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| Sprache: | Englisch |
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2026
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| Online-Zugang: | https://doi.org/10.5281/zenodo.19384716 |
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| _version_ | 1866901869806223360 |
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| author | Vergucht, Maarten |
| author_facet | Vergucht, Maarten |
| contents | <p>During a migraine aura, patients experience sparkling, brilliant white light with vivid spectral colours. Two independent lines of neurophysiological evidence reveal that this luminous experience coincides not with increased neural activity but with its suppression. First, magnetoencephalography (MEG) recorded during a scintillating scotoma shows that alpha-band power, the rhythm associated with active cortical inhibition, drops to zero for the duration of the scintillations and returns abruptly the moment they cease (Hall et al. 2004). Gamma-band power likewise decreases, ruling out compensatory excitation. Second, VEP studies beginning with MacLean, Appenzeller, Cordaro, and Shambaugh (1975) and confirmed by Nyrke et al. (1989) and Coppola et al. (2019) show that visually evoked potentials (VEPs), the cortex's measurable electrical response to external light, are suppressed or abolished during the aura. The cortex does not respond to light from the outside world, yet the patient perceives brilliant inner light.</p> <p>The conventional disinhibition explanation (removal of inhibition causes spontaneous excitation) is addressed: VEPs show the cortex is less responsive, not more; gamma power decreases rather than increases; and the phenomenological quality (structured, coloured, beautiful, lasting minutes) does not match disinhibited cortical firing (brief, chaotic phosphenes lasting seconds). The temporal match between scintillation duration (5-30 minutes) and the depression phase of spreading depolarisation (5-30 minutes), rather than the depolarisation burst (seconds), supports the interpretation that scintillations correspond to sustained cortical silence, not transient excitation.</p> <p>Clinical evidence from ischemic scintillation (Klingebiel et al. 2008; Olesen et al. 1993; Biousse et al. 1998) and the double dissociation between retinal ischemia (darkness) and cortical ischemia (brilliant light) confirm the pattern. The production model predicts darkness when the cortex fails. The filter theory (Bergson 1896; Huxley 1954; Kastrup 2019) predicts light. Only the filter theory correctly predicts both outcomes. If this light correlates with the absence of neural activity, it has no neural correlate. It is not produced by the brain. It is revealed by the brain's silence.</p> <p> </p> |
| format | Recurso digital |
| id | zenodo_https___doi_org_10_5281_zenodo_19384716 |
| institution | Zenodo |
| language | eng |
| publishDate | 2026 |
| publisher | Zenodo |
| record_format | zenodo |
| spellingShingle | scintillating scotoma: when the cortex fails, brilliant inner white light appears Vergucht, Maarten scintillating scotoma double dissociation amaurosis fugax transmission theory filtertheory of consciousness cortical ischemia carotid artery stenosis spreading depolarisation neural correlates of consciousness migraine aura visual phenomenlolgy hard problem of consciousness <p>During a migraine aura, patients experience sparkling, brilliant white light with vivid spectral colours. Two independent lines of neurophysiological evidence reveal that this luminous experience coincides not with increased neural activity but with its suppression. First, magnetoencephalography (MEG) recorded during a scintillating scotoma shows that alpha-band power, the rhythm associated with active cortical inhibition, drops to zero for the duration of the scintillations and returns abruptly the moment they cease (Hall et al. 2004). Gamma-band power likewise decreases, ruling out compensatory excitation. Second, VEP studies beginning with MacLean, Appenzeller, Cordaro, and Shambaugh (1975) and confirmed by Nyrke et al. (1989) and Coppola et al. (2019) show that visually evoked potentials (VEPs), the cortex's measurable electrical response to external light, are suppressed or abolished during the aura. The cortex does not respond to light from the outside world, yet the patient perceives brilliant inner light.</p> <p>The conventional disinhibition explanation (removal of inhibition causes spontaneous excitation) is addressed: VEPs show the cortex is less responsive, not more; gamma power decreases rather than increases; and the phenomenological quality (structured, coloured, beautiful, lasting minutes) does not match disinhibited cortical firing (brief, chaotic phosphenes lasting seconds). The temporal match between scintillation duration (5-30 minutes) and the depression phase of spreading depolarisation (5-30 minutes), rather than the depolarisation burst (seconds), supports the interpretation that scintillations correspond to sustained cortical silence, not transient excitation.</p> <p>Clinical evidence from ischemic scintillation (Klingebiel et al. 2008; Olesen et al. 1993; Biousse et al. 1998) and the double dissociation between retinal ischemia (darkness) and cortical ischemia (brilliant light) confirm the pattern. The production model predicts darkness when the cortex fails. The filter theory (Bergson 1896; Huxley 1954; Kastrup 2019) predicts light. Only the filter theory correctly predicts both outcomes. If this light correlates with the absence of neural activity, it has no neural correlate. It is not produced by the brain. It is revealed by the brain's silence.</p> <p> </p> |
| title | scintillating scotoma: when the cortex fails, brilliant inner white light appears |
| topic | scintillating scotoma double dissociation amaurosis fugax transmission theory filtertheory of consciousness cortical ischemia carotid artery stenosis spreading depolarisation neural correlates of consciousness migraine aura visual phenomenlolgy hard problem of consciousness |
| url | https://doi.org/10.5281/zenodo.19384716 |