How stable is perceived direction of gravity over extended periods in darkness?

A. A. Tarnutzer, D. P. Fernando, A. G. Lasker, David Samuel Zee

Research output: Contribution to journalArticle

Abstract

Previous studies reported linear drift of perceived vertical for brief (≤10 min) observation periods. Here, we repeated estimates of direction of gravity up to 60 min to evaluate whether the drift is sustained, shows saturation or even reverses over time. Fifteen healthy human subjects repetitively adjusted a luminous line along subjective visual vertical (SVV) and horizontal (SVH) over periods of 5 min (constituting one block). We obtained seven blocks within 60 min in each subject for SVV and SVH. In between the first six blocks, subjects remained in darkness for 5 min each, whereas the lights were briefly turned on before block 7. We noted significantly (p <0.05) increased errors in perceived direction of gravity by block 2 (SVV) and 3 (SVH). These increases disappeared after turning on the lights before block 7. Focusing on blocks 2-6, significant drift started from similar offset positions and pointed to the same direction in a majority of runs in 9/15 (SVV) and 11/15 (SVH) subjects. When pooling data from all blocks, orthogonality of errors was lost in all subjects. Trial-to-trial variability remained stable over the seven runs for SVV and SVH. Only when pooling all runs, precision was significantly (p <0.05) higher for the SVH. Our findings suggest that perceived direction of gravity continues to fluctuate over extended recording periods with individuals showing unique patterns of direction-specific drift while variability remains stable. As subjects were upright during the entire experiment and as drift persisted over several blocks, sensory adaptation seems unlikely. We therefore favor a central origin of this kind of drift.

Original languageEnglish (US)
Pages (from-to)427-436
Number of pages10
JournalExperimental Brain Research
Volume222
Issue number4
DOIs
StatePublished - Oct 2012

Fingerprint

Darkness
Gravitation
Light
Meta-Analysis
Healthy Volunteers
Observation
Direction compound

Keywords

  • Drift
  • Perception
  • Subjective visual horizontal
  • Subjective visual vertical
  • Vestibular

ASJC Scopus subject areas

  • Neuroscience(all)

Cite this

How stable is perceived direction of gravity over extended periods in darkness? / Tarnutzer, A. A.; Fernando, D. P.; Lasker, A. G.; Zee, David Samuel.

In: Experimental Brain Research, Vol. 222, No. 4, 10.2012, p. 427-436.

Research output: Contribution to journalArticle

Tarnutzer, A. A. ; Fernando, D. P. ; Lasker, A. G. ; Zee, David Samuel. / How stable is perceived direction of gravity over extended periods in darkness?. In: Experimental Brain Research. 2012 ; Vol. 222, No. 4. pp. 427-436.
@article{a84e2f14f6074b4c9bfa094c41000c2e,
title = "How stable is perceived direction of gravity over extended periods in darkness?",
abstract = "Previous studies reported linear drift of perceived vertical for brief (≤10 min) observation periods. Here, we repeated estimates of direction of gravity up to 60 min to evaluate whether the drift is sustained, shows saturation or even reverses over time. Fifteen healthy human subjects repetitively adjusted a luminous line along subjective visual vertical (SVV) and horizontal (SVH) over periods of 5 min (constituting one block). We obtained seven blocks within 60 min in each subject for SVV and SVH. In between the first six blocks, subjects remained in darkness for 5 min each, whereas the lights were briefly turned on before block 7. We noted significantly (p <0.05) increased errors in perceived direction of gravity by block 2 (SVV) and 3 (SVH). These increases disappeared after turning on the lights before block 7. Focusing on blocks 2-6, significant drift started from similar offset positions and pointed to the same direction in a majority of runs in 9/15 (SVV) and 11/15 (SVH) subjects. When pooling data from all blocks, orthogonality of errors was lost in all subjects. Trial-to-trial variability remained stable over the seven runs for SVV and SVH. Only when pooling all runs, precision was significantly (p <0.05) higher for the SVH. Our findings suggest that perceived direction of gravity continues to fluctuate over extended recording periods with individuals showing unique patterns of direction-specific drift while variability remains stable. As subjects were upright during the entire experiment and as drift persisted over several blocks, sensory adaptation seems unlikely. We therefore favor a central origin of this kind of drift.",
keywords = "Drift, Perception, Subjective visual horizontal, Subjective visual vertical, Vestibular",
author = "Tarnutzer, {A. A.} and Fernando, {D. P.} and Lasker, {A. G.} and Zee, {David Samuel}",
year = "2012",
month = "10",
doi = "10.1007/s00221-012-3230-5",
language = "English (US)",
volume = "222",
pages = "427--436",
journal = "Experimental Brain Research",
issn = "0014-4819",
publisher = "Springer Verlag",
number = "4",

}

TY - JOUR

T1 - How stable is perceived direction of gravity over extended periods in darkness?

AU - Tarnutzer, A. A.

AU - Fernando, D. P.

AU - Lasker, A. G.

AU - Zee, David Samuel

PY - 2012/10

Y1 - 2012/10

N2 - Previous studies reported linear drift of perceived vertical for brief (≤10 min) observation periods. Here, we repeated estimates of direction of gravity up to 60 min to evaluate whether the drift is sustained, shows saturation or even reverses over time. Fifteen healthy human subjects repetitively adjusted a luminous line along subjective visual vertical (SVV) and horizontal (SVH) over periods of 5 min (constituting one block). We obtained seven blocks within 60 min in each subject for SVV and SVH. In between the first six blocks, subjects remained in darkness for 5 min each, whereas the lights were briefly turned on before block 7. We noted significantly (p <0.05) increased errors in perceived direction of gravity by block 2 (SVV) and 3 (SVH). These increases disappeared after turning on the lights before block 7. Focusing on blocks 2-6, significant drift started from similar offset positions and pointed to the same direction in a majority of runs in 9/15 (SVV) and 11/15 (SVH) subjects. When pooling data from all blocks, orthogonality of errors was lost in all subjects. Trial-to-trial variability remained stable over the seven runs for SVV and SVH. Only when pooling all runs, precision was significantly (p <0.05) higher for the SVH. Our findings suggest that perceived direction of gravity continues to fluctuate over extended recording periods with individuals showing unique patterns of direction-specific drift while variability remains stable. As subjects were upright during the entire experiment and as drift persisted over several blocks, sensory adaptation seems unlikely. We therefore favor a central origin of this kind of drift.

AB - Previous studies reported linear drift of perceived vertical for brief (≤10 min) observation periods. Here, we repeated estimates of direction of gravity up to 60 min to evaluate whether the drift is sustained, shows saturation or even reverses over time. Fifteen healthy human subjects repetitively adjusted a luminous line along subjective visual vertical (SVV) and horizontal (SVH) over periods of 5 min (constituting one block). We obtained seven blocks within 60 min in each subject for SVV and SVH. In between the first six blocks, subjects remained in darkness for 5 min each, whereas the lights were briefly turned on before block 7. We noted significantly (p <0.05) increased errors in perceived direction of gravity by block 2 (SVV) and 3 (SVH). These increases disappeared after turning on the lights before block 7. Focusing on blocks 2-6, significant drift started from similar offset positions and pointed to the same direction in a majority of runs in 9/15 (SVV) and 11/15 (SVH) subjects. When pooling data from all blocks, orthogonality of errors was lost in all subjects. Trial-to-trial variability remained stable over the seven runs for SVV and SVH. Only when pooling all runs, precision was significantly (p <0.05) higher for the SVH. Our findings suggest that perceived direction of gravity continues to fluctuate over extended recording periods with individuals showing unique patterns of direction-specific drift while variability remains stable. As subjects were upright during the entire experiment and as drift persisted over several blocks, sensory adaptation seems unlikely. We therefore favor a central origin of this kind of drift.

KW - Drift

KW - Perception

KW - Subjective visual horizontal

KW - Subjective visual vertical

KW - Vestibular

UR - http://www.scopus.com/inward/record.url?scp=84867742583&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84867742583&partnerID=8YFLogxK

U2 - 10.1007/s00221-012-3230-5

DO - 10.1007/s00221-012-3230-5

M3 - Article

C2 - 23053369

AN - SCOPUS:84867742583

VL - 222

SP - 427

EP - 436

JO - Experimental Brain Research

JF - Experimental Brain Research

SN - 0014-4819

IS - 4

ER -