Working Memory Located In More Than One Place In The Brain
A recent study by British and German scientists found that the part of the brain usually associted wtih long-term memory may also be associated with working memory. The study focused on the hippocampus which has traditionally been thought to have a role in long-term memory, spatial memory and navigation. This is also one of the first parts of the brain to suffer in patients with Alzheimer’s disease.
The study looked at patients with temporal lobe epilepsy which causes problems in the hippocampus leading to short-term memory problems. The researchers said, “The patients could not distinguish the studied images from new images after 60 minutes but performed normally after five seconds.” Professor Emrah Duzel of University College London went on to say that a striking deficit emerged even at five seconds when the subjects were asked to recall the detailed arrangements of objects within scenes in photographs.
The study concluded that there are two distinct short-term memory networks within the brain. The other one that is separate from the hippocampus remains intact in patients with hippocampus-related disorders.
Nathan Cashdollar, also from University College London said, “This is the fist functional and anatomical evidence showing which mechanisms are shared between short-term and long-term memory and which are independent.”
The findings of this study, I think, are interesting in showing that there are distinct elements to short-term memory and that they are located in different areas of the brain. When I was in Dr. Attila Turgay’s (one of the leading experts on ADHD in Canada) office last year he did three separate tests for short-term memory: verbal, numerical and spatial. It was only spatial short-term memory with which I had trouble. If indeed this function is located in a different part of the brain than either verbal or numeric working memory it does make sense that one aspect of working memory would by dysfunctional while the other two are intact.