Sean Polyn's new study may mean that he can tell what people are thinking.
Polyn -- a post-doctoral researcher in the Psychology Department at Penn -- studies complex patterns in human brain activity. A study he released over winter break indicates that different thoughts leave distinct patterns than can be measured and identified.
Scientists call the phenomenon "mental time travel" because, Polyn said, "you're trying to make the brain look like it did at some time in the past."
Polyn first published an article on his research in the Dec. 23 issue of Science magazine. Since then, he has received a slew of media attention, with stories about his work appearing on MSNBC, Bloomberg News and the BBC World Service, as well as in Seed magazine and The Guardian, a British newspaper.
Polyn's study is "a landmark in our understanding of human memory retrieval," Penn psychology professor Michael Kahana said.
Polyn, who has been at Penn since last summer, came to the University to work with Kahana in Penn's Computational Memory Lab because of its "cutting-edge research in human memory," he said.
Polyn himself has high expectations for the benefits his research may provide in understanding how the mind works and have medical applications.
Polyn hopes that his work -- which indicates that scientists may be able predict whether their subjects are remembering a face, a place or an item -- will help create a more detailed model of how the human memory system works. This could could be useful in treating a variety of memory-related disorders, including Alzheimer's disease.
In the study -- which Polyn completed in May while a graduate student at Princeton University -- he asked nine subjects to look at 30 photos of celebrity faces, famous locations and common objects while connected to magnetic resonance imaging machines, which can measure changes in brain activity.
Photos included Halle Berry, Brad Pitt, the Eiffel Tower, tweezers and dice.
Later, he told subjects to recall as many photos as possible in any order. Polyn was able to predict which category of photo -- face, location or item -- a subject was going to name several seconds beforehand because each category elicited distinctive brain activity.
The study appears to show that the patterns of brain activity involved in memory are the same patterns involved in experiencing or seeing something for the first time.
One of the advances Polyn utilized in his study is the ability to see pictures of brain activity changing as subjects search their memories, he said.
With the more detailed model, psychologists could compare people with memory-related disorders to healthy people and "see where the process is running off the rails," said Princeton psychology professor Ken Norman, who worked on the study with Polyn.
The model could also help neurosurgeons avoid damaging or removing brain regions important for memory.
