By BBC News Online's Caroline Ryan in Boston

We gathered information on the moment when the brain gives birth to various forms of memory

Prof Anthony Wagner, MIT

Using modern brain imaging techniques, scientists have recorded the patterns in activity that change depending on whether memories are going to be stored or deleted.

The study was done by a team from the Massachusetts Institute of Technology (MIT) and reported to the American Association for the Advancement of Science annual meeting, which this year is in Boston.

The researchers identified a number of different brain parts involved in the very complex process of creating and storing memories.

Future tests

In their tests, healthy men and women were shown a list of words or pictures while they were scanned using functional magnetic resonance imaging (fMRI), which recorded activity in the brain.

They were then given a surprise quiz 20 minutes later to see what they remembered. Researchers could then match the brain patterns to the stored memories.

Professor Anthony Wagner, who led the research team, said: "Using this brain imaging technique allowed us to characterise the human brain while it was in the process of building new memories."

In addition to telling scientists more about how memory works, the technique could also one day be used to identify early signs of conditions such as Alzheimer's disease, where the brain's memory circuits stop working effectively.

Professor Wagner said: "We can then use that exact same technology and look for changes in these circuits in individuals who haven't been clinically diagnosed as having Alzheimer's disease, but you'd like to catch them as early as possible, and this could be a diagnostic tool."