Scientists from the Britain’s University of Cambridge have identified a chemical in the brain’s “memory” region that allows us to suppress unwanted thoughts.
They found people who had the highest concentrations of GABA in their brain’s hippocampus (or memory hub) were best at blocking unwanted thoughts or memories.
GABA, or gamma-aminobutyric acid, is often thought of as a sort of “downer” chemical because of its tendency to tamp down on hyperactive brain cells.
A region at the front of the brain known as the prefrontal cortex is known to play a key role in controlling our actions and has more recently been shown to play a similarly important role in stopping our thoughts.
The prefrontal cortex acts as a master regulator, controlling other brain regions, the motor cortex for actions and the hippocampus for memories.
Led by Prof. Michael Anderson and Dr. Taylor Schmitz, the researchers submitted a group of healthy test subjects to what’s known as a Think/No-Think procedure.
This involved first teaching the subjects to associate a series of words with other unrelated words, such as associating the word “ordeal” with “roach.”
Next, they were asked to recall the associated word when shown the first word, but only if the letters of that first word were colored green. If the letters were red, they were instead supposed to suppress any thoughts of the associated word.
While this was happening, the research team analyzed the participants’ brains with a combination of fMRI (brain imaging) and magnetic resonance spectroscopy, which measures chemical changes.
The results showed that concentrations of the neurotransmitter GABA in the hippocampus, a brain area central to memory, made all the difference as to whether someone was able to manage the unwanted thought from materializing.
“Our ability to control our thoughts is fundamental to our wellbeing,” said Michael Anderson from the University of Cambridge in the UK.
“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,” said Anderson.
“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.
Scientists now have a better grasp of how healthy people shut down a negative thought and they think their findings could one day help people suffering from psychiatric diseases, too.
Still, the study has some limitations in terms of its applications for people with psychiatric diseases. The study was published in the journal Nature Communications.