A recent study into the effects of repetitive transcranial magnetic stimulation (rTMS) suggests that fewer stimulations of the brain during the treatment could be more efficient, as neurons ‘get tired’ when stimulated too fast, resulting in the brain ceasing to respond to the therapy.

The study was led by Professor Ido Kanter from Bar-Ilan University in Israel and was conducted in collaboration with a group of neurologists led by Professor Walter Paulus from University Medical Center Göttingen in Germany.

The theory the researchers are proposing contradicts the idea that faster and more intense training of the human brain is the most effective kind of therapeutic strategy.

rTMS is widely considered to be one of the most promising non-invasive brain therapy methods and is most often used to treat severe depression. It can also be used to treat a variety of other brain functionality disorders such as stroke and multiple sclerosis. The procedure involves placing a magnetic coil near the head of the patient, transmitting a magnetic pulse to the targeted region in the brain.

Currently, one of the main challenges of the treatment is the struggle to enhance its efficiency by optimising the timing of the magnetic pulses.

The researchers demonstrated that each neuron has a maximal firing rate that is much lower than previously assumed. Therefore, neuronal response failures occur if neurons are stimulated too fast. The team argues this newly-discovered principle of neurons is advantageous because it stabilises brain activity and prevents hyperactivity.

“Neurons are like people,” Kanter said. “Stuttering occurs when we speak too fast, errors occur when we type too fast, and confusion emerges when we learn too fast.

“We evaluated a variety of existing rTMS scheduling protocols which offered conflicting results and no clear guideline for the temporal organisation of brain stimulations. Our findings suggest that slower rates of stimulation may be more effective in brain therapy, and we suggest that this method be adopted in order to maximise effective brain therapy.

“While modern computers are composed of very reliable elements, the brain is composed of unreliable elements, since neurons ‘tire’ and frequently fail to respond.”