Memory unreliable by nature

Hindsight may be 20/20, but mind your step when you stroll down Memory Lane.

A new study in The Journal of Neuroscience suggests our memories are anything but steady, because we subconsciously adjust them in relation to present experience. How you recall your first job may be different on the first day of a new one than it was on the day you lost the old one, but that's OK, says one researcher at Northwestern University. It's just your brain helping you adapt to changing environments.

This study builds on earlier research to help scientists explain why we can feel very certain that something happened when it didn't (or the reverse). It may also be why eyewitness testimony is notoriously unreliable. Some Alzheimer's researchers believe the same phenomenon may be a factor for those patients; their memories "freeze" so they are unable to relate them to the present.

Memory isn't static. Each time we retrieve one we have the opportunity to change it, and we tend to do just that. As University of Auckland (New Zealand) professor Donna Addis commented on this area of research, our memories are less a photographic snapshot of the past than they are "a record of our current view on the past."

Instead of putting memories in a file drawer and using a different part of the brain to retrieve them, research suggests both are done with the same area - the hippocampus. This also relates to hopes for the future. Depression and post-traumatic stress can disrupt this entire process, making it literally more difficult to feel positive about the future, because the brain is stuck in particular points in the memory retrieval process.

This relationship between memory and its associated emotions - how we feel not just at the time the memory was formed, but also (perhaps more so, this research suggests) how we feel at the moment we retrieve memories - may also be a key component in creative imagination. It also plays a role in social interaction, providing flexibility so we may adjust to new information and surroundings to see others, and the world, differently. As we change, so do our interpretations of what we recall and how those experiences impact us today.

Gandhi (also attributed to Anais Nin, Stephen Covey, The Talmud, Charles Lamb...) said we see the world not as it is, but as we are. Apparently that's also how we remember it, so whoever said it perhaps the lesson is to simply consider "truth" a lifelong pursuit.

Sholeh Patrick is a columnist for the Hagadone News Network. Sholeh@cdapress.com.