April 25, 2025

Sophia Lin

9th Grade

Brooklyn Technical High School

What is the Hippocampus?

The hippocampus is a crucial part of the brain located deep in the medial temporal lobe. Its main functions are to form and store memories, learn spatial memory, and emotional processing. It is also a part of the human limbic system—a group of brain structures that regulate your smells, emotions, memories, and autonomous behaviours, such as breathing and sweating. Naturally, the depreciation of the hippocampus can cause severe neuropsychiatric disorders. 

What Can Happen to the Hippocampus?

Atrophy of the hippocampus is the shrinkage of the structure. This type of damage can lead to many psychological problems, such as Alzheimer’s disease, epilepsy, depression, and dementia. Though the decrease in the volume of the hippocampus is considered natural, usually declining during midlife and shrinking at roughly 1.18% annually, quite a few factors can play the role of speeding up the decline of hippocampus atrophy; one of which is sleep deprivation. 

Digital Media’s Correlation to Sleep Deprivation

Over these past few decades, people have been sleeping less and less, likely due to the increased usage of digital media. Of course, this correlation between these two events isn't purely coincidental; a possible theory for the correlation is known as the “bright light hypothesis,” in which bright light during nighttime can suppress the secretion of melatonin, a hormone correlated with sleep. Less melatonin in the body leads to more alertness, keeping you up later and later. The increase in arousal is exerted by short-wavelength lights, usually perceived as blue-to-green light emitted by the usual electronic devices like phones. With the growth of use of light-emitting-diode (LED) technology, the increase of blue light emissions from screens are naturally increasing the amount of alertness in the evenings.  A research-based study by Van der Ley and colleagues showed that people who used a screen three hours before sleep led to an elevated amount of pre-sleep alertness.

After the bright light hypothesis, sleep latency appeared to be shorter when a person used brighter screens, rather than without. Due to the increased use of digital media today, sleep deprivation is almost inevitable. 

What Can Sleep Deprivation Do to the Hippocampus?

Sleep deprivation can decrease the volume of the hippocampus, thus impairing hippocampus-dependent memories. A reduction in sleep has been found to lead to poor school performance—slower processing speeds, reduced attention spans, poor memory, and an increase in emotional lability (mood swings). Recent research showed that sleep deprivation can cause changes to the synaptic structure of the hippocampus, pressure or anxiety on the nervous system, and cause detrimental effects on human cognitive functions (Atrooz and Salim, 2020). Sleep deprivation can also affect the human repair systems and stop the removal of metabolites in the brain, resulting in an increased amount of stress and even damage to neurons. Over time, sleep deprivation can cause irreversible harm to the brain and hippocampus. Sleep deprivation has also been found to change gene expression, increasing the risk of dementia.

What Can We Do to Prevent Damaging Our Hippocampus?

There isn’t a “correct” path to solve this growing issue. Sure, you can tell people to stop going online or lock their screens, but truthfully, digital media is just going to continue growing no matter what. Most everyone already relies on cell phones— for example, they hold personal information, it is a form of entertainment, and some may use it for work-related activities. 

Learning to control ourselves and limit our usage of digital devices is the best way to begin. For instance, you should avoid going on your device a couple of hours before bed to maximize melatonin secretion. You should also not pull any all-nighters and sleep instead. Your brain controls your body; without it, you are nothing. So, take care of it and, in return, it will take care of you.