Dim lights may hamper your ability to learn: study Dim lights may hamper your ability to learn: study The Study, Published In The Journal Hippocampus, Is The First To Show That Changes In Environmental Light, In A Range Normally Experienced By Humans, Leads To Structural Changes In The Brain. PTI | Updated on: 06 Feb 2018, 12:06:03 PM Washington: Spending too much time in dimly lit rooms and offices may change the brain’s structure and reduce people’s ability to remember and learn, a study has found. Researchers from Michigan State University (MSU) in the US studied the brains of Nile grass rats after exposing them to dim and bright light for four weeks.