High motor excitability means better working memory

If you have high motor excitability -- which means excitability of neurons in the prefrontal cortex of the brain -- you are better equipped to memorise a phone number, or your girlfriend's birthday, than those who don't have it.

Humans with a high motor excitability have a better working memory than humans with a low excitability, according to a new study.

Moreover, said scientists at University of Basel in Switzerland, by measuring motor excitability, they can define general cortical excitability that lead to overall cognitive performance.

"The motor cortical excitability can be easily studied with transcranial magnetic stimulation," Nathalie Schicktanz, lead author of the study, was quoted as saying.

During this procedure, said the study, electromagnetic impulses with increasing intensity were applied over the motor cortex of 188 healthy people.

For people with high motor excitability, already weak impulses are sufficient to trigger certain muscles such as those of the hand to show a visible twitch.

The scientists found that people with a high motor excitability had increased working memory performance as compared to subjects with a low excitability.

"By measuring the excitability of the motor cortex, conclusions can be drawn as to the excitability of other cortical areas," added Schicktanz.

The results might also have important clinical implications, as working memory deficits are a component of many neuro-psychiatric disorders like schizophrenia or attention deficit hyperactivity disorder.

"The findings help us to understand the importance of neuronal excitability for cognitive processes in humans," added Kyrill Schwegler, co-author of the study.