A device that gives the brain electric shocks has prompted hope for Alzheimer’s patients after an initial trial showed it could improve memory by 15 per cent.

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.