New research pairing virtual navigation with brain scans finds that stressed people have less access memory, and are less able to think flexibly.
Remembering past events is key to keeping us safe in the present. For example, recalling the pain of touching a hot stove often prevents us from doing it again. But when under pressure, we may be less able to access the memories that we need to make effective decisions according to a new study published in Current Biology.
Researchers at Stanford University conducted a number of experiments wherein 42 adult men navigated through 12 different virtual towns over three days. On the first two days, the men meandered through each town along a pre-determined route, but could also explore short-cuts through side streets to get to a desired destination.
On day three, some participants were told that they might receive a mild electric shock while rambling through these virtual towns. Before starting their journey, all of the men were virtually held up at the beginning of the route at which time their brain activity was measured using functional magnetic resonance imaging (fMRI).
Stress inhibits memory and flexible thinking
Researchers detected several notable differences between those who were stressed by the anticipation of a shock and those who were not.
Stressed individuals were less likely to investigate novel short cuts from prior adventures, and more inclined to stick to habitual routes. They also showed less activation in the hippocampus, suggesting that stress may have limited their ability to access memories of previously explored paths. Researchers also found less activity in stressed participants’ frontal-parietal lobe networks, indicating that anticipating a shock may have impeded their ability to efficiently achieve their goals.
Results of the study are some of the first to directly link stress to deficits in processing in the hippocampal-frontal lobe network, adding to our understanding of how stress can impede brain function. The study’s authors are particularly interested in seeing how these findings might apply to older adults who often have memory concerns coupled with financial and health stressors.