Love going back to your dimly lit room and catching up on some reading at night? Well, you might want to reconsider that thought, especially since dim light could make you dumber.
Spending too much time in dimly lit rooms and offices can change the structure of your brain, hurting your ability to remember and learn, suggests neuroscientists from Michigan State University.
The experiment revealed that exposure to dim light caused a 30 percent loss in the capacity of the hippocampus, a critical region of your brain responsible for learning and memory-based tasks and on spatial tasks as well.
Exposure to bright light, on the other hand showed a significant improvement in spatial tasks. In fact, 4 weeks of exposure to bright light (after a month-long break), can help your brain recover to its full capacity, performing at it’s peak when it came performance.
This is first study, published in the journal Hippocampus, of its kind that highlights how changes in environmental light leads to structural changes in the human brain.
“When we exposed the rats to dim light, mimicking the cloudy days of Midwestern winters or typical indoor lighting, the animals showed impairments in spatial learning,” said Antonio “Tony” Nunez, psychology professor and co-investigator on the study. “This is similar to when people can’t find their way back to their cars in a busy parking lot after spending a few hours in a shopping mall or movie theatre.”
Sustained exposure to dim light led to significant reductions in a substance called brain derived neurotrophic factor-a peptide that helps maintain healthy connections and neurons in the hippocampus-and in dendritic spines, or the connections that allow neurons to “talk” to one another.
Interestingly, light does not directly affect the hippocampus, meaning it acts first on other sites within the brain after passing through the eyes.
“For people with eye disease who don’t receive much light, can we directly manipulate this group of neurons in the brain, bypassing the eye, and provide them with the same benefits of bright light exposure?,” said Lily Yan, associate professor of the paper.
This project could have implications for the elderly and people with glaucoma, retinal degeneration or cognitive impairments.