Do you have a long shopping list that you need? remember? Or the names of those invited to an important meeting?
There are memory tricks that are used to train the brain so that it works better: the so-called “software” method to improve mental capacity.
But could we also use hardwarethat is, devices that give an electrical impulse to the brain?
So far, this technology has been developed to help restore brain function in certain neurological conditions.
Deep brain stimulation (DBS) is one example: a complex technique that has been used for many years to treat people with movement disorders such as Parkinson’s disease.
Brain pacemaker
Professor Francesca Morgante, from City St George’s University in London, has observed the impact of deep brain stimulation (DBS) on his patients.
“[La ECP] “It is considered for those whose medication fails to control symptoms,” he told the BBC World Service’s CrowdScience programme.
In Parkinson’s disease, the cells that produce dopamine, the chemical messenger, die.
Dopamine is necessary for signaling in the parts of the brain that control body movements. Without enough dopamine, Parkinson’s sufferers may experience symptoms such as tremors, stiffness, and slowness of movement.
The disease worsens over time and currently has no cure.
DBS involves surgically implanting a pulse generator under the skin, usually just below the collarbone. This is connected to wires or electrodes that are inserted into the affected brain areas to stimulate them with a small electrical current.
The device acts as a brain pacemaker, Morgante explains, helping to restore normal brain signaling.
There is no one-size-fits-all approach.
While deep brain stimulation can help relieve some of the symptoms of Parkinson’s, it is not always effective.
The ways in which the vast network of neurons send electrical signals to each other are complex and, as yet, not fully understood.
“There are many more symptoms than just tremors and mobility problems,” says Dr Lucia Ricciard, also from City St George’s University, London. “They include symptoms such as depression, anxiety, lack of motivation, memory problems and sleeping difficulties.”
And he adds that studies suggest that deep brain stimulation may also help relieve some of these symptoms, such as depression and anxiety.but more research is needed.
Additionally, there are individual considerations. Each brain is highly complex and unique, so there is no one-size-fits-all approach.
The implanted leads used in DBS consist of multiple independent segments that connect to different neurons.
Experts must determine which segments to stimulate to achieve the greatest impact on the patient’s symptoms.
“The decision of which one to activate and with what parameter in terms of frequency, amplitude and pulse: there are many aspects we have to consider,” says Ricciard.
This personalized calibration process, traditionally done through trial and error, is constantly improving, especially now that AI can suggest which combinations are best for each brain.
A memory booster?
It is not yet clear whether brain stimulation serves to improve other functions such as memory. However, that is currently the subject of investigation.
Human memory is centered in a brain region called the hippocampus.
It receives information from other parts of the brain, such as the smell, sound and image of an experience, and converts it into a code that is stored short or long term, explained Dr. Robert Hampson, a memory expert at Wake Forest University in the United States.
Several years ago, his team conducted experiments with small rodents, giving them a task that required the use of memory, and observing the appearance of specific electrical patterns before the animal decided what to do.
“If the lab rat is going to turn left, I get a pattern I call ‘left,’ and if the lab rat is going to turn right, I get a pattern I call ‘right,’” Hampson explained.
“We discovered that there are patterns associated with the correct functioning of memory and its possible failure”, he stated.
Hampson began to wonder if it might be possible to influence these patterns and “repair memory when it fails.”
His team pioneered the first human tests of a device called a hippocampal neural prosthesis, although Hampson described it as “more like a crutch or a cast” than a prosthesis.
Similar to DBS, it involves the surgical implantation of numerous electrodes, this time aimed at the hippocampus.
The technology is not yet fully developed. Therefore, instead of a pacemaker, the electrodes are connected to a large external computer that can send and receive signals from the brain.
“We try to restore function when it is weakened or lost,” he said.
The first signs are promising when tested in people with epilepsy.
“We saw a 25% to 35% improvement in the ability to retain information during this time, from about an hour to 24 hours.“Hampson commented. “This was observed in the subjects who had greater memory problems at the beginning of the test.”
Possibilities for the future
This technology could one day help those suffering from memory problems such as Alzheimer’s, according to Hampson.
But could the brain of anyone be improved, not just those who suffer from degenerative diseases?
Hampson believes we still have a lot to learn about why some people’s memories work better than others.
“We don’t necessarily have enough information to say, ‘Can we improve (the brain) beyond normal?’” he said.
And, of course, there are ethical hurdles to consider, in addition to the risks of brain surgery itself.
“Memory is the essence that defines us, and the only thing we don’t want is to change it” commented Dr. Hampson.