Evoked Structural Brittleness Under Photic Stimulation in Alzheimer Disease and Frontotemporal Dementia

This working paper analyzes photic-stimulation EEG in Alzheimer disease, frontotemporal dementia, and healthy controls using an article-local NeuralManifoldDynamics workflow anchored to matched resting-state baselines. It introduces Evoked Structural Brittleness (ESB-2), a perturbational deviation score that quantifies departure from a healthy evoked response template. The strongest disease-versus-healthy separation appears at 15 Hz, with capacity-led effects and bounded support from cross-fitted, leave-one-out, and permutation-based quality-control analyses.