Our minds are primed for efficiency and have a few tricks that they use to help us work around our limitations. When it comes to our memory, our minds “help” us recreate our experiences by literally filling in the blanks.
Like everything in our bodies, our brains have limits on how much information we can take in at any one point in time. While there are slight differences in these reported limits, the average person can take in around 120 “bits” of information per second. A “bit” of information might be the tone of a voice, the expression on a face, the lighting in a room, the background noise, and so the list continues. Of course we don’t always take note of everything we are exposed to, and what we do focus on is a matter of both relevance and attention.
When we think about a memory, we in fact re-create the memory with all of the information we have stored about that experience. Of course in many situations our actual data is incomplete. Because we are visual creatures and our brains like “complete” pictures, we often fill in the blanks to create the whole scene. This might be something as insignificant as the colour of clothing, however depending on the relevance and attention we paid to the experience we might miss a lot of detail. The song “I remember it well” from Gigi makes comical reference to this all too common occurrence.
Research has been used to explore the extent of these changes. A study, undertaken directly after the September 11 twin towers attack asked 2000+ people to recall the tragic events that unfolded on that day. Study participants were followed up 1, 3 and 10 years after the event. Even by the time 3 years has passed, the accuracy of some of the details had almost halved! While people’s memories about the actual events were most accurate (perhaps reinforced by media coverage post event), memories about where people were when the planes crashed were significantly different.
What’s even more interesting is that the more a memory is recalled, the more convinced the person becomes that these “blanks” filled in by the brain are factual information. By knowing and understanding this, you can appreciate how this can be a source of conflict as two people will often recall different stories from the same experience. Have you ever recalled a memory only to be told that some of the details are incorrect?