ACT-R Basics: Declarative and Procedural Memory Systems

The basic unit of the procedural system is the production. This is an IF -> THEN pattern.

Think of productions like the atomic thinking steps involved in solving a problem.

Unlike the sprawling, interlinked declarative memory, productions ar...

All scientific theories are built on paradigms .A paradigm is an example that you take as central for describing a phenomenon.

Newton had falling apples and orbiting planets. Obviously, ...

Why two separate systems? A single system would be simpler. But there’s an impressive range of evidence arguing that these systems are distinct in the brain:

• Amnesiacs can learn through the procedural system, but not the declarative system .
• Procedural ...

The declarative memory structure is vast, but only a few chunks are active at any one time.

This reflects the distinction between conscious awareness and memory. When we need to remember something, we search through the network.

• For practiced memories

ACT-R explains complex skills as an ongoing interaction between these two systems.

• The declarative system represents the outside world, your inner thoughts and intentions.
• The procedural system acts on those representations to make ov...

The basic unit of declarative memory is the chunk. This is a structure that binds approximately three pieces of information.

The idea is that, through experience, we connect these chunks into elaborate networks. We can then traverse these ...

How do we learn to perform complex skills like programming, physics, or piloting a plane? What changes in our brain allow us to perform these skills?

These are hard questions. Most experiments only attempt to address narrow slices of the problem.

This is what makes J...

In the ACT-R theory, learning skills is thought to be a process of acquiring and strengthening productions.

Initially, productions are learned via analogy. We search our long-term declarative memories for a similar problem. Then we try to match this to our current represent...

How do nodes get activated?

1. First, you perceive things from the outside world that automatically activate nodes in memory .
2. Second, you can rehearse things internally to maintain them in memory
3. Third, nodes can activate conne...

1. You form a representation of the problem in your declarative system . .
2. Productions compete with each other based on this current representation .
3. As each production is executed, it changes your present state .

ACT-R argues that we don’t learn by explicit instruction, only by example.

When we appear to learn via instruction, we first generate an example based on the instruction and then use this example to create a new production.

Once created, productions are strengthened ...