Principle Investigator

Krystal Parker, Ph.D.

Assistant Professor             

Department of Psychiatry (Primary Appointment) and Psychological and Brain Sciences (Secondary Appointment)

Iowa Neuroscience Institute 

University of Iowa
Iowa City, IA 52242


Dr. Parker received her Ph.D in Neuroscience from Iowa State University in the Department of Biomedical Sciences. She completed two post doctoral fellowships at the University of Iowa. The first, clinical based fellowship was part of Nancy Andreasen's T32 Training Program Major Psychoses/Clinical Neurobiology (now the INSPIRE program). Subsequently, Dr. Parker learned advanced techniques in animal physiology and optogenetics under the mentorship of Dr. Nandakumar Narayanan. In 2017, Dr. Parker was hired as the first faculty recruit of the Iowa Neuroscience Institute and the Department of Psychiatry. 






Postdoctoral Fellows

Hunter Halverson


Victoria Muller Ewald

Although originally from Southern Brazil, Victória moved to the American Mid-west for her scientific training. She received B.S.s in Biology and Psychology from Luther College and a PhD in Neuroscience from the University of Iowa. During her graduate training, Victória studied the role of the rodent infralimbic cortex in the inhibition of cocaine seeking. In the Parker laboratory, Victória’s work focuses on investigating neural oscillation patterns in patients with psychiatric disorders and exploring the use of cerebellar modulation to rescue frontal activity. Victória greatly enjoys mentoring the students in the laboratory, and one of her main goals is to increase the number of women involved in coding. In 2020, Victória was named an INSPIRE fellow in the Dept. of Psychiatry. In her spare time, Victória likes to spoil her dog and listen to podcasts.

Graduate Students


Farzana Rimi


Parker Abbott

Parker is originally from Wausau, Wisconsin and he received his bachelor's degree in Neuroscience from the University of Minnesota-Twin Cities in 2015. After that, he moved to Iowa City and the University of Iowa to work in the lab of Hanna Stevens MD, PhD as a post-baccalaureate research assistant. He is currently enrolled in the Neuroscience Graduate Program at Iowa, with an interest in biological psychiatry and understanding psychiatric disorders at the neuronal level. In his free time, Parker enjoys curling and skiing (two ways to make a Midwest winter enjoyable), as well as other non-winter activities such as traveling, keeping up with the Minnesota Twins, eating and cooking new foods.

Jessica Purnell

Jessica received her bachelor's degree in Behavioral Neuropsychology and Biology at St. Ambrose University in 2018. She is currently a graduate student in the University of Iowa's Neuroscience Graduate Program. She is interested in how the cerebellum interacts with other brain regions for proper cognitive and affective function. In her free time she enjoys listening to podcasts, canoeing, and caring for her three cats and numerous plants.




Undergraduate Students

Luke Zaabel

Lilian Montilla

Jenna Yang

Ainsley Rothgeb

Quinn Mattison


Lab Alumni


Nathan Cremers

Kelsey Heslin

Kelsey is originally from Lancaster, Pennsylvania and received her bachelor's degree in Psychology from Duquesne University. Next, she obtained her MS in Experimental Psychology at Villanova University. She is currently a student in the University of Iowa's Neuroscience Graduate Program. She is interested in defining cerebellar contribution to executive functions, especially in the context of disordered cognition in schizophrenia. In her spare time she enjoys cooking and listening to numerous podcasts. 

Ben De Corte


Lilian McKenzie




Ryan Williams

Ryan Williams

Ryan is currently a freshman at the university and is double majoring in neuroscience and economics and is minoring in theatre arts. Ryan enjoyed participating in several choirs, the track and cross country team, and drama in high school. He earned “elite all-state” honors in track, and was “all-state” in drama and choir. In his free time, he likes to play the guitar and sing, and plans to join the track club next year. He is thrilled to be working in the Parker lab, and looks forward to the opportunities to come.

Jonah Heskje

Jonah is a native of Cedar Rapids and graduated from the University of Iowa in May 2017 with a B.S. in Biology. Jonah started in the Parker lab straight out of college and will continue until either the cerebellum is completely understood or he is accepted into an MD/PhD program, whichever comes first. Looking forward, Jonah would like to work with patients who have intractable epilepsy for the purpose of improving their clinical care and studying the unique insight they provide for cognitive science via intracranial recordings. Jonah likes dogs, mugs, and the entire month of October.

Kyle Walsh

Kyle grew up in Sioux City, IA and received a bachelor's degree in history in 2015 from the University of Notre Dame. Knowing he wanted to pursue a career in medicine, Kyle went on to receive a master's degree in physiology and biophysics from Georgetown University in 2016. Kyle joined the Parker lab in 2016 as a University of Iowa Post-Baccalaureate research intern. While setting up the Parker Lab, Kyle found out that he was accepted to the University of Iowa Carver College of Medicine as part of the class of 2021. Kyle also spent the summer of 2018 in the Parker lab, supported by a Carver College of Medicine Summer Research Fellowship. His project entitled "The influence of chronic cerebellar stimulation on cognitive function and circuitry" was awarded the Robert Robertson Research Award in Psychiatry. Kyle is also a volunteer firefighter/EMT in his spare time.


Aaron Nessler

Aaron worked in the Parker Lab from 2014-2016 while completing his coursework for a degree in Biomedical Engineering from the University of Iowa. He graduated in 2016 and will be working as an engineer as he prepares to apply for medical school.

Abinav Jyotis    

Abinav Jyotis is originally from St. Louis Missouri and is pursuing his undergraduate studies in Bio-Chemistry from the University of Iowa. Abinav joined the Parker Lab in August 2017 and he hopes to get into medical school after he graduates. On the side, Abinav plays competitive badminton and is the President of University of Iowa Badminton Club. He also practices in classical Carnatic music, and through the influence from his artistic family, has had many opportunities to sing for cultural events, and organizations in both US and around the world.