles: causes, consequences, and cures. La Coruña, Spain, 15–17 April 2002Google Scholar
- Mann CW (1950) Studies in space perception. Naval School of Aviation Medicine, PensacolaGoogle Scholar