Pattern recognition and active vision in chickens

Abstract

Recognition of objects or environmental landmarks is problematic because appearance can vary widely depending on illumination, viewing distance, angle of view and so on. Storing a separate image or 'template' for every possible view requires vast numbers to be stored and scanned, has a high probability of recognition error and appears not to be the solution adopted by primates. However, some invertebrate template matching systems can achieve recognition by 'active vision' in which the animal's own behaviour is used to achieve a fit between template and object, for example by repeatedly following a set path. Recognition is thus limited to views from the set path but achieved with a minimal number of templates. Here we report the first evidence of similar active vision in a bird, in the form of locomotion and individually distinct head movements that give the eyes a similar series of views on different occasions. The hens' ability to recognize objects is also found to decrease when their normal paths are altered.

Parallel Working Memory for Spatial Location and Food-Related Object Cues in Foraging Pigeons: Binocular and Lateralized Monocular Performance

“…First, pigeons could use one or the other eye alternately when memorizing various views at different locations in the maze. This theory is supported by a recent study on active vision in chickens (Dawkins and Woodington 2000). When hens were orienting toward landmarks indicating the location of a reward, they repeated similar views on consecutive trials.…”

Homing pigeons develop local route stereotypy

“…there is no single best route that can explain the marginal tortuosity at stability), suggests that the main function of route recapitulation is not to reduce navigational risk. A more probable explanation (though not incompatible with a risk reduction strategy) is that route recapitulation reduces cognitive load in a way analogous to the active vision demonstrated in invertebrates (Collett 1992(Collett , 1995Zeil 1995) and more recently in chickens (Dawkins & Woodington 2000), which is thought to allow minimization of the number of images that must be remembered. The recognition of threedimensional visual landmarks requires a high memory load because of the range of angles and distances from which landmarks may be viewed.…”

Can Bees See at a Glance?

“…Extended integration times might involve continuous 'online' sampling of the world around them. Such active vision, where animals sometimes follow repeated paths to memorise contingencies between own movements and object views for target recognition has been observed in a number of insect species Collett and Zeil, 1996), and also in birds (Dawkins and Woodington, 2000;Gall and Fernández-Juricic, 2010). Active vision has also been suggested to play a role in colour perception .…”

“…An alternative strategy might be to hinder bees from following their accustomed flight paths near the target, to measure the extent to which this impedes target recognition (Dawkins and Woodington, 2000). An ideal experimental scenario would be to work with tethered bees in a virtual flight arena, and to record the bee's self-generated motor output and use it to control the visual simulation in predictable ways (Liu et al, 2006;Luu et al, 2011).…”

“…In our experiments, the flight movements of bees were not evaluated in detail; it would be highly informative to explore how flight paths near the targets depend on the nature of the discrimination or detection task (Philippides et al, 2013), and to explore whether different individuals have acquired individually different strategies for tracing visual patterns Dawkins and Woodington, 2000). An alternative strategy might be to hinder bees from following their accustomed flight paths near the target, to measure the extent to which this impedes target recognition (Dawkins and Woodington, 2000).…”