A memory system model based on processing mode rather than state of consciousness

The involvement of consciousness and types of memory?

People say that they have a strong or a weak memory, but I suspect that memory may have several types.

In my case, for instance, I am not good at remembering people’s faces and names, but that does not mean that my memory is weak in general.

My episodic memory, which relates to things others have said or done or things that have happened, is so good that people are surprised at the things I remember, and I rarely forget the taste of foods that I have eaten.

I wonder if there are different types of memory like this, and if everyone has a field of memory that they are stronger in.

Memory can be classified into:

• short-term and long-term memory;

or

• declarative and nondeclarative memory.

* Declarative memory: memories that can be expressed in words (such as various events, the names of kings and queens, and the meaning of the word “apple”)

* Nondeclarative memory: memories that cannot be expressed in words (such as how to ride a bicycle or memories about the feel of something in one’s mouth)

The paper I discuss today proposes a new method for classifying memory.

So, what is this new method?

The classification methods for memory to date have divided memory according to whether consciousness is involved when making or recalling memories.

Divisions were apparently made between memories made without express consciousness, such as how to place the skis when skiing or the angle of the wrists when hitting a spike in volleyball, and memories made with express consciousness, such as recollections from last year’s travel or the meaning of the word “apple”,

but the paper I discuss today proposes thinking about classifications of memory without talking about matters like consciousness.

In that case, how should memory be divided?

One way is by time, and another way is by vagueness.

Dividing by time means dividing according to whether the memory is encoded immediately or slowly over time. Immediately encoded memories are things like episodic memory, such as recollections from travel, or familiarity memory, such as having been to a place or having met a person before. By contrast, memories that are encoded more slowly would be things like how to ride a bicycle or how to judge distance.

Vagueness refers to the way that, for example, travel memories are vague and are remembered as a blurred integration of information on place, time and order.

In contrast, the word “apple” has only one meaning and is not vague, and procedural memories like how to wrap things are encoded in a fairly strict way.

Considering this, it seems possible to divide memory into:

• vague, immediately remembered things (episodic memory);
• clear, slowly remembered things (procedural memory, classical conditioning (Pavlov’s dog), meaning memory); and
• clear, immediately remembered things (familiarity memory, priming memory).

Using this method of classification means that the consciousness when encoding has nothing to do with how things are divided.

I understand the paper to be suggesting that each of these has its corresponding brain activity, and that classifying memory by the brain activity may be clearer.

If you want to know more, I hope this diagram will be as easy to understand as it was for me.

Reference URL for the diagram

[Abstract]

Prominent models of human long-term memory distinguish between memory systems on the basis of whether learning and retrieval occur consciously or unconsciously. Episodic memory formation requires the rapid encoding of associations between different aspects of an event which, according to these models, depends on the hippocampus and on consciousness. However, recent evidence indicates that the hippocampus mediates rapid associative learning with and without consciousness in humans and animals, for long-term and short-term retention. Consciousness seems to be a poor criterion for differentiating between declarative (or explicit) and non declarative (or implicit) types of memory. A new model is therefore required in which memory systems are distinguished based on the processing operations involved rather than by consciousness.

Reference URL: A model for memory systems based on processing modes rather than consciousness.