Invisible multi-luminaire 40 Hz flicker does not entrain human electroencephalography
Journal
Journal of Alzheimer’s Disease
Journal Volume
106
Journal Issue
4
Start Page
1355
End Page
1359
ISSN
1387-2877
1875-8908
Date Issued
2025-05-21
Author(s)
Abstract
Background: Multi-luminaire light stimulation is a novel technique based on luminance flicker with low modulation depth created by two spatially adjacent light sources aimed to deliver 40 Hz neural stimulation while reducing discomfort, offering potential non-pharmacological, noninvasive, and in-home interventions for Alzheimer's disease and dementia. However, these cognitive effects have never been validated with electroencephalography (EEG). Objective: In this study we aim to assess the ability of multi-luminaire light stimulation to evoke a 40 Hz EEG response under two conditions: direct viewing and indirect viewing. Methods: The M + BrainCare light by Delta Electronics was used in this study. Participants were stimulated either directly by looking at the light (direct viewing condition), or off of the reflection from a piece of paper to mimic everyday reading (indirect viewing condition). EEG power at 40 Hz from these conditions were compared to a positive control of 40 Hz luminance flicker with 100% modulation depth (stroboscopic flicker). Results: In both multi-luminaire conditions, there was no significant 40 Hz EEG oscillations. In contrast, stroboscopic control elicited robust entrainment in all participants, propagating to frontal regions. Conclusions: Our results question the efficacy of multi-luminaire technology, specifically the Delta M + BrainCare light, for evoking 40 Hz neural responses. Future studies involving multi-luminaire technology should pay special attention to EEG validation prior to making claims about neural oscillation and brain health.
Subjects
Alzheimer's disease
dementia
gamma oscillation
GENUS
neural entrainment
noninvasive brain stimulation
sensory entrainment
SDGs
Publisher
SAGE Publications
Type
journal article