Local mechanisms for the separation of optic flow-field components in the land crab, Cardisoma guanhumi: A role for motion parallax?
Although a number of global mechanisms have been proposed over the years that explain how crabs might separate the rotational and translational components of their optic flow field, there has been no evidence to date that local mechanisms such as motion parallax are used in this separation. We descr...
Saved in:
Published in | Visual neuroscience Vol. 21; no. 6; pp. 905 - 911 |
---|---|
Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
New York, USA
Cambridge University Press
01.11.2004
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | Although a number of global mechanisms have been proposed over the
years that explain how crabs might separate the rotational and
translational components of their optic flow field, there has been no
evidence to date that local mechanisms such as motion parallax are used
in this separation. We describe here a study that takes advantage of a
recently developed suite of computer-generated visual stimuli that
creates a three-dimensional world surrounding the crab in which we can
simulate translational and rotational optic flow. We show that, while
motion parallax is not the only mechanism used in flow-field
separation, it does play a role in the recognition of translational
optic flow fields in that, under conditions of low overall light
intensity and low contrast ratio when crabs find the distinction
between rotation and translation harder, smaller eye movements occur in
response to translation when motion parallax cues are present than when
they are absent. Thus, motion parallax is one of many cues that crabs
use to separate rotational and translational optic flow by showing
compensatory eye movements to only the former. |
---|---|
Bibliography: | ark:/67375/6GQ-NWFJ5XB8-Q istex:95773430BCCFF5A5E14E9415CD78EEA6D65A4CD9 PII:S0952523804216108 PMID:15733345 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0952-5238 1469-8714 |
DOI: | 10.1017/S0952523804216108 |