Eyes closed, eyes open qEEG — why you need both, and what the difference reveals for clinical practice

Eyes closed. Eyes open. One contrast that changes everything.

Clinicians using qEEG have long recorded resting-state EEG — but most still choose a single condition and move on. The eyes closed/eyes open (EC/EO) contrast is one of the most evidence-backed and underused paradigms in clinical qEEG, yielding biomarkers linked to Alzheimer's disease, Lewy body dementia, Parkinson's, ADHD, and depression that neither condition reveals alone. At the center of it is alpha reactivity — a dynamic, cholinergically sensitive index that tracks disease severity, predicts amyloid burden, and improves diagnostic classification. LucerumCarto computes EC/EO qEEG biomarkers automatically from your EEG data, giving clinicians the full contrast picture without manual calculation. Here's what the research shows — and why recording both conditions should be standard practice.