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Faculty Research Spotlight

Carmen Westerberg, Psychology

Collaborative Team Explores Links between Sleep and Memory


1.	Omalys Biggs Rodriguez, winner of the McKnight Foundation Pecot fellowship, models the headband used for recording brain waves during sleep.
Omalys Biggs Rodriguez, winner of the McKnight Foundation Pecot fellowship, models the headband used for recording brain waves during sleep.

“This new line of research represents the first ever analysis of sleep physiology in HSAM and will explore the provocative idea that specific aspects of sleep can forestall forgetting.”

Carmen Westerberg
Dr. Carmen Westerberg

For unknown reasons, people with highly superior autobiographical memory (HSAM) possess the ability to instantly recall details from nearly every day of their adult lives. When asked about a random date from the past, HSAM individuals can tell you the day of the week, details of what they were doing, any newsworthy events that occurred that day, and much more. However, their abilities are limited to autobiographical or personally relevant facts and do not extend to other types of memories. Over 70 individuals with HSAM have been identified in the United States.

To date, attempts to explain HSAM have failed to identify a compelling reason for why these individuals have such an amazing ability to remember events from their lives. Brain imaging has revealed structural differences in brain regions that might relate to the tendency for HSAM individuals to show subclinical obsessive-compulsive behaviors. However, explaining HSAM as a byproduct of this tendency is difficult to reconcile with the memory impairments and other symptoms typically present in obsessive-compulsive disorder.

In collaboration with Dr. Ken Paller at Northwestern University, I am currently testing the intriguing possibility that enhanced memory consolidation during sleep underlies the extraordinary resistance to forgetting in HSAM individuals. After learning, for a memory to last, a transitional process of consolidation must ensue. During sleep, memories become stronger and more resistant to interference as they become integrated with existing knowledge. It is possible that enhanced sleep physiology in HSAM individuals allows for the superior consolidation and retention of autobiographical memories. This hypothesis is consistent with the fact that HSAM individuals do not learn information more efficiently than other people. Rather, their superior memory stems from their ability to retain information over time.

2.	Undergraduate research assistant in Dr. Westerberg’s lab, Gage Smith, demonstrates how to sleep while wearing the sleep recording headband.
Undergraduate research assistant in Dr. Westerberg’s lab,
Gage Smith, demonstrates how to sleep while wearing the
sleep recording headband. 

In one experiment, we are obtaining detailed measures of sleep physiology in HSAM individuals and matched control participants through the use of state-of-the-art sleep recording equipment. This is a collaboration with Dr. Gregg Marshall at the Ascension Seton Williamson Sleep Center at Texas State’s Round Rock campus. In particular, we hypothesize that the very slow electrical oscillations that characterize deep sleep, sleep spindles (1-3 second bursts of high frequency brain activity during sleep), and the synchronization between slow oscillations and sleep spindles, will be stronger in HSAM individuals than in controls. Associate Professor of Psychology Dr. Logan Trujillo is playing a key role in designing cutting edge analysis techniques to examine these aspects of sleep.

A second experiment attempts to directly link sleep physiology to exceptional memory in HSAM. Participants monitor their sleep at home over the course of one month with an easy-to-use wireless headband that records their brain waves, and memory is assessed through Zoom meetings at multiple time points throughout the month. We are also presenting subtle sound cues associated with memories during sleep, which has been shown to improve memory in controls. We are interested in learning if this technique enhances memory to a greater extent in individuals with HSAM compared to controls.

3.	Dr. Westerberg staging sleep data in her office.
Dr. Westerberg staging sleep data in her office.

This new line of research represents the first ever analysis of sleep physiology in HSAM and will explore the provocative idea that specific aspects of sleep can forestall forgetting. Not only will the results increase knowledge about HSAM, but they will also be informative for understanding how sleep may be useful to reduce forgetting in other populations. We hope to identify aspects of sleep physiology that could be leveraged to help reduce forgetting in individuals with memory problems. For example, if sleep spindles are implicated in superior memory, this work could pave the way for the development of pharmacological, electrical, or other interventions that increase spindle activity and in turn help alleviate some frustrations experienced by patients with memory problems.

This project is funded by a $300,000 grant from the McKnight Foundation for Neuroscience, awarded to myself and Dr. Paller. In addition, my undergraduate student Omalys Biggs Rodriguez earned the Matthew Pecot Underrepresented Minority Fellowship from the McKnight Foundation in April 2021, which provides her with $16,500 to work on this and related projects in my Cognitive Neuroscience Laboratory. Omalys is a biology major with biochemistry and psychology minors at Texas State University.

Many factors go into getting a research project funded, including matching the goals of the funding agency, clearly and concisely describing your idea and why it is important, demonstrating how your team has the right background knowledge, personnel, and facilities to complete the project, and of course a little bit of luck.

4.	Dr. Westerberg and Dr. Trujillo discuss data analysis strategies.
Dr. Westerberg and Dr. Trujillo discuss data analysis strategies.

This project in particular depends on a highly collaborative team. Dr. Paller has been a respected researcher in the cognitive neuroscience of memory for the past 30 years. When I was a postdoctoral fellow in his lab, we developed a strong track record of publications and successful grants in the newly emerging research area examining how sleep contributes to memory consolidation, and he provided the resources necessary to collect the pilot data we needed for the grant application. Dr. Marshall, director of the Round Rock campus Sleep Center, has also been a valuable collaborator, offering a state-of-the-art facility for us to collect overnight sleep data. Finally, Dr. Trujillo has extensive skill and experience in the analysis of electrophysiological signals, and his contributions will help us use cutting-edge analyses to examine specific aspects of sleep physiology.

Before my postdoc fellowship at Northwestern, I received a PhD in cognitive and biological psychology from the University of Minnesota. In fall 2011, I joined Texas State as an assistant professor and was promoted to associate professor in fall 2017. I will also be associate chair of psychology starting in fall 2021. In the psychology department, I teach undergraduate classes called Brain and Behavior and Cognitive Processes and a graduate class called Cognitive Neuroscience. When I’m not teaching or doing research, I enjoy playing trivia, cheering on the Minnesota Twins, and spending time with family and friends.