| During the last decade there has been much speculation concerning the communicative and cognitive capacity of the dolphin. Recent language acquisition studies involving the chimpanzee, the gorilla, and the African Grey parrot have suggested strategies for developing symbolic communication with these species.; This research focused on the following goals: (1) to provide replicable methodology for assessing the dolphin's capability to use a symbolic system of communication, (2) to test the dolphin's ability to discriminate visual forms in air, (3) to test the dolphin's ability to interactively communicate as opposed to merely responding to commands, (4) to illustrate the effectiveness of a pragmatic approach using the referents as reinforcers rather than generalized reinforcement based upon deprivation and satisfaction of tissue needs, and (5) to provide comparative data for the language acquisition studies with other species.; In the 3 month study a newly captured 4 year old female Atlantic Bottlenose dolphin (Tursiops truncatus) was able to learn to visually discriminate in air, three dimensional white symbols of different shapes. Standard match-to-sample procedures were used with fish as reinforcement for all correct responses. The dolphin was able to generalize the concept of match-to-sample using novel visual stimuli such as bottles and different parts of fish. Using the same training apparatus and procedures, the sample was replaced with one of three preferred toys and the dolphin learned to differentially choose the correct symbol for the referent toy depending on which toy was displayed. She also demonstrated the ability to select the correct toy out of two toys when one symbol was displayed. Rather than using fish reinforcement, all correct responses were rewarded by giving the dolphin the specific toy which was shown as the stimulus for the correct response. Free choice trials in which three symbols were presented in randomized positions, gave the dolphin the opportunity to initiate and explore the contingencies of symbol use. All responses resulted in the referent or associated toy being given to the dolphin for a fixed period of time. Analysis of the frequency of specific choices revealed a linear correlation between symbol selection and toy preferences determined by previous preference testing. |
