Research

Quantitative Analyses:
Fourier Analyses (FFT) at a fingertip, Complex Demodulation in the Time Domain by a mouse click, Joint-Time-Frequency-Analyses (JTFA), 3-Dimensional LORETA current density and Source Correlations at your fingertip. Re-montage to bipolar, common reference, average reference and Laplacian current density with a mouse click. Adaptive Gabor functions, complex demodulation and integrated spectral analyses that are flexible and dynamic for the investigation of the electrical energies of the brain. Compute instantaneous power, coherence and phase as the mouse is dragged over the EEG tracings.

Statistics:
NeuroStat (an add on product) seamlessly allows for pre vs. post treatment or pre vs post medication statistical analyses with a few mouse clicks. Individual statistics for analyses such as pre vs post treatment and group statistics for comparative statistics include ANOVA, independent t-tests and paired t-tests. Group statistics include descriptive statistics such as group means and standard deviations, paired t-tests and ANOVA. LORETA 3-dimensional individual and group statistics including descriptive statistics, paired t-tests and individual t-tests.

NeuroGuide Tools:
Written in windows ‘C’ NeuroGuide provides simple mouse click access to a suite of sophisticated analytic tools. Digital signal processing tools such as referencing, FFT, Complex Demodulation, Annotation of the EEG tracings, bitmap screen capture, topographic color maps, coherence, phase delays, peak frequency analysis, discriminant functions and learning disability discriminant functions, LORETA 3-D current density and LORETA 3-D source correlations are some of the most useful tools.

Batch Analyses:
NeuroBatch (an add on product) provides automatic analyses of large numbers of EEG subjects using different montages and export options in preparation for NeuroStat when using certain group statistics. Flexible group statistic options and montage selections and different edit selections by a mouse click.

Joint-Time-Frequency-Analysis (JTFA):
Use the Adaptive Gabor Transform and Complex Demodulation to analyze the fine temporal detail of the EEG. Decompose an EEG segment into its elemental atoms and reconstruct the EEG.  Use the JTFA tools to visualize spike and wave processes and to identify blink artifact and muscle artifact and other features of the EEG traces. View instantaneous power, coherence and phase by dragging the mouse over the EEG tracings. View the first and second derivatives of the EEG time series as well as the instantaneous frequency spectrum and compute phase reset using the first derivative of the instantaneous phase delay.

LORETA Source Correlations:
Compute the time series spatial-temporal correlation between a MRI registered region of interest (ROI) and other regions of the brain. View the strength of spatial-temporal correlation in 2-D color contour maps that order the distance from the reference ROI in centimeters over 1 to 40 Hz. Use the Key Institute Viewer to display the source correlation from a reference ROI in 1 Hz increments co-registered to the Montreal Neurological Institute’s standardized MRI.

Connectivity Analyses:
Compute 171 channel combinations of coherence, phase differences, correlation (comodulation), cross-spectra, co-spectra, quad-spectra and phase reset.  Calculate volume conduction vs. non-volume conduction contributions to the EEG. Separate and analyse “Instantaneous Connectivity” and “Lagged Connectivity”.  Quantify phase reset and phase locking.

Phase Reset:
View phase shift and phase lock as the 1st derivative of the time series of phase differences and compare to the raw EEG traces. Quantification of phase shift duration and phase lock duration for all 171 channel combinations which is a volume conduction free measure of neural dynamics.

Dynamic Bi-Spectral Analyses:
Compute the Cross-Frequency Power Correlation from 1 to 50 Hz for all combinations of electrodes as well as the Cross-Frequency Phase Synchrony. Cross frequency phase synchrony includes cross-frequency phase shift duration and phase lock duration. Dynamic Bi-Spectral analyses include the FFT of the time series of the instantaneous envelope of power and the instantaneous coherence, phase and phase reset over the frequency range from 0.03 Hz to 10 Hz with log-log and linear plots.

EEG Spindle and Burst Analyses:
Calculate the number of bursts per second in different frequency bands as well as the average duration of bursts, the average amplitude of bursts and the average inter-burst interval.

Signal Generator:
Mathematical production of pure sine waves, square waves and sawtooth waves or mixtures of different waves to simulate the EEG. Explore the FFT by selecting different amplitudes for different waves located at different 10/20 electrode locations. Includes phase shifts and the ability to add gaussian noise so that coherence and phase delays and other spectral properties of the EEG can be simulated and mathematically evaluated. This is a great learning tool and is a standard part of NeuroGuide.

Export Functions:
Multiple export functions are available. Click File > Export and then save data in ASCII format or Lexicor format. The ASCII format files can be saved with or without a channel header and are immediately importable into programs such as Excel or Systat or SPSS and similar statistical programs. Click Tools > Power Spectral analyses to export power spectra and power spectral Z scores or click Tools > LORETA Export to export ASCII digital data in Lexicor format which is compatible with the Key Institute LORETA programs. Finally, all of the raw spectral data and Z score data for power, peak frequency, power ratios, coherence, phase delays, amplitude asymmetries, discriminant functions and the brain performance index are exportable in tab delimited format by clicking File > Save > Tab Delimited in the Analysis Output window.

Ready for Publication Topographic Maps:
Color topographic maps of absolute power, relative power and ratios of power can be saved as Bit Maps which are ready to publish as is, or imported into Power Point or other imaging programs to add arrows and text and other features for a publication. Coherence and phase delay and amplitude asymmetry connection maps are also in Bit Map format and publication ready.