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| Format: | Recurso digital |
| Language: | English |
| Published: |
Zenodo
2026
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| Online Access: | https://doi.org/10.5281/zenodo.19409674 |
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Table of Contents:
- <p> </p> <p>During a migraine aura, patients experience a scintillating scotoma: sparkling, brilliant white light with vivid spectral colours that expands across the visual field. This luminous experience is often described as beautiful and awe-inspiring. Yet two independent lines of neurophysiological evidence reveal that this light coincides not with increased neural activity, but with its profound suppression. Magnetoencephalography (MEG) shows that alpha-band power collapses to zero for the duration of the scintillations, while gamma-band power likewise decreases. Simultaneously, visually evoked potentials (VEPs) -- the cortex's measurable electrical response to external light -- are suppressed or completely abolished, as demonstrated by MacLean et al. (1975) and confirmed by Nyrke et al. (1990). The cortex does not respond to light from the outside world, yet the patient perceives brilliant inner light.</p> <p>Key findings include:<br>- MEG Evidence: During scintillating scotoma, alpha-band power drops to zero and gamma-band power decreases, ruling out compensatory excitation. The brain is demonstrably silent.<br>- VEP Evidence: Flash-VEPs show that the early components (P1, N1, P2) are suppressed or completely abolished in the hemisphere contralateral to the visual disturbance. The cortex is functionally offline for visual processing.<br>- Disinhibition Fails: The disinhibition hypothesis is refuted by decreased VEPs and gamma power. The phenomenological quality of the aura (prolonged, structured, beautiful) does not match chaotic cortical firing.<br>- Temporal Match: Scintillations correlate precisely with the prolonged depression phase (5-30 minutes) of cortical spreading depolarisation, not the brief depolarisation burst (seconds), indicating sustained cortical silence.<br>- Terminal Spreading Depolarisation (TSD): The irreversible wave of cortical silencing at death (TSD) is the intense, permanent version of the reversible cortical spreading depression (CSD) seen in migraine. If the mild scintillating light of migraine corresponds to reversible cortical depression, the profound light of near-death experiences plausibly corresponds to the permanent cortical depression of TSD.<br>- Clinical Confirmation: Ischemic scintillations in patients with carotid stenosis, where brilliant light arises directly from cortical ischemia, further support this pattern.<br>- Double Dissociation: Retinal ischemia (eye fails, cortex intact) leads to darkness, while cortical ischemia (cortex fails, eye intact) leads to brilliant light. The production model predicts darkness in both cases. Only the filter theory correctly predicts both outcomes.</p> <p>If this brilliant light correlates with the absence of neural activity rather than its presence, it has no neural correlate. It is not produced by the brain. It is revealed by the brain's silence.</p> <p>Ultimately, a profound contrast emerges: physical, external light that is blocked (as in retinal ischemia) results in darkness, whereas inner, non-physical light increases when cortical depression sets in. These two phenomena appear to be mutually exclusive: the perception of physical light precludes the experience of non-physical light, and the emergence of non-physical light requires the exclusion of physical light.</p> <p>Keywords: filter theory; consciousness; scintillating scotoma; migraine aura; MEG; alpha desynchronization; visually evoked potentials; double dissociation; cortical ischemia; spreading depolarization; terminal spreading depolarization; near-death experience</p> <p>Resource Type: Preprint<br>License: Creative Commons Attribution 4.0 International (CC BY 4.0)</p>