Information Technology Reference
In-Depth Information
Table 1.
Examples of declarative and procedural knowledge in 4*4 Sudoku
Knowledge Example
Declarative Knowledge (chunk-type Sudoku x1 x2 x3 x4)
(Chunk-Type, Chunk) (chunk-type quesdata a1 a2 a3 a4 . . . )
(p1 isa Sudoku x1 1 x2 2 x3 3 x4 4) . . .
Procedural Knowledge visual-?, visual-row, visual-col, visual-box
(Production Rules)
encode-row, encode-col, encode-box
get-answer, pressing, . . .
2.2
ACT-R Model
Although some results have been obtained from fMRI data, such as BOLD re-
sponse of five brain regions, these results cannot tell us detail information pro-
cessing processes to understand how the problem solving is processed [14] and
how these cognitive processes work on the change of BOLD response of brain
regions. Therefore, ACT-R modeling is combined with fMRI data to help us
solving these problems [1, 4].
The Steps of Modeling
. In general, the following steps are involved to set up
a cognitive model in ACT-R.
-
Simulating stimulus environment. This is the first step in ACT-R modeling
that makes the model performing the task as a real participant.
-
Defining declarative knowledge and procedural knowledge. Two knowledge
definitions are the main components of an ACT-R model that help to set up
a successful model.
-
Setting parameters for a new model. Most of parameters are default except
some of them may not fit to a new task.
-
Debugging and running the model to get a prediction of behavioral data RT
and functional fMRI BOLD response.
Two Knowledge Definitions of the Model
. In ACT-R, declarative knowl-
edge is presented as chunk defined by chunk-type and slots while procedural
knowledge is presented as production rules like if/then patterns. Table 1 lists
the two knowledge definitions of 4*4 Sudoku (only part of them): chunks like
the form of 1 to 4, the information related '?', production rules like encode '?'
and encode heuristic information in row, column and box dimension, and so on.
Parameters
. Table 2 lists the parameters of the model for predicting the BOLD
response in five predefined brain regions, where
m
is the scales the magnitude of
the response,
s
is the time scale and
b
is the exponent. Others are using default
values.
Hypotheses of Cognitive Process
. The cognitive processes of 4*4 Sudoku
problem solving are supposed as follows. Firstly, participants encode the ob-
ject '?', and then they shift to related dimensions to encode the information to
retrieve heuristics and omit irrelative information. While gathering the digits
