Middle- and Long-Latency Auditory Evoked Potentials in Response to Oddball Stimuli in the Bottlenose Dolphin (Tursiops truncatus)

Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)



First Advisor

Stan Kuczaj

Advisor Department



The long latency auditory evoked potentials (AEP) in response to repeated tones and oddball tones of a different frequency were recorded in four bottlenose dolphins (Tursiops truncatus ) with differing levels of experience with this recording paradigm. The stimuli used were 100 ms pure tones, and the AEP was recorded from stimulus onset to 500 ms after stimulus onset. Difference waves that were calculated by subtracting the waveform evoked by the repeated tone from the waveform evoked by the oddball tone showed that in the latency range of 40 to 60 ms after stimulus onset showed that the response to the oddball was higher in amplitude to that of the repeated tone, especially for large differences in frequency. This trend was termed the P50 difference, and may be a useful metric of auditory discrimination in the bottlenose dolphin. Some caution should be made in interpreting these results because of the possible effects of experience on AEP recording, and because of the degree of individual differences.