Stress affects memory in complex ways. Generally, stress can interfere with both the ability to encode memories (forming new memories) and recall them later. Stress hormones, especially cortisol, play a key role by impacting brain regions critical to memory such as the hippocampus, amygdala, and prefrontal cortex. Acute stress can enhance memory formation, especially for emotionally charged or negative events, making those memories stronger and more vivid. This is because cortisol can increase connectivity within certain brain areas involved in emotional memory. However, chronic or high levels of stress typically impair memory, especially the ability to retrieve long-term memories and disrupt working memory. Stress often reduces the efficiency of the prefrontal cortex during stressful challenges, impairing working memory, but might simultaneously enhance amygdala responses related to emotional memory. In summary:
- Acute stress helps form stronger emotional memories.
- Chronic or high stress impairs memory retrieval and working memory.
- Stress impacts different memory types differently.
- It acts through stress hormones like cortisol that affect brain structures involved in memory.
This explains why stressful experiences are often vividly remembered yet stress can cause forgetfulness and difficulty concentrating in other contexts.
