Psychophysical detection thresholds for unmodulated electrical pulse trains or for sinusoidally amplitude-modulated (SAM) pulse trains were estimated in deaf juvenile cats using a conditioned avoidance paradigm. Biphasic current pulses (0.2 ms/phase) were delivered by scala tympani electrodes consisting of 4–8 electrode contacts driven as bipolar pairs. Electrical auditory brainstem response (EABR) thresholds were obtained periodically, and at the conclusion of behavioral training, response thresholds were obtained for neurons in the inferior colliculus (IC) and the primary auditory cortex (A1) in acute physiological experiments in the same animals. The results of the study include: (1) detection thresholds for unmodulated pulse trains and for SAM pulse trains were virtually identical; (2) EABR thresholds and behavioral thresholds were significantly correlated, although EABR thresholds consistently overestimated behavioral thresholds; (3) the lowest thresholds in the IC and the A1 were significantly correlated with behavioral thresholds, and (4) mean lowest thresholds in the IC and the A1 were essentially the same as the mean psychophysical detection threshold in the trained deaf cats.

Keywords:
Psychophysical threshold, Neurophysiological threshold, Inferior colliculus, Primary auditory cortex, Deafness, Electrical cochlear stimulation, Sinusoidal amplitude modulation
1.
Abbas PJ, Brown CJ: Electrically evoked auditory brainstem response: Growth of response with current level. Hear Res 1991;51:123–138.
2.
Beitel RE, Snyder RL, Schreiner CE, Leake PA: Psychophysical and neurophysiological thresholds for electrical stimulation of the cochlea in the deaf cat. Abstr 18th Midwinter Res Meet, Assoc Res Otolaryngol, St. Petersburg Beach, 1995.
3.
Elberling C, Don M: Threshold characteristics of the human auditory brain stem response. J Acoust Soc Am 1987;81:115–121.
4.
Green DM, Swets JA: Signal Detection Theory and Psychophysics. New York, Wiley, 1966.
5.
Heffner RS, Heffner HE: Hearing range of the domestic cat. Hear Res 1995;19:85–88.
6.
Hultcrantz M, Snyder R, Rebscher S, Leake P: Effects of neonatal deafening and chronic intracochlear electrical stimulation on the cochlear nucleus. Hear Res 1991;54:272–282.
7.
Leake PA, Hradek GT, Snyder RL, Rebscher SJ: Chronic intracochlear electrical stimulation induces selective survival of spiral ganglion cells in neonatally deafened cats. Hear Res 1991;54:251–271.
8.
Lustig LR, Leake PA, Snyder RL, Rebscher SJ: Changes in the cat cochlear nucleus following neonatal deafening and chronic intracochlear electrical stimulation. Hear Res 1994;74:29–37.
9.
Montney LM, Morris DJ, Bledsoe SC, Pfingst BE: The relationship between guinea pig psychophysical and single-unit (ICC) strength-duration functions for pulsatile electrical stimulation. Abstr 21st Midwinter Res Meet, Assoc Res Otolaryngol, St. Petersburg Beach, 1998.
10.
Moon AK, Zwolan TA, Pfingst BE: Effects of phase duration on detection of electrical stimulation of the human cochlea. Hear Res 1993;67:166–178.
11.
Parkins CW, Colombo J: Auditory-nerve single-neuron thresholds to electrical stimulation from scala tympani electrodes. Hear Res 1987;31:267–286.
12.
Pfingst BE: Comparisons of psychophysical and neurophysiological studies of cochlear implants. Hear Res 1988;34:243–252.
13.
Pfingst BE: Psychophysical constraints on biophysical/neural models of threshold; in Miller JM, Spelman FA (eds): Cochlear Implants: Models of the Electrically Stimulated Ear. New York, Springer, 1990, pp 161–183.
14.
Pfingst BE, Montney LM, Bledsoe SC: Comparison of psychophysical and single-unit thresholds in response to electrical stimulation of the cochlea in guinea pig (abstract). J Acoust Soc Am 1998;103:2846.
15.
Raggio MW, Schreiner CE: Neuronal responses in cat primary auditory cortex to electrical cochlear stimulation: Intensity dependence of firing rate and onset latency. J Neurophysiol 1994;72:2334–2359.
16.
Shannon RV: Threshold and loudness functions for pulsatile stimulation of cochlear implants. Hear Res 1985;18:135–143.
17.
Shannon RV: A model of threshold for pulsatile electrical stimulation of cochlear implants. Hear Res 1989;40:197–204.
18.
Shannon RV: Temporal modulation transfer functions in patients with cochlear implants. J Acoust Soc Am 1992;91:2156–2164.
19.
Smith DW, Finley CC, van den Honert C, Olszyk VB, Konrad KEM: Behavioral and electrophysiological responses to electrical stimulation in the cat. I. Absolute thresholds. Hear Res 1994;81:1–10.
20.
Snyder RL, Leake PA, Rebscher SJ, Beitel R: Temporal resolution of neurons in cat inferior colliculus to intracochlear electrical stimulation: Effects of neonatal deafening and chronic stimulation. J Neurophysiol 1995;73:449–467.
21.
Snyder RL, Rebscher SJ, Cao K, Leake PA: Chronic intracochlear electrical stimulation in the neonatally deafened cat. I. Expansion of central representation. Hear Res 1990; 50:7–33.
22.
Snyder RL, Rebscher SJ, Leake PA, Kelly K, Cao K: Chronic intracochlear electrical stimulation in the neonatally deafened cat. II. Temporal properties of neurons in the inferior colliculus. Hearing Res 1991;56:246–264.
23.
Vallbo AB, Johansson RS: Skin mechanoreceptors in the human hand: Neural and psychophysical thresholds; in Zotterman Y (ed): Sensory Functions of the Skin in Primates. Oxford, Pergamon Press, 1976, pp 185–197.
24.
Vollmer M, Beitel RE, Snyder RL: Temporal processing and response thresholds to electrical pulse trains in deaf cats: Psychophysics and responses of inferior colliculus (IC) neurons. Abstr 22nd Midwinter Res Meet, Assoc Res Otolaryngol, St. Petersburg Beach, 1999.
25.
Vureck LS, White M, Fong M, Walsh SM: Optoisolated stimulators used for electrically evoked BSER. Ann Otol Rhinol Laryngol 1981;90(suppl 82):21–24.
26.
Wilson BS, Finley CC, Lawson DT, Wolford RD, Eddington DK, Rabinowitz WM: Better speech recognition with cochlear implants. Nature 1991;352:236–238.
© 2000 S. Karger AG, Basel
2000
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.