Human Cognitive Neurophysiology Laboratory

Publications

Xiaojian Kang; E. William Yund; Timothy J. Herron; David L. Woods (2007)
Improving the resolution of functional brain imaging: analyzing functional data in anatomical space
Magn Reson Imaging 25:1070-1078 [Abstract] [PDF version] downloads.

Teemu J. Rinne; G. Christopher Stecker; Xiaojian Kang; E. William Yund; Timothy J. Herron; David L.Woods (2007)
Attention modulates sound processing in human auditory cortex but not the inferior colliculus
NeuroReport 18:1311-1314 [Abstract] [PDF version] downloads.

David L. Woods, PhD; E. William Yund, PhD (2007)
Perceptual training of phoneme identification for hearing loss
Semin Hear 28:110-119 [Abstract] [PDF version] downloads.

G. Christopher Stecker, PhD; Glen A. Bowman, BA; E. William Yund, PhD; Timothy J. Herron, MA; Christina M. Roup, PhD; David L. Woods, PhD (2006)
Perceptual training improves syllable identification in new and experienced
J Rehabil Res Dev 43(4):537-552 [Abstract] [PDF version] downloads.
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E. William Yund, PhD; Christina M. Roup, PhD; Helen J. Simon, PhD; Glen A. Bowman, BA (2006)
Acclimatization in wide dynamic range multichannel compression and linear amplification hearing aids
J Rehabil Res Dev 43(4):517-536 [Abstract] [PDF version] downloads.

Xiaojian Kang, Olivier Bertrand, Kimmo Alho, E. William Yund, Timothy J. Herron and David L. Woods (2004)
Local landmark-based mapping of human auditory cortex
NeuroImage; 22(4): 1657-1670. [Abstract] [PDF version] downloads.

Christopher I Petkov, Xiaojian Kang, Kimmo Alho, Olivier Bertrand, E William Yund & David L Woods (2004)
Attentional modulation of human auditory cortex
Nature Neuroscience, 7:658-663 [Abstract] [PDF version] downloads.
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Shihui Han,, E. William Yund, David L. Woods (2003)
An ERP study of the global precedence effect: the role of spatial frequency
Clinical Neurophysiology 114 1850–1865 [Abstract] [PDF version] downloads.

S.O. Murray, B.A. Olshausen, and D.L. Woods (2003)
Processing Shape, Motion, And Three-Dimensional Shape-From-Motion In The Human Cortex
Cereb. Cortex 13: 508-516. [Abstract] [PDF version] downloads.

Shihui Han, Janelle A. Weaver, Scott O. Murray, Xiaojian Kang, E. William Yund, and David L. Woods (2002)
Hemispheric Asymmetry in Global/Local Processing: Effects of Stimulus Position and Spatial Frequency
NeuroImage 17, 1290-1299 [Abstract] [PDF version] downloads.

Scott O. Murray , Daniel Kersten , Bruno A. Olshausen , Paul Schrater , and David L. Woods (2002)
Shape perception reduces activity in human primary visual cortex
Proceedings of the National Academy of Sciences, 99: 15164-15169. [Abstract] [PDF version] downloads.
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David L. Woods, Claude Alain, Rodney Diaz, Dell Rhodes, and Keith H. Ogawa (2001)
Location and Frequency Cues in Auditory Selective Attention
Journal of Experimental Psychology: Human Perception and Performance, 27: 65-74. [Abstract] [PDF version] downloads.

Shihui Han, Yan Song, Yulong Ding, E. William Yund, and David L. Woods (2001)
Neural substrates for visual perceptual grouping in humans
Psychophysiology, 38 (2001), 926<96>935. Cambridge University Press. [Abstract] [PDF version] downloads.

David L. Woods and Claude Alain (2001)
Conjoining Three Auditory Features: An Event-Related Brain Potential Study
Journal of Cognitive Neuroscience 13:4, pp. 492-509. [Abstract] [PDF version] downloads.

Zhao XQ, Yuan C, Hatsukami TS, Frechette EH, Kang XJ, Maravilla KR, Brown BG (2001)
Effects of Prolonged Intensive Lipid-Lowering Therapy on the Characteristics of Carotid Atherosclerotic Plaques In Vivo by MRI
Arterioscler Thromb Vasc Biol. 2001 Oct;21(10):1623-9. [Abstract] [PDF version] downloads.

Kang X, Polissar NL, Han C, Lin E, Yuan C. (2000)
Analysis of the measurement precision of arterial lumen and wall areas using high-resolution MRI.
Magn Reson Med. 2000 Dec;44(6):968-72. [Abstract] [PDF version] downloads.

Shihui Han, Wanzhan Liu, E. William Yund and David L. Woods (2000)
Interactions between spatial attention and global/local feature selection: an ERP study
NeuroReport 11:2753-2758. [Abstract] [PDF version] downloads.

Lamb, M. R., Yund, E. W. (2000)
The role of spatial frequency in cued shifts of attention between global and local forms
Perception and Psychophysics 62, 753-761. [Abstract] [PDF version] downloads.

Claude Alain,Andre Achim, and David L. Woods (1999)
Separate Memory-Related Processing for Frequency and Auditory Patterns
Psychophysiology, 36: 737-744 [Abstract] [PDF version] downloads.

Michael D. Szymanski, E. William Yund, David L. Woods (1999)
Phonemes, intensity and attention: Differential effects on the mismatch negativity (MMN)
J. Acoustical Society of Am., 106: 3492-3505 [Abstract] [PDF version] downloads.

Szymanski, Michael, D.*, Yund, E. William, and Woods, David. L. (1999)
Human Brain Specialization for Phonetic Attention
Neuroreport, 10:1605-1608 [Abstract] [PDF version] downloads.

Claude Alain & David L. Woods (1999)
Age-Related Changes in Processing Auditory Stimuli During Visual Attention: Evidence for Deficits in Inhibitory Controls and Sensory Memory
Psychology and Aging, 14: 507-519 [Abstract] [PDF version] downloads.

E. William Yund, Akira Uno and David L. Woods (1999)
Preattentive Control of Serial Auditory Processing in Dichotic Listening
Brain & Language, 66:358-376 [Abstract] [PDF version] downloads.

Picton, T.W., Alain, C., Woods, D.L, John, M.S.,Scherg, M., Valdes-Sosa, P., Bosch-Bayard, J. (1999)
Intracerebral Sources of Human Auditory Evoked Potentials
Audiology and Neuro-Otology, 4: 64-79 [Abstract] [PDF version] downloads.

Lamb, M. R., Yund, E. W. & Pond, H. M (1999)
Is attentional selection to different levels of hierarchical structure based on spatial frequency?
Journal of Experimantal Psychology: General 10: 88-94. [Abstract] [PDF version] downloads.

Efron, R. & Yund, E. W. (1999)
Attentional Inhibition or Paraconstrast?
Brain and Cognition 41: 111-149. [Abstract] [PDF version] downloads.

Chu CM, Ball M, Brabson B, Budnick J, Ellison M, Fung KM, Hamilton B, Hsi WC, Jeon D, Kang X, Kiang LL, Lee SY, Ng KY, Pei A, Riabko A, Sloan T. (1999)
Effects of overlapping parametric resonances on the particle diffusion process.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1999 Nov;60(5 Pt B):6051-60. [Abstract] [PDF version] downloads.

Jeon D, Ball M, Budnick J, Chu CM, Ellison M, Hamilton B, Kang X, Kiang LL, Lee SY, Ng KY, Pei A, Riabko A, Sloan T, Syphers M (1998)
A mechanism of anomalous diffusion in particle beams
Physics Review Letter 1998; 80(11): 2314-7. [Abstract] [PDF version] downloads.

David L. Woods , Claude Alain, and Keith H. Ogawa (1998)
Conjoining Auditory and Visual Features During High-Rate Serial Presentation: Processing and Conjoining Two Features Can Be Faster than Processing One
Perception and Psychophysics 60:239-249. [Abstract] [PDF version] downloads.

C. Alain, R. Hargrave and D.L. Woods (1998)
Processing of auditory stimuli during visual attention in patients with schizophrenia
Biological Psychiatry, 44: 1151-1159 [Abstract] [PDF version] downloads.

E. William Yund (1998)
Multichannel compression in the normal ear and as a signal processing algorithm for the hearing impaired
ISCAS '98 Proceedings. [Abstract] [PDF version] downloads.

Claude Alain, David L. Woods and Robert T. Knight (1998)
A Distributed Cortical Network for Auditory Sensory Memory in Humans
Brain Research 812: 23-37 [Abstract] [PDF version] downloads.

Woods, D. L., Alain, C., & Ogawa, K. H. (1998).
Conjoining Auditory and Visual Features During High-Rate Serial Presentation: Processing and Conjoining Two Features Can Be Faster Than Processing One.
Perception and Psychophysics, 60, 239-249. [Abstract] [PDF version] downloads.

Roup, C., Wiley, T., Safadi, S., Stoppenbach, D.T. (1998)
Tympanometric Screening Norms for Adults
American Journal of Audiology 7: 1-6. [Abstract] [PDF version] downloads.

Beattie, R. C., Barr, T., & Roup, C. (1997)
Normal and hearing-impaired word recognition scores for monosyllabic words in quiet and noise
British Journal of Audiology 31: 153-164. [Abstract] [PDF version] downloads.

Alain, C., & Woods, D. L. (1997).
Attention modulates auditory pattern memory.
Psychophysiology, 34, 534-546. [Abstract] [PDF version] downloads.

Alain, C., Woods, D. L., & Covarrubias, D. (1997).
Activation of duration- sensitive auditory cortical neurons in humans.
Electroencephalography and Clinical Neurophysiology, 104, 531-539. [Abstract] [PDF version] downloads.

Alain, C., Hargrave, R., & Woods, D. L. (1997).
Auditory short-term memory in schizophrenia: An event-related brain potential study.
Brain and Cognition, 35, 348-351. [Abstract] [PDF version] downloads.

Yund, E. W. & Crain, T. R. (1997)
Voiced stop consonant discrimination with multichannel expansion hearing loss simulations.
In: Modeling Sensorineural Hearing Loss (W. Jesteadt, Ed.) Lawrence Erlbaum Associates, Mahwah, New Jersey: 149-167. [Abstract] [PDF version] downloads.

Yund, E. W. (1997)
Amplification of spatial nonuniformities by guided search mechanisms.
In: Cerebral Asymmetries in Sensory and Perceptual Processing (S. Christman, Ed.) Elsevier Science B. V., Amsterdam: 161-195. [Abstract] [PDF version] downloads.

Lamb, M. R. & Yund, E. W. (1996)
Spatial frequency and interference between global and local levels of structure.
Visual Cognition 3: 193-219. [Abstract] [PDF version] downloads.

Lamb, M. R. & Yund, E. W. (1996)
Spatial frequency and attention: Effects of level-, target-, and location-repetition on the processing of global and local forms.
Perception and Psychophysics 58: 363-373. [Abstract] [PDF version] downloads.

Efron, R. & Yund, E. W. (1996)
Spatial nonuniformities in visual search.
Brain and Cognition 31: 331-368. [Abstract] [PDF version] downloads.

Yund, E. W. & Efron, R. (1996)
Guided search: The effects of learning.
Brain and Cognition 31: 369-386. [Abstract] [PDF version] downloads.

Alain, C., Ogawa, K. H., & Woods, D. L. (1996).
Aging and the segregation of auditory stimulus sequences.
Journal of Gerontology, 51, 91-93. [Abstract] [PDF version] downloads.

Andrews, R., & Woods, D. L. (1996).
Functional localization: Evoked Potential Mapping.
In R. Andrews (Ed.), Intraoperative Neuroprotection . New York: L. Erlbaum. [Abstract] [PDF version] downloads.

Riabko A., Bai M., Brabson B., Chu C. M., Kang X., Jeon D., Lee S. Y., Zhao X. (1996)
Particle dynamics in quasi-isochronous storage rings
Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1996; 54(1): 815-829. [Abstract] [PDF version] downloads.

Chu CM, Ball M, Budnick J, East G, Ellison M, Hamilton B, Kang X, Lee SY, Liu JY, Pei A, Riabko A, Sloan T, Wang L (1996)
A Method of Detecting Coherent Synchrotron Modes
Nuclear Instruments Methods in Physics Research A 1996; 381(2-3): 215-8. [Abstract] [PDF version] downloads.

Jeon D, Bai M, Chu CM, Kang X, Lee SY, Riabko A, Zhao X (1996)
Role of parametric resonances in global chaos
Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1996; 54(4): 4192-4201. [Abstract] [PDF version] downloads.

Lee SY, Ball M, Brabson B, Budnick J, Caussyn DD, Colestock P, East G, Ellison M, Hamilton B, Hedblom K, Kang X, Li D, Liu JY, Ng KY, Pei A, Riabko A, Syphers M, Wang L. (1996)
Effect of magnetized electron cooling on a Hopf bifurcation
Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1996; 53(1): 1287-1290. [Abstract] [PDF version] downloads.

Woods, D. L. (1995)
The component structure of the N1 wave of the human auditory evoked potential.
Electroencephalography and Clinical Neurophysiology Supplement. Perspectives on Event-Related Potential Research, 44, 102-109. [Abstract] [PDF version] downloads.

Woods, D. L., Alain, C., Covarrubias, D., & Zaidel, O. (1995)
Middle latency auditory evoked potentials to tones of different frequency.
Hearing Research, 85, 69-75. [Abstract] [PDF version] downloads.

Yund, E. W. & Buckles, K. M. (1995)
Multichannel compression hearing aids: Effect of number of channels on speech discrimination in noise.
Journal of the Acoustical Society of America 97: 1206-1223. [Abstract] [PDF version] downloads.

Yund, E. W. & Buckles, K. M. (1995)
Enhanced speech perception at low signal-to-noise ratios with multichannel compression hearing aids.
Journal of the Acoustical Society of America 97: 1224-1240. [Abstract] [PDF version] downloads.

Yund, E. W. & Buckles, K. M. (1995)
Discrimination of multichannel-compressed speech in noise: Long-term learning in hearing-impaired subjects.
Ear and Hearing 16: 417-427. [Abstract] [PDF version] downloads.

Crain, T. R. & Yund, E. W. (1995)
Effect of multichannel compression on vowel and stop- consonant discrimination in normal-hearing and hearing-impaired subjects.
Ear and Hearing 16: 529-543. [Abstract] [PDF version] downloads.

Caussyn D. D., Ball M., Budnick J., East G., Ellison M., Hamilton B., Hedblom K., Kang X., Lee S. Y., Li D., Liu J. Y., Ng K. Y., Riabko A., Wang L., Wang Y. (1995)
Effects of a nonlinear damping force in synchrotrons with electron cooling
Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1995; 51(5): 4947-4957. [Abstract] [PDF version] downloads.

Riabko A., Ellison M., Kang X., Lee S. Y., Li D., Liu J. Y., Pei X., Wang L. (1995)
Hamiltonian formalism for space charge dominated beams in a uniform focusing channel
Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1995; 51(4): 3529-3546. [Abstract] [PDF version] downloads.

Woods, D. L., Alho, K., & Algazi, A. (1994).
Stages of auditory feature conjunction: An event-related brain potential study.
Journal of Experimental Psychology: Human Perception and Performance, 22, 81-94. [Abstract] [PDF version] downloads.

Alain, C., & Woods, D. L. (1994).
Signal clustering modulates auditory cortical activity in humans.
Perception & Psychophysics, 56, 501-516. [Abstract] [PDF version] downloads.

Alho, K., Woods, D. L., & Algazi, A. (1994).
Processing of auditory stimuli during auditory and visual attention as revealed by event-related potentials.
Psychophysiology, 31, 469-479. [Abstract] [PDF version] downloads.

Alho, K., Woods, D. L., Algazi, A., Knight, R. T., & Naatanen, R. (1994)
Lesions of frontal cortex diminish the auditory mismatch negativity.
Electroencephalography and Clinical Neurophysiology, 91, 354-362. [Abstract] [PDF version] downloads.

Alain, C., Woods, D. L., & Ogawa, K. H. (1994)
Brain Indices of Automatic Pattern Processing.
Neuroreport, 6, 140-144. [Abstract] [PDF version] downloads.

Liu J. Y., Ball M., Brabson B., Budnick J., Caussyn D. D., East G., Ellison M., Hamilton B., Jones W. P., Kang X., Lee S. Y., Li D., Ng K. Y., Riabko A., Rich D., Sloan T., Wang L. (1994)
Bifurcation of resonance islands and Landau damping in the double-rf system.
Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1994; 50(5): R3349-R3352. [Abstract] [PDF version] downloads.

Woods, D. L., Alho, K., & Algazi, A. (1993)
Intermodality selective attention: Evidence for processing in tonotopic auditory fields.
Psychophysiology, 30, 287-295. [Abstract] [PDF version] downloads.

Woods, D. L., Alain, C., Covarrubias, D., & Zaidel, O. (1993)
Frequency- related differences in the speed of human auditory processing.
Hearing Research, 66, 46-52. [Abstract] [PDF version] downloads.

Woods, D. L., & Alain, C. (1993)
Feature processing during high-rate auditory selective attention.
Perception & Psychophysics, 53, 391-402. [Abstract] [PDF version] downloads.

Alain, C., & Woods, D. L. (1993)
Distractor clustering enhances detection speed and accuracy during selective listening.
Perception & Psychophysics, 54, 509-514. [Abstract] [PDF version] downloads.

Woods, D. L., Knight, R. T., & Scabini, D. (1993)
Anatomical substrates of auditory selective attention: Behavioral and electrophysiological effects of posterior association cortex lesions.
Cognitive Brain Research, 1, 227-240. [Abstract] [PDF version] downloads.

Simon, H. J. & Yund, E. W. (1993)
Frequency discrimination in listeners with sensorineural hearing loss.
Ear and Hearing, 14: 190-201. [Abstract] [PDF version] downloads.

Lamb, M. R. & Yund, E. W. (1993)
The role of spatial frequency in the analysis of hierarchically organized stimuli.
Perception and Psychophysics, 54: 773-784. [Abstract] [PDF version] downloads.

Woods, D. L., Alho, K., & Algazi, A. (1992)
Intermodal selective attention I: Effects on event-related potentials to lateralized auditory and visual stimuli.
Electroencephalography and Clinical Neurophysiology, 82, 341-355. [Abstract] [PDF version] downloads.

Alho, K., Woods, D. L., Algazi, A., & Naatanen, R. (1992)
Intermodal selective attention II. Effects of attentional load on processing auditory and visual stimuli in central space.
Electroencephalography and Clinical Neurophysiology, 82, 356-368. [Abstract] [PDF version] downloads.

Woods, D. L. (1992)
Auditory selective attention in middle-aged and elderly subjects: An event-related brain potential study.
Electroencephalography and Clinical Neurophysiology, 84, 456-468. [Abstract] [PDF version] downloads.

Singh, J., Knight, R. T., Rosenlicht, N., Kotun, J. M., Beckley, D. J., & Woods, D. L. (1992)
Abnormal premovement brain potentials in schizophrenia.
Schizophrenia Research, 8, 31-41. [Abstract] [PDF version] downloads.

Woods, D. L., Algazi, A., & Alho, K. (1991)
Brain potential signs of feature processing during auditory selective attention.
NeuroReport, 2, 189-192. [Abstract] [PDF version] downloads.

Nielsen-Bohlman, L., Knight, R. T., Woods, D. L., & Woodward, K. (1991)
Differential auditory processing continues during sleep.
Electroencephalography and Clinical Neurophysiology, 79, 281-290. [Abstract] [PDF version] downloads.

Ostrosky-Solis, F., Efron, R. & Yund, E. W. (1991)
Visual detectability gradients: Effect of illiteracy.
Brain and Cognition, 17: 42-51. [Abstract] [PDF version] downloads.

Buckles, K. M., Yund, E. W. & Efron, R. (1991)
Visual detectability gradients: Effect of high- speed visual experience.
Brain and Cognition, 17: 52-63. [Abstract] [PDF version] downloads.

Woods, D. L. (1990)
The physiological basis of selective attention: Implications of event-related potential studies.
In J. W. Rohrbaugh, R. Johnson, & R. Parasuraman (Eds.), Event-Related Brain Potentials: Issues and Interdisciplinary Vantages (pp. 178-209). New York: Oxford University Press. [Abstract] [PDF version] downloads.

Woods, D. L. (1990)
Selective auditory attention: Complex processes and complex ERP generators.
Behavioral Brain Sciences, 13, 160-161. [Abstract] [PDF version] downloads.

Singh, J., Knight, R. T., Woods, D. L., Beckley, D. J., & Clayworth, C. (1990)
Lack of age effects on human brain potentials preceding voluntary movements.
Neuroscience Letters, 119, 27-31. [Abstract] [PDF version] downloads.

Singh, J., Woods, D. L., & Knight, R. T. (1990)
Psychophysiology of movement related brain potentials: Task dependence and neural generators.
In K. A. Sinha (Ed.), Progress in Clinical Neurosciences (vol. 6, pp. 63-78). Patna, Bihar: Catholic University Press. [Abstract] [PDF version] downloads.

Yund, E. W., Efron, R. & Nichols, D. R. (1990)
Detectability gradients as a function of target location.
Brain and Cognition 12: 1-16. [Abstract] [PDF version] downloads.

Efron, R., Yund, E. W. & Nichols, D. R. (1990)
Serial processing of visual spatial patterns in a search paradigm.
Brain and Cognition 12: 17-41. [Abstract] [PDF version] downloads.

Yund, E. W., Efron, R. & Nichols, D. R. (1990)
Detectability as a function of spatial location: Effects of selective attention.
Brain and Cognition 12: 42-54. [Abstract] [PDF version] downloads.

Efron, R., Yund, E. W. & Nichols, D. R. (1990)
Detectability as a Function of Target Location: Effects of Spatial Configuration.
Brain and Cognition 12: 102-116. [Abstract] [PDF version] downloads.

Yund, E. W., Efron, R. & Nichols, D. R. (1990)
Target detection in one visual field in the presence or absence of stimuli in the contralateral field by right- and left-handed subjects.
Brain and Cognition 12: 117-127. [Abstract] [PDF version] downloads.

Efron, R., Yund, E. W. & Nichols, D. R. (1990)
Visual detectability gradients: The effect of distractors in the contralateral field.
Brain and Cognition 12, 128-143. [Abstract] [PDF version] downloads.

Knight, R. T., Scabini, D., Woods, D. L., & Clayworth, C. C. (1989)
Contributions of temporal-parietal junction to the human auditory P3.
Brain Research, 502, 109-116. [Abstract] [PDF version] downloads.

Knight, R. T., Singh, J., & Woods, D. L. (1989)
Pre-movement parietal lobe input to human sensori-motor cortex.
Brain Research, 498, 190-194. [Abstract] [PDF version] downloads.

Knight, R. T., Scabini, D., & Woods, D. L. (1989)
Prefrontal cortex gating of auditory transmission in humans.
Brain Research, 504, 338-42. [Abstract] [PDF version] downloads.

Knight, R. T., Scabini, D., Woods, D. L., & Clayworth, C. (1988)
The effects of lesions of superior temporal gyrus and inferior parietal lobe on temporal and vertex components of the human AEP.
Electroencephalography and Clinical Neurophysiology, 70, 499-509. [Abstract] [PDF version] downloads.

Woods, D. L., Clayworth, C. C., Knight, R. T., Simpson, G. V., & Naeser, M. (1987)
Generators of middle- and long-latency auditory evoked potentials: Implications from studies of patients with bitemporal lesions.
Electroencephalography & Clinical Neurophysiology: Evoked Potentials, 68, 132-148. [Abstract] [PDF version] downloads.

Hink, R. F., & Woods, D. L. (1987)
How humans process uncertain knowledge: An introduction for knowledge engineers.
AI Magazine, 8, 41-53. [Abstract] [PDF version] downloads.

Woods, D. L., Kwee, I., Clayworth, C. C., Kramer, J. H., & Nakada, T. (1987)
Sensory and cognitive evoked potentials in a case of congenital hydrocephalus.
Electroencephalography & Clinical Neurophysiology: Evoked Potentials, 68, 202-208. [Abstract] [PDF version] downloads.

Woods, D. L., & Courchesne, E. (1987)
Intersubject variability elucidates the cerebral generators and psychological correlates of ERPs.
Electroencephalography and Clinical Neurophysiology (Suppl)., 40, 293-299. [Abstract] [PDF version] downloads.

Clayworth, C. C., & Woods, D. L. (1987)
Subcortical contributions to the auditory N1: A comparison of distributions of the N1 and wave V of the BAEP.
Electroencephalography and Clinical Neurophysiology(Suppl),, 40 445-451. [Abstract] [PDF version] downloads.

Woods, D. L., & Clayworth, C. C. (1987)
Scalp topographies dissociate N1 and Nd components during auditory selective attention.
Electroencephalography and Clinical Neurophysiology (Suppl)., 40, 155-162. [Abstract] [PDF version] downloads.

Efron, R., Yund, E. W. & D. R. Nichols. (1987)
Scanning the Visual Field Without eye Movements: A Sex Difference.
Neuropsychologia 25: 637-644. [Abstract] [PDF version] downloads.

Yund, E. W., Simon, H. J. & Efron, R. (1987)
Speech discrimination with an 8-channel compression hearing aid and conventional aids in a background of speech-band noise.
Journal of Rehabilitation Research and Development 24: 161-180. [Abstract] [PDF version] downloads.

Woods, D. L., & Knight, R. T. (1986).
Electrophysiologic evidence of increased distractibility after dorsolateral prefrontal lesions.
Neurology, 36, 212- 216. [Abstract] [PDF version] downloads.

Woods, D. L., & Courchesne, E. (1986)
The recovery functions of auditory event-related potentials during split-second discriminations.
Electroencephalography & Clinical Neurophysiology: Evoked Potentials, 65, 304-315. [Abstract] [PDF version] downloads.

Woods, D. L., & Clayworth, C. C. (1986)
Age-related changes in human middle latency auditory evoked potentials.
Electroencephalography & Clinical Neurophysiology: Evoked Potentials, 65, 297-303. [Abstract] [PDF version] downloads.

Woods, D. L., & Elmasian, R. (1986)
The habituation of event-related potentials to speech sounds and tones.
Electroencephalography & Clinical Neurophysiology: Evoked Potentials, 65, 447-459. [Abstract] [PDF version] downloads.

Woods, D. L., & Courchesne, E. (1986)
Event-related potentials during split second auditory and visual decision making.
Electroencephalography and Clinical Neurophysiology Suppl, 38, 152-154. [Abstract] [PDF version] downloads.

Woods, D. L., Ridgway, S. H., Carder, D. G., & Bullock, T. H. (1986)
Middle and long-latency auditory event-related potentials in the dolphin.
In R. Buhr, R. Schusterman, J. Thomas, & F. Wood (Eds.), Dolphin Cognition and Behavior: A Comparative Perspective. (pp. 61-78). New York: Lawrence Erlbaum Associates. [Abstract] [PDF version] downloads.

Curry, S. H., Woods, D. L., & Low, M. D. (1986)
Applications of cognitive ERPs in neurosurgical and neurological patients.
In W. C. McCallum, R. Zappoli, & F. Denoth (Eds.), Cerebral Psychophysiology: Studies in Event- Related Potentials (EEG Suppl. 38) (pp. 469-485). Amsterdam: Elsevier. [Abstract] [PDF version] downloads.

Woods, D. L., & Clayworth, C. C. (1985)
Click spatial position influences middle latency auditory evoked potentials (MAEPs) in humans.
Electroencephalography & Clinical Neurophysiology, 60, 122-129. [Abstract] [PDF version] downloads.

Efron, R., Yund, E. W., Nichols-Mello, D. and Crandall, P. H. (1985)
An ear asymmetry for gap detection following anterior temporal lobectomy.
Neuropsychologia 23: 43-50. [Abstract] [PDF version] downloads.

Hillyard, S. A., Simpson, G. V., Woods, D. L., Van Voorhis, S., Munte, T., & Ajmon-Marsan, C. (1984)
Event-related brain potentials and selective attention to different modalities.
In F. R. Suarez (Ed.), Cortical Integration (pp. 395-414). New York: Raven Press. [Abstract] [PDF version] downloads.

Woods, D. L., Knight, R. T., & Neville, H. J. (1984)
Bitemporal lesions dissociate auditory evoked potentials and perception.
Electroencephalography & Clinical Neurophysiology, 57, 208-220. [Abstract] [PDF version] downloads.

Woods, D. L., Hillyard, S. A., & Hansen, J. C. (1984)
Event-related brain potentials reveal similar attentional mechanisms during selective listening and shadowing.
Journal of Experimental Psychology: Human Perception & Performance, 10, 761-777 [Abstract] [PDF version] downloads.

Burger, L. H., Wertz, R. T., & Woods, D. L. (1983)
A response to treatment in a case of cortical deafness.
In R. H. Brookshire (Ed.), Clinical Aphasiology Conference Proceedings (pp. 127-136). Minneapolis: BRK Publishers. [Abstract] [PDF version] downloads.

Gregory, A. H., Efron, R., Divenyi, P. L. & Yund, E. W. (1983)
Central auditory processing: I. Ear dominance - a perceptual or an attentional asymmetry?
Brain and Language 19: 225-236. [Abstract] [PDF version] downloads.

Efron, R., Crandall, P. H., Koss, B., Divenyi, P. L. & Yund, E. W. (1983)
Central auditory processing: III. The "cocktail party" effect and anterior temporal lobectomy.
Brain and Language 19: 254-263. [Abstract] [PDF version] downloads.

Efron, R., Koss, B. & Yund, E. W. (1983)
Central auditory processing: IV. Ear dominance - spatial and temporal complexity.
Brain and Language 19: 264-282. [Abstract] [PDF version] downloads.

Efron, R., Snyder, E., Yund, E. W. & Martin, F. (1983)
Central auditory processing: VI. Detecting ear dominance by evoked potentials.
Brain and Language 20: 54-64. [Abstract] [PDF version] downloads.

Yund, E. W., Morgan, H. & Efron, R. (1983)
The micropattern effect and visible persistence.
Perception and Psychophysics 34: 209-213. [Abstract] [PDF version] downloads.

Neville, H. J., Snyder, E., Woods, D. L., & Galambos, R. (1982)
Recognition and surprise alter the human visual evoked response.
Proceedings of the National Academy of Sciences, 79, 2121-2123. [Abstract] [PDF version] downloads.

Elmasian, R., Neville, H. J., Woods, D. L., Schuckit, M., & Bloom, F. (1982)
Event-related brain potentials are different in individuals at high and low risk for developing alcoholism.
Proceedings of the National Academy of Sciences, 79, 7900-7903. [Abstract] [PDF version] downloads.

Yund, E. W. (1982)
Comments on "Ear dominance and sequential interactions". [J. Acoust. Soc. Am. 67, 220-228 (1980)].
Journal of the Acoustical Society of America 71: 1287-1290. [Abstract] [PDF version] downloads.

De Valois, R. L., Yund, E. W. & Hepler, N. K. (1982)
The orientation and direction selectivity of cells in macaque visual cortex.
Vision Research 22: 531-544. [Abstract] [PDF version] downloads.

Ridgway, S. H., Bullock, T. H., Carder, D. A., Seeley, R. L., Woods, D. L., & Galambos, R. (1981)
Auditory brainstem response in dolphins.
Proceedings of the National Academy of Sciences, 78, 1943-47. [Abstract] [PDF version] downloads.

Knight, R. T., Hillyard, S. A., Woods, D. L., & Neville, H. J. (1981)
The effects of frontal cortex lesions on event-related potentials during auditory selective attention.
Electroencephalography and Clinical Neurophysiology, 52, 571-582. [Abstract] [PDF version] downloads.

Woods, D. L., Hillyard, S. A., Courchesne, E., & Galambos, R. (1980)
Electrophysiological signs of split-second decision-making.
Science, 207, 655-657. [Abstract] [PDF version] downloads.

Knight, R. T., Hillyard, S. A., Woods, D. L., & Neville, H. J. (1980)
The effects of frontal and temporal-parietal lesions on the auditory evoked response in man.
Electroencephalography and Clinical Neurophysiology, 50, 112-124. [Abstract] [PDF version] downloads.

Woods, D. L., Courchesne, E., Hillyard, S. A., & Galambos, R. (1980)
Recovery cycles of event-related potentials in multiple detection tasks.
Electroencephalography and Clinical Neurophysiology, 50, 335-347. [Abstract] [PDF version] downloads.

Woods, D. L., Courchesne, E., Hillyard, S. A., & Galambos, R. (1980)
Split- second recovery of the P3 component in multiple decision tasks.
Progress in Brain Research, 54, 322-330. [Abstract] [PDF version] downloads.

Hillyard, S. A., & Woods, D. L. (1979)
Electrophysiological analysis of human brain function.
In M. Gazzaniga (Ed.), Handbook of Behavioral Neurobiology (pp. 345-377). New York: Plenum. [Abstract] [PDF version] downloads.

Woods, D. L., & Hillyard, S. A. (1979)
Attention at the cocktail party: Brainstem evoked responses reveal no peripheral gating.
In D. Otto (Ed.), New Perspectives on Event-related Potential Research (pp. 230-233). Washington, D. C.: U.S. Environmental Protection Agency. [Abstract] [PDF version] downloads.

Picton, T. W., Woods, D. L., Stuss, D. T., & Campbell, K. B. (1979)
Methodology and meaning of human evoked potential scalp distribution studies.
In D. Otto (Ed.), New Perspectives on Event-related Potential Research (pp. 515-522). Washington, D. C.: U. S. Environmental Protection Agency. [Abstract] [PDF version] downloads.

De Valois, K. K., De Valois, R. L. & Yund, E. W. (1979)
Responses of striate cortex cells to grating and checkerboard patterns.
Journal of Physiology 291: 483-505. [Abstract] [PDF version] downloads.

Yund, E. W., Efron, R. & Divenyi, P. L. (1979)
The effect of bone conduction on the intensity independence of dichotic chords.
Journal of the Acoustical Society of America 65: 259-261. [Abstract] [PDF version] downloads.

Efron, R., Yund, E. W. & Divenyi, P. L. (1979)
Individual differences in the perception of dichotic chords.
Journal of the Acoustical Society of America 66: 75-86. [Abstract] [PDF version] downloads.

Picton, T. W., Woods, D. L., & Proulx, G. B. (1978)
Human auditory sustained potentials: II Stimulus relationships.
Electroencephalography & Clinical Neurophysiology, 45, 198-210. [Abstract] [PDF version] downloads.

Picton, T. W., Woods, D. L., & Proulx, G. B. (1978)
Human auditory sustained potentials: I The nature of the response.
Electroencephalography & Clinical Neurophysiology, 45, 186-197. [Abstract] [PDF version] downloads.

Picton, T. W., Woods, D. L., Baribeau-Braun, J., & Healey, T. M. G. (1977)
Evoked Potential Audiometry
Journal of Oto-Laryngology, 6, 90-119. [Abstract] [PDF version] downloads.

De Valois, R. L., Snodderly, D. M., Yund, E. W. & Hepler, N. K. (1977)
Responses of macaque lateral geniculate cells to luminance and color figures.
Sensory Processes 1: 244-259. [Abstract] [PDF version] downloads.

Yund, E. W., Snodderly, D. M., Hepler, N. K. & De Valois, R. L. (1977)
Brightness contrast effects in monkey lateral geniculate nucleus.
Sensory Processes 1: 260-271. [Abstract] [PDF version] downloads.

Efron, R., Bogen, J. E. & Yund, E. W. (1977)
Perception of dichotic chords by normal and commisurotomized human subjects.
Cortex 13: 137-149. [Abstract] [PDF version] downloads.

Efron, R., Dennis, M. & Yund, E. W. (1977)
The perception of dichotic chords by hemispherectomized subjects.
Brain and Language 4: 537-549. [Abstract] [PDF version] downloads.

Yund, E. W. & Efron, R. (1977)
Model for the relative salience of the pitch of pure tones presented dichotically.
Journal of the Acoustical Society of America 62: 607-617. [Abstract] [PDF version] downloads.

Efron, R., Tanis, D. C. & Yund, E. W. (1977)
Effects of signal intensity and noise on the pitch mixture of dichotic chords.
Journal of the Acoustical Society of America 62: 618-623. [Abstract] [PDF version] downloads.

Divenyi, P. L., Efron, R. & Yund, E. W. (1977)
Ear dominance in dichotic chords and ear superiority in frequency discrimination.
Journal of the Acoustical Society of America 62: 624-632. [Abstract] [PDF version] downloads.

Yund, E. W. & Efron, R. (1976)
Dichotic competition of simultaneous tone bursts of different frequencies: IV. Correlations with dichotic competition of speech signals.
Brain and Language 3: 246-254. [Abstract] [PDF version] downloads.

Efron, R. & Yund, E. W. (1976)
Ear dominance and intensity independence in the perception of dichotic chords.
Journal of the Acoustical Society of America 59: 889-898. [Abstract] [PDF version] downloads.

Yund, E. W. & Efron, R. (1975)
Dichotic competition of simultaneous tone bursts of different frequency: II. Suppression and ear dominance functions.
Neuropsychologia 13: 137-150. [Abstract] [PDF version] downloads.

Efron, R. & Yund, E. W. (1975)
Dichotic competition of simultaneous tone bursts of different frequencies: III. The effect of stimulus parameters on suppression and dominance functions.
Neuropsychologia 13: 151-161. [Abstract] [PDF version] downloads.

Yund, E. W. & Armington, J. C. (1975)
Color and brightness contrast effects as a function of spatial variables.
Vision Research 15: 917-929. [Abstract] [PDF version] downloads.

Efron, R. & Yund, E. W. (1974)
Dichotic competition of simultaneous tone bursts of different frequency: I. Dissociation of pitch from lateralization and loudness.
Neuropsychologia 12: 249-257. [Abstract] [PDF version] downloads.

Yund, E. W. & Efron, R. (1974)
Dichoptic and dichotic micropattern discrimination.
Perception and Psychophysics 15: 383-390. [Abstract] [PDF version] downloads.

Improving the resolution of functional brain imaging: analyzing functional data in anatomical space

Xiaojian Kang; E. William Yund; Timothy J. Herron; David L. Woods (2007)

The accurate mapping of functional magnetic resonance imaging (fMRI) activations to anatomical structures is critical for fMRI studies of brain organization. In the commonly used functional space analysis method, functional images are realigned to a functional reference image and processed in low-resolution functional space. The average functional activations are then projected into high-resolution anatomical space for visualization. Here, we describe a new technique, anatomical space analysis (ASA), whereby low-resolution functional images are first coregistered and resampled directly into high-resolution anatomical space with all subsequent data processing performed in high-resolution space. A major advantage of ASA is that minor scanner sampling instabilities and small head movements can increase spatial resolution by providing multiple samples of the relationship between functional and anatomical space. Both simulations and analyses of real fMRI data show that ASA improves the precision, objectivity and reproducibility of functional brain mapping.

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Attention modulates sound processing in human auditory cortex but not the inferior colliculus

Teemu J. Rinne; G. Christopher Stecker; Xiaojian Kang; E. William Yund; Timothy J. Herron; David L. Woods (2007)

Auditory attention powerfully inœuences perception and modulates sound processing in auditory cortex, but the extent of attentional modulation in the subcortical auditory pathway remains poorly understood.We examined the effects of intermodal attention using functional magnetic resonance imaging of the inferior colliculus and auditory cortex in a demanding intermodal selective attention task using a silent imaging paradigmdesigned to optimize inferior colliculus activations. Both the inferior colliculus and auditory cortex showed strong activations to sound, but attentional modulations were restricted to auditory cortex.

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Perceptual Training of Phoneme Identification for Hearing Loss

David L. Woods and E. William Yund (2007)

Semin Hear 28:110-119 (2006)

Synaptic connections in the auditory system change throughout life in response to the changing acoustic environment. These changes help to compensate for sensorineural hearing loss (SNHL) and the consequent impairment of high-frequency hearing by enhancing the efficiency of synaptic transmission of low-frequency signals. They also help to compensate for the inevitable deterioration in the central auditory system that occurs with normal aging even without clinically significant hearing loss. However, in many cases the neuroplastic changes are insufficient to maintain optimal speech comprehension. Indeed, the enhanced transmission of low-frequency phonetic cues that occurs with longstanding SNHL may interfere with a patient’s ability to utilize the high-frequency phonetic cues that are restored by hearing aids. Adaptive perceptual training using tasks that require high-frequency phonetic cue processing can drive neuroplastic change in auditory cortex that improves speech discrimination. We tested the benefits of at-home PC-based phoneme identification training in new hearing aid (HA) users and found that it produced significant benefit in phoneme identification by reducing phonetic confusions and enhancing the patient's abilities to identify previously difficult syllables. Perceptual training is a promising and cost-effective tool for enhancing speech perception in HA users who have difficulty in understanding everyday speech.

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Perceptual training improves syllable identification in new and experienced

G. Christopher Stecker, PhD; Glen A. Bowman, BA; E. William Yund, PhD; Timothy J. Herron, MA; Christina M. Roup, PhD; David L. Woods, PhD (2006)

J Rehabil Res Dev 43(4):537-552 (2006)

We assessed the effects of perceptual training of syllable identification in noise on nonsense syllable test (NST) performance of new (Experiment 1) and experienced (Experiment 2) hearing aid (HA) users with sensorineural hearing loss. In Experiment 1, new HA users were randomly assigned to either immediate training (IT) or delayed training (DT) groups. IT subjects underwent 8 weeks of at-home syllable identification training and in-laboratory testing, whereas DT subjects underwent identical in-laboratory testing without training. Training produced large improvements in syllable identification in IT subjects, whereas spontaneous improvement was minimal in DT subjects. DT subjects then underwent training and showed performance improvements comparable with those of the IT group. Training-related improvement in NST scores significantly exceeded improvements due to amplification. In Experiment 2, experienced HA users received identical training and testing procedures as users in Experiment 1. The experienced users also showed significant training benefit. Training-related improvements generalized to untrained voices and were maintained on retention tests. Perceptual training appears to be a promising tool for improving speech perception in new and experienced HA users.

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Acclimatization in wide dynamic range multichannel compression and linear amplification hearing aids

E. William Yund, PhD; Christina M. Roup, PhD; Helen J. Simon, PhD; Glen A. Bowman, BA (2006)

J Rehabil Res Dev 43(4):517-536 (2006)

Acclimatization was studied in hearing-impaired patients with no previous hearing aid (HA) experience who were fit bilaterally with either wide dynamic range multichannel compression (WDRMCC) or linear amplification (LA) HAs. Throughout 40 weeks of normal HA use, we monitored changes in nonsense syllable perception in speech-spectrum noise. Syllable recognition for WDRMCC users improved by 4.6% over the first 8 weeks, but the 2.2% improvement for LA users was complete in 2 to 4 weeks. Consonant confusion analyses indicated that WDRMCC experience facilitated consonant identification, while LA users primarily changed their response biases. Furthermore, WDRMCC users showed greater improvement for aided than unaided stimuli, while LA users did not. These results demonstrate acclimatization in new users of WDRMCC HAs but not in new users of LA HAs. A switch in amplification type after 32 weeks produced minimal performance change. Thus, acclimatization depended on the type of amplification and the previous amplification experience.

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Local landmark-based mapping of human auditory cortex

Xiaojian Kang, Olivier Bertrand, Kimmo Alho, E. William Yund, Timothy J. Herron and David L. Woods

NeuroImage 2004; 22(4): 1657-1670.

Mammalian sensory cortex is functionally partitioned into cortical fields that are specialized for different processing operations. In theory, averaging functional and anatomical images across subjects can reveal both the average anatomy and the mean functional organization of sensory regions. However, this averaging process must overcome at least two obstacles: (1) the relative locations and sizes of cortical sensory areas vary in different subjects so that across-subject averaging introduces spatial smearing; (2) the relative locations and sizes of cortical areas vary between hemispheres, making it difficult to compare activations between hemispheres or to combine activations across hemispheres. These difficulties are particularly acute for small cortical regions such as auditory cortex. In whole-brain averaging procedures, considerable intersubject variance in the location and orientation of auditory cortex is introduced by variance of the size and shape of structures outside auditory cortex. Here, we compared these global methods with local landmark-based methods (LLMs) that use warping based on local anatomical landmarks. In comparison to maps made with global methods, LLMs produced anatomical maps of auditory cortex with clearer gyral and sulcal structure, and produce functional maps with improved resolution. These results suggest that LLMs have significant advantages over global mapping procedures in studying the details of auditory cortex organization.

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Attentional modulation of human auditory cortex

Christopher I Petkov, Xiaojian Kang, Kimmo Alho, Olivier Bertrand, E William Yund & David L Woods

Nature Neuroscience, 7:658-663 (2004)

Attention powerfully influences auditory perception, but little is understood about the mechanisms whereby attention sharpens responses to unattended sounds. We used high-resolution surface mapping techniques (using functional magnetic resonance imaging, fMRI) to examine activity in human auditory cortex during an intermodal selective attention task. Stimulus-dependent activations (SDAs), evoked by unattended sounds during demanding visual tasks, were maximal over mesial auditory cortex. They were tuned to sound frequency and location, and showed rapid adaptation to repeated sounds. Attention-related modulations (ARMs) were isolated as response enhancements that occurred when subjects performed pitch-discrimination tasks. In contrast to SDAs, ARMs were localized to lateral auditory cortex, showed broad frequency and location tuning, and increased in amplitude with sound repetition. The results suggest a functional dichotomy of auditory cortical fields: stimulus determined mesial fields that faithfully transmit acoustic information, and attentionally labile lateral fields that analyze acoustic features of behaviorally relevant sounds.

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An ERP study of the global precedence effect: the role of spatial frequency

Shihui Han,, E. William Yund, David L. Woods

Clinical Neurophysiology 114 (2003) 1850–1865

Objective: This study investigated the neural mechanisms underlying the effects of removal of low spatial frequency (SF) contents from stimulus displays on the processing of global and local properties of compound stimuli. Methods: Event-related brain potentials (ERPs) were recorded from 16 subjects who selectively attended to the global or local features of compound letters, which were either white on a gray background containing broadband SFs or were contrast-balanced (CB) to eliminate low SFs, and were randomly presented in the left or right visual fields. ERPs were analyzed to examine how global/local attention modulations of neural substrates were influenced by SF manipulations. Results: We found that an early process of global recognition was indexed by a negativity peaking at 190 ms over contralateral occipitotemporal cortex and was eliminated by contrast balancing. The late stage of global recognition was reflected in a late negativity peaking at 300 ms and was only retarded by contrast balancing. Global-to-local interference was characterized by enhanced occipito-temporal negativities and was evident for both broadband and CB stimuli. Conclusions: The results clarify distinct cognitive and neural mechanisms underlying the global precedence and interference effects, which were different in terms of the independence of low SFs in compound stimuli.

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Neural substrates for visual perceptual grouping in humans

Shihui Han, Yan Song, Yulong Ding, E. William Yund, and David L. Woods (2001)

Psychophysiology, 38 (2001), 926–935. Cambridge University Press.

Two experiments investigated the neural mechanisms of Gestalt grouping by recording high-density event-related brain potentials (ERPs) during discrimination tasks. In Experiment 1, stimulus arrays contained luminance-defined local elements that were either evenly spaced or grouped into columns or rows based on either proximity or similarity of shape. Proximity grouping was indexed by a short-latency positivity (110–120 ms) over the medial occipital cortex and a subsequent right occipitoparietal negativity. Grouping by similarity was reflected only in a long-latency occipitotemporal negativity. In Experiment 2, proximity grouping was examined when local elements were defined by motion cues, and was again associated with a medial occipital positivity. However, the subsequent long-latency negativity was now enhanced over the left posterior areas. The implications of these results to the neural substrates subserving different grouping processes are discussed.

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Bifurcation of resonance islands and Landau damping in the double-rf system.

Liu J. Y., Ball M., Brabson B., Budnick J., Caussyn D. D., East G., Ellison M., Hamilton B., Jones W. P., Kang X., Lee S. Y., Li D., Ng K. Y., Riabko A., Rich D., Sloan T., Wang L.

Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1994; 50(5): R3349-R3352.

The attractors of a double-rf system subject to rf phase modulation, in the presence of a weak damping force, were measured as a function of the modulation frequency. We found that the phase amplitudes of the attractors followed a simple predictable path related to the synchrotron tune of the double-rf system. These attractors were found to bifurcate at a modulation frequency near the maximum synchrotron frequency. We also found that the coherent synchrotron oscillations decohered rapidly at small synchrotron amplitudes but showed little decoherence at large synchrotron amplitudes. The experimental result has some implications for the Landau damping of coherent beam instabilities.

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Particle dynamics in quasi-isochronous storage rings

Riabko A., Bai M., Brabson B., Chu C. M., Kang X., Jeon D., Lee S. Y., Zhao X.

Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1996; 54(1): 815-829.

The synchrotron equation of motion in quasi-isochronous ~QI! storage rings is transformed to a universal Weierstrass equation, where the solution is given by Jacobian elliptic functions. Scaling properties of the QI Hamiltonian are derived. The effects of phase space damping and the sensitivity of particle motion to external harmonic modulation are studied. We find that the rf phase modulation is particularly enhanced in QI storage rings. Exact formula and sum rules for resonance strength coefficients are derived. When the QI dynamical system is subject to harmonic modulation, it exhibits a sequence of period-2 bifurcations leading to global chaos in a region of modulation tune. This means that the operators of QI storage rings should pay special attention to rf phase noise.

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Effects of a nonlinear damping force in synchrotrons with electron cooling

Caussyn D. D., Ball M., Budnick J., East G., Ellison M., Hamilton B., Hedblom K., Kang X., Lee S. Y., Li D., Liu J. Y., Ng K. Y., Riabko A., Wang L., Wang Y.

Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1995; 51(5): 4947-4957.

The longitudinal dynamics of a stored proton beam bunch, under the influence of a nonlinear damping force produced by electron cooling, was studied experimentally. The effect of the nonlinear damping force was explored by varying the relative velocity between the cooling electrons and the stored protons. Maintained longitudinal oscillations developed, which grew rapidly once a critical threshold in the relative velocity was exceeded. The bifurcation of a fixed point into a limit cycle is also known as a Hopf bifurcation. Comparisons of experimental data with numerical simulations and analytical calculations are made. Implications for cooled beam acceleration will be discussed.

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Hamiltonian formalism for space charge dominated beams in a uniform focusing channel

Riabko A., Ellison M., Kang X., Lee S. Y., Li D., Liu J. Y., Pei X., Wang L.

Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1995; 51(4): 3529-3546.

We employ the Kapchinskij-Vladimirskij envelope Hamiltonian [I. M. Kapchinskij and V. V. Vladimirskij, in 2 The Proceedings of the 9th International Conference on High Energy Accelerators, edited by L. Kowarski (CERN, Geneva, 1959), p. 274] to describe the envelope evolution and the particle Hamiltonian to describe particle motion in a space charge dominated beam. Properties of the envelope function in a mismatched uniform focusing channel are studied. Parametric resonances of the particle Hamiltonian due to envelope oscillations of a mismatched beam are studied. We find that the Hamiltonian dynamics depends only on a single effective space charge parameter, the ratio of the space charge perveance to the focusing strength. The onset of global chaos exhibits a first order phase-transition-like behavior when the amplitude of envelope oscillations for a mismatched beam is larger than a critical value. This global chaos can greatly enhance the halo formation. The relation between the critical envelope mismatch for the halo formation and the effective space charge parameter is numerically obtained. Possible experiments are suggested.

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A Method of Detecting Coherent Synchrotron Modes

Chu CM, Ball M, Budnick J, East G, Ellison M, Hamilton B, Kang X, Lee SY, Liu JY, Pei A, Riabko A, Sloan T, Wang L

Nuclear Instruments Methods in Physics Research A 1996; 381(2-3): 215-8.

A method for measuring coherent longitudinal synchrotron modes is developed and tested at the Indiana University Cyclotron Facility Cooler Ring. This method can be used to detect the onset of coherent instability and can provide important diagnosis for the control of beam brightness. Some possible improvement of this technique is discussed.

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Role of parametric resonances in global chaos

Jeon D, Bai M, Chu CM, Kang X, Lee SY, Riabko A, Zhao X

Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1996; 54(4): 4192-4201.

The quasi-isochronous (QI) dynamical system, in the presence of synchrotron radiation damping and rf phase modulation, exhibits a sequence of period-2 bifurcations en route towards global chaos (instability) in a region of modulation tune. The critical modulation amplitude for the onset of the global chaos shows a cusp as a function of the modulation tune. This cusp is shown to arise from the transition from the 2:1 to the 1:1 parametric resonances. We have also studied the effect of the rf voltage modulation on the QI dynamical system and found that the tolerance of the rf voltage modulation is much larger than that of the rf phase modulation.

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Effect of magnetized electron cooling on a Hopf bifurcation

Lee SY, Ball M, Brabson B, Budnick J, Caussyn DD, Colestock P, East G, Ellison M, Hamilton B, Hedblom K, Kang X, Li D, Liu JY, Ng KY, Pei A, Riabko A, Syphers M, Wang L.

Physical Review. E. Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 1996; 53(1): 1287-1290.

We have observed longitudinal limit cycle oscillations of a proton beam when a critical threshold in the relative velocity between the proton beam and the cooling electrons has been exceeded. The threshold for the bifurcation of a fixed point into a limit cycle, also known as a Hopf bifurcation, was found to be asymmetric with respect to the relative velocity. Further experiments were performed to verify that the asymmetry was related to electron beam alignment with respect to the stored proton beam. The measured amplitudes of the ensuing Limit cycle were used to determine the cooling drag force, which exhibits the essential characteristics of the magnetized cooling, where the limit cycle attractor can coexist with a damping-free region and/or a fixed point attractor.

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A mechanism of anomalous diffusion in particle beams

Jeon D, Ball M, Budnick J, Chu CM, Ellison M, Hamilton B, Kang X, Kiang LL, Lee SY, Ng KY, Pei A, Riabko A, Sloan T, Syphers M

Physics Review Letter 1998; 80(11): 2314-7.

Experimental observation of particle diffusion mechanism in the presence of overlapping parametric resonances generated by a time dependent rf phase modulation is analyzed. We find that the regime of fast emittance growth is associated with the rapid particle motion along the separatrix of a dominant parametric resonance, the slow growth regime is related to particle diffusion in the chaotic sea, and the emittance saturation occurs when beam particles fill the chaotic region bounded by an invariant torus. Experimental data observed at the Indiana University Cyclotron Facility (IUCF) Cooler Ring are shown to agree well with the theoretical analysis.

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Effects of overlapping parametric resonances on the particle diffusion process.

Chu CM, Ball M, Brabson B, Budnick J, Ellison M, Fung KM, Hamilton B, Hsi WC, Jeon D, Kang X, Kiang LL, Lee SY, Ng KY, Pei A, Riabko A, Sloan T.

Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 1999 Nov;60(5 Pt B):6051-60.

The evolution of the beam distribution in a double-rf system with a phase modulation on either the primary or secondary rf cavity was measured. We find that the particle diffusion process obeys the Einstein relation if the phase space becomes globally chaotic. When dominant parametric resonances still exist in the phase space, particles stream along the separatrices of the dominant resonance, and the beam width exhibits characteristic oscillatory structure. The particle-tracking simulations for the double-rf system are employed to reveal the essential diffusion mechanism. Coherent octupolar motion has been observed in the bunch beam excitation. The evolution of the longitudinal phase space in the octupole mode is displayed.

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Analysis of the measurement precision of arterial lumen and wall areas using high-resolution MRI.

Kang X, Polissar NL, Han C, Lin E, Yuan C.

Magn Reson Med. 2000 Dec;44(6):968-72.

High-resolution MRI may be used to monitor the progression of human carotid atherosclerosis by measuring the lumen and wall area changes over time. The purpose of this study was to analyze the precision of quantitative measurements of lumen and wall areas. Two independent MR scans near the carotid bifurcation were conducted on eight patients within 2 weeks. The error of lumen area measurement was 6. 2%, 9.2%, and 9.7% for T(1), proton density, and T(2)-weighted images, respectively, and the error of wall area measurement was 10. 8%, 10.9%, and 12.0%. The precision of area measurement correlates strongly with image quality.

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Effects of Prolonged Intensive Lipid-Lowering Therapy on the Characteristics of Carotid Atherosclerotic Plaques In Vivo by MRI

Zhao XQ, Yuan C, Hatsukami TS, Frechette EH, Kang XJ, Maravilla KR, Brown BG

Arterioscler Thromb Vasc Biol. 2001 Oct;21(10):1623-9.

High-resolution magnetic resonance imaging (MRI) with flow suppression not only provides useful information on luminal and wall areas of the carotid artery but also can identify the principal tissue components of the carotid atherosclerotic plaque. The effects of intensive lipid-lowering therapy on these MRI tissue characteristics were examined in patients with coronary disease (CAD). Eight CAD patients who have been receiving intensive lipid-lowering treatment (niacin 2.5 g/d, lovastatin 40 mg/d, and colestipol 20 g/d) for 10 years in the Familial Atherosclerosis Treatment Study (FATS) follow-up were randomly selected from among 60 such treated patients. Eight CAD patients who were matched to the treated patients for age (+/-3 years), baseline low density lipoprotein (+/-5 mg/dL), and triglycerides (+/-50 mg/dL) but who had never been treated with lipid-lowering drugs were selected as controls. For each of these 32 carotid arteries, luminal and plaque areas were measured by planimetry, in a blinded protocol, from the magnetic resonance image that showed most plaque. Fibrous tissue, calcium, and lipid deposits were identified on the basis of established criteria. Plaque composition was estimated as a fraction of total planimetered area. Patients treated with 10-year intensive lipid-lowering therapy, compared with control subjects, had significantly lower low density lipoprotein cholesterol levels (84 versus 158 mg/dL, respectively; P<0.001) and higher high density lipoprotein cholesterol levels (51 versus 37 mg/dL, respectively; P<0.001). As a group, treated patients, compared with untreated control subjects, had a smaller core lipid area (0.7 versus 10.2 mm(2), respectively; P=0.01) and lipid composition (1% versus 17%, respectively). Group differences in luminal area (55 [treated] versus 44 [control] mm(2), P=NS) and plaque area (58 [treated] versus 64 [control] mm(2), P=NS) tended to favor treatment. MRI appears useful for estimating carotid plaque size and composition. Hyperlipidemic CAD patients frequently (97%) have at least moderate (>/=40% area stenosis) carotid plaque. In this case-control study, prolonged intensive lipid-lowering therapy is associated with a markedly decreased lipid content, a characteristic of clinically stable plaques.

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Tympanometric Screening Norms for Adults

Roup, C., Wiley, T., Safadi, S., Stoppenbach, D.T. (1998)

American Journal of Audiology 7: 1-6.

The purpose of this study was to reexamine the Margolis and Heller (1987) normative tympanometric data (also American Speech-Language-Hearing [ASHA], 1990 interim norms) using a strict control over subject age and gender. Normative values for peak, compensated static acoustic admittance (Peak Ytm), acoustic equivalent volume (Vea), and tympanometric width (TW) were determined for 102 young adults with normal hearing. Relative to the Margolis and Heller normative values, signigicant differences were found for Vea and TW. Although statistically significant, these differences were small and of little clinical importance. However, significant and clinically important gender differences in young adults were observed for each of the tympanometric measures. Compared to males, females had lower Peak Ytm values, smaller Vea values, and higher TW values.

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Normal and hearing-impaired word recognition scores for monosyllabic words in quiet and noise

Beattie, R. C., Barr, T., & Roup, C. (1997)

British Journal of Audiology 31: 153-164.

The effects of noise on word recognition scores were assessed with normal-hearing and hearing-impaired subjects. Fifty-one normal-hearing subjects were tested at 50 dB HL using signal-to-noise ratios (S/Ns) of 5, 10, and 15 dB. Thirty subjects with mild-to-moderate sensorineural hearing losses were tested in quiet and in noise at S/Ns of 10 dB and 15 dB. Monosyllabic words in a Multitalker Noise were selected for testing. Mean scores for the normal-hearing subjects were 45% at the 5 dB S/N, 74% at the 10 dB S/N, and 87% at the 15 dB S/N. For the hearing-impaired subjects, scores were 85% in quiet, 60% at the 15 dB S/N, and 40% at the 10 dB S/N. These results suggest that background noise which is mildly disruptive for normal hearing subjects can be highly disruptive to hearing-impaired subjects. Moreover, these findings indicate that subjects with mild-to-moderate sensorineural hearing loss require a more favorable S/N than normal listeners to achieve comparable word recognition scores. Test-retest differences for word recognition scores revealed variability that agreed closely with predictions based on the binomial distribution for both groups of subjects. Speech-in-noise abilities must be measured directly because regression equations revealed that speech-in-noise scores cannot be predicted accurately from either puretone thresholds or speech-in-quiet scores. Word recognition functions are presented from several hearing-impaired subjects and demonstrate the value of testing in noise.

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Dichotic competition of simultaneous tone bursts of different frequency: I. Dissociation of pitch from lateralization and loudness.

Efron, R. & Yund, E. W. (1974)

Neuropsychologia 12: 249-257.

Subjects were presented with two 50 msec tone bursts of 1500 Hz and 1900 Hz separated by one second. One ear received the 1500-1900 sequence at one intensity level while the other ear simultaneously received the reversed (1900-1500 Hz) sequence at another intensity level. The subject was required to report which sequence he heard and its lateralization. A strong ear dominance effect was demonstrated in all 5 subjects for pitch information. A similar dominance for loudness and lateralization was absent. The existence of an ear dominance for pitch but not for lateralization and loudness indicates a striking dissociation in the neural processing of these two types of acoustic information.

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Dichoptic and dichotic micropattern discrimination.

Yund, E. W. & Efron, R. (1974)

Perception and Psychophysics 15: 383-390.

Ss compared two rapidly successive, brief, discriminably different stimulus elements, called a micropattem, with a second micropattern composed of the same two stimulus elements presented in reverse temporal order. Discriminations could be made between two such micropatterns in the monaural (monocular) as well as in the dichotic (dichoptic) modes of presentation. Discrimination between micropatterns was based on the perceptual dominance of the temporally trailing stimulus element in both modalities and in both modes of presentation. While monaural (monocular) micropattern discrimination is significantly superior to dichotic (dichoptic) discrimination, the existence of dichotic (dichoptic) discrimination demonstrates that no essential peripheral process is required for micropattern discrimination.

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Dichotic competition of simultaneous tone bursts of different frequency: II. Suppression and ear dominance functions.

Yund, E. W. & Efron, R. (1975)

Neuropsychologia 13: 137-150.

The perceptual interaction of the two tones of a dichotically presented chord was studied as a function of the differences in the intensity between the right and left ear tones. Large but highly consistent differences in perceptual interactions were found in thirty subjects. In 23 per cent of the subjects the pitch of the tones presented to the right ear dominated the pitch of the dichotically perceived chord. In 40 per cent the left ear was dominant, and in 37 per cent there was no marked ear asymmetry. These and other differences between the individual psychometric curves were accounted for by postulating the existence of two independent functional properties of dichotic interactions—a suppression function and an ear dominance function.

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Dichotic competition of simultaneous tone bursts of different frequencies: III. The effect of stimulus parameters on suppression and dominance functions.

Efron, R. & Yund, E. W. (1975)

Neuropsychologia 13: 151-161.

The perceptual interaction of the two tones of a dichotically presented chord was studied as a function of the differences in the intensity between the right and left ear tones. The further effects of (a) absolute sound pressure level (ASPL), (b) tone duration, (c) frequency difference between the two tones (Δ∫), and (d) the temporal asynchrony between the two tones on the perceptual interaction were analyzed in terms of their effects on the magnitude of the suppression and dominance functions defined in the companion paper. The magnitude of the suppression function increased with a decrease of ASPL, an increase in tone duration, and an increase in frequency difference, but was not altered by temporal asynchrony between the two tones of the chord. The ear dominance function in all subjects was unaffected by intensity levels and tone durations. For some subjects the ear dominance function was influenced by frequency differences between the two tones.

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Color and brightness contrast effects as a function of spatial variables.

Yund, E. W. & Armington, J. C. (1975)

Vision Research 15: 917-929.

The contrast effect was measured at the center of a circular center-surround stimulus display for three color combinations and one (non-colored) brightness combination. For each combination, the magnitude of the contrast effect was determined for a series of different center and surround sizes using consecutive matching procedures. The amount of contrast was influenced by the dimensions of the display in the expected way; the effect on the center was greatest when the surround was large and the center was small. The contrast magnitudes were plotted against four theoretically selected abscissae: (1) surround width, R1 – R2; (2) surround area, R1² – R2²; (3) area ratio, (R1²– R2²)/R2²; and (4) edge-distance expression l/R2 - l/R1, where R2 is the radius of the central test area and R1 is the outer radius of the surround. For each color combination, both graphical and correlational analyses demonstrated that contrast magnitude is more closely related to the edge-distance expression than to the other spatial expressions. This result provides support for an edge-distance model based on two assumptions: (1) that edges in the stimulus, and edge detectors in the visual system, are the important determinants of color and brightness; and (2) that edges closer to a point contribute more to the determination of the color and brightness at that point than do edges that are further away.

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Dichotic competition of simultaneous tone bursts of different frequencies: IV. Correlations with dichotic competition of speech signals.

Yund, E. W. & Efron, R. (1976)

Brain and Language 3: 246-254.

Presentation of dichotic chords to thirty subjects showed that 23% were right ear dominant, 40% were left ear dominant and 37% had no marked ear dominance. Presentation of dichotic consonant-vowel (CV) signals to the same subjects showed that 70% were right ear dominant and 30% were left ear dominant. Despite the fact that an ear dominance effect was present for both speech and non-speech sounds there was no significant correlation (either positive or negative) between an individual's performance on the two tasks. The performance of native speakers of tonal languages and of musicians was not significantly different from the experimental group of English speaking subjects. These results suggest that the two ear dominance effects are unrelated.

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Ear dominance and intensity independence in the perception of dichotic chords.

Efron, R. & Yund, E. W. (1976)

Journal of the Acoustical Society of America 59: 889-898.

The perceived pitch mixture of two tones of a dichotically presented chord was studied as a function of the difference between the intensities of the right- and left-ear tones (∆I). Previous experiments have shown that, within a wide range of ∆I, the pitch mixture is independent of ∆I. This intensity independence of the pitch mixture of dichotic chords is not seen with monaural chords. Within the range of ∆I over which intensity independence is seen, the pitch mixture of the dichotic chord is determined by another property of the central pitch processor—the ear dominance function. In previous experiments the intensity independent function could only be detected in those subjects with a weak ear dominance function. In the present experiments subjects adjusted the relative intensities of the two tones of a binaural chord to match the pitch mixture of a dichotic chord. Using this method, the intensity independent function was measured directly in all subjects. In addition, the present method provides a direct measure of the magnitude of the subject's ear dominance function and clarifies the relationship between the effects of the two functions.

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Responses of macaque lateral geniculate cells to luminance and color figures.

De Valois, R. L., Snodderly, D. M., Yund, E. W. & Hepler, N. K. (1977)

Sensory Processes 1: 244-259.

The spatial tuning of macaque lateral geniculate neurones was compared for luminance-based and color-based lines. Lines of various widths were flashed on and centered on the cell's rece