PLACAV · Polarized light as an alternative to colour in animal vision
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2015-03-01 → 2017-02-28
- EU contribution
- €195,455
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Polarized light as an alternative to colour in animal vision
Most animals see the world very differently from us. For example, some are sensitive to colours beyond our own visible spectrum (e.g. bees use ultraviolet colours when viewing flowers). Other animals use a different property of light altogether, its polarization. The polarization of light refers to the angle of the electromagnetic waves of light as they travel through space. By aligning photopigments in the eye, animals such as crabs and some insects can discriminate polarization, and use it for a variety of tasks. Until now it has been unclear how and why some species see in polarization across their whole visual field. This project aimed to address this, focussing on the fiddler crab as a model organism. These animals live in tropical mudflats across the world, and use their compound eyes to detect conspecifics and threats. Understanding how and why these animals see in polarization can inspire and inform future directions in biomimetic technology, such as the development of polarization-sensitive camera chips and the use of polarization-based algorithms to enhance contrast in digital images. The project had two main objectives. First, to determine how polarization information is incorporated into the contrast vision system of fiddler crabs; and second, to investigate the use of polarization cues to fiddler crabs in their natural environment.
Data: CORDIS, © European Union
Project objective
Imagine life without colour. Many of the rich layers of information in our visual world would disappear and simple tasks, such as finding a red apple in a tree, would be far more difficult. There are many examples of animals in nature that have limited colour vision, yet some have managed to develop high-performance eyes that, in some respects, far surpass our own visual capabilities. One of the ways that animals have achieved this is to make use of the polarization of light rather than colour. The reasons behind this are not understood and represent a novel area for scientific exploration.Many animals have been shown to be sensitive to the polarization of light, but nearly all research to date has focussed on dedicated eye structures for detecting specific cues such as the polarized sky field for navigation (e.g. in honey bees, ants, and locusts). The recent discovery that some animals make use of a highly developed sensitivity to polarized light across the whole visual field of their image-forming eyes opens the way for new investigations into the use of polarized light for object detection and discrimination, a field previously dominated by the study of colour and intensity visual systems.I have shown in recent investigations that fiddler crabs have highly-acute sensitivity to polarized light across their whole visual field. These animals have been model species for behavioural ecology research over the past 50 years and so represent an ideal organism for developing a clear understanding of image-based polarization vision. The central question of what has caused evolution, in the case of fiddler crabs, to develop high performance polarization vision rather than colour vision will be addressed at both the physiological and behavioural levels by asking the following two broad questions:Q1 – How is polarized light information processed in the nervous system of fiddler crabs?Q2 – How do fiddler crabs use polarized light information in their natural environment?
Original text from CORDIS.
Participants
- UNIVERSITY OF BRISTOL · BRISTOLCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union