The scenario is probably familiar: You have been preparing for a presentation all week, cramming in all the relevant information. As you start to present, the pressures sets in, and you forget everything. Moments like these are vexing, but science may have some answers. Neurologists are just beginning to unearth the subtle properties that control memory formation and retention. Retaining new information involves the complex interplay of brain cells—primarily in the hippocampus and prefrontal cortex. Gretchen Voss explains these interactions in Women’s Health:
“Picture each neuron as an old-fashioned telephone, but with multiple wires snaking out from the receiver. Some of those wires are called axons, and they intersect with other wires called dendrites at connections called synapses. The brain creates and retains memories in part by growing thicker, more efficient communication lines between groups of neurons”
Stress Hormones
Cramming for an exam and stressing out until the last minute may be detrimental to success. Periods of stress excite the hypothalamus, the body’s hormone regulation center. In turn, the hypothalamus releases hormones that stimulate the adrenal gland, which ignites the fight-or-flight response by secreting adrenaline. When stress persists for several minutes, the steroid hormone, cortisol, is released into the bloodstream by the adrenal gland.
Excess cortisol leads a full frontal assault on neurons, retarding their ability to reinforce and create new connections in the prefrontal cortex and hippocampus. Subsequently, the brains ability to retain new memories and access archival memories is diminished. Therefore, in periods of sustained stress people can become flustered, struggling to drag memories to the surface.
The Brain Drain
Cortisol release monopolizes arterial blood that is carrying precious glucose, the body’s primary source of energy. A large proportion of blood is diverted to skeletal muscles, virtually withholding the brain from vital resources. With resources on the decline, the hippocampus and prefrontal cortex are unable to efficiently form new connections, precipitating in memory deficits.
Overcoming the Stress Response
Following high stress events, cortisol levels decrease, halting the cascade of adverse events. Studies indicate that the negative consequences of cortisol’s impact on the brain are reversible. John W. Newcomer, M.D., assistant professor of psychiatry and psychology at Washington University of St. Louis states “The evidence suggests that these kinds of cortisol levels are not neurotoxic themselves…perhaps sustained, high levels make neurons vulnerable to other types of injury, but we don’t believe the memory impairments…are in any way associated with an irreversible process. In fact, our evidence shows that this memory impairment is quickly reversible.”
High stress levels cause the release of cortisol, limiting the brain’s ability to retain and access memories. The reversibility of cortisol’s adverse effects on the brain presents an opportunity to prevent subsequent events. By virtue of these facts it becomes evident that relieving stress can have a positive impact on the brain’s ability to retain memories. By employing relaxation techniques such as yoga, meditation, and massage in conjunction with the awareness of stress’s deleterious effects it is possible to unlock the door to the genius mind.
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