A new study has found that research on how people forget things may have unintentionally stimulated better memories among participants.
This experiment was first conducted in 2012. It was intended to examine the role of the left dorsolateral anterior cortex (DLPFC), in voluntary forgetting.
The 2012 experiment proved that forgetting is something the DLPFC actively managed. However, there was a bonus in its data.
Reanalysis shows that the right frequency of magnetic stimulation can be used to stimulate this area of the brain as we learn new material.
Simon Hanslmayr, a cognitive neuroscientist at the University of Glasgow, said that they were surprised to see these effects in the initial study. This was a study designed to examine a different question.
Researchers conducted another experiment to verify that the results weren't just random. It involved 24 healthy adults being presented with two lists of ten words and asked to remember them. Both lists were shown separately twelve times.
The participants were then asked to recall the words on the lists.
Half of the group was given a single hertz slow repetitive transcranial magnet stimulation (rTMS), to the prefrontal cortex while the words were being spoken. Half of the group received a hertz rTMS at the top of their heads.
Participants in the DLPFC control group performed better than those who received magnetic stimulation.
Although the stimulation did not seem to improve participants' ability to remember the order of words, it did help them recall each word individually.
This new study was limited to two dozen healthy adults. It is important that you take the findings with a grain. The results are not conclusive.
They not only support the findings of the 2014 study but also match similar studies that have been done on DLPFC and its role for memory formation.
Studies that actively stimulated DLPFC have previously shown a decrease in memory performance. However, rTMS is a different kind of stimulation. This slow stimulation appears to have an inhibitory effect in most cortexes, and not an excitatory.
Major depressive disorder sufferers may find the new treatment of rTMS to be a promising option.
These inhibitory effects could even spread from the DLPFC into a nearby area known as the parietal cortex.
This brain area is responsible for attention and perception. Brain imaging studies show that when this activity is decreased, our focus and memory performance tend to improve.
For instance, during the 2012 study, scientists observed a decrease in electrical activity in the parietal area of brain stimulation patients.
Mircea van der Plas, a neuroscientist at the University of Glasgow, says that "our electrophysiological results indicate that frontal stimulation affects an broader network and improves memories formation by inhibiting paraietal areas."
"These are interesting, complex effects that need further research to understand their neural basis."
Before we can determine how widespread these effects may be, the results must be replicated in larger groups.
Noninvasive brain stimulation (NIST) has been emerging as a promising treatment for memory loss, and other neurological conditions, such as Alzheimer's disease, that can affect memory.
Although neuroscientists are still trying out to determine which brain parts to stimulate and how to get the best results, progress is being made slowly.
In a brain imaging study, a 2019 brain imaging study found that multiple sessions of high frequency magnetic stimulation to the hippocamp improved the neural markers of memory loss. Behavioral hallmarks of memory impairment were also reduced in older adults.
A 2014 study that focused on the right DLPFC but not the left also found improved memory performance through magnetic stimulation during memory code.
While more research is required to unravel the mysteries of magnetic stimulation and memory, re-analyzing existing datasets and replicating those findings could be a good step in gaining more information.
The study was published by PLOS Biology.
