Mary Ellen Hayden

Mary Ellen Hayden, Ph.D., ABPP (Retired)

Dr. Hayden founded Pate Rehabilitation over thirty years ago. For many years Dr. Hayden led Pate’s research initiatives and clinical direction. Her research in improving skills transfer from the clinical setting to the real world led to her creation of an innovative clinical tool called the PERPOS (Pate Environmentally Relevant Outcome System). 

Dr. Hayden’s insight that the rehabilitation setting itself influenced outcomes led her to identify two key environmental factors that could be modified to increase rehabilitation success. These are distractions and structure.

The PERPOS provides a way to measure a given environment and each patient’s unique tolerances for structure and distraction. The PERPOS guides Pate therapists in modifying the clinical environment over time to increase distractions and lessen structure. Throughout rehabilitation, PERPOS tracks the patient’s improvements and provides essential insight, leading to better skills transfer and eventual outcomes.

Building patient tolerances for high distraction/low structure environments positively affects outcomes. PERPOS allows Pate therapists to fit the setting to the patient, rather than fitting the patient into the setting.

PERPOS was validated in the peer reviewed journal Neurorehabilitation in 2017.  The PERPOS is a significant contribution to brain injury research that can be used in any rehabilitation setting across the country and across the world.




Post-doctoral: University of Texas Health Science Center (1979) 

Training: University of Houston (1976)





Hayden, M.E., Plenger, P., Bison, K., Kowalske, K., Masel, B., & Qualls, D. (2013, April). Treatment Effect Versus Pretreatment Recovery in Persons With Traumatic Brain Injury: A Study Regarding the Effectiveness of Post acute Rehabilitation. PM&R, 5.(4):319-27.


Hayden, M.E., Moreault, A.M., LeBlanc, J., & Plenger, P. (2000). Reducing Level of Handicap in Traumatic Brain Injury:  an Environmentally Based Model of Treatment. Journal of Head Trauma Rehabilitation.15(4), 1000-1021.


Kowalske, K., Plenger, P., Lusby, B., & Hayden, M.E. (2000). Vocational Reentry Following TBI: an Enablement Model. Journal of Head Trauma Rehabilitation, 15(4), 989-999.


LeBlanc, J., Hayden, M.E. (2000).  Issue editors for special issue on Ecological Validity in Traumatic Brain Injury. Journal of Head Trauma Rehabilitation. 15(4).


LeBlanc, J. M., Hayden, M.E., &  Paulman, R.G. A Comparison of Neuropsychological and Situational Assessment for Predicting Employability After Closed Head Injury. Journal of Head Trauma Rehabilitation. 15(4), 1022-1040. (2000)


Hayden, M.E. Mild Traumatic Brain Injury: A Primer for Understanding its Impact on Employee Return to Work. AAOHN Journal. 45(12), 635-645. (1997)





Marquez de la Plata, C., Morgan, L., Hayden, M.E., Qualls, D., & Plenger, P. Psychometric Properties of an Ecologically Relevant PABIR Outcome Measure. Oral presentation at the Santa Clara Valley Brain Injury Conference, (2015)


Marquez de la Plata, C., Bison, K., Hayden, M.E., & Qualls, D., & Plenger, P. Timeliness of PABIR Impacts Functional Outcome After TBI. , Brain Injury Summit,  (2015)