Why you can’t stop those unwanted thoughts
HAVE you ever wondered why your mind keeps going back to that drunken mistake you have tried to erase from your memory?
The reason why you can't stop thinking about it might be because your brain lacks a specific chemical that allows you to suppress unwanted thoughts.
This is according to a study that explored the region at the front of the brain known as the prefrontal cortex - the area that plays a key role in controlling our actions and thoughts.
Participants were asked either recall or suppress information based on different cues, with researchers observing brain activity by using a combination of functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy.
Professor Michael Anderson said he and his colleagues were able to discover the ability to inhibit unwanted thoughts relies on a neurotransmitter known as GABA - a chemical within the brain that allows messages to pass between nerve cells.
"Before, we could only say 'this part of the brain acts on that part', but now we can say which neurotransmitters are likely important - and as a result, infer the role of inhibitory neurons - in enabling us to stop unwanted thoughts," he wrote in statement.
"Where previous research has focused on the prefrontal cortex - the command centre - we've shown that this is an incomplete picture. Inhibiting unwanted thoughts is as much about the cells within the hippocampus - the 'boots on the ground' that receive commands from the prefrontal cortex."
Prof. Anderson said missing the key chemical within the "memory" region of the brain might not be worrying when our thoughts are positive, but suggested it could be problematic for people constantly forced to remember unpleasant or traumatic events.
"Our ability to control our thoughts is fundamental to our well-being," he said. "When this capacity breaks down, it causes some of the most debilitating symptoms of psychiatric diseases: intrusive memories, images, hallucinations, ruminations and pathological and persistent worries.
"These are all key symptoms of mental illnesses such as PTSD, schizophrenia, depression and anxiety."
While the study does not examine any immediate treatments, Prof. Anderson believes it could offer a new approach to tackling intrusive thoughts in these disorders.
"Our study suggests that if you could improve GABA activity within the hippocampus, this may help people to stop unwanted and intrusive thoughts," he said.