Colour categorization by domestic chicks

Citation
Cd. Jones et al., Colour categorization by domestic chicks, P ROY SOC B, 268(1481), 2001, pp. 2077-2084
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Experimental Biology
Journal title
PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON SERIES B-BIOLOGICAL SCIENCES
ISSN journal
0962-8452 → ACNP
Volume
268
Issue
1481
Year of publication
2001
Pages
2077 - 2084
Database
ISI
SICI code
0962-8452(20011022)268:1481<2077:CCBDC>2.0.ZU;2-V
Abstract
Spectral stimuli form a physical continuum, which humans divide into discre te non-overlapping regions or categories that are designated by colour name s. Little is known about whether non-verbal animals form categories on stim ulus continua, but work in psychology and artificial intelligence provides models for stimulus generalization and categorization. We compare predictio ns of such models to the way poultry chicks (Gallus gallus) generalize to n ovel stimuli following appetitive training to either one or two colours. If the two training colours arc (to human eyes) red and greenish-yellow or gr een and blue, chicks prefer intermediates, i.e. orange rather than red or y ellow and turquoise rather than green or blue. The level of preference. for intermediate colours implies that the chicks interpolate between the train ing stimuli. However, they do not extrapolate beyond the limits set by the training stimuli, at least for red and yellow training colours. Similarly, chicks trained to red and blue generalize to purple, but they do not genera lize across grey after training to the complementary colours yellow and blu e. These results are consistent with a modified version of a Bayesian model of generalization from multiple examples that was proposed by Shepard and show, similarities to human colour categorization.