Related Experiment Video
Updated: Jul 18, 2026
06:14
The Combination of Transcranial Alternating Current Stimulation and Electroencephalogram
Published on: October 10, 2025
Time frequency characterization of evoked brain activity in multiple electrode recordings
Nivedita S Majumdar1, Karl H Pribram, Terence W Barrett
1Department of Computational Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA. nmajumda@gmu.edu
IEEE Transactions on Bio-Medical Engineering
|December 13, 2006
Summary
This study reveals distinct EEG signal patterns preceding visual perception shifts. These findings suggest internally generated neural activity, applicable to blind source separation in biological signals.
Area of Science:
- Neuroscience
- Signal Processing
- Biomedical Engineering
Background:
- Electroencephalography (EEG) is crucial for understanding brain activity.
- Time-frequency analysis offers insights into dynamic neural processes.
- Characterizing EEG signals during perceptual shifts aids in understanding cognitive processes.
Purpose of the Study:
- To explore global time-frequency analysis of EEG signals.
- To characterize EEG activity during the perception of a Necker cube orientation reversal.
- To identify internally initiated EEG signal sources for blind signal processing.
Main Methods:
- Utilized the Wigner Distribution Function and Symmetric Ambiguity Function for EEG analysis.
- Analyzed EEG data from Frontal, Central, and Occipital electrodes in human subjects.
- Focused on the temporal and frequency characteristics of neural signals.
Main Results:
- Observed high-energy activity patterns with significant waveform dissimilarities in Frontal and Occipital electrodes.
- Identified these patterns approximately 200-600 ms before premotor potentials in medial electrodes.
- Demonstrated an internally initiated EEG signal source, independent of external stimuli.
Conclusions:
- The Wigner Distribution Function and Symmetric Ambiguity Function are effective for EEG analysis.
- EEG analysis reveals distinct pre-perceptual neural activity.
- The methods are broadly applicable to various neural and biological signals.
