Fall Semester 2007

Information Processing in the Auditory Cortex

HCS-6335

Meeting time: Fridays 2-4:45pm Meeting location: GR4.208

Instructor: Dr. Michael P. Kilgard
Office: Green 4.504
Office hours: Mondays 3:00 -4:00 p.m.
Office phone: (972) 883-2339
E-mail address: kilgard@utdallas.edu

Course Description

    This course will review the basic principles of neural information processing with special emphasis on the central nervous system processes underlying hearing and speech perception.

    Lectures will provide students with the appropriate background for each topic, and discussions will explore classic and modern primary papers. Workload will consist of readings, class presentations, class participation, and weekly written critiques.

    This first aim of the course is to provide a complete and up-to-date understanding of the concepts involved in a well-defined aspect of brain function: information processing in the auditory cortex. The focused nature of this course will be a useful supplement to a general education of brain function based on surveys of many fields. Because the same principles of information processing are used throughout the brain the detailed description of auditory cortex function provided by this course will serve as a conceptual starting point for thinking about any brain function. An additional aim of this course is to relate the discussed concepts to clinically relevant issues. This course assumes only a general understanding of basic neuroscience principles and will be useful to students interested in neuroscience, communication disorders, cognitive science, developmental psychology, biology, computer science, or neural networks.

Material Discussed

Concepts:

• Topographic organization
• Temporal information processing
• Parallel and serial distributed processing
• Receptive fields and dynamic filtering
• Lateral inhibition
• Cortical dynamics
• Columnar and laminar cortical organization
• Convergence/Divergence
• Feedback and Re-entrant circuits
• Information bearing parameters
• Learning and plasticity
• Coding of speech stimuli

Techniques/Approaches:

• Neurophysiology
• Functional imaging (MEG, fMRI, PET)
• Neuroethology (echolocation and bird song)
• Development
• Behavioral effects of brain lesions
• Optical imaging
• Linear description
• Correlation analysis
• Stimulation/inactivation experiments
• Single cell physiology

Course Requirements

    All assigned readings must be completed before each class.

Critiques -- one-third of final grade.

    Each week you will need to type a concise, thoughtful critique of one of the papers for discussion. Support your conclusions using concrete evidence and quotations, not merely your opinion. The following outline is suggested: (1) Summarize in 1-2 sentences the key take-home message(s) of the paper. (2) Place the paper in context within the literature we have covered in class. What central problems does it address? How does it differ from other work we studied? How does it advance the field? (3) Critique the methods and conclusions. Are there any flaws in technique or logic? Are the experiments or conclusions believable? (4) Discuss the paper in terms of key concepts we have covered in class. (5) Suggest improvements or additional work. What important related questions does the paper leave open? Critique assignments should be about a page long and should be on the primary research papers not the review articles.

Individual class participation -- two-thirds of final grade (this will be highly quantitative).

• Raise questions about unfamiliar or interesting terms and concepts.
• Actively discuss readings, critiques, and scientific issues, in class.
• Discussion of papers and concepts with classmates outside of class is strongly encouraged.

Objectives
        On completion of this course, students should be able to:

• Pick up a primary research article related to auditory processing and understand the major new findings.
• Place new findings within the historical context of previous experiments.
• Critically evaluate the logic of experimental design.
• Effectively use library and internet resources to answer their own questions and expand on material presented in the introduction of the paper.
• Lead a coherent discussion of primary research articles.

Topics (and papers for discussion):

1. Introduction Sensory Cortex – 8/24

a. Chapter 30 of Kandell (Principles of Neural Science)

b. Chapter 1 of The Mammalian Auditory Pathway: Neurophysiology (printouts in lab)

c. Chapter 2 of Auditory Cortex: Structural and Functional Bases of Auditory Perception

d. Chapter 27 and 28 of Kandell (suggested)

2. Primary Auditory Cortex - 8/31

a. Merzenich 1975

b. Sally and Kelly 1988

c. Ehret G. The auditory cortex. J Comp Physiol. 1997 Dec;181(6):547-57

3. Auditory Cortex - 9/7

a. Sutter ML, et al  Physiology and topography of neurons with multipeaked tuning curves in cat primary auditory cortex.  J Neurophysiol. 1991 May;65(5):1207-26.

b. Spectral envelope coding in cat primary auditory cortex, 1: Eur J Neurosci. 1998;10(3):926-40.

c. Phillips DP Representation of acoustic events in the primary auditory cortex.  J Exp Psychol Hum Percept Perform. 1993 Feb;19(1):203-16

4. Temporal Processing and Forward Masking - 9/14

a. Distributed representation of spectral and temporal information in rat primary auditory cortex  Hear Res 1999 Aug;134(1-2):16-28 Kilgard MP, Merzenich MM

b. Brosch M, et al Time course of forward masking tuning curves in cat primary auditory cortex. J Neurophysiol. 1997 Feb;77(2):923-43.

c. He J, et al Temporal integration and duration tuning in the dorsal zone of cat auditory cortex.  J Neurosci. 1997 Apr 1;17(7):2615-25.

5. Non-Primary Auditory Fields - 9/21

a. Schreiner CE, et al Representation of amplitude modulation in the auditory cortex of the cat. II. Comparison between cortical fields. Hear Res. 1988 Jan;32(1):49-63.

b. Functional Specialization in Rhesus Monkey Auditory Cortex, Science. 2001 Apr 13;292(5515):290-3.

6. Sound Localization - 9/28

a. Jenkins WM, et al. Role of cat primary auditory cortex for sound-localization behavior.  J Neurophysiol. 1984 Nov;52(5):819-47.

b. Sound localization during homotopic and heterotopic bilateral cooling deactivation of primary and nonprimary auditory cortical areas in the cat, Malhotra S, Lomber SG., J Neurophysiol. 2007 Jan;97(1):26-43.

c. A Panoramic Code for Sound Location by Cortical Neurons

7. Information Bearing Parameters - Bat - 10/5

a. Suga N Biosonar and Neural Computation in Bats, Scientific American, June, 1990

b. Suga N Auditory Neuroethology and Speech Processing 1988 Chapter 23 of Auditory Function: Neurological Baes of Hearing

c. O'Neill WE, et al.  Encoding of target range and its representation in the auditory cortex of the mustached bat.      J Neurosci. 1982 Jan;2(1):17-31.

8. Neuroethology - 10/12

a. Yan J, et al. Corticofugal modulation of time-domain processing of biosonar information in bats.   Science. 1996 Aug 23;273(5278):1100-3.

b. Esser KH, et al. Syntax processing by auditory cortical neurons in the FM-FM area of the mustached bat Pteronotus parnellii. Proc Natl Acad Sci U S A. 1997 Dec 9;94(25):14019-24.

c. Schreiner CE. Spatial distribution of responses to simple and complex sounds in the primary auditory cortex. Audiol Neurootol. 1998 Mar-Jun;3(2-3):104-22. (optional)

d. Wang X, et al.  Representation of a species-specific vocalization in the primary auditory cortex of the common marmoset: temporal and spectral characteristics. J Neurophysiol. 1995 Dec;74(6):2685-706.

e. Phillips DP Sensory Representation, the auditory cortex, and speech perception, 1998 (optional)

9. Development and Lesion induced Plasticity - 10/19

a. Robertson D, Irvine DR. Plasticity of frequency organization in auditory cortex of guinea pigs with partial unilateral deafness. J Comp Neurol. 1989; 282:456-71.

b. Rainer Klinke, Andrej Kral, Silvia Heid, Jochen Tillein, Rainer Hartmann, Recruitment of the Auditory Cortex in Congenitally Deaf Cats by Long-Term Cochlear Electrostimulation, Science, 1999: 285(1729 – 1733)

c. Induction of visual orientation modules in auditory cortex, Sharma J, Angelucci A, Sur M. Nature. 2000; 404:841-7.

10. Adult Plasticity - 10/26

a. Recanzone GH, et al Plasticity in the frequency representation of primary auditory cortex following discrimination training in adult owl monkeys.  J Neurosci. 1993 Jan;13(1):87-103.

b. Robert C. Froemke*, Michael M. Merzenich & Christoph E. Schreiner Synaptic components of acetylcholine-induced cortical receptive field plasticity (unpublished manuscript)

c. Polley DB, Steinberg EE, Merzenich MM. Perceptual learning directs auditory cortical map reorganization through top-down influences. J Neurosci. 2006 May 3;26(18):4970-82.

d. Kilgard MP, Merzenich MM Cortical map reorganization enabled by nucleus basalis activity, Science. 1998 Mar 13;279(5357):1714-8. (optional)

e. Kaas JH Plasticity of Sensory Representation in the Auditory and Other Systems of Adult mammals, Chaper 17. (optional)

11. Coding - 11/9

a. Buonomano DV, et al Temporal information transformed into a spatial code by a neural network with realistic properties. Science. 1995 Feb 17;267(5200):1028-30.

b. Primary cortical representation of sounds by the coordination of action-potential timing. Nature 1996 Jun 13;381(6583):610-3 deCharms RC, Merzenich MM

12. Clinical implications - 11/16

a. Schreiner CE, et al Neuronal responses in cat primary auditory cortex to electrical cochlear stimulation. II. Repetition rate coding.   J Neurophysiol. 1996 Mar;75(3):1283-300.

b. Merzenich M, et al  Cortical plasticity underlying perceptual, motor, and cognitive skill development: implications for    neurorehabilitation. Cold Spring Harb Symp Quant Biol. 1996;61:1-8

c. Wakita M Recovery of function after neonatal ablation of the auditory cortex in rats. Behav Brain Res. 1996 Aug;78(2):201-9.

d. Tallal P Development and Disorders of Speech and Language:  Implications for neural and behavioral plasticity, 1995 (optional)

13. Student-selected topic discussion and course synthesis - 11/30