Information Technology Reference
In-Depth Information
on-
task
on-
task
Au1 Au2
Au1 Au2
+
+
Ad1
Ad1
Ad2
Ad2
=
=
Response and Rest time
Response and Rest time
Au1
…
Au1
…
off-
task
off-
task
Rn1
Rn1
Rn2 Rn3
Rn2 Rn3
Rn4
Rn4
Rn5 Rn6 Rn7
Rn5 Rn6 Rn7
Rn8
Rn8
Response and Rest time
Response and Rest time
Rn1
Rn1
…
…
[s]
[s]
…
…
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
1.0
8.0
8.0
Au : Augend
Ad : Addend
Au : Augend
Ad : Addend
Rn : Random number
: Trigger signal
Rn : Random number
: Trigger signal
Fig. 3.
Timing diagram of all tasks
movement measurement (2ch) is also used. The sampling frequency is 1000 Hz.
The number of experimental subjects is 7.
4
Data Analysis and Simulation
The same mental arithmetic tasks as described in Section 3 are used to combine
ERP/potential topography analyses and ACT-R simulation from the viewpoint
of spatiotemporal characteristics. This is because ERP analysis provides an ex-
cellent temporal resolution. The advantage of potential topography analysis is
that it catches the electrical fluctuation and gives a rough visualization of the
spatiotemporal characteristics for recognizing distribution and appearance of
positive and negative potentials. Furthermore, ACT-R simulation can predict
the process of information processing in a 5 msec scale and can specify acti-
vated areas by modularized units for the real brain ERP data. By using such a
multi-aspect approach, we attempt understand human problem solving process
in depth.
4.1
ERP Data Analysis
For the measured EEG data, a maximum of 102 addition average processing were
performed, and the ERPs were derived by using Brain Vision Analyzer (Brain
Products, Munich, Germany). Generally speaking, the Wernicke area of a left
temporal lobe and the prefrontal area are related to the computation process [7].
In this study, we pay attention to recognition of the number, short-term memory
andintegratedprocessing,vision,aswell as comparing Level 1 and Level 2 by
focusing on the following three important channels: AFz, CP3, and Oz.
Figure 4 shows the ERP with respect to the three important channels: AFz,
CP3, and Oz. First of all, from the on-task related waves, some remarkably
results are found in each stage of the computation process, such as augend,
plus, addend, and equal. For instance, it can be confirmed that P250 appears
in channel AFz, P300 or P400 appears in CP3 that is near the part of language
interpretation, and N250 appears in the visual projection area Oz. Furthermore,
although it is large in the stages of augend and addend presented, the reaction
is small in the stage of the equal sign presented.
