Researchers believe a drug used to treat people with Parkinson's Disease could be used to improve thinking ability in all older people.
A chemical called dopamine in the brain helps us interpret actions and make better decisions in the future, but as we age this chemical's ability diminishes.
However, a study conducted by the Wellcome Trust Centre for Neuroimaging at University College London found a commonly-used Parkinson's drug could reverse this process.
Dr Rumana Chowdhury, who led the study, said: "We found that when we treated older people who were particularly bad at making decisions with a drug that increases dopamine in the brain, their ability to learn from rewards improved to a level comparable to somebody in their twenties."
The drug, L-DOPA, was given to 32 healthy people in their seventies. Their brain activity was then monitored and compared to results from 22 volunteers in their twenties.
The study has been published in the journal Nature Neuroscience.