Why do we forget what we were going to do when we changed rooms?

He arrives at the kitchen with a clear idea, but as he crosses the door, something blurs. He no longer remembers why he came . And he stands for a few seconds in front of the refrigerator, as if the cold might refresh the intention that had been lost with the change of location.

This phenomenon has been studied by cognitive psychology and is known as the "doorway effect" (or location updating effect). Simply passing through a door is enough for the brain to interpret that one function has ended and another begins.

This happens because our semantic memory (the one we use to remember concepts) works best when it's associated with episodic memory (the one we use to remember places), and the latter is linked to contextual cues. Therefore, when we return to the original context—with some discretion, if someone is present—we usually recover the lost information.

A fleeting farce that could easily be performed on the stage of the iconic and carnivalesque Gran Teatro Falla in Cádiz, in front of which I am writing these words.

In the late 1970s, British psychologist Alan Baddeley (world-renowned for his studies on memory) and other colleagues conducted several studies with a curious cast.

In his most famous experiment, he asked a university diving team to memorize lists of words in two different environments: underwater and on land. He then tested the participants' ability to recall those words in both the same learning environment and the other. The result was clear: those who learned and remembered in the same location (water-water or land-land) performed better.

Over time, a hodgepodge of studies confirmed that context (and even mood) plays a key role in memory .

In other words, memory is like a theater actress who will play her role especially well if the set, costumes, and even the lighting are the same as in rehearsals. But if she hasn't studied the script thoroughly, she will succumb to the scene change that comes with walking through a door.

The term "threshold effect" was first coined in 2011, but it began to be studied in 2006. In that first study, the research team asked participants to memorize objects in a virtual space and then move (virtually) to another room. They found that, just after crossing a threshold, the ability to remember those objects decreased significantly.

Multiple subsequent investigations reinforced this general principle of memory updating. Furthermore, it was shown that the decline in performance was not due to the distance traveled or the time elapsed, but to the simple fact of changing the "scene."

These results support the idea of the "event horizon model": when the context changes, the associated information is segmented and becomes less accessible. Forgetting occurs even if we simply imagine walking through a door.

As has been shown throughout this article, it's not the door itself that erases our memory, but the change of scenery. The brain interprets this as the beginning of a new event and partially disconnects the information from the previous event.

Along these lines, several recent studies conducted using virtual reality have also confirmed that what matters is the transition between environments, not the act of crossing a threshold.

One of the main causes of these lapses appears to be multitasking. When we perform several actions at once, the brain divides its attention as best it can, and some information falls by the wayside. Our cognitive capacity is limited, and when the context changes, non-priority tasks can fade away.

Fortunately, these everyday forgetfulnesses don't indicate any serious impairment. They've been shown to affect young and old alike. This suggests that it's a side effect of how our minds organize experience, and not a warning sign of possible dementia.

In this sense, Nietzsche wrote: "Forgetting is a positive faculty in the strictest sense, a guardian, a guarantor of order and calm." If we didn't have the ability to forget, we would be overloaded with memories and have no room for action.

In fact, the 'threshold effect' has its positive side: changing rooms or spaces helps us remember new information better. By changing contextual cues, the location is updated and there is less interference with previous tasks. Thus, the brain takes advantage of the new environment to learn more clearly.

There's also the possibility of going "blank" without changing the scene: when we see a special and deeply loved person in an unexpected place and it takes us a while to recognize them. This happens because the brain needs to search for clues in the usual settings to make sense of them. This situation isn't indicative of a cognitive deficit either: the mind (and heart) is reconstructing itself in the face of an extraordinary and beautiful cloud of memories.

This article was originally published on The Conversation .