Short Term and Long Term Memory

Hi, my name is Philip Tseng. Today we’ll be focusing on the role of short-term memory in supporting consciousness . As you can see on the chart here, there are many different types of memory, and this chart is far from being a complete list. We’re quite familiar with the concept of muscle memory and long-term memory, while things like iconic, or sensory memory, or different subtypes of short-term memory, might be less familiar to us. But most people have an intuitive idea of what short-term memory and long-term memories are. Basically, long-term memory is what I can remember forever, or at least for a very long time while short-term memory is not.

But when you start asking people, so how short of a duration does it have to be. Toqualify as short-term memory, answers start to vary. Even among cognitive psychologists, some people might say hours and minutes. And some might say seconds, and some might even say less than a second for short-term memory.

There is no clear answer at the moment, but most studies in the field of short-term memory have focused on the range of seconds and minutes for practical purposes. Because if you can’t even remember something for a few seconds or minutes, it’s pointless to talk hours. As you can see in the chart, there are many memory systems that go beyond the short-term and long-term dichotomy. Some of these systems, like muscle memory, also known as procedural memory. On the right, and sensory memory, they’re not always subject to conscious awareness, or experience. Whereas other systems such as episodic and semantic memory systems they often are.

So how different are short-term and long-term memory? Besides their duration, the most noticeable difference is their speed and capacity. Long-term memory has unlimited capacity but requires some time in order to access it. Short-term memory is like a complete opposite, it has very fast access but also very limited capacity. So if you don’t rehearse everything in your short-term memory right away, such as a new friend’s phone number that you just got, You’re very likely to forget it within a few minutes. It’s almost like comparing between the rams and hard drives of your computer if it helps,

Now why is short-term memory related to consciousness？ The rationale is that short-term memory has rapid access a limited capacity, which sounds a lot like our consciousness. Where we can think of different things quickly but we’re bad at thinking about multiple things, or maintaining them all in our mind atthe same time. So the short-term memory consciousness, are they the same？ Maybe, maybenot. One question we can ask ourselves is are people with amnesia have memory problems？ Are they conscious? And I think the answer is obviously a yes.

So what happens is that if you lose your ability to form and maintain short-term memory, then all you have is the memory of now, because you don’t have or you don’t know or remember what just happened, and you don’t know what to expect later, because you don’t remember what happened before. So it sounds like a quick way to become the ultimate zen master, but anyway you should still be conscious even though you have amnesia. But it would be a bunch of fragmented conscious moments that do not necessarily connect witheach other, and they fade away very quickly. So it’s not a very functional form of consciousness, if you don’t have your short-term memory.

Therefore perhaps a milder claim is that short-term memory is one of the many important building blocks of consciousness.