Michael Leon

Picture of Michael Leon
Professor Emeritus, Recalled, Neurobiology and Behavior
School of Biological Sciences
Ph.D., University of Chicago
Fax: (949) 824-2447
Email: mleon@uci.edu
University of California, Irvine
2205 McGaugh Hall
Mail Code: 4550
Irvine, CA 92697
Research Interests
Environmental Enrichment
Academic Distinctions
2007 Professor of the Year, UCI
2011 Medical Technology Acceleration Award, Jacobs School of Engineering, UCSD
2014 D.G. Marquis Award, American Psychological Association
Research Abstract
Autism spectrum disorder (ASD) is expressed as a social-behavioral imbalance that often involves communication difficulties, maladaptive behaviors, cognitive dysfunction, anxiety, motor (movement) problems, seizures, and gastrointestinal distress. Commonly, individuals with ASD experience some form of atypical sensory responsiveness, including sensory over-sensitivity, sensory unresponsiveness, or sensory-seeking behaviors.

In animal models of autism, increases in both sensory stimulation and motor activity have been shown to result in many benefits, including improvements in learning and memory, reduction in aggressive behavior, decreased anxiety, and reduction of repetitive behaviors.

We have translated this approach to humans, and we have been studying the benefits of increased sensory-motor activity in children with ASD. In a clinical trial, we examined the effects of sensory-motor enrichment in children with ASD, age 3-12, and found that 42% of the children receiving the sensory-motor enrichment had a clinically significant improvement on the Childhood Autism Rating Scale (CARS). In addition, statistically significant improvements in cognition were observed in the sensory-motor enrichment group compared to the control group. Finally, 69% of parents in the sensory-motor enrichment group and 31% of parents in the control group reported improvement in their child over the 6-month study (2015).

In a second randomized clinical trial, Sensory Enrichment Therapy was again used to treat 3-6 year-old children with classic autism, Woo, Donnelly, Steinberg-Epstein & Leon (2015) again found significant improvements in the cognitive scores of enriched children using the Leiter-R, with enriched children gaining 8.42 IQ points, while the standard-care group gained 1.53 IQ points over 6 months, a statistically significant difference. A significant improvement for the enriched children was also found in receptive language, using the Reynell Developmental Language Scales, another objective test of symptom improvement. Enriched children gained 7.42 points on the receptive language scale, whereas the standard-care group had an average increase of 3.63 points on that assessment.
Leon, M. and Woo, C.C. (2018). Environmental enrichment and successful aging. Frontiers in Neurobiology and Behavior, 12, 155.
Aronoff, E., Hillyer, R., & Leon, M. (2016). Environmental Enrichment Therapy for Autism: Outcomes with Increased Access. Neural Plasticity, 2016, 2734915.
Woo, C.C., Donnelly, J.H., Steinberg-Epstein, R., & Leon, M. (2015). Environmental enrichment as a therapy for autism: A clinical trial replication and extension. Behavioral Neuroscience, 129, 412-422.
Woo, C.C. and Leon, M. Environmental enrichment as an effective treatment for autism: A randomized controlled trial. Behavioral Neuroscience, 2013, published online.
Johnson, B.A., Ong, J., and Leon, M. Glomerular activity patterns evoked by natural odor objects in the rat olfactory bulb are related to patterns evoked by major odorant components. Journal of Comparative Neurology, 2010, 518, 1542–1555.
Leon, M. and Johnson, B.A. Is there a space-time continuum in olfaction? Cellular and Molecular Life Sciences, 2009, 66, 2135-2150.
Johnson, B.A., and Leon, M. Glomerular map. Encyclopedia of Neuroscience. (Binder, M.D., Hirokawa, N., and Windhorst, U., Eds.) Springer-Verlag, Berlin Heidelberg, 2009, 1745-1748.
Johnson, B.A., Xu, Z., Ali, S.S., and Leon, M. Spatial representations of odorants in olfactory bulbs of rats and mice: Similarities and differences in chemotopic organization. Journal of Comparative Neurology, 2009, 514, 658-673.
Cleland, T., Johnson, B.A., Leon, M., and Linster, C. Relational representation in the olfactory system. Proceedings of the National Academy of Sciences, U.S.A. 2007, 104, 1953-1958
Johnson, B.A., Woo, C., Zeng, Y., Hingco, E.E., Ong, J., and Leon, M. Prolonged stimulus exposure reveals prolonged neurobehavioral response patterns. Journal of Comparative Neurology, 2010, 518, 1617-1629.
Professional Societies
Graduate Programs
Neurobiology and Behavior
Research Centers
Center for Neurobiology of Learning and Memory
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