The perception of object size in microgravity. Jorges, B, Bury, N., McManus, M., Bansal, A., Allison, R. S., Jenkin, M. R. M., & Harris, L. R. In 2022 Scientific Abstracts: The First Canadian Space Health Research Symposium, pages 8. 2022.
abstract   bibtex   
Exposure to microgravity can influence the visual perception of object size, however the mechanism remains an object of debate. Gravity might serve as a reference frame in which visual information is interpreted. The absence of gravity should make size judgements then more variable due to the inability to anchor these judgements. We tested this hypothesis by assessing accuracy and variability of astronauts' size judgements before, during, and after a six-month or longer microgravity exposure in orbit. 12 astronauts were tested before take-off, within 7 days of arrival on the ISS, around 90 days after arrival, within 7 days of return to Earth and at least 60 days after return. We found that variability was, indeed, higher upon arrival on the ISS (p = 0.03), but not later during space flight. Further, astronauts but not control participants – surprisingly – perceived the object to be significantly smaller (p = 0.04) at their last test session than at their first session, suggesting lasting changes in their perception. Overall, our data provides additional support that gravity may indeed serve as a reference frame in which visual input is interpreted for size judgements.
@incollection{Jorges:2022ux,
	abstract = {Exposure to microgravity can influence the visual
perception of object size, however the mechanism
remains an object of debate. Gravity might serve as
a reference frame in which visual information is
interpreted. The absence of gravity should make
size judgements then more variable due to the
inability to anchor these judgements. We tested
this hypothesis by assessing accuracy and
variability of astronauts' size judgements before,
during, and after a six-month or longer
microgravity exposure in orbit. 12 astronauts were
tested before take-off, within 7 days of arrival on
the ISS, around 90 days after arrival, within 7 days
of return to Earth and at least 60 days after return.
We found that variability was, indeed, higher upon
arrival on the ISS (p = 0.03), but not later during
space flight. Further, astronauts but not control
participants -- surprisingly -- perceived the object to
be significantly smaller (p = 0.04) at their last test
session than at their first session, suggesting lasting
changes in their perception. Overall, our data
provides additional support that gravity may
indeed serve as a reference frame in which visual
input is interpreted for size judgements.},
	annote = {The symposium will start early morning on November 17, 2022, and end late afternoon on November 18, 2022 in Calgary},
	author = {Jorges, B and Bury, N. and McManus, M. and Bansal, A. and Allison, R. S. and Jenkin, M. R. M. and Harris, L. R.},
	booktitle = {2022 Scientific Abstracts: The First Canadian Space Health Research Symposium},
	date-added = {2022-11-30 13:51:32 -0500},
	date-modified = {2022-11-30 13:51:32 -0500},
	keywords = {Optic flow & Self Motion (also Locomotion & Aviation)},
	pages = {8},
	title = {The perception of object size in microgravity},
	year = {2022}}

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