Johnny Mnemonic

Every wondered what, as Seinfeld would say, is the deal with memories?

Newly born brain cells, thousands of which are generated each day, help "time stamp" memories, according to a computer simulation by scientists at the Salk Institute for Biological Studies in La Jolla, California, and the University of Queensland in Australia. The research was published in the journal Neuron.

These cells do not record an exact, absolute date -- such as January 28, 2009 -- but instead encode memories that occur around the same time similarly. In this way, the mind knows whether a memory happened before, after or alongside something else.

Neuroscientists believe that if the same neurons are active during two events, a memory linking the two may be formed.