Stages of Memory

Doctor Josh Dubnau explains that memories seem to be formed in different stages that evolve over time. These include acquisition, short-term storage, and consolidation.

One of the most fascinating things about memory in all animals is that memories are not one thing. Aristophanes said thousands of years ago something to the effect of, “My memories have two forms; long and short.” What that statement says is that, even thousands of years ago, people noticed just by introspection, that the quality of a memory changes over time from when you first learn it until moments, hours, days, weeks, months or years later. What we know is that the quality of a memory evolves over time and taps into different mechanisms, and that’s why it has a different qualitative feeling to us when we think of trying to remember a phone number when we are dialing it versus remembering our phone number. During this process of memory storage, memories are sequentially transferred into different forms that have different characteristics. We have an early stage of acquisition when an animal first learns about the relationship amongst stimuli in the environment, and then we have a short-term memory period where that association that’s learned is stored for a short period of time in a way that is very robust in a sense that we have access to that memory very easily, but very labile in a sense that it’s easy to disrupt. Then there is a period of time when that memory can be consolidated, which is jargon for transferring it into a form that is much more stable, but maybe less easily accessed. And then there is the retrieval, which is the time when we activate an old memory; when stimuli in the environment remind us of something in our past, and that old experience comes back into the forefront and is experienced in a vivid way again.