Professor Emeritus — Ph.D., Indiana University
- E-mail: email@example.com
- Phone: (512) 471-4324
- Office: SEA 4.226
- Campus Mail Code: A8000
Dennis McFadden received his doctoral degree in Sensory Psychology from Indiana University in 1967. That fall he began as an Assistant Professor at UT, and he has been here ever since. In 1984 he received a five-year Jacobs Javits Neuroscience Investigator Award from the NIH, in 1987 he was awarded a Piper Professorship, and in 1998 UT made him an Ashbel Smith Professor in Experimental Psychology. Dr. McFadden has been a member of the Executive Committee of the UT Institute for Neuroscience since 1985, and he recently became a member of the Executive Committee for the UT Center for Perceptual Systems. He has served as Associate Editor for Psychological Acoustics for the Journal of the Acoustical Society of America, and his research has been continuously funded by NIH since 1969. For many years, Dr. McFadden's research involved psychophysical measurements on various aspects of hearing--sound localization, masking, pitch perception, the aftereffects of exposure to intense sound, auditory adaptation, and comodulation masking, among other topics. In recent years, his interests have turned to more physiological measures of the auditory system, especially otoacoustic emissions (OAEs), which are sounds generated in the inner ear and monitored using a sensitive microphone system placed in the ear canal. Initially, Dr. McFadden was interested in the heritability of the individual differences observed in OAEs and that led to an interest in the sex differences seen in OAEs (females have more and stronger OAEs than males). While searching for possible explanations for the sex differences in OAEs, Dr. McFadden discovered that OAEs are atypically expressed in certain special populations of subjects. For example, monozygotic female twins have far more OAEs than all other females, females having male co-twins have far fewer OAEs than all other females, and female homosexuals and bisexuals also have far fewer OAEs than other females. The most plausible explanation for all of these facts is that prenatal exposure to androgens affects the expression of OAEs, an idea that is currently under test in two populations of rhesus monkeys that were exposed to androgenic or anti-androgenic agents during gestation. The OAEs of these monkeys are being measured and compared with the OAEs of control animals. In related work, Dr. McFadden has collaborated with Dr. Craig Champlin of UT's Department of Communication Sciences and Disorders to show that the auditory evoked potentials (AEPs) of homosexuals are also different from those of heterosexuals. Additional AEP studies are planned on other special populations of subjects. So, in this recent work on sex differences and special populations, Dr. McFadden has been using physiological measures of the auditory system as tools for studying phenomena related to prenatal development and sexual differentiation. Another recent interest is in the relationship between OAEs and the relative lengths of the index and ring fingers. This 2D:4D ratio also exhibits a large sex difference and large differences for certain special populations of subjects. The implication is that OAEs and 2D:4D may be under similar prenatal hormonal influences, and that implication is currently being tested experimentally.
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.