About the Memory Health Center

Our goal at the Memory Health Center at Summit Research is to expand scientific knowledge as it pertains to memory loss and brain health while maintaining the highest quality patient care. 

Summit Research is a medical research organization located in the greater Portland, Oregon area. Since 1976, we remain dedicated to improving medical treatment by conducting high quality scientific research and patient care.  We work in cooperation with pharmaceutical companies to develop better future treatments and better health for individuals with medical and mental health conditions.  Our expanded services include the Memory Health Center within Summit Research to focus on dementia and other age related memory conditions.

In 2021, Summit Research joined Headlands Research integrated network of clinical trials sites.


What kind of research is done at the Memory Health Center?

We perform research studies, also known as clinical trials, of approved and investigational medications. Some of these studies are undertaken to enhance our understanding of currently available medications (for example; determining optimal dose schedules). We also conduct research on medications that are not available to the general public except in research studies.

All medications available by prescription in the U.S. must go through this highly regulated, scientific process to evaluate whether an investigational medication can be approved and made available to all.   

Many of our studies involve comparisons between an investigational study medication, and a placebo (inactive substance). Placebo groups are included in some of our studies because the status of patients in the placebo group provides a comparison base for evaluating the effectiveness of active medications. Almost all of the studies at the Memory Health Center require a study partner to accompany the patients to visits. A study partner is usually a close friend or family member and is and a very important part of the research study team.  

Whether on a placebo or the investigational medication, all participants receive all research-related care, evaluations, and supervision by our professional and experienced staff. All of these services are provided at no cost to the patient and health insurance is not required for any study required visits or procedures. In addition, many of our clinical trials provide study participants with a stipend or compensation for time and travel.



James R. Hockley, M.B.A

With Summit Since 1984

Jim started with Summit Research (previously Pacific Northwest Clinical Research Center) in December, 1984. He helped navigate Summit’s growth over the years and helped open sites in multiple locations. He has primary responsibility for business development and the overall management of the business. In his spare time, Jim plays tennis, lifts weights and spends time with his family.


Scott Losk, PHD

Principal Investigator / Clinical Director
With Summit Since 1990

Dr. Losk is a clinical psychologist and neuropsychologist who has maintained a clinical and research practice with Summit Research in Portland, OR since 1990. He has been a principal investigator on over 60 clinical trials in Alzheimer’s disease and other dementias and has done research on all of the current FDA-approved drugs for Alzheimer’s disease. He has been a sub-investigator in over 125 clinical trials evaluating treatments of other central nervous system disorders (e.g., depression, anxiety disorders, ADHD, bipolar disorder, schizophrenia, migraine, fibromyalgia, etc.). Dr. Losk is active in the Alzheimer’s community providing talks and presentations to caregivers and other professionals.

Dr. Losk has extensive clinical and research experience in all aspects of cognitive disorders and because of his background, experience and contacts in the pharmaceutical industry he has access to all of the latest research studies in Alzheimer’s disease.

When he is not working, he enjoys spending time with his family, running, home and yard projects, the guitar, and his dogs.
Jim Bergthold, MD

Principal Investigator
With Summit Since 2001

James Bergthold, MD has been with Summit Research since 2001. He received a bachelor’s degree in biology in 1986 from Biola University and a medical degree from the Medical College of Wisconsin in 1992. Following his residency in Internal Medicine from Oregon Health Sciences University in 1995, he was a partner at HealthFirst Medical Group and later at Providence Medical Group. Dr. Bergthold’s special interests include geriatric medicine, cardiology and diabetes. He has been an investigator in well over 100 clinical trials. He has been a Principal Investigator in studies involving hypertension, diabetes, multiple sclerosis, chronic pain, obesity, Alzheimer’s dementia, Lewy Body Dementia, insomnia, and migraine headaches.
MaryAnn Conrad, MD

Principal Investigator
With Summit Since 2002

MaryAnn Conrad, MD, graduated from the University of Washington with a bachelor’s degree in psychology in 1987, and a medical degree in 1991. She is board certified in internal medicine and completed her internal medicine residency at the University of Hawaii in 1995. Before joining Summit Research in 2002, Dr. Conrad practiced as a primary care physician for Providence Medical Group and Kaiser Permanente. At Summit she enjoys focusing on clinical research, mental health and women’s health. When not taking care of patients at Summit, Dr. Conrad enjoys hanging out with her husband and cat, watching Blazer games, hiking, going to the Oregon coast, and photography.
Beal Essink, MD

Principal Investigator
With Summit since 2021

Beal Essink, MD, is the newest member of our Summit Research Investigator team. He hails from the Midwest, where he graduated with Distinction from the University of Nebraska Medical Center in 1996. He has been an Alpha Omega Alpha member since 1996 and completed the Psychiatry Residency Training Program at Oregon Health Sciences University in 2000. In residency, he served as a Chief Resident and was elected Psychiatry Resident of the Year in 2000. Since 2002, he has been a Diplomate of the American Board of Psychiatry and Neurology, and he won the Distinguished Services Award at OHSU in 2003.

Dr. Essink has psychiatric experience in both inpatient and outpatient settings, but his true passion has always been research. He has been conducting clinical research studies since 2003 and has been an Investigator for over 250 trials.

When Dr. Essink is not working, he enjoys rock climbing at the gym, hiking in the forest, watching football, and playing card and board games.


Mary Horton, RN, ANP

Sub-Investigator / Rater
With Summit Since 1998

Mary Horton graduated from Walla Walla School of Nursing and the Nurse Practitioner program at Kaiser Permanente. She is Board Certified by the ANCC, the certifying organization for Nurse Practitioners. She joined Summit Research in 1998 and has participated in over 100 clinical trials involving mental health, dementia, migraine & fibromyalgia and other medical issues. Prior to coming to SRN, she worked at Kaiser Permanente in primary care. In her free time she enjoys gardening, travel and playing with her grandchildren.
Carrie Crider, BS

Research Clinician / Rater
With Summit Since 2005

Carrie Crider, BS, received her bachelor's in Psychology at Portland State University. She has been a Research Clinician at Summit for since 2005. Carrie has clinical trial experience in studies focusing on depression, anxiety, bipolar disorder and Alzheimer’s disease. At Summit, Carrie has been a sub-investigator on over 60 studies. Prior to working at Summit, Carrie attended school at Queens College in New York and worked in a research and publishing capacity studying the effects of dementia on emotion under Dr. Joan Borod. Before this, Carrie worked at OHSU on a cognitive remediation program for children who were cancer survivors.
Barb Siaroff OTR/L

Research Clinician / Rater
With Summit:  1999-2006; 2019 to present

Barb Siaroff OTR/L graduated from Colorado State University in 1988 with a Bachelor of Science in Occupational Therapy. Barb has worked for the Memory Health Center at Summit Research since 1999 as a psychometrician on clinical drug studies for Alzheimer’s disease, MCI and other types of dementias. Work experience includes 10 years working on an inpatient rehabilitation unit, 3 years on an inpatient Geriatric Psychiatry unit, 17 years working at Providence Home Health.


Lisa Calmettes

Accounting Manager
With Summit Since 1994

Lisa began working with Summit Research Management, Inc (SRN) as a contractor in 1994, she owned a bookkeeping service for small business and SRN was a client. She became a fulltime employee with SRN in 1999. She manages the financial aspects of the business, as well as payroll and tracking our Human Resource services. In her free time, she loves traveling to warm destinations and spending time with her family, especially her grandkids.
Annika Truitt

Manager - Research Operations
With Summit Since 1994

Annika received her bachelor's degrees in biology and statistics from Washington State University in 1994. She was the senior recipient of the Herbert J. Eastlick Young Sciences award that year and completed an internship at Pacific Northwest Asthma and Allergy that got her “hooked” on research. Following graduation, Annika started working at Summit Research and has had the opportunity to provide oversight on over 150 trials in pediatric ADHD, Alzheimer’s and many other central nervous system and medical studies. In her free time, Annika enjoys running, spending time with family and cuddling with her Shiba Inu pups.
Kim Plank, BS, CCRC

Clinical Research Manager
With Summit Since 1996

Kim graduated from the University of Oregon with a bachelor’s degree in psychology. She started working with Summit Research in 1996. Her work started as a clinical research coordinator and evolved over the years to include various roles including regulatory compliance specialist, auditor, research coordinator manager and clinical research manager. Kim has had the opportunity to be the primary coordinator on over 125 clinical trials in central nervous system and medical studies. In 1999 she successfully passed the certification exam through the Association of Clinical Research Professionals making her a Certified Clinical Research Coordinator (CCRC). In her free time, Kim enjoys spending time with her family, going to Duck football games and traveling.


Rachel Wirth, BS, CCRC

Certified Clinical Research Coordinator
With Summit Since 2003

Rachel started at Summit Research as a coordinator assistant in 2003 and quickly moved into a primary study coordinator role. She received her certification through the Association of Clinical Research Professionals in 2007 making her a Certified Clinical Research Coordinator. She has experience coordinating in almost all of the areas Summit studies, but spends much of her time with the medical studies. When she is not working at Summit, she spends a lot of time cheering her talented daughter at gymnastic events and meets and enjoys travel as her schedule permits.
Amanda Feldman, BBA, CCRC

Certified Clinical Research Coordinator
With Summit Since 2007

Amanda started working with Summit Research in 2007. Her work started as one of two front desk coordinators. She completed her Bachelor of Business Administration degree in 2014 while transitioning into her current position as a clinical research coordinator. In 2017, she successfully passed the certification exam through the Association of Clinical Research Professionals making her a Certified Clinical Research Coordinator (CCRC). In her free time, Amanda likes to cuddle with her fur babies, spend time with her husband, and work on their fixer-upper.
Elizabeth Kelner, BS,CCRC

Certified Clinical Research Coordinator
With Summit Since 2015

Elizabeth started at Summit as a part-time coordinator and front desk employee in the winter of 2015. She transitioned to her role as a full-time coordinator in Jan. 2017 and has achieved certification as a Clinical Research Coordinator. She has specifically enjoyed her time involved with research in the field of Alzheimer’s disease / Dementia. As a northwest native, she enjoys weekends hiking in the rain and scrolling the stacks at Powell’s Books.
Alexa Voelker, BS

Clinical Research Coordinator
With Summit Since 2017

Lexi Voelker received a bachelor's degree in Biology with a minor in Chemistry from Southern Oregon University in 2017. While in college she focused her studies on medical and health sciences. After graduating she worked as a registrar at Providence Portland Medical Center before coming to Summit Research in 2018. Since joining the Summit team she has worked on a variety of studies including depression, anxiety and Alzheimer’s disease. Lexi enjoys spending time with friends and family, traveling, hiking, knitting, and sewing.

Linda Johnson, AAS

Assistant Clinical Research Coordinator
With Summit Since 2008

Linda started working at Summit Research in 2008. Her first position started as a Telephone Screener and evolved to an Assistant Clinical Research Coordinator. Prior to coming to Summit, Linda worked as a Senior Research Associate at the VA Medical Center in Portland, Oregon, Los Angeles, California and Milwaukee, Wisconsin. She has also worked as the Business Office Manager at Regency Park Assisted Living. Linda truly enjoys working with patients and also with the wonderful team at Summit Research.
Ally Yoshioka

Assistant Clinical Research Coordinator
With Summit Since 2020

Ally Yoshioka graduated in 2020 from Portland State University (PSU) with bachelor’s degrees in Public Health and General Science with minors in Psychology and Aging Services. At PSU, Ally was president of the American Medical Women’s Association during which she fortified a mentorship program at 5 local high schools. Prior experience also includes scribing in the Emergency Department at Providence from 2018 and volunteering at the OHSU oncology center from 2017. As a passionate community member, she is a member of the Association of American University Women to advocate for political causes and fundraise for women’s scholarships since 2018. Ally began at Summit Research in 2020 as a research coordinator assistant and underwent phlebotomy training as well. She is already an integral member of the team and looks forward to continued contributions at Summit.


Rachael Young, ST, MA

Lead Lab Technician
With Summit Since 2016

Rachael has been working with Summit since 2016. Her first position was as a recruitment specialist completing interviews with potential research participants. Since this first position, she has transitioned to coordinator assistant and is now putting her MA skills to even greater use as Summit’s lab lead. She has been a MA since 2004. Her current duties include patient procedures such as starting IV infusions, setting blood draw ports, drawing blood, ECG’s, vital signs and saliva testing. Processing and shipping samples per specific protocol requirements is also an important part of Rachael’s role. About Summit, Rachael says, “I love the work I get to do here at Summit, it is fast paced and ever changing. I find it challenging as well as very interesting. I am happy to be here on the front lines of medical research.”


Missy Bruinenberg

Contracts Coordinator
With Summit Since 2005

Missy joined the Summit team in April of 2005. She's been able to learn many different aspects of the business working in the administrative department. Most of Missy’s time is spent reviewing contracts and budget spreadsheets for new and ongoing studies. She is also responsible for entering contract and budget details into the site’s database to ensure accurate scheduling and accounting. Her role involves communicating with the front office, coordinating, accounting and administrative teams to ensure accuracy in contracts and budgets. In addition to contracts, Missy is a “team player” and takes on many different tasks when asked. She really enjoys what she does. This job challengers her daily, keeps her busy and she continues to learn new things! At home, Missy stays busy with her husband and son. They enjoy playing games, taking trips to the beach and working with the kids of their youth group.


Karen Wilson, RN, MA

Caregiver Support Group Facilitator / Community Outreach and Education
With Summit Since 1989

Karen received her Bachelor of Science in Nursing from OHSU (Formerly University of Oregon School of Nursing). She had 12 years of chronic pain rehabilitation experience prior to joining Summit Research. As a research clinician she has experience in clinical trials for conditions such as dementia, depression and anxiety. She received her Masters of Arts in Counseling from Western Seminary in 1997. As a member of the Memory Health Center team at Summit, she has participated in the National Memory Screening event sponsored by the Alzheimer’s Foundation of America for many years. She is the facilitator of our Caregiver Support Group, which is affiliated with the Alzheimer’s Association. She received training as a Certified Geriatric Wellness Instructor is actively involved in community outreach and education.

Leave a Reply