Knowledge can be thought of as the consolidation of a collection of memories. Information enters the mind in many ways, and the nature of it determines which part of the brain will react the most to it. For example expert knowledge of bicycle riding creates procedural memories that start in the cerebellum and eventually become ingrained in caudate nucleus, but the amygdala and the cortex will also likely store fear and episodic memories of learning experiences of things like near crashes and will then inform semantic memories which can be expressed as knowledge. (1). During this time the information is stored in the hippocampus for up to three years, where it is relayed to the cortex and then rehearsed until it becomes a memory and the hippocampus is no longer needed for its recall (1).

The function of the hippocampus is essential to the recall needed to turn experiences into a body of knowledge. However, it is also particularly sensitive to the glucocorticoids that are released during stress. Although glucocorticoids also delay stress reactions and even prime the human brain for the formation of memories (2,3), numerous studies show that “chronic high glucocorticoid exposure” causes “neurodegeneration and cell death” and the remaining neural networks in the hippocampus function in an impaired capacity while continuing to degrade (4). When this happens, the “consolidation of declarative memories” that makes learning possible, is gone (4).

 

Next we will examine how one can protect and strengthen their ability to learn, even during times of stress.

 Sources

1. Carter R. Mapping the Mind. Berkeley: University of California Press; 1998.

2. Rajnish PR, Snilkumar S, McEwen B, Chattarju S. Glucocorticoids Protect Against the Delayed Behavioral and Cellular Effects of Acute Stress on the Amygdala. Biol Psychiatry [Internet]. 2012 [cited 2015 Feb 20];72(6):466-475. Available from: http://www.biologicalpsychiatryjournal.com/article/S0006-3223(12)00359-9/abstract

3. Schwabe L, Joëls M, Roozendaal B, Wolf OT, Oitzl MS. Stress effects on memory: an update and integration. Neurosci Biobehav Rev [Internet]. 2012 [Cited 2015 Feb 20];36(7):1740-9. Available from: Medline [doi: 10.1016/j.neubiorev.2011.07.002].

4. Austin D. Killing them Softly: Neuroscience Reveals how brain cells die from law school stress and how neural self-hacking can optimize cognitive performance. Loyola Law Rev. 2013;59(4):791-859).

Index

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