Effects of stress on neurophysiology Working memory is impaired by acute and chronic psychological stress. This phenomenon was first discovered in animal studies by Arnsten and colleagues, who have shown that stress-induced catecholamine release in PFC rapidly decreases PFC neuronal firing and impairs working memory performance through feedforward, intracellular signaling pathways that open potassium channels to rapidly weaken prefrontal network connections. This process of rapid changes in network strength is called Dynamic Network Connectivity, and can be seen in human brain imaging when cortical functional connectivity rapidly changes in response to a stressor. Exposure to chronic stress leads to more profound working memory deficits and additional architectural changes in PFC, including dendritic atrophy and spine loss, which can be prevented by inhibition of protein kinase C signaling. fMRI research has extended this research to humans, and confirms that reduced working memory caused by acute stress links to reduced activation of the PFC, and stress increased levels of catecholamines. Imaging studies of medical students undergoing stressful exams have also shown weakened PFC functional connectivity, consistent with the animal studies. The marked effects of stress on PFC structure and function may help to explain how stress can cause or exacerbate mental illness. The more stress in one's life, the lower the efficiency of working memory in performing simple cognitive tasks. Students who performed exercises that reduced the intrusion of negative thoughts showed an increase in their working memory capacity. Mood states (positive or negative) can have an influence on the neurotransmitter dopamine, which in turn can affect problem solving.
Effects of stress on neurophysiology Working memory is impaired by acute and chronic psychological stress This phenomenon was first discovered in animal studies by Arnsten and colleagues who have shown that stress-induced catecholamine release in PFC rapidly decreases PFC neuronal firing and impairs working memory performance through feedforward intracellular signaling pathways that open potassium channels to rapidly weaken prefrontal network connections This process of rapid changes in network strength is called Dynamic Network Connectivity and can be seen in human brain imaging when cortical functional connectivity rapidly changes in response to a stressor Exposure to chronic stress leads to more profound working memory deficits and additional architectural changes in PFC including dendritic atrophy and spine loss which can be prevented by inhibition of protein kinase C signaling fMRI research has extended this research to humans and confirms that reduced working memory caused by acute stress links to reduced activation of the PFC and stress increased levels of catecholamines Imaging studies of medical students undergoing stressful exams have also shown weakened PFC functional connectivity consistent with the animal studies The marked effects of stress on PFC structure and function may help to explain how stress can cause or exacerbate mental illness The more stress in one's life the lower the efficiency of working memory in performing simple cognitive tasks Students who performed exercises that reduced the intrusion of negative thoughts showed an increase in their working memory capacity Mood states (positive or negative) can have an influence on the neurotransmitter dopamine which in turn can affect problem solving