<p><b>Neuroguide</b></p><p>Robert Thatcher’s Neuroguide database was collected at the University of Maryland in 1990, where initially a sample of 625 normal subjects constituted the normative database. This database included clinical selection criteria, an age range of 2 months to 282 years, cross-validation tests, demographics.</p><p>The NeuroGuide database has been tested and re-tested and the sensitivity of the statistical distributions has been calculated for each montage and condition. Normalcy was determined by response to a neurological history questionnaire which was given to the child’s parents and/or filled out by each subject. IQ and other age appropriate psychometric testing, academic achievement, as well as classroom performance as determined by school grades and teacher reports also were used in determining normalcy. Nine hundred and forty-three (943) variables were computed for each subject including measures of absolute and relative power, coherence, phase, asymmetry, and power ratios. Z-score transforms are available in single Hz bins. Sliding averages were used to compute age-appropriate norms. Results were inspected for Gaussian distribution (for further details see Thatcher, Walker, Biver, North, &amp; Curtin, Sensitivity and cross-validation of a lifespan normative EEG database — at: http://www.applied neuroscience.com/LSNDB.htm.) Recording with task challenges was not performed. The construction and composition of this database are relatively well documented.&nbsp;</p><p>The NeuroGuide software allows the user to import previously recorded EEG data, edit and analyze data, and process the data into maps and necessary statistics. Neuroguide is built from 625 normative comparisons of relative power, absolute power, power ratios, coherence, and phase and amplitude asymmetry.</p><p>Some of the attributes of Neuroguide include automatic artifact rejection, dynamic FFTs with comparisons to FFT lifespan, and Eyes Open and Eyes Closed Norms covering ages from birth to 82 years of age. NeuroGuide includes a Traumatic Brain Injury and Learning Disability discriminant functions, as well as an integrated statistical package. It also includes predictions of neuropsychological test scores using the Brain Performance Index.</p><p>One of the tools is EEG Neuroimaging to evaluate Brodmann Areas and nodes and connections of functional networks in the brain likely linked to symptoms, statically or in real-time.</p><p>NeuroGuide provides a retrospective view of EEG waveforms and offline artifact rejection. NeuroGuide also offers calculations of Spectral Energy, Power and Coherence along with discriminant Functions, Signal Generator, LORETA Norms, and Brain Performance Index (QEEG Information).</p><p>NeuroGuide uses a Fast Fourier Transform (FFT) with .5Hz and 1Hz resolution to provide color headmaps with a bandwidth of 0-40Hz, a Joint-Time-Frequency Analysis component to identify time events greater or less than a threshold value, as well as LORETA analysis. Montage selection and creation are allowed, as well, including bipolar montages, current source density montages and average reference montages in eyes closed and eyes open conditions.</p><p>The mathematical details of complex demodulation used to compute the instantaneous Z scores as contained in the Applied Neuroscience, Inc. “dll” are published in Otnes and Enochson, (1977);Granger and Hatanaka, (1964); Bloomfield, 2000; Thatcher et al, (2007). Complex demodulation is a time domain digital method of spectral analysis&nbsp;<span style="font-size: 1rem;">whereas the fast Fourier transform (FFT) is a frequency domain method.&nbsp; These two&nbsp;</span><span style="font-size: 1rem;">methods are related by the fact they both involve sines and cosines and both operate in the complex domain and in this way represent the same mathematical descriptions of the power spectrum.&nbsp; The advantage of complex demodulation is that it is a time&nbsp;</span><span style="font-size: 1rem;">domain method and less sensitive to artifact and it does not require windowing nor&nbsp;</span><span style="font-size: 1rem;">even integers of the power of 2 as does the FFT.&nbsp; &nbsp;The FFT integrates power in a&nbsp;</span><span style="font-size: 1rem;">frequency band over the entire epoch length and requires windowing functions which can dramatically effect the power values whereas, as mentioned previously, complex demodulation does not require windowing (Otnes and Enochson, 1972).&nbsp; &nbsp;Complex demodulation was&nbsp;</span><span style="font-size: 1rem;">computed for the linked ears and eyes open and eyes closed conditions for all 625 subjects in the normative database.&nbsp;</span></p><p><br></p>