Health Desk: 06 February 2018: According to a study, spending too much time in dimly lit rooms and offices may actually change the brain's structure and hurt one's ability to remember and learn.
The Michigan State University researchers studied the brains of Nile grass rats (which, like humans, are diurnal and sleep at night) after exposing them to dim and bright light for four weeks.
The rodents exposed to dim light lost about 30 percent of capacity in the hippocampus, a critical brain region for learning and memory, and performed poorly on a spatial task they had trained on previously.
The rats exposed to bright light, on the other hand, showed significant improvement on the spatial task. Further, when the rodents that had been exposed to dim light were then exposed to bright light for four weeks (after a month-long break), their brain capacity - and performance on the task - recovered fully.
The study is the first to show that changes in environmental light, in a range normally experienced by humans, leads to structural changes in the 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 theater."
The project could have implications for the elderly and people with glaucoma, retinal degeneration or cognitive impairments.
The findings have been published in the journal Hippocampus.