This is one of the more interesting studies I’ve come across this year:

A new study led by Gabriel Radvansky shows that the simple act of walking through a doorway creates a new memory episode, thereby making it more difficult to recall information pertaining to an experience in the room that’s just been left behind.

Dozens of participants used computer keys to navigate through a virtual reality environment presented on a TV screen. The virtual world contained 55 rooms, some large, some small. Small rooms contained one table; large rooms contained two: one at each end. When participants first encountered a table, there was an object on it that they picked up (once carried, objects could no longer be seen). At the next table, they deposited the object they were carrying at one end and picked up a new object at the other. And on the participants went. Frequent tests of memory came either on entering a new room through an open doorway, or after crossing halfway through a large room. An object was named on-screen and the participants had to recall if it was either the object they were currently carrying or the one they’d just set down.

The key finding is that memory performance was poorer after travelling through an open doorway, compared with covering the same distance within the same room. “Walking through doorways serves as an event boundary, thereby initiating the updating of one’s event model [i.e. the creation of a new episode in memory]” the researchers said.

But what if this result was only found because of the simplistic virtual reality environment? In a second study, Radvansky and his collaborators created a real-life network of rooms with tables and objects. Participants passed through this real environment picking up and depositing objects as they went, and again their memory was tested occasionally for what they were carrying (hidden from view in a box) or had most recently deposited. The effect of doorways was replicated. Participants were more likely to make memory errors after they’d passed through a doorway than after they’d travelled the same distance in a single room.

Another interpretation of the findings is that they have nothing to do with the boundary effect of a doorway, but more to do with the memory enhancing effect of context (the basic idea being that we find it easier to recall memories in the context that we first stored them). By this account, memory is superior when participants remain in the same room because that room is the same place that their memory for the objects was first encoded.

The full paper is here. I am not entirely convinced the effect is causal, but I certainly believe there is a relationship between the walking through a doorway and forgetting. In fact, one of the superstitions that I’ve heard since childhood is that if I have forgotten something, I should turn around and return to the place where I last remembered it. That often involved passing from one room to another via a doorway.