Bradley D. Hatfield , Ph.D.

Professor

Sport Psychology

Books:

Iso-Ahola, S.E., & Hatfield, B. (1986).
Psychology of Sports: A Social Psychological Perspective. Dubuque, Iowa: William C. Brown Co. (original edition).

Refereed Journals:

Note: Manuscripts in preparation not listed.

Hatfield, B.D. (Invited paper).
Neuroimaging studies of exercise and the aging brain. International Journal of Sport Psychology.

McAllister, L.D., & Hatfield, B.D. (Submitted).
Attentional processes and psychomotor expertise: An event-related potential study. International Journal of Psychophysiology.

Spalding, T.W., Lyon, L.A., Steel, D.H., & Hatfield, B.D. (In press).
Aerobic exercise training and cardiovascular reactivity to psychological stress in young normotensive men and women. Psychophysiology.

Hung T.M., Santa Maria, D.L., Spalding, T.W., & Hatfield, B.D. (In press).
Attentional flexibility and motor preparedness for reactive psychomotor performance: An electrophysiological study of high-level table tennis players. Journal of Sport and Exercise Psychology.

Hatfield, B.D., Haufler, A.J., Hung, T.M., & Spalding, T.W. (Invited paper in press).
Electroencephalographic (EEG) studies of skilled psychomotor performance. Journal of clinical Neurophysiology.

Kerick, S.E., Douglass, L.W., & Hatfield, B.D. (2004).
Cerebral cortical adaptations associated with visuomotor practice. Medicine and Science in Sports and Exercise. 36, 118-129.

Spalding, T.W., Schleifer, L.M., Hatfield, B.D., Kerick, S., & Cram, J.R. (2003).
Removing the influence of the heart from surface-recorded EMG. Biofeedback. 31, 6-10.

Hatfield, B.D., Spalding, T.W., Haufler, A.J., SantaMaria, D.L., & Apparies, R.J. (2003).
The relationship of physical activity history of pattern reversal evoked potential components in young and older men and women. Journal of Aging and Physical Activity. 11, 167-188.

McDowell, K., Kerick, S.E., Santa Maria, D.L., & Hatfield, B.D. (2003).
Aging, physical activity, and cognitive processing: an examination of P300. Neurobiology of Aging. 24, 597-606.

Deeny, S.P., Hillman, C.H., Janelle, C.M., & Hatfield, B.D. (2003).
Cortico-cortical communication and superior performance in skilled marksmen: An EEG coherence analysis. Journal of Sport and Exercise Psychology. 25, 188-204.

McDowell, K., Jeka, J.J., Schoner, G., & Hatfield, B.D. (2002).
Behavioral and electrocortical evidence of an interaction between probability and task metrics in movement preparation. Experimental Brain Research. 144, 303-313.

Hillman, C.H., Weiss, E.P., Hagberg, J.M., & Hatfield, B.D. (2002).
The relationship of age and cardiovascular fitness to cognitive and motor processes. Psychophysiology. 39, 301-312.

Haufler, A.J., Spalding, T.W., SantaMaria, D.L., & Hatfield, B.D. (2002).
Neuro-cognitive activity during a self-paced visuospatial task: comparative EEG profiles in marksmen and novice shooters. Biological Psychology. 59(1), 87-88.

Kerick, S.E., McDowell, K., Hung, T.M., Santa Maria, D.L., Spalding, T.W., & Hatfield, B.D. (2001)
The role of the left temporal region under the cognitive motor demands of shooting in skilled marksmen. Biological Psychology. 58(3), 263-277.

Bixby, W.R., Spalding, T.W., & Hatfield, B.D. (2001)
Temporal dynamics and dimensional specificity of the affective response to exercise of varying intensity: Differing pathways to a common outcome. Journal of Sport and Exercise Psychology. 23, 171-190.

Haufler, A.J., Spalding, T.W., SantaMaria, D.L., & Hatfield, B.D. (2000).
Neuro-cognitive activity during a self-paced visuospatial task: comparative EEG profiles in marksmen and novice shooters. Biological Psychology. 53(2-3), 131-160.

Janelle, C.M., Hillman, C.H., Apparies, R.J., Murray, N.P., Meili, L., Fallon, E.A., & Hatfield, B.D. (2000).
Expertise differences inn cortical activation and gaze behavior during rifle shooting. Journal of Sport and Exercise Psychology, 22 (2), 167-182.

Janelle, C.M., Hillman, C.H., Apparies, R.J., & Hatfield, B.D. (2000).
Concurrent measurement of electroencephalographic and ocular indices of visual attention during rifle shooting: An exploratory case study. International Journal of Sports Vision. 6, 21-29.

Hillman, C.H, Apparies, R.J., & Hatfield, B.D. (2000).
Motor and non-motor event-related potentials during a complex processing task. Psychophysiology. 37(6), 731-736.

Brody, E.B., Hatfield, B.D., Spalding, T.W., Frazer, M.B., & Caherty, F.J. (2000).
The effect of a psyching strategy on neuromuscular activation and force production in strength-trained men. Research Quarterly for Exercise and Sport, 71 (2), 162-170.

Kerick, S.E., Iso-Ahola, S.E., & Hatfield, B.D. (2000).
Psychological momentum in target shooting: Cortical, cognitive-affective and behavioral responses. Journal of Sport and Exercise Psychology, 22, 1-20.

Hillman, C.H., Apparies, R.J., Janelle, C.M., & Hatfield, B.D. (2000).
An electrocortical comparison of executed and rejected shots in skilled marksmen. Biological Psychology, 52, 71-83.

Spalding, T.W., Jeffers, L.S., Porges, S.W., & Hatfield, B.D. (2000).
Vagal and cardiac reactivity to psychological stressors in trained and untrained men. Medicine and Science in Sports and Exercise, 32, 581-591.

Bond, V.Jr., Vaccaro, P., Caprarola, M., Mills, R.M., Blakely, R., Wood. R., Roltsch, M., Fairfax, J., Franks, D., Williams, D., Davis, G., & Adams, R.G. (2000).
Blood pressure reactivity to mental stress and aerobic fitness in normotensive young African-American males with parental history of hypertension. Stress Medicine. 16, 219-227.

Bond, V.Jr., Mills, R.M., Caprarola, M., Vaccaro, P., Adams, G., Blakely, R., Roltsch, M., Hatfield, B., Davis, G.C., Franks, B.D., Fairfax, J., & Banks, M. (1999).
Aerobic exercise attenuates blood pressure reactivity to cold pressor test in normotensive, young adult, African-American women. Ethnicity and Disease, 9, 104-110.

Hatfield, B.D., Spalding, T.W., Santa Maria, D.L., Porges, S.W., Potts, J.T., Byrne, E.A., Brody, E.B., & Mahon, A.D. (1998).
Respiratory sinus arrhythmia during exercise in aerobically trained and untrained men. Medicine and Science in Sports and Exercise, 30, 206-214.

Lawton, G.W., Hung, T.M., Saarela, P., & Hatfield, B.D. (1998).
Electroencephalography and mental states associated with elite performance. Journal of Sport and Exercise Psychology, 20, 35-53.

Hatfield, B.D., Spalding, T.W., Mahan, A.D., Slater, B.A., Brody, E.B., & Vaccaro, P. (1992).
The effect of psychological strategies upon cardiorespiratory and muscular activity during treadmill running. Medicine and Science in Sports and Exercise, 24(2), 218-225.

Goldfarb, A.H., Hatfield, B.D., Potts, J. & Armstrong, D. (1991).
Beta-endorphin time-course response to intensity of exercise: Effects of training status. International Journal of Sports Medicine, 12(3), 264-268.

Petruzzello, S.J. Landers, D.M., Hatfield, B.D., Kubitz, K. & Salazar, W. (1991).
A meta-analysis on the anxiety-reducing effects of acute and chronic exercise: Outcomes and mechanisms. Sports Medicine, 11(3), 143-182.

Goldfarb, A.H., Hatfield, B.D., Armstrong, D., & Potts, J. (1990).
Plasma beta-endorphin levels in response to intensity and duration of exercise. Medicine and Science in Sports and Exercise, 22(2), 241-244.

Brody, E.B., Hatfield, B.D., & Spalding, T.W. (1988).
Generalization of self-efficacy to a continuum of stressors upon mastery of a high-risk sport skill. Journal of Sport and Exercise Psychology, 10 (1), 32-44.

Hatfield, B.D., & Landers, D.M. (1987).
Psychophysiology in exercise and sport research: An overview. Exercise and Sport Sciences Reviews, 15, 351-388.

Hatfield, B.D., Landers, D.M., & Ray, W.J. (1987).
Cardiovascular-CNS interactions during a self-paced, intentional attentive state: Elite marksmanship performance. Psychophysiology, 24, 542-549.

Hatfield, B.D., Goldfarb, A.H., Sforzo, G.A., & Flynn, M.G. (1987).
Serum Beta-endorphin and affective responses to graded exercise in young and elderly men. Journal of Gerontology, 42, 429-431.

Goldfarb, A.H., Hatfield, B.D., Sforzo, G.A., & Flynn, M.G. (1987).
Serum B-endorphin levels during a graded exercise test to exhaustion. Medicine and Science in Sports and Exercise, 19, 78-82.

Hatfield, B.D., & Walford, G.A. (1987).
Understanding anxiety: implications for sport performance. National Strength and Conditioning Association Journal, 9(2), 58-65.

Hatfield, B.D., Wrenn, J.P., & Bretting, M.M. (1987).
Comparison of job responsibilities of intercollegiate athletic directors and professional sport general managers. Journal of Sport Management, 1, 129-145.

Moore, T.J., SantaMaria, D.L., Hatfield, B.D., Ryder, M.N., & Weiner, L.B. (1986).
The mandibular orthopedic repositioning appliance and its effect on power production in conditioned athletes. The Physician and Sports Medicine, 14(12), 137-145.

Hatfield, B.D., Vaccaro, P., & Benedict, G.J., (1985).
Self-concept responses of children to participation in an eight-week precision jump-rope program. Perceptual and Motor Skills, 61, 1275-1279.

Benedict, G., Vaccaro, P., & Hatfield, B.D. (1985).
Physiological effects of an eight week precision jump rope program in children. American Corrective Therapy Journal, 39, 108-111.

Hatfield, B.D., Landers, D.M., & Ray, W.J. (1984).
Cognitive processes during self- paced motor performance: An electroencephalographic profile of skilled marksmen. Journal of Sport Psychology, 6, 42-59.

Hatfield, B.D. & Landers, D. M. (1983).
Psychophysiology - A new direction for sport psychology. Journal of Sport Psychology, 5, 243-259.

Landers, D.M., Wilkinson, M.O., Hatfield, B.D., & Barber, H. (1982).
Causality and the cohesion-performance relationship. Journal of Sport Psychology, 4, 170-183.

Hatfield, B.D., Landers, D.M., Ray, W.J., & Daniels, F.S. (February 1982).
An electroencephalographic study of elite rifle shooters. The American Marksman, 7, 6-8.

Hatfield, B., & Daniels, F.S. (1981).
The use of hypnosis as a stress management technique. Motor Skills: Theory Into Practice, 5, 62-68.

Daniels, F.S., & Hatfield, B. (1981).
Biofeedback. Motor Skills: Theory Into Practice, 6, 69-72.

Landers, D.M. Christina, R.W., Hatfield, B.D., Daniels, F.S., Wilkinson, M.O., & Doyle, L.A. (1980).
Moving competitive shooting into the scientist's lab. The American Rifleman, 128(4), 36-27, 76-77.

Hatfield, B.D., & Landers, D.M. (1978).
Observer expectancy effects upon appraisal of gross motor performance. Research Quarterly, 49, 53-61.

Chapters in Edited Books and Proceedings:

Hatfield, B.D. (Invited Chapter).
The psychology of superior sport performance: A cognitive neuroscience perspective.

Hatfield, B.D., & Kaplan, P. (2004, in press).
Exercise psychology. In T. Baechle & R. Earle (Eds.), Essentials of Personal Training. Champaign, IL: Human Kinetics Publishers.

Hatfield, B.D. & Hillman, C.H. (2001).
The psychophysiology of sport: A mechanistic understanding of the psychology of superior performance. In R.N. Singer, H. Hausenblas, & C. Janelle (Eds.), Handbook of Sport Psychology (2nd Ed.), New York: John Wiley & Sons, pp.362-388.

Hatfield, B.D., & Brody, E.B. (2000).
The psychology of athletic preparation and performance: The mental management of physical resources. In T. Baechle (Ed.), Essentials of Strength Training Principles. Champaign, IL: Human Kinetics Publishers (Second edition), pp. 187-208.

Hatfield, B.D., & Brody, E.B. (1994).
The psychology of athletic preparation and performance: The mental management of physical resources. In T. Baechle (Ed.), Essentials of Strength Training Principles. Champaign, IL: Human Kinetics Publishers (pp 163-187).

Hatfield, B.D. (1991).
Exercise and mental health: The mechanisms of exercise-induced psychological states. In L. Diamant (Ed.) Psychology of Sports, Exercise and Fitness. Washington, D.C.: Hemisphere Publishing Co. (pp. 17-50).

Hatfield, B.D., & Sullivan, K.T. (1987).
The business of sport and the athlete. In J.R. May and M.J. Asken (Eds.), Sport Psychology: The Psychological Health of the Athlete. Great Neck, New York: PMA Publishing Corporation, pp. 231-253.

Ingram, A., Hatfield, B., & Vaccaro, P. (1986).
Sport survey of participation attitudes reported by sex. Physical Education, Recreation and Sport: Lifelong Participation Proceedings of the International Association of Physical Education and Sport for Girls & Women, Tenth Congress, Oxford, England: Joshua Associates Limited, pp. 243-256.

Hatfield, B.D. (1984).
Psychological knowledge and its emerging role in the physical education curriculum. Proceedings of the National Association for Physical Education in Higher Education, Champaign, Illinois: Human Kinetics Publishers, pp. 60-68.

Book Reviews, Other Articles, and notes:

Hatfield, B., (1986).
The measurement of cohesion in team sports: The group environment questionnaire by Widmeyer, W.N., Brawley, L.R. and Carron, A.V., Research Quarterly for Exercise and Sport, 57, 347-349.

Hatfield,B.D. (1986).
Sporting body, sporting mind, by Syer, J. and Connolly, C., Journal of Sport Psychology, 8, 250-251.

Hatfield, B.D. (1990).
Advances in pediatric sport sciences (vol 2). Behavioral issues, by Gould, D. and Weiss, M., Pediatric Exercise Science, 2, 83-84.

Haufler, A.J., Hatfield,B.D., & SantaMaria, D.L. (1997).
The psychology of expert performance: Comparative brain activation profiles in marksmen and novice shooters. (Technical report submitted October, 1997 to the Research and Advanced Concepts Offic, Army Research Institute for the Behavioral and Social Sciences).

Daniels, F.S., Landers, D.M., Silkinson, M.O., & Hatfield, B.D.
Heart rate and its effect on performance. (Available from D.M. Landers, PEBW, Arizona State University, Tempe, AZ 85287.)

Landers, D.M., Hatfield, B.D., McGovern, L., & Tooman, M.E.
EEG patterning among women basketball players. (Available from D.M. Landers, PEBW, Arizona State University, Tempe, AZ 85287.)

Published Abstracts:


Hillman, C.,Weiss, E.,Deeny, J., Hagberg, J., & Hatfield, B. (2000).
Physical fitness and neuro-cognitive processes in older adults. Journal of Sport and Exercise Psychology, 22 (supplement), S51.

Kerick, S.E., Haufler, A.J., & Hatfield, B.D. (2000).
The psychology of superior performance: An electroencephalographic (EEG) comparison between skilled and novice target shooters. Journal of Sport and Exercise Psychology, 22 (supplement), S57.

Hillman C.H., Weiss, E.P., Deeny, S.P., Zooker, C.C., Roltsch, M.H., Hagberg, J.M., & Hatfield, B.D. (2000).
Age and fitness effects on ERPs: Implications for exercise on the aging brain. Medicine and Science in Sports and Exercise, 32(5) (supplement), S43.

Spalding, T.W., Lyons, L.A., & Hatfield, BD (2000).
Effect of aerobic exercise training on cardiovascular reactivity to psychological stressors. Medicine and Science in Sports and Exercise, 32(5) (supplement), S294.

Bixby, W.R., Spalding, T.W., & Hatfield, BD (2000).
The temporal dynamics of affect during and following exercise. Medicine and Science in Sports and Exercise, 32(5) (supplement), S301.

Petruzzello, S.J., Hatfield, BD, Boutcher, S.H., & Cacioppo, J.T. (2000).
Mind-body perspectives on exercise and mental health. Medicine and Science in Sports and Exercise, 32(5) (supplement), S343.

Bixby, W.R., Hatfield, B., & Spalding, T.W. (1999).
Temporal dynamics of hemispheric asymmetry and affect associated with an acute bout of aerobic exercise. Medicine and Science in Sports and Exercise, 31(5) (supplement), S173.

Bond, B., Vaccaro, P., Adams, R., Caporarola, M., Roltsch, M., Hatfield, B., Blakely, R., Fairfax, J., & Franks, BD (1999).
Aerobic fitness level and family history of hypertension influence blood pressure reactivity to mental stress in African Americans. Medicine and Science in Sports and Exercise, 31(5) (supplement), S216.

Spalding, T.W., Jeffers, L.S., Porges, S.W., & Hatfield, BD (1999).
Respiratory sinus arrhythmia during psychological stress and recovery in aerobically trained and untrained young men. Medicine and Science in Sports and Exercise, 31(5) (supplement), S289.

McDowell, K.,Hatfield, BD, & Jeka, J.J. (1999).
Motor area activation for a two-choice directional movement task. Journal of Cognitive Neuroscience, (supplement - annual meeting program), p. 87

Kerick, S.E., Iso-Ahola, SE, and Hatfield, BD, & Gruber, K. (1998).
Psychological momentum in target shooting: Behavioral, affective, and brain responses. Journal of Applied Sport Psychology, 10(supplement), S136.

Apparies, R.J., Hillman, C.H., & Hatfield, BD (1998).
Slow potentials and P300 in motor and nonmotor processing during cognitive challenge. Psychophysiology, 35, (S1), S17.

Haufler, A.J., Hatfield, BD, & SantaMaria, D.L. (1998).
Brain activation profiles of marksmen and novices: an examination of a model of psychomotor performance. Medicine and Science in Sports & Exercise, 30(5) (supplement), S119.

Apparies, R., Hatfield, B., & SantaMaria, L. (1998).
The effect of fitness on pattern reversal visual evoked potential in the elderly. Medicine and Science in Sports & Exercise, 30(5) (supplement), S128.

Haufler, A., Hatfield, B., & SantaMaria, D.L. (1997).
The cognitive correlates of skilled performance in marksmen: An examination of brain activation profiles. Psychophysiology, 34(1) (supplement), S42.

Snyder-Bauer, R., Hatfield, B., Haufler, A., Lockwood, P., & Hung, T. (1997).
Effect of exercise-induced hypoglycemia on CNS activation in elite cyclists. Medicine and Science in Sports and Exercise, 29(5) (supplement), S223.

Hatfield, B. (1997).
Toward dynamic models of exercise and sport behavior: The convergence of sport psychology and cognitive neuroscience. Journal of Sport and Exercise Psychology, 19 (supplement), S13.

Hatfield, B., & SantaMaria, D. (1997).
Extending our understanding of exercise induced psychological change: The contribution of neuroscience. Journal of Sport and Exercise Psychology, 19 (supplement), S14.

Apparies, R., Hatfield, B., SantaMaria, L., & Spalding, T. (1997).
Cortical and autonomic measures of attentional challenge. Journal of Sport and Exercise Psychology, 19 (supplement), S26.

Hung, T., Hatfield, B., & SantaMaria, D. (1997).
Are fast-action sport athletes characterized by greater attentional flexibility and motor preparedness? An electrophysiological study of table tennis players. Journal of Sport and Exercise Psychology, 19 (supplement), S68.

Hung, T., Hatfield, B., & SantaMaria, D. (1997).
Understanding attention in fast-action sports athletes: Behavioral and brain processes. Journal of Sport and Exercise Psychology, 19 (supplement), S25.

Hatfield, B., SantaMaria, D., Spalding, T., Blanchard, C., Haufler, A., Hung, T., Kerick, S., Lockwood, P., McAllister, L., Saarela, P., Apparies, R., Lanter, J., & McDowell, K. (1996).
The association of age and aerobic activity history with 40-Hz EEG activity during cognitive challenge. Psychophysiology, 33 (supplement 1), S44.

Apparies, R., Hatfield, B., SantaMaria, L., & Spalding, T., (1996).
The role of stimulus- preceding negativity and heart rate deceleration as an index of attention. Psychophysiology, 33 (supplement 1), S20.

Haufler, A., Hatfield, B., SantaMaria, D.L., Blanchard, C., Hung, T., Lockwood, P., McAllister, L., Saarela, P., & Apparies, R. (1996).
Is cardiovascular activity history associated with math and spatial cognitive processing in younger and older adults?: An examination of the efficiency hypothesis. Journal of Sport and Exercise Psychology, 18 (supplement), S33.

Bond, V., Vaccaro, P., Hatfield, B., Caprarola, M., Fairfax, J., Franks, BD, Curry, C., Harrell, J., Roltsch, M., Gills, S., & Mendez, T. (1996).
Cardiovascular fitness is not related to cardiovascular reactivity in African Americans. Medicine and Science in Sports and Exercise, 28 (supplement), S174.

Hatfield, B., Santa Maria, D.L., Spalding, T., Blanchard, C., Donofrio, D., Haufler, A., Hung, T., Lockwood, P., McAllister, L., Saarela, P., Slater, B., Apparies, R., & Drazin, H. (1995).
Does cardiovascular activity history impact upon cognitive processing in older people? Psychophysiology, 32 (supplement 1), S39.

SantaMaria, D.L., Hatfield, BD, & Slater, B.A. (1993).
Relationship of aerobic training status to central nervous system function in older males. Research Quarterly for Exercise and Sport, 64(1) (supplement), A104.

Slater, BA, Hatfield, BD, & SantaMaria, D.L. (1992).
Aerobic training relates to increased inhibitory function of the central nervous system of older males. Psychophysiology, 29(4a) (supplement), 65.

Slater, BA, Hatfield, BD, SantaMaria, D.L., Krotz, AJ., & Blesy-Krohn, C. (1992).
The relationship of aerobic training status to cortical coupling of EEG in older males. Medicine and Science in Sports and Exercise, 24(5) (supplement), 24.

SantaMaria, D.L., Hatfield, BD, Slater, BA, Krotz, A.J., & Blesy-Krohn, C. (1992).
The relationship of aerobic training status to motor, sensory, and cognitive tasks for older males. Males and Science in Sports and Exercise, 24 (5) (supplement), 24.

Morales, J.O. Santa Maria, D.L., & Hatfield, BD (1992).
The comparative effect of a combined velocity and a traditional resistive training program on muscular power. Sports Medicine,.Training and Rehabilitation, 3, 223.

Brody, E.B., Slater, BA, Hatfield, BD, & SantaMaria, D.L. (1991).
The effects of varying cognitive states upon biceps and triceps brachii EMG activity and force during elbow flexion. Psychophysiology, 28(3) (supplement), S13.

Abstracts submitted in 2003:

Spalding, T.W., Lyon, L.a., & Hatfield, B.D.
Relative Efficacy of Aerobic exercise Traiing and Cognitive-Behavioral Stress Management Education on Cardiovascular Reactivity to Psychological Stressors. Paper to be presented at the annual meeting of the American College of Sports Medicine. Indiannapolis, IN, May 28-June 1, 2004.

Zimmerman, J., Stover, H., Wallace, B., Deeny, S., Goodman, R., Pangelinan, M., Haufler, A., & Hatfield, B.D.
Effects of a low intensity short duration activity intervention on cognitive function in older adults. Paper to be presented at the annual meeting of the American College of Sports Medicine. Indiannapolis, IN, May 28-June 1, 2004.

Goodman, R., Price, R., Zimmerman, J., Stover, H., Deeny, S., Wallace, B., Bixby, W., Haufler, A., & Hatfield, B.D.
Attenuation of frontal lobe decline with physical activity: a neuroimaging study. Paper to be presented at the annual meeting of the North American Society for the Psychology of Sport and Physical Activity. Vancouver, CANADA, June, 2004.

Zimmerman, J., Stover, H., Deeny, S., Wallace, B., Price, R., Bixby, W., Haufler, A., & Hatfield, B.D.
Relationship of physical activity with neurocognitive functioning during an executive function task in older men and women. Paper to be presented at the annual meeting of the North American Society for the Psychology of Sport and Physical Activity. Vancouver, CANADA, June, 2004.

Other:

Haufler, A.J., Hatfield, B.D., & SantaMaria, D.L. (Submitted).
The psychology of expert performance: Comparative brain activation profiles in marksmen and novice shooters. (Technical report submitted October, 1997 to the Research and Advanced Concepts Office, Army Research Institute for the Behavioral and Social Sciences).