New Directions in Live ZScore Neurofeedback Thomas F
New Directions in Live ZScore Neurofeedback Thomas F. Collura, Ph. D. Brain. Master Technologies, Inc. August 11, 2010
Current LZT Methods • • Individual Z-Scores Range Training Multiple Range Training PZOK
LZT Display
Current Status • PZOK can train “inliers” or “outliers” • Narrow Targets, low percentage = challenge – ignores outliers • Wide Targets, high percentage = nonchallenge – emphasizes outliers
Motivation for Z-Plus • Continue with PZOK, add new capability • Train outliers by their tendency to move inward • Monitor global tendency toward normal • Watch z-scores in action
PZOK Training
Z-Plus • • Z-Motive Z-Mean Z-Bars Z-Maps
Z-Motive • Measures instantaneous change in all zscores outside the targets • Negative (<0) if z-scores are moving away • Positive (>0) if z-scores are moving toward normal • Maximum value = 100 if all z-scores suddenly go inside their targets • “Tendency to normalize”
ZMotive
Z-Mean • Mean (absolute value) distance of all zscores that are outside targets • Reflects average size of all outlying zscores • Typical value: 2. 0 – 4. 0. • Changes “slowly” • “How abnormal are we? ”
Z-Mean
Z-Plus Event Trends Simulation
Z-Plus Event Trends Live EEG Training
Z-Plus Event Trends Widening Target Sizes
Z-Bars • Shows each and every Z-Score in two forms • One: Bar graph showing average (damped) value • Two: line and dot showing most recent change • Allows use to visualize all Z-Scores at once • See which Z-Scores are important
Z-Bars Delta Absolute Power 19 channels
Z-Bars 4 channels 248 Z-Scores
Z-Bars Delta Coherence 19 -channel
19 -channel Coherence (partial)
Planetary Analogy • Targets = “sun” • Z-Scores = “planets” • PZOK = “how many planets are within the defined range • PZMO = “what is the tendency to move inward” (gravity) • PZME = “how far are they on average (size of solar system) • GOAL: A compact (normal) solar system
Sun and Planets
Z-Plus - Summary • • • New metrics to guide and assess training New displays to visualize changes Enhanced visibility of brain dynamics Addresses Outliers directly Addresses Global level of normality Appeals to notion of z-scores as “planets” and normality as “gravity”
- Slides: 27