Combined Stimulus Control of Peak Frequency and Source Level in the Echolocating Dolphin (Tursiops truncatus)

摘要

Research trainers demonstrated stimulus control over dolphin echolocation emission in past discrimination studies. Other research revealed control can also be exerted over emitted source levels during detection studies. Combined control over the peak frequency and the source level of the echolocation emission of the dolphin has recently been achieved to 85% performance levels. The dolphin is trained to emit clicks from a fixed position on a bite-plate/tail-rest station to ensure accuracy in click evaluation. Sessions are conducted in a pre-determined random schedule of testing. A collecting hydrophone relays echolocation clicks to a microcomputer system which reinforces the animal when criterion is satisfied. Initial training consists of shifting the source level (or amplitude) of the echolocation clicks while solving a detection task. The separate discriminative stimuli of two underwater tones gain control over high and low amplitude levels of the emitted clicks. A third one, with two distinct repetition rates, is used to train the control over peak frequency output. The separate behaviors are combined by superimposing the repetition rate of the peak frequency stimulus over the pure tone of the amplitude stimulus. Keywords: Animal training, Animal behavior modification, Echolocation, Marine biology. (KT)