Team Explores How Brain’s Anterior Shift Predicts Memory Clarity

One of the signs of cognitive aging is the fading ability to retrieve details of one’s experiences. This phenomenon has now been tied to the so-called anterior shift: When a memory is retrieved, the region of the brain that is most active is farther forward than when the memory was encoded.

Researchers from UT Dallas’ Center for Vital Longevity (CVL) published a study March 2, 2022, in The Journal of Neuroscience that shows that the greater the size of the shift, the foggier the recall.

While age is a factor in the size of the anterior shift, it is not the only one, the researchers found.

“We are the first research group to report the shift when recalling faces as well as scenes,” said CVL director Dr. Michael Rugg, holder of the Distinguished Chair in Behavioral and Brain Sciences. “And our study is the first to show that the shift is … larger in older people than younger people — although it varies.”

Forty-eight healthy participants — half with a mean age of 22 and half with a mean age of 70 — underwent functional MRI (fMRI) as they viewed word-image pairs for two seconds. The image was either a face or a scene.

After 10 to 15 minutes, participants viewed a series of words and were asked if they remembered seeing each word in the first phase of the experiment and, if so, whether it had been paired with a face or a scene.

The fMRI scans allowed the researchers to pinpoint which brain regions were active during each phase of the experiment. Those with the best memory for the word-image pairs had the smallest anterior shift.

“Whether you’re aged 20 or 70, the bigger your anterior shift, the worse your memory performance,” Rugg said.

– Stephen Fontenot