The Mind Science Foundation
117 West El Prado Drive
San Antonio, TX, 78212, USA
Tel: (210) 821-6094
What can dreams teach us about the brain?
Dreams have long been a source of fascination and an area of keen investigation for the Foundation. Dream-related studies funded by MSF include Peter Morgan of Yale University. His recently completed investigation of the brain regions involved in dreams resulted in publication in a highly regarded open-access scientific journal. Here are his thoughts about the results written in layman’s terms:
Dreams are an enduring puzzle. Why do we have them? What do they mean? Are they experiences? Can they teach us about consciousness and the experience of our world? In this new work we use a neuropsychological approach to dreaming. Neuropsychology involves giving people behavioral tests with pen and paper or a computer – tests that engage particular regions of the brain. From other studies of people who have localized brain damage, we know which parts of the brain are involved in doing the tests. In our study we hoped to try to understand the brain regions that might be involved in dreaming. By comparing those regions to the parts of the brain involved in other processes, like mental illnesses, we hoped to understand the relevance of dreams to psychiatry.
Psychiatrists thought for a long time that solving the puzzles posed by dreams would provide the key to mental illnesses, to people’s complex inner lives. This idea fell out of favor as we discovered medications that could help mental illnesses in the 1950s and 1960s. The rise of biological psychiatry coincided with a decrease in interest in dreams in mainstream psychiatry. However, more recently people have studied dreams more and more because they might represent a model or proxy for symptoms of serious mental illnesses like schizophrenia. We call schizophrenia a psychotic illness because it makes people confuse reality with imagination, leading to symptoms like hallucinations; seeing and hearing things that did not occur, and delusions; believing things that other people find unlikely, untrue or bizarre.
In our study, we focused on two groups of healthy people, those who were more aware of their dreams, and those who were less aware who experience their dreams less vividly. We studied memory in these two groups, examining how they sensed familiarity for pictures and used that familiarity to judge whether they remembered seeing the pictures before. Our memory test is hard for people who have had damage to the connections between two parts of the brain: the striatum and the orbitofrontal cortex. The striatum is deep in the brain. It is involved in coordinating our thoughts, emotions and motor actions. It is involved in Parkinson’s disease. The drugs we use to treat schizophrenia act in the striatum. The orbitofrontal cortex is at the front of your brain, behind your eyes. It is involved in processing important events that you experience, using your memories for those experiences to guide your behavior. When the striatum and orbitofrontal cortex are disconnected e.g. by a stroke or a bang on the head, people get confused about where they are in space and time, they think that they are in a place in their past. Their brains and minds create a reality, a story that is influenced by random, unrelated things that they see in the world. This is called spontaneous confabulation. People who spontaneously confabulate feel false familiarity for the new pictures in our task.
We thought dreams might be a bit like confabulation. Our idea was that people with high dream awareness might experience false familiarity. We thought they would incorrectly remember having seen a picture before – like Déjà vu. This is what we found. People who were very aware of their dreams seemed to feel false familiarity. They remembered seeing things they had not seen before. We think this is exciting because it suggests that dreams might be a window on to studying the brain and behavioral mechanisms relevant to the symptoms of serious mental illnesses like schizophrenia, illnesses that are hard to study because people that suffer them are often very ill, they suffer from stigma and stress and the medications they take can also change their memory and concentration. Dreams might yet be useful to psychiatrists, not their content but what they tell us about how our brains construct our reality, a process that is affected in serious mental illnesses like schizophrenia.
For more information on Dr. Morgan, visit his lab page.