Seeing the light: illumination as a contextual cue to color choice behavior in bumblebees.
The principal challenge faced by any color vision system is to contend with the inherent ambiguity of stimulus information, which represents the interaction between multiple attributes of the world (e.g., object reflectance and illumination). How natural systems deal with this problem is not known, although traditional hypotheses are predicated on the idea that vision represents object reflectance accurately by discounting early in processing the conflating effects of illumination. Here, we test the merits of this general supposition by confronting bumblebees (Bombus terrestris) with a color discrimination task that can be solved only if information about the illuminant is not discounted but maintained in processing and thus available to higher-order learned behavior. We show that bees correctly use the intensity and chromaticity of illumination as a contextual cue to guide them to different target colors. In fact, we trained bees to choose opposite, rather than most similar, target colors after an illumination change. This performance cannot be explained with a simple color-constancy mechanism that discounts illumination. Further tests show that bees do not use a simple assessment of the overhead illumination, but that they assess the spectral relationships between a floral target and its background. These results demonstrate that bees can be color-constant without discounting the illuminant; that, in fact, they can use information about the illuminant itself as a salient source of information.
Lotto
R Beau
RB
Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, United Kingdom. lotto@ucl.ac.uk
Chittka
Lars
L
D000818:Animals; D001516:Bees / Q000502:physiology*; D003116:Color; D003118:Color Perception / Q000502:physiology*; D003463:Cues; D008027:Light; D010775:Photic Stimulation
Anim Behav. 1998 Jan;55(1):139-52
9480680
Sci Am. 1977 Dec;237(6):108-28
929159
Proc Natl Acad Sci U S A. 2000 Nov 7;97(23):12834-9
11058148
J Cogn Neurosci. 2001 Jul 1;13(5):547-55
11506656
Nature. 2003 Jul 24;424(6947):388
12879057
J Comp Physiol A. 1988 May;163(1):145-50
3385666
J Exp Biol. 1989 Sep;146:39-62
2689569
J Comp Physiol A. 2000 Sep;186(9):885-96
11085641
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2004 Feb;190(2):105-14
14652688
J Vis. 2002;2(6):493-504
12678647
J Vis. 2004 Feb 18;4(2):57-81
15005648
J Comp Physiol A. 1992 Jan;170(1):23-40
1573568
Vision Res. 1995 Feb;35(3):389-412
7892735
Science. 2004 Apr 16;304(5669):405-8
15087541
J Exp Biol. 2000 Dec;203(Pt 23):3521-30
11060214
J Exp Biol. 2001 Jul;204(Pt 14):2391-9
11511654
J Neurosci. 1988 Jan;8(1):156-9
3339405
Nat Neurosci. 1999 Nov;2(11):1010-4
10526341
J Opt Soc Am A Opt Image Sci Vis. 1994 May;11(5):1553-63
8006721