Object representation in the bottlenose dolphin (Tursiops truncatus): integration of visual and echoic information.
A dolphin performed a 3-alternative matching-to-sample task in different modality conditions (visual/echoic, both vision and echolocation: visual, vision only; echoic, echolocation only). In Experiment 1, training occurred in the dual-modality (visual/echoic) condition. Choice accuracy in tests of all conditions was above chance without further training. In Experiment 2, unfamiliar objects with complementary similarity relations in vision and echolocation were presented in single-modality conditions until accuracy was about 70%. When tested in the visual/echoic condition, accuracy immediately rose (95%), suggesting integration across modalities. In Experiment 3, conditions varied between presentation of sample and alternatives. The dolphin successfully matched familiar objects in the cross-modal conditions. These data suggest that the dolphin has an object-based representational system.
Harley
H E
HE
Social Sciences Division, New College, University of South Florida, Sarasota 34243. harley@virtu.sar.usf.edu.
Roitblat
H L
HL
Nachtigall
P E
PE
D000818:Animals; D004289:Dolphins; D004455:Echolocation; D005260:Female; D007858:Learning / Q000502:physiology; D010775:Photic Stimulation; D014795:Visual Pathways / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*