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Biomedical subjects

A T Bennett

Publications and source records attributed to A T Bennett.

3 recordsLinked to original sources
PubMed1996

Do animals have cognitive maps?

Drawing on studies of humans, rodents, birds and arthropods, I show that 'cognitive maps' have been used to describe a wide variety of spatial concepts. There are, however, two main definitions. One, sensu Tolman, O'Keefe and Nadel, is that a cognitive map is a powerful memory of landmarks which allows novel short-cutting to occur. The other, sensu Gallistel, is that a cognitive map is any representation of space held by an animal. Other definitions with quite different meanings are also summarised. I argue that no animal has been conclusively shown to have a cognitive map, sensu Tolman, O'Keefe and Nadel, because simpler explanations of the crucial novel short-cutting results are invariably possible. Owing to the repeated inability of experimenters to eliminate these simpler explanations over at least 15 years, and the confusion caused by the numerous contradictory definitions of a cognitive map, I argue that the cognitive map is no longer a useful hypothesis for elucidating the spatial behaviour of animals and that use of the term should be avoided.

Animals↗
PubMed1994

Ultraviolet vision in birds: what is its function?

Although UV vision was first demonstrated in birds in the early 1970s, its function is still unknown,. Here we review the evidence for UV vision in birds, discuss the special properties of UV light, lay out in detail hypotheses for the function of UV vision in birds and discuss their plausibility. The main hypotheses are that UV vision functions: (i) in orientation, (ii) in foraging and (iii) in signaling. The first receives support from studies of homing pigeons, but it would be unwise to conclude that orientation is UV's primary function in all birds. It is especially important to test the signalling hypothesis because bird plumage often reflects UV and tests of theories of sexual selection have virtually always assumed that birds perceive plumage "colours" as humans do. A priori this assumption is unlikely to be correct, for unlike humans, birds see in the UV, have at least four types of cones and have a system of oil droplets which filters light entering individual cones.

Animals↗