Core Contributors


Dr. Richards collaborates with several principal investigators and junior researchers from UCSF and the SFVA Stress and Health Research Program.  In addition to these ongoing collaborations, core scientific contributors to the Richards Lab pursuits are listed below.



Leslie Yack, B.S., RPSGT

Senior Sleep Technician

Ms. Yack is an expert polysomnography technician and the senior sleep technologist on the Richards team. She is critical in PSG visual scoring, data collection, data analysis, and study design in Richards Lab Projects.


Nikhilesh Natraj, PhD

Research Investigator

Dr. Nikhilesh Natraj is a bioengineer and neuroscientist, and is a former UCSF post-doc and current UCSF staff researcher. He collaborates with Dr. Richards to study the role of sleep in emotional information processing and the relevance of this role to PTSD.


Tom Metzler, PhD


Dr. Metzler is a seasoned biostatistician who has collaborated with Dr. Richards for over a decade, providing expert statistical support for Richards Lab projects.


Gunnar Mattson, MPH

Study Coordinator and Student Researcher

Gunnar graduated from Johns Hopkins University with a BS in Biomedical Engineering and then received an MPH with a concentration on Global Environmental Sustainability & Health from Johns Hopkins Bloomberg School of Public Health. He is a Research Coordinator for a study on interest in climate change and health among health professionals and trainees.


Induni Wickramasinghe, MS

Volunteer Research Assistant

Induni (Indy) Wickramasinghe received her Master of Science in Psychology from Palo Alto University in 2021 and is currently working towards her doctorate. Her clinical and research interests involve risk and resilience factors in PTSD, particularly in marginalized groups. She has completed clinical training in VA outpatient settings and is currently a clinical interviewer with the VASFHCS Stress and Health Research Program.