The device noticed when patients struggled to learn a word CREDIT: DR ROBERT FRIEDLAND

The US study was described as “promising” by British Experts, but they cautioned it was too early to say for sure if it promises a treatment for dementia.

The machine works by monitoring the brain for indications they are not learning words properly and giving short bursts of electricity to neurons.

Stimulating a specific area that processes language "reliably and significantly" boosted patients ability to remember words, the researchers said.

Other examples of neurostimulation technology have been used to improve sleep and curb anxiety.

The experiment involved 25 patients and focused on the medial temporal lobe, which is understood to play a significant role in the formation and consolidation of new memories.

The lobe was stimulated with the device detected, by the position of the participant’s head, indicated they were struggling to memorise a particular word.

The patients were asked to memorise 12 common words which appeared on a screen for 1.6 seconds.

They were then given a number of arithmetical tasks to distract them before being asked to recite the words back.

Dr David Reynolds, chief scientific officer at Alzheimer's Research UK, said: "While dementia involves a range of complex symptoms, memory problems are among the most common and can have a devastating impact on many people's lives.

"Brain function depends on electrical as well as chemical signals, and as technology advances, research is beginning to investigate whether direct electrical stimulation of certain areas brain could help improve aspects of memory and thinking.

He added: "Ways to improve memory and thinking skills is a key goal in dementia research, but it has now been over 15 years since researchers developed a new drug that is able to do this.”

The study carried out at the University of Pennsylvania was published in Nature Communications.