Subject(s)
Cochlea/pathology , Cochlear Implants , Electric Stimulation/adverse effects , Animals , Cats , Cochlear Implants/adverse effects , Deafness/therapy , Electrodes, Implanted , Organ of Corti/pathology , Spiral Ganglion/pathology , Spiral Lamina/pathology , Vestibulocochlear Nerve/pathologyABSTRACT
The effects of pulse width and interstimulus interval of electrocochlear stimulation on behavioral reaction times were investigated in cats. It was determined that square wave biphasic stimuli with pulse widths of 0.5 msec. elicited faster reaction times than did pulse widths of 0.2 msec. On the other hand, stimuli of 1.0 msec pulse widths showed no appreciable difference in reaction times when compared to 0.5 msec pulse widths. The effects of interstimulus interval (ISI) on reaction times are also discussed. An interstimulus interval of 2 msec demonstrated no marked difference in reaction time when compared to the same stimulus with an ISI of 4 msec.
Subject(s)
Auditory Threshold , Cochlear Implants , Loudness Perception/physiology , Reaction Time , Animals , Cats , Conditioning, Operant , Electric StimulationSubject(s)
Auditory Threshold/physiology , Cochlea/physiology , Animals , Electrophysiology , Guinea PigsABSTRACT
Guinea pigs have been trained to press a lever for a food reward. Then the behavior was used to obtain the auditory thresholds for six guinea pigs. The thresholds obtained in the present study agree with those previously obtained by Heffner, et al. The most important aspect of the training process was the habituation of the guinea pigs. Once the guinea pig was accustomed to the food and training cage, he could be trained in a manner similar to that used to train many other species.
Subject(s)
Auditory Threshold , Behavior, Animal , Conditioning, Operant , Reward , Animals , Female , Food , Guinea Pigs , Habituation, Psychophysiologic , MaleABSTRACT
Potentials evoked by tonal pulses and recorded with a monopolar electrode on the pial surface over the auditory cortex of the guinea pig are presented. These potentials are compared with average potentials recorded in previous studies with an electrode on the dura. The potentials recorded by these two techniques have similar waveforms, peak latencies and thresholds. They appear to be generated within the same region of the cerebral cortex. As can be expected, the amplitude of the evoked potentials recorded from the pial surface is larger than that recorded from the dura. Consequently, averaging is not needed to extract the evoked potential once the dura is removed. The thresholds for the evoked cortical potential are similar to behavioral thresholds for the guinea pig at high frequencies; however, evoked potential thresholds are eleveate over behavioral thresholds at low frequencies. The removal of the dura and the direct recording of the evoked potential appears most appropriate for acute experiments. The recording of an evoked potential with dura electrodes empploying averaging procedures appears most appropriate for chronic studies.
