Biomaterial Database

Size constancy in goldfish (Carassius auratus). 1988

R H Douglas, and J Eva, and N Guttridge

Department of Optometry and Visual Science, City University, London, U.K.

This study examines whether fish are able to judge the real size of objects taking distance into account, or if size judgements are based purely on the angle objects subtend on the retina. Goldfish were trained to discriminate between 2 targets which differed from one another only in their diameters (5 cm and 10 cm), presented initially equidistantly from the fish. A choice of the correct target was rewarded either by food or by access to other fish. Following successful training, the targets were shifted so that they both subtended the same visual angle. The fish continued to choose the target to which they had been trained, showing that they display size constancy. This ability was present in both monocular and binocular animals.

UI	MeSH Term	Description	Entries
D003216	Conditioning, Operant	Learning situations in which the sequence responses of the subject are instrumental in producing reinforcement. When the correct response occurs, which involves the selection from among a repertoire of responses, the subject is immediately reinforced.	Instrumental Learning,Learning, Instrumental,Operant Conditioning,Conditionings, Operant,Instrumental Learnings,Learnings, Instrumental,Operant Conditionings
D004193	Discrimination Learning	Learning that is manifested in the ability to respond differentially to various stimuli.	Discriminative Learning,Discrimination Learnings,Discriminative Learnings,Learning, Discrimination,Learning, Discriminative
D004215	Distance Perception	The act of knowing or the recognition of a distance by recollective thought, or by means of a sensory process which is under the influence of a set of prior experiences.	Distance Discrimination,Discrimination, Distance,Discriminations, Distance,Perception, Distance
D006054	Goldfish	Common name for Carassius auratus, a type of carp (CARPS).	Carassius auratus
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D012858	Size Perception	The sensory interpretation of the dimensions of objects.	Perception, Size,Perceptions, Size,Size Perceptions
D015348	Vision, Binocular	The blending of separate images seen by each eye into one composite image.	Binocular Vision
D015349	Vision, Monocular	Images seen by one eye.	Monocular Vision,Monovision