Thinking Cap Maps Memories
Byline: Greg Bolt The Register-Guard
A professor at the University of Oregon for the first time has punched a tiny peephole through the wall surrounding human memory.
In a study published today in Nature magazine, cognitive psychology professor Edward Vogel describes a new technique that allows him literally to watch as the brain stores visual information in its short-term memory. What's more, Vogel is able to tell how many images of things in their surroundings people are able to stash away for immediate use and can even get a rough idea of what those memories are.
"At a very coarse level, we're kind of reading their minds," Vogel said of his breakthrough research. "It's like it opens a window to us being able to directly observe the process by which people hold things in their awareness."
Actual mind reading is unlikely at best, but Vogel's research could help understand and diagnose attention deficit disorders and provide new insight into mental illnesses such as schizophrenia. Understanding how this crucial part of memory works also could lead to new techniques to boost memory capacity or stave off the memory-robbing effects of aging.
Vogel's research centers on a particular kind of short-term memory known as visual working memory. That's a process in the brain that stores images for immediate use, helping us do things such as pick out the best apples in a bin at the grocery store or drive a car down a busy street.
It turns out that a particular type of brainwave - which Vogel discovered during research on a different topic and named contralateral delay activity, or CDA - offers a window into the process of working memory. His research showed that the level of CDA activity in a region near the back of the brain known as the posterior parietal cortex correlates with the number and type of images being stored in visual working memory.
To glimpse the memory process at work, Vogel attaches electrodes to the scalps of subjects and monitors brainwave activity using sensitive electroencephalography equipment.
Vogel's experiments involved subjects looking at a brief image on a computer screen showing varying numbers of colored squares. Then they are shown another image in which either one or none of the colors is different and are asked if anything has changed.
Previous work by Vogel and others gave an approximate idea of how many images the brain can hold onto at any given moment, but this new research allowed him to make the first precise measurement of the memory holding tank based on electrical impulses. …