  The emphasis on visual perception in most of these examples, no doubt reflects a primatocentric bias.  We human primates are highly visual creatures, and, as Nagel (1974) argued, we face considerable hurdles in imagining (again, a visual metaphor) the subjective experiences of creatures in modalities in which humans are weak or completely unendowed. The examples of research also reflect an anthropocentric bias in that much of the animal experimentation is explicitly targeted at relieving human disorders. Although there is good work by neuroethologists on the psychophysics of echolocation by bats and dolphins, or on the sensory capacities of weakly electric fish, questions of subjective awareness are generally not broached in that literature.