Professor Emeritus — Ph.D., Indiana University
Ashbel Smith Professor Emeritus in Experimental Psychology
- E-mail: email@example.com
- Phone: (512) 471-4324
- Office: SEA 4.226
- Campus Mail Code: A8000
Dr. McFadden received his Ph.D. from Indiana University. His research Interests are sensation and perception, audition, sex differences in the auditory system, prenatal hormonal effects on the auditory system, and the effects of drugs on the auditory system.
Historically, I have been interested in various aspects of auditory performance--sound localization, masking, adaptation-like effects, and the effects of drugs and intense sound on the auditory system. In recent times, I have become interested in certain sex differences in audition and have been using the auditory system as a tool for studying hormonal effects during early development. One measure we have used is otoacoustic emissions (OAEs) which are sounds produced in the inner ear and recorded from the ear canal. OAEs are stronger and more numerous in females than in males, and this sex difference exists in newborns as well as in adults. We have been trying to understand the mechanisms underlying these sex differences. The evidence suggests that prenatal differences in exposure to androgens contribute to the sex difference in OAEs--just as it does for other sex differences in the body and the brain. Some of this evidence comes from work on special populations of humans such as females with male co-twins, homosexual and bisexual females, and children diagnosed with attention-deficit/hyperactivity disorder (ADHD). Also, we have recorded OAEs in spotted hyenas and rhesus monkeys that have been treated with androgenic or anti-androgenic agents during prenatal development and found them generally to be altered in the predicted direction--the greater the exposure to androgens, the weaker the OAEs. We believe that OAEs can act as a marker for the degree of androgen exposure a person receives during early development, and thus, they have the potential to serve as an noninvasive supplemental tool for scientists interested in a wide array of topics other than audition itself. My Macintosh-based lab is equipped to synthesize and generate simple and complex auditory waveforms, and to test up to eight human subjects simultaneously in a wide array of standard psychoacoustical tasks. We also have an advanced system for recording and analyzing otoacoustic emissions. We have the capability to obtain OAE measurements from distant locations over the internet. We use LabVIEW for generating waveforms, controlling experiments, and some data analysis.
McFadden, D., Garcia-Sierra, A., Hsieh, M.D., Maloney, M.M., Chaplin, C.A, & Pasanen, E.G. (2012) Relationships between otoacoustic emissions and a proxy measure of cochlear length derived from the auditory brainstem response. Hearing Research (Accepted)
McFadden, D., Pasanen, E.G., Leshikar, E.M., Hsieh, M.D. & Maloney, M.M. (2012) Comparing behavioral and physiological measures of combination tones: Sex and race differences. J. Acoust. Soc. Am. (Resubmitted)
McFadden, D (2011) Sexual orientation and the auditory system. (Invited) Frontiers of Neuroendocrinology, 32, 201-213.
Walsh, K.P., Pasanen, E.G., and McFadden, D. Walsh, K.P., Pasanen, E.G., and McFadden, D. (2010) Overshoot measured physiologically and psychophysically in the same human ears. Hearing Research, 268, 22-37.
Dennis McFadden, Michelle D. Hsieh, Adrian Garcia-Sierra, & Craig A. Champlin (2010) Differences by Sex, Ear, and Sexual Orientation in the Time Intervals between Successive Peaks in Auditory Evoked Potentials, Hearing Research, 270, 56-64.
Walsh, K.P., Pasanen, E.G., and McFadden, D. (2010) Properties of a nonlinear version of the stimulus-frequency otoacoustic emission. J. Acoust. Soc. Am., 127, 955-969.
McFadden, D. (2009) Masculinization of the mammalian cochlea. Hearing Research, 252, 37-48.
McFadden, D. and Bracht, M.S. (2009) Sex and race differences in the relative lengths of metacarpals and metatarsals in human skeletons. Early Human Development, 85, 117-124.
McFadden, D., Pasanen, E., Valero, M.D., Roberts, E.K., and Lee, T.M. (2009) Effect of prenatal androgens on click-evoked otoacoustic emissions in male and female sheep (Ovis aries). Hormones and Behavior, 55, 98-105.
McFadden, D. (2008) What do sex, twins, spotted hyenas, ADHD, and sexual orientation have in common? Perspectives in Psychological Science, 3(4), 309-323. PDF
McFadden, D. & Bracht, M. (2008) Sex and race differences in the relative lengths of metacarpals and metatarsals in human skeletons. Early Human Development, 85, 117-124.
Valero, M., Pasanen, E., McFadden, D. & Ratnam, R. (2008) Distortion product otoacoustic emissions in the common marmoset (Callithrix jacchus): Parameter optimization. Hearing Research, 243, 57-68.
McFadden, D., Martin, G., Stagner, B. & Maloney, M. (2008) Sex differences in distortion-product and transient-evoked otoacoustic emissions compared. Journal of the Acoustical Society of America, 125, 239-246.
McFadden, D., Pasanen, E., Valero, M., Roberts, E. & Lee, T. (2008) Dissociation between distortion-product and click-evoked otoacoustic emissions in sheep (Ovis aries). Journal of the Acoustical Society of America.
McFadden, D., Pasanen, E., Raper, J., Lange, H. & Wallen, K. (2006) Sex differences in otoacoustic emissions measured in rhesus monkeys (Macaca mulatta). Hormones and Behavior, (50), 274-284. PDF
McFadden, D., Pasanen, E., Weldele, M., Glickman, S. & Place, N. (2006) Masculinized otoacoustic emissions in female spotted hyenas (Crocuta crocuta). Hormones and Behavior, (50), 285-292. PDF
Loehlin, J., McFadden, D., Medland, S. & Martin, N. (2006) Population differences in finger-length ratios: Ethnicity or latitude? Archives of Sexual Behavior, (35), 739-742. PDF
McFadden, D. & Bracht, M. (2005) Sex differences in the relative lengths of metacarpals and metatarsals in gorillas and chimpanzees. Hormones and Behavior, (47), 99-111. PDF
McFadden, D., Loehlin, J., Breedlove, S., Lippa, R., Manning, J. & Rahman, Q. (2005) A reanalysis of five studies on sexual orientation and the relative length of the 2nd and 4th fingers (the 2D:4D ratio). Archives of Sexual Behavior, (34), 341-356. PDF
McFadden, D., Westhafer, J., Pasanen, E., Carlson, C. & Tucker, D. (2005) Physiological evidence of hypermasculinization in boys with the inattentive type of attention-deficit/hyperactivity disorder (ADHD). Clinical Neuroscience Research, (5), 233-245.
McFadden, D. & Pasanen, E. (2004) Collecting data from afar over the Internet. Echoes, (14), 8-8. PDF
McFadden, D. & Bracht, M. (2003, September) The relative lengths and weights of metacarpals and metatarsals in baboons (Papio hamadryas). Hormones and Behavior, (43), 347-355.
McFadden, D. & Shubel, E. (2003) The relationships between otoacoustic emissions and relative lengths of fingers and toes in humans. Hormones and Behavior, (43), 421-429. PDF
Loehlin, J. & McFadden, D. (2003) Otoacoustic emissions, auditory evoked potentials, and traits related to sex and sexual orientation. Archives of Sexual Behavior, (32), 115-127.
McFadden, D. (2002, September) Masculinization effects in the auditory system. Archives of Sexual Behavior, (31), 93-105.
McFadden, D. & Shubel, E. (2002, September) Relative lengths of fingers and toes in human males and females. Hormones and Behavior, (42), 492-500.
Harkrider A.W., Champlin C. & McFadden D. (2001, September) Acute effect of nicotine on nonsmokers: I. OAEs and ABRs. Hearing Research, (160), 73-88.
McFadden, D. (2001) Otoacoustic emissions as a window onto prenatal development and sexual differentiation. Seminars in Hearing, 22, 347-360.
McFadden, D. (2000) Masculinizing effects on otoacoustic emissions and auditory evoked potentials in women using oral contraceptives. Hearing Research, (142), 23-33.
McFadden, D. & Champlin, C. (2000, September) Comparison of auditory evoked potentials in heterosexual, homosexual, and bisexual males and females. Journal of the Association for Research in Otolaryngology, (1), 89-99.
Pasanen E. & McFadden D. (2000, September) An automated procedure for identifying spontaneous otoacoustic emissions. Journal of the Acoustical Society of America, (108), 1105-1116.
McFadden, D. & Callaway, N. (1999, September) Better discrimination of small changes in commonly encountered than in less commonly encountered stimuli. Journal of Experimental Psychology: Human Perception and Performance, (25), 543-560.
McFadden, D. & Pasanen, E. (1999, September) Spontaneous otoacoustic emissions in heterosexuals, homosexuals, and bisexuals. Journal of the Acoustical Society of America, (105), 2403-2413.
McFadden, D. (1998, September) Sex differences in the auditory system. Developmental Neuropsychology, (14), 261-298.
McFadden, D. (1998) Possible hormonal contributions to sex differences in otoacoustic emissions and in hearing. In A. Palmer, A. Rees, A. Summerfield & R. Meddis (Eds.), Psychophysical and Physiological Advances in Hearing (pp.65-72). London: Whurr.
McFadden, D. & Pasanen, E. (1998, September) Comparison of the auditory systems of heterosexuals and homosexuals: Click-evoked otoacoustic emissions. Proceedings of the National Academy of Sciences USA, (95), 2709-2713.
McFadden, D., Pasanen, E. & Callaway, N. (1998, September) Changes in otoacoustic emissions in a transsexual male during treatment with estrogen. Journal of the Acoustical Society of America, (104), 1555-1558.
McFadden, D. (1998) Evidence of prenatal hormonal effects on the auditory system. Proceedings of the 16th International Congress on Acoustics and 135th meeting of the Acoustical Society of America Seattle: Proceedings of the 16th International Congress on Acoustics and 135th meeting of the Acoustical Society of America.
McFadden, D., Loehlin, J. & Pasanen, E. (1996, September) Additional findings on heritability and prenatal masculinization of cochlear mechanisms: Click-evoked otoacoustic emissions. Hearing Research, (97), 102-119.
McFadden, D. & Loehlin, J. (1995, September) On the heritability of spontaneous otoacoustic emissions: A twins study. Hearing Research, (85), 181-198.
McFadden, D. & Pasanen, E. (1994, September) Otoacoustic emissions and quinine sulfate. Journal of the Acoustical Society of America, (95), 3460-3474.