Have you ever thought about how many moments you have lived in your life and have you forgotten? How many things do you overlook every day? Have you ever wondered why? The truth is that our memory is very fragile and needs to be “recharged”.
One study published in Nature Communications showed a new scientific approach that can help our memory (and hence brain activity) with deep brain stimulation.
The impression of easy measurability of memory is not so well founded. Understanding how information can be processed by the nervous system and can be stored in the memory is a very complex process. Scientists at the University of Pennsylvania have decided to apply targeted stimulation to the lateral temporal cortex by enhancing memory through a neural device.
Brain stimulation: new discoveries
US researchers have found that information is remembered or forgotten based on the neural events that occur during the coding phase, which is the first stage that characterizes memory functioning and allows an event to be recorded as a pattern, image or concept.
A very promising tool for the modulation of neural activity seems to be precisely the direct stimulation of the lateral temporal cortex, thanks to the use of the electric current that is applied through electrodes implanted directly in the brain parenchyma.
The analysis of memory in real time
From Ebbinghaus to today, there have been countless studies on memory. Suffice it to mention Craik and Lockhart, according to whom it was necessary to analyze the mechanisms that allow us to remember information. In fact, they distinguished between a superficial encoding of information (based on the physical characteristics of the stimulus) and a deep codification (based on meaning).
The University of Pennsylvania study, on the other hand, carefully assessed the use of the lateral temporal cortex and stimulated it during the mnemonic activity. Specifically, the researchers used multivariate classifiers, distinct for each subject to decode neural activity during the coding phase and to understand the patterns of brain activity associated with the next phase of forgetfulness.
In short, the researchers analyzed brain activity in real time during the delivery of electrical impulses and produced customized models for each of the 25 patients undergoing the study. In this way, they could observe when the memory would fail and intervene with stimulation.
The study found that the stimulation of the left lateral temporal cortex increases the probability of recall of 15%. The subjects stimulated in the lateral temporal cortex were also more inclined to remember elements on which no stimulation had been performed.
Reliable results at the service of medicine
The results demonstrate that stimulating neural populations outside the MTL (short-term memory) reliably improves memory results.
Using a new method to apply stimulation, specific models have been developed for the neural activity of each patient, used to classify brain states related to memory. Stimulation was activated to intervene directly at times when memory was thought to be more scarce.
By demonstrating that the lateral temporal cortex is the primary objective for modulating the encoding phase of memory, we have gone beyond the previous work that attempted to influence episodic memory by stimulating the hippocampus and MTL. Therefore, the study could have significant consequences on the development of new therapies for the treatment of memory dysfunctions.
Direct brain stimulation is already regularly active in the treatment of Parkinson’s disease and the onset of epileptic seizures and has recently been explored as therapy in psychiatry.
The substantial difference compared to the past lies in the “closed circuit” system patented by US researchers, able to indicate when the brain is in a state of poor learning and to send electrical impulses to stimulate the brain area.
However, there have already been criticisms of this study which, although considered valid for the innovative methodological approach, is considered by some to be too invasive.
The hypothesis of such a traumatic approach, even in an experimental key, in the treatment of dementia is to be considered absolutely out of the question, at least until the results will be of these content.
A small reflection
Let us dwell on one thing: how much today we train our memory or do it in a different way than our parents. Reminding us is another US study published in the Memory journal, which underlines the emergence of the phenomenon of “cognitive offloading”, that is the tendency to use the Internet as a support for memory.
It has become so simple to type the keys of a smartphone to get information about anything that maybe we are no longer interested in remembering on their own. The other side of the coin is that we can be able to expand our capabilities with new technologies. Just like with the University of Pennsylvania study: a new frontier of science for the development of medicine on memory disorders.