Say “prosthetic” and most of us think of artificial limbs, important devices that help people regain essential functions lost to injury or disease. Modern prosthetics, however, are a long way from that image. Today, they’re often an integration of electronics and living tissue and can support much more than physical locomotion. New bionic technologies aid hearing and sight. Soon, they may help thinking itself. Some researchers are even looking beyond replacement of lost capabilities to providing capabilities we weren’t born with. If they succeed, the effect may revise our concepts of what defines a “normal” human.
Memories are pretty important to most us. As collections of our experiences they anchor us to a personal sense of reality. Memories are pretty important to science, too; some of the earliest studies in psychology focused on their capabilities and qualities and they remain a major research topic today.
At a functional level, we know that memories are more like reconstructions than photographic records. Recall is an active process, and an imperfect one, so what we remember is rarely an accurate copy of the original event. We forget, we repress, and we confuse elements of some memories with elements of others (characteristics that make eyewitness testimony so unreliable).
What physical and biochemical processes in the brain can account for these functional properties? What actually happens when we form memories, and what happens when we forget? Two new studies, both from MIT, tackled these questions directly, and an effect of this work is to point out some weighty questions about how firmly our memories are tied to “reality” and what we could (or should) do to change them.