The 3 Stages of Memory

Photo by Robina Weermeijer on Unsplash

Our current theory on memory is that though we have one memory system, it has three separate stages — sensory, short-term, and long-term.

Sensory memory is very short-term. This memory lasts less than half a second. That seems almost useless, but it allows you to capture an image, sound, or other sensation. These very brief not-even-moments then move immediately into short-term memory.

Short-term memory (which some theorists prefer to call "working memory") is both a filter and temporary storage. In this stage, we will either push out the memory or put it into long-term memory storage.

When a login code is sent to my phone that temporary popup is in my short-term memory, used, and then filtered out as non-essential. I certainly can't recall it a minute later. So, the filtering of these memories and discarding is a good thing. I don't want to remember everything I experience, see or hear forever.

Long-term memory holds valuable memories, although how that value is determined is not really understood. These memories are about as permanent as our memory gets and theoretically long-term memory can store unlimited amounts of information indefinitely.

These memories are stronger. It is why you can recall something from your childhood that happened 40 years ago. There are several reasons why these memories are retained. For example, recalling an event multiple times does put it more securely into long-term storage. Retelling that funny story from your vacation to multiple people over the course of months and years not only helps retain it but actually alters the memory.

The part that interests me more and more and I and my friends and family age is short-term memory since that is the part we lose as we get older.

Short-term memory seems to be temporarily stored for only 15-30 seconds. Brain studies have shown that the consolidation of short-term memories into long-term memories largely takes place in the hippocampus. But we don't have a "place" in the brain for short-term memory.

I take a deeper dive into short-term memory and some ways you might be able to improve it in an article I wrote at Weekends in Paradelle.