Try to remember a conversation without hearing it in your head. It is difficult, because sound has an impact on the formation of our memory. That’s why we forget about the milk at the store and leave without the one thing we came for: we heard the instructions, but we didn’t really listen.
This cognitive ability to keep sounds in mind for a short period of time was the subject of an article Posted in Neuron by a team from McGill University Brain Imaging Center. The study tested the effectiveness of a non-invasive brain therapy called transcranial magnetic stimulation, or TMS. Using a hand-held device placed against the scalp, the researchers positioned the targeted oscillating pulses (at 5 Hz) in the brain to stimulate nerve cells. (The pulses would not be painful.)
The group found surprising results. TMS appeared to directly improve the working memory of 17 participants in a recall task. Participants had to recognize a melody when the order of the notes played was reversed. After the TMS treatment, they were able to remember the series of sounds faster and more accurately.
“The most exciting aspect is that we have found a causal link between the brain and the behavior” Philippe Albouy, one of the study’s co-authors, told The Daily Beast. “TMS is easy to control because the stimulation is targeted. When you target a certain brain region, you are sure to hit that region.
TMS recently obtained FDA approval to treat depression, and the treatment is covered by some health insurance plans. McGill University study focused on theta wave activity in the auditory system back current, a pathway in the brain that helps us process speech. The group also compared the data to the control condition of 5 Hz TMS with non-rhythmic pulses. The brain activity of the participants was monitored simultaneously with two technologies: a huge cocoon magnetoencephalography (MEG) scanner, which records the magnetic fields produced by “brain waves”; And one electroencephalogram (EEG), a set of small, cap-shaped discs (electrodes) glued all over the scalp to track electrical activity in the brain.
“This means that we can use brain activity as a marker for subsequent interventions,” Albouy said. “That’s the interesting part.”
“TMS is easy to control because the stimulation is focused. When you target a certain brain region, you are sure to hit that region.“
– Philippe Albouy
The results of the study suggest broader clinical applications, according to Albouy. TMS, a “relatively painless” which does not require anesthesia or hospitalization, has the potential to treat other patients with working memory deficits, such as people with Parkinson’s or Alzheimer’s disease, or children and adults with ADHD.
“I think you can tell this method could apply to almost anything,” Albouy said. “The only thing is you have to set a brain marker for a given task. The task can be whatever you want. It can be attention, visual perception or memory. Once you have this marker and the region of interest, you can apply rhythmic stimulation during the task to improve performance.
Although TMS is an emerging experimental technology, some studies have shown – although with sometimes mixed results – that the technique has the potential to improve the lives of people with autism and post-traumatic stress disorder (PTSD), and those who fight against addiction, and chronic pain. A similar study in Science by a team of researchers from the University of Wisconsin-Madison demonstrated that TMS can help us remember: recent memories can be brought back and recalled.
Still, the researchers couldn’t find a way to help participants maintain their improved working memory. Usually, their performance drops after leaving the TMS machine.
The Albouy team is working on this problem. He is currently developing a study with HIV-positive patients who face memory deficits.
“We are trying to see if we can see any aftereffects. Then we will apply it to a clinical population, step by step, ”said Albouy. “We are trying to find models. It is a promising approach.
The TMS technique described in the study has the potential to be ready for clinical applications within a year (next spring), Albouy said. “I’m not sure. I can’t really predict that. We’re really in the early stages of this approach, so it’s hard to predict,” he said.
Another promising avenue for research is the impact of sound on long-term memory rather than on work. Evocative or emotionally charged sounds can change what we can remember and what we forget. Sound can take over what we think and feel. This is how a song brings you back. This is how accents move across families and time zones. It’s anticipating the break before someone tries to say your last name. (The author’s last name, for example, “Beebe,” is pronounced bee-bee, like two buzzing insects.) It’s the voice of the person you love, the music of their way of speaking, to laugh, shout or sing.