Summary: Stress reduces activity in the hippocampus and frontal-parietal networks, impairing memory-based decision-making and the ability to plan ahead.
Source: Stanford University
Stress Impairs Memory-Based Planning, New Stanford Study Finds
New research from Stanford University shows that acute psychological stress can undermine our capacity to form effective plans by preventing us from using memory when making decisions. The study, led by psychologist Anthony Wagner and published in Current Biology, demonstrates how stress suppresses neural systems that support memory retrieval and goal-directed behavior, making planning less efficient and flexible.
“We draw on memory not just to project ourselves into the past but to project ourselves forward, to plan,” said Anthony Wagner, the Lucie Stern Professor in the Social Sciences at Stanford’s School of Humanities and Sciences and senior author of the paper. “Stress can rob you of the ability to use the cognitive systems underlying memory and goal-directed behavior that help you solve problems more quickly, efficiently and effectively.”
Virtual navigation reveals planning differences under stress
The researchers used an immersive virtual navigation task combined with fMRI to observe how stress affects neural activity and behavior during planning. Participants first learned winding routes through a set of virtual towns until they were familiar with the environments. Later, while undergoing brain scanning, they were placed on those routes and asked to navigate to specific goal locations.
To induce acute psychological stress in a subset of participants, researchers warned that they might receive a mild electric shock during the task, unrelated to their performance. Participants without that threat tended to imagine and take efficient shortcut routes based on memories of previous journeys. By contrast, stressed participants relied more often on familiar, habitual paths and were less likely to take novel shortcuts.
Importantly, brain scans recorded during a brief pause before navigation showed that stressed participants had lower activation in the hippocampus—the region involved in recalling past experiences—and reduced activity in frontal-parietal networks that align mental processes with current goals. Earlier work from this group had already linked stress to impaired retrieval and use of memories; this study is the first to show that stress disrupts hippocampal–frontal network interactions that support memory replay during prospective planning.
“It’s like the brain is pushed into a more low-level mode of thought, and that corresponds with reduced planning behavior,” said Thackery Brown, lead author of the paper and a former postdoctoral scholar in Wagner’s Memory Lab.
Broader implications and aging
These findings have broader implications for understanding how stress affects daily decision-making across different populations. Wagner and colleagues suggest that people who are free from acute stress may possess a kind of neurocognitive advantage: they can draw more effectively on memory systems to plan and act optimally. Conversely, individuals coping with health, financial, or other stressors may be at a neurologically based disadvantage when it comes to flexible planning.
The researchers are particularly interested in how stress-related disruption of memory and planning may affect older adults. Aging populations often face health concerns, financial strain, and worries about memory loss—all potential stressors that could further reduce the ability to recall and use memories for planning. Brown has begun similar virtual navigation studies with participants aged 65 to 80 to explore how stress, memory, and planning interact in later life.
“It’s powerful to consider how stressful events might affect planning in older relatives,” Brown said. “Stress affects us in youth and again as we care for or become older family members; understanding these effects matters across the lifespan.”
Study authors and support
The paper lists Thackery I. Brown as lead author, with Stephanie A. Gagnon and Anthony D. Wagner as co-authors. Wagner is also affiliated with Stanford Bio-X and the Wu Tsai Neurosciences Institute. Funding was provided by the Brain and Behavior Research Foundation, the National Institutes of Health, the Marcus and Amalia Wallenberg Foundation, the John Templeton Foundation, and the John D. and Catherine T. MacArthur Foundation.
Original research
Original article title: “Stress Disrupts Human Hippocampal-Prefrontal Function during Prospective Spatial Navigation and Hinders Flexible Behavior.” Published in Current Biology. Authors: Thackery I. Brown, Stephanie A. Gagnon, Anthony D. Wagner. DOI: 10.1016/j.cub.2020.03.006.
Highlights from the study
- Human participants completed a virtual reality navigational planning task while undergoing fMRI scanning.
- Psychological stress was induced after learning, during a subsequent planning phase.
- Neural markers of memory replay tracked prospective route planning in non-stressed participants.
- Stress disrupted memory and control circuitry, reduced neural replay, and decreased flexible shortcut behavior.
Abstract summary
Anticipating and flexibly planning for the future depends on memory retrieval and neural systems that support goal-directed behavior. Using a combination of fMRI, neuroendocrine measures, machine learning, and virtual navigation, the researchers show that acute psychological stress impairs mnemonic retrieval and mental simulation during planning. Participants under stress were less likely to use efficient shortcut routes and more likely to rely on habitual paths. These behavioral changes were associated with disrupted neural replay of spatial memories, providing mechanistic insight into how stress can lead to less efficient planning.
About this research article
Source: Stanford University News. Media contact: Taylor Kubota – Stanford. Image adapted from the Stanford news release.
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