Many researchers have assumed that short term memory was a function distributed over many parts of the brain. Nature reports that two new studies have produced the suprising result of showing that short term memory is actually located in a specific part of the brain about the size of a penny. While short term memory capacity could be measured with psychological tests already, it can now be seen in MRI scans. One of the studies was led by Edward Vogel of the University of Oregon and used electrodes attached to the scalp to measure electrical activity associated with short term memory. The other study was led by René Marois of Vanderbilt University and used MRI scans to localize short term memory associated with vision. Data from both groups pointed to the same brain area and both groups were able to predict the short term memory capacity of subjects. The story is also mentioned on Slashdot under the title "Brain's Cache Memory Found".