Professor of the Practice of Law University of Denver Sturm College of Law

The Neuroscience of Stress and Cognition

Mar 19, 2020

Introduction

Chronically stressed brains cannot think as effectively as non-stressed brains.  Stress hormones damage or kill brain cells in the memory-processing hippocampus, while at the same time slowing the birth of new brain cells there.  The hippocampus is simply not as functional in times of chronic stress, making learning, memory formation, and recalling information very challenging.

While we deal with the health and economic challenges of the current environment, this version of The Lawyer Well-being Newsletter is much longer than normal and the recommendation is that you do what you can to minimize your stress and that of your loved ones, because long-term stress is very harmful to the brain and body.

Memory Formation

Semantic memory is the knowledge-base that education enhances, such as the acquisition of terminology, facts, and concepts. It is declarative memory because it requires conscious thought to be recalled, and it is stored in a neural network of brain cells that loops between the memory-processing hippocampus and the cerebral cortex.

The life cycle of declarative memory has four stages: encoding, storing, retrieving, and forgetting. Encoding begins when information in the form of memory traces enters the cerebral cortex via the senses, and travels to the hippocampus for processing. The hippocampus starts to encode the information for permanent storage along chains of firing neurons. The strongest information travels back to the cerebral cortex where it was first registered by the senses. During law school, “consolidation (enhanced by creating and studying law class outlines) makes temporarily stored fragile information (from reading and class lectures) more stable for later retrieval (on law school exams) by strengthening neural connections of the information circuit between the hippocampus and the cortex.”

Complete consolidation of a fragile memory to a stable memory takes from two to ten years. The memory retrieval process, used by law students during exams or lawyers recalling a statute number, relies on the same circuit of brain cells that is used for memory consolidation, demonstrating the need for a healthy hippocampus. When law students and lawyers work to develop expertise in a course or discipline, the brain is consolidating information for later retrieval.

The Stress Response

There are two kinds of stress: acute stress where the fight-or-flight system is initiated to martial resources to deal with a physical or psychological challenge; and chronic stress where long-lasting life challenges prolong fight-or-flight system activation. The fight-or-flight stress response evolved to help humans escape from predators, and the rest-and-digest system curbs the stress response, calming the body and brain.

The stress response begins in the brain’s panic button, the amygdala, which signals the hypothalamus to release the stress hormones adrenalin (epinephrine) and glucocorticoids (the main glucocorticoid is cortisol). Stress hormones mobilize energy, and elevate heart rate and blood pressure to help law students deal with challenges, while at the same time suppressing digestion and immune response. Chronic stress, when the stress response is in overdrive, can cause psychological problems such as irritability, anxiety, panic attacks, and depression; and physical effects including increased blood pressure, heart palpitations, breathlessness, dizziness, chest pain, digestive problems, muscle tension, sweating, and chills. Long-term elevated levels of stress hormones have been associated with impaired immune response; increased appetite, food cravings, body fat, PMS and menopause symptoms; and decreased muscle mass and bone density.

Chronic stress triggers inflammation in the body and brain, which increases the risk of heart disease and diabetes. Inflammation in the brain can impair motivation and mental agility.   Elevated stress hormone levels disrupt sleep, and increase the risk of anxiety, depression, and burnout. Chronic stress can also impact serotonin, a neurotransmitter that is important to mood regulation, cognition, and well-being.

Stress and Cognition

One of the brain’s superpowers is its ability to grow new brain cells in the hippocampus in a process called neurogenesis. This process is suppressed during the stress response. The hippocampus is also extremely vulnerable to damage from stress hormones because it has extensive glucocorticoid receptors. Chronic high levels of glucocorticoids cause hippocampal neuron degeneration and death. The hippocampal brain cells that remain after damage from stress are not as effective, and the complexity of neural networks is degraded as the connections at the synapses are weakened or disconnected.

Research reveals that cognitive performance deteriorates during the stress response. The negative effects of stress on cognition include impaired concentration, memory, problem-solving capacity, and language and math processing. Motivation, creativity, and curiosity are inhibited as well. Jessica Minahan describes anxiety as a transient learning disability that interferes with a student’s working memory, learning, recall, and capacity to complete tasks.

Brain cells in the hippocampus, critical to memory processing and recall, can be weakened or killed by exposure to stress hormones creating significant implications for lawyers, law students, and legal educators. Brain scans indicate that the hippocampi (there is one in each brain hemisphere) shrink in people who experience stress, depression, and PTSD. Adults in midlife with increased levels of cortisol had reduced brain structure and cognitive capacity. Data from 2,018 Framingham Heart Study participants, of an average age of 48, showed that participants with an elevated cortisol level performed worse on memory and other cognitive tasks than participants with average cortisol levels. Higher cortisol was also associated with smaller brain volumes in those subjects.

Takeaway: Lawyers and law students should strive to manage their stress during challenging times. Exercise, yoga, mindfulness, meditation, and gratitude are protective against stress.

Note: For a detailed explanation of stress and cognition, as well as the science behind the recommendations for managing stress, see Killing Them Softly below. For recommendations for enhancing mental strength, see Windmills of your Mind below.

Sources

Debra S. Austin, Killing Them Softly: Neuroscience Reveals How Brain Cells Die From Law School Stress and How Neural Self-Hacking Can Optimize Cognitive Performance, 59 Loy. L. Rev. 791 (2013) https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2227155.

Muzaffer Kaser, Barbara Jacquelyn Sahakian and Christelle Langley, How Chronic Stress Changes the Brain, and What you can do to Reverse the Damage, Neuroscience News, Mar. 14, 2020, https://neurosciencenews.com/chronic-stress-reversal-15918/.

Katrina Schwartz, 20 Tips to Help Deescalate Interactions with Anxious or Defiant Students, Mind/Shift (April 21, 2016) available at https://ww2.kqed.org/mindshift/2016/04/21/20-tips-to-help-de-escalate-interactions-with-anxious-or-defiant-students/.

Debra S. Austin, Windmills of your Mind: Understanding the Neurobiology of Emotion, 54 Wake Forest L. Rev. 931 (2019), https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3374006.

%d bloggers like this: