FFT transformed quantitative EEG analysis of short term memory load

Area of Science:

• Neuroscience
• Cognitive Science
• Biomedical Engineering

Background:

• The electroencephalogram (EEG) is fundamental to understanding brain signaling.
• EEG oscillations' role in human information processing is a key research area.

Purpose of the Study:

• To investigate the quantitative EEG correlates of short-term memory load.
• Utilized the Sternberg memory test to assess memory load.

Main Methods:

• Recorded EEG from 34 healthy male students using 19 scalp locations (10-20 system).
• Employed an individual alpha frequency (IAF)-based method for frequency band selection to analyze EEG signals.
• Measured absolute power in six frequency bands at 19 electrode positions using FFT.

Main Results:

• Short-term memory load decreased absolute power in the Upper alpha band across most electrode sites.
• Observed increased Theta band power in the Fronto-Temporal region.
• Detected increased Lower 1 alpha band power in the Fronto-Central region; Beta and Gamma bands showed no significant changes.

Conclusions:

• Short-term memory load induces distinct EEG patterns associated with mental stress.
• Decreased Upper alpha band power reflects a departure from a relaxed mental state.
• Fronto-temporal Theta power variations may be linked to memory encoding and task execution.