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Unit on Computational Decision Neuroscience (CDN)

Meet the Team

Silvia Lopez-Guzman, M.D., Ph.D.| Principal Investigator

Silvia Lopez-Guzman headshot

Dr. Lopez-Guzman received her M.D. from Pontificia Universidad Javeriana in Bogotá, Colombia and completed her Ph.D. in Neuroscience at New York University’s Center for Neural Science. She joined NIMH as Chief of the Unit on Computational Decision Neuroscience and became a NIH Distinguished Scholar in 2021. Dr. Lopez-Guzman also holds a joint appointment with the National Institute on Drug Abuse (NIDA), where she is part of the Translational Addiction Medicine Branch.

Mandy Renfro, Ph.D. | Postdoctoral Fellow

Mandy Renfro headshot

Dr. Amanda Renfro is a cognitive neuroscientist serving as a postdoctoral fellow in the Computational Decision Neuroscience Laboratory at the National Institute of Mental Health (NIMH) under Dr. Silvia Lopez-Guzman. Dr. Renfro earned a B.S. in Psychology and terminal M.S. in Experimental Psychology from Eastern Kentucky University, then went on to receive a non-terminal M.S. in Psychology and her Ph.D. in Cognitive Neuroscience from Florida International University under the mentorship of Dr. Aaron Mattfeld. Her research interests focus primarily on cognitive processes which influence decision-making, as well as the neurobiological mechanisms which give rise to these phenomena. In her doctoral studies, Dr. Renfro used functional neuroimaging techniques to investigate prospective memory-guided decision-making and is now interested in how value may also influence choice for both clinical and non-clinical populations.

Morkeh Blay-Tofey, M.D., M.B.A. | Clinical Fellow 

Morkeh Blay-Tofey headshot

Dr. Blay-Tofey is a Clinical Fellow at the National Institute of Mental Health (NIMH). Before joining NIMH, he completed three-years of Psychiatry Residency at Baylor Scott and White Medical Center. He holds a B.A. in History of Science and Medicine from Yale College and a dual M.D./M.B.A. degree from Texas Tech Health Sciences Center School of Medicine. Dr. Blay-Tofey's interests lie in the neural mechanisms of decision-making and learning, particularly when affected by psychopathology, and the development of digital interventions to enhance mental health accessibility and quality.

Clara Haeffner, B.S. | Postbaccalaureate Fellow

Clara Haeffner headshot

Clara graduated from the University of Wisconsin-Madison with Comprehensive Honors in Neurobiology in 2023. There, she studied interactions among affective chronometry, neuroscience, and well-being. Her undergraduate work culminated in an honors thesis analyzing associations between lifetime stress history, hippocampal and amygdala volumes, and cortisol responses to acute psychosocial stress. She plans to pursue a Ph.D. to further investigate the intersection of affective and cognitive neuroscience, especially pertaining to how these processes interact with individual differences in life experience and psychopathology. Outside of the lab, Clara spends her time doing yoga, hiking, and finding live music.

Alexander Maksiaev, B.A. | Postbaccalaureate Fellow

Alexander Maksiaev

Alexander graduated from the University of Virginia in 2024 earning a Bachelor of Arts with Highest Distinction in Cognitive Science concentrating in Neuroscience. He also completed a second major in Computer Science. Alexander’s main research interests sit at the intersection between mental health, affect, language, and computation – a combination he used in his Distinguished Majors Program thesis in which he conducted exploratory sentiment analysis on textbooks with autism content. After his time at CDN, Alexander plans to pursue a Ph.D. to further investigate how computation can be used to answer questions about human emotion. Outside of research, Alexander enjoys illustration, crochet, and running.

Sydney Trowbridge, B.S. | Postbaccalaureate Fellow

Sydney Trowbridge

Sydney graduated from the University of California, Santa Barbara in 2022 with a Bachelor of Science in Biopsychology and a Minor in Art. Since graduating, she has spent time investigating applications of machine learning in neuroscience. Sydney has a very broad interest in the field of neuroscience, but is particularly interested in the role of large-scale brain networks in psychopathology and how machine learning and neuroscience can be mutually beneficial. After her time with CDN, Sydney intends on pursuing a Ph.D. in neuroscience. In her free time, she enjoys spending time with her pitbull, Daisy.

Justine Trudeau, B.S. | Postbaccalaureate Fellow

Justine Trudeau

Justine graduated from The Catholic University of America with honors in Psychological and Brain Sciences, minoring in French and Francophone Studies. Her research interests include cognition underlying social behavior, as well as integration of sense and perceptual information in decision making. Her undergraduate thesis investigated deficits in empathy for distress and inhibitory control as mechanisms underlying aggression. After conducting research in CDN, she plans to pursue a Ph.D. in the fields of psychology or affective neuroscience. Outside the lab, Justine likes to spend time hiking and biking, doing fine arts, and watching theater with friends in D.C.

Faraz Hassan | Summer Intern

Faraz Hassan

Faraz is a rising senior at the University of Michigan, studying Life Sciences Informatics. His research interests primarily involve translational studies that utilize computational and data analytics to improve patient outcomes. His undergraduate honors thesis analyzes neural network differences across psychiatric disorders. Faraz is a part of the Undergraduate Scholarship Program at the NIH and aims to come back for a postbaccalaureate year at the NIH to further hone his interests in research. He ultimately aims to attend medical school after his undergraduate education and training. Outside the lab, Faraz spends his time making music, hiking, spending time with friends and family, and exploring new cities and cuisines.


Daniel Pine, M.D., Ph.D. | Chief, Section on Development and Affective Neuroscience, NIMH

Lauren Atlas, Ph.D. | Chief, Section on Affective Neuroscience and Pain, NCCIH

Amy Janes, Ph.D. | Chief, Cognitive and Pharmacological Neuroimaging Unit, NIDA

Nora Volkow, M.D. | Director, Laboratory of Neuroimaging, NIDA

Melissa Brotman, Ph.D. | Chief, Neuroscience and Novel Therapeutics Unit, NIMH

Elizabeth Ballard, Ph.D. | Staff Scientist, Experimental Therapeutics and Pathophysiology Branch, NIMH

Kareem Zaghloul, M.D., Ph.D. | Senior Investigator, Functional Neurosurgery Section, NINDS

Kathleen Merikangas, Ph.D. | Chief, Genetic Epidemiology Research Branch, NIMH

Corey Ziemba, Ph.D. | Postdoctoral Fellow, University of Texas-Austin


Cassie Raymond, B.A.| Postbaccalaureate Fellow

Ricardo Pizzaro, Ph.D. | Data Scientist

Santiago Guardo-Maya | Visiting Fellow

Miryam Kiderman, Psy.D. | Staff Clinician

Savana Agyemang | Postbaccalaureate Fellow

Dhruv Govil | Postbaccalaureate Fellow

Ben Gorman | Summer Student


June 10th 2024: Welcome to Sydney, Alexander, Justine, and Faraz, the newest members of CDN!

May 29th 2024: Congratulations to Clara Haeffner, postbaccalaureate IRTA, for being awarded a 2024 Postbac Poster Day Outstanding Poster Award!

April 1st 2024: Best of luck to Cassie Raymond, postbaccalaureate IRTA, as she continues her research career pursuing a PhD in Clinical Psychology at Arizona State University!