Localization of activated areas and directional EEG patterns during mental arithmetic

Area of Science:

• Neuroscience
• Cognitive Science
• Brain Activity Analysis

Background:

• Understanding the neural basis of cognitive processes like mental arithmetic is crucial.
• Electroencephalography (EEG) offers insights into brain activity.
• Localized EEG desynchronization can indicate cortical activation.

Purpose of the Study:

• To identify physiological correlates of mental activity during mental arithmetic.
• To map localized cortical activation using EEG.
• To examine directional brain activity patterns using information flow measures.

Main Methods:

• Assessed EEG desynchronization using the irregularity index (II) of the EEG power spectrum.
• Employed topographic mapping of II to visualize cortical activation.
• Utilized directed mutual information to measure information flow.
• Compared measures between resting and mental arithmetic states in 10 right-handed and 1 left-handed subjects.

Main Results:

• The irregularity index (II) significantly increased in the left temporo-centro-parietal region during mental arithmetic in right-handed subjects.
• Significant changes in information flow were observed, primarily from the temporo-centro-parietal region to other areas and within the frontal region.
• Increased information flow was noted from the left temporal and mid-frontal areas, with decreased flow from the left hemisphere.
• The left-handed subject showed increased II in the right post-temporal area.

Conclusions:

• Left temporo-centro-parietal activation is specifically associated with calculation processing.
• Frontal information flow patterns are linked to the active performance of mental arithmetic.
• These findings contribute to understanding the neural mechanisms underlying mathematical cognition.