The vOICe vision BCI 🧠🇪🇺(YouTube) #Ganzflicker: Using light-induced hallucinations to predict divergent perceptual experiences https://www.youtube.com/watch?v=NPIMa3wNiqs&t=2s by @kerblooee
YouTube
Flicker light stimulation induces thalamocortical hyperconnectivity with LGN and higher-order thalamic nuclei https://doi.org/10.1162/imag_a_00033 Do there perhaps also exist #multisensory stimuli that "mess" with relaying auditory inputs to visual cortex? #Ganzfeld #Ganzflicker #neuroscience
Flicker light stimulation induces thalamocortical hyperconnectivity with LGN and higher-order thalamic nuclei
Abstract. The thalamus is primarily known as a relay for sensory information; however, it also critically contributes to higher-order cortical processing and coordination. Thalamocortical hyperconnectivity is associated with hallucinatory phenomena that occur in various psychopathologies (e.g., psychosis, migraine aura) and altered states of consciousness (ASC; e.g., induced by psychedelic drugs). However, the exact functional contribution of thalamocortical hyperconnectivity in forming hallucinatory experiences is unclear. Flicker light stimulation (FLS) can be used as an experimental tool to induce transient visual hallucinatory phenomena in healthy participants. Here, we use FLS in combination with fMRI to test how FLS modulates thalamocortical connectivity between specific thalamic nuclei and visual areas. We show that FLS induces thalamocortical hyperconnectivity between lateral geniculate nucleus (LGN), early visual areas, and proximal upstream areas of the ventral visual stream (e.g., hV4, VO1). Further, an exploratory analysis indicates specific higher-order thalamic nuclei, such as anterior and mediodorsal nuclei, to be strongly affected by FLS. Here, the connectivity changes to upstream cortical visual areas directly reflect a frequency-dependent increase in experienced visual phenomena. Together, these findings contribute to the identification of specific thalamocortical interactions in the emergence of visual hallucinations.
#Ganzflicker experience page https://www.seeingwithsound.com/ganzflicker.html
Effect of #frequency and #rhythmicity on #flicker light-induced #hallucinatory phenomena https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0284271 "flicker rhythmicity critically contributes to the effects of FLS beyond the effects of frequency alone, indicating that #neural #entrainment may drive the induced phenomenal experience."
Fortunately this means that I need not change my #rhythmic #Ganzflicker online demo https://www.seeingwithsound.com/ganzflicker.html?f=10.0
Effect of frequency and rhythmicity on flicker light-induced hallucinatory phenomena
Flicker light stimulation (FLS) uses stroboscopic light on closed eyes to induce transient visual hallucinatory phenomena, such as the perception of geometric patterns, motion, and colours. It remains an open question where the neural correlates of these hallucinatory experiences emerge along the visual pathway. To allow future testing of suggested underlying mechanisms (e.g., changes in functional connectivity, neural entrainment), we sought to systematically characterise the effects of frequency (3 Hz, 8 Hz, 10 Hz and 18 Hz) and rhythmicity (rhythmic and arrhythmic conditions) on flicker-induced subjective experiences. Using a novel questionnaire, we found that flicker frequency and rhythmicity significantly influenced the degree to which participants experienced simple visual hallucinations, particularly the perception of Klüver forms and dynamics (e.g., motion). Participants reported their experience of geometric patterns and dynamics was at highest intensity during 10 Hz rhythmic stimulation. Further, we found that frequency-matched arrhythmic FLS strongly reduced these subjective effects compared to equivalent rhythmic stimulation. Together, these results provide evidence that flicker rhythmicity critically contributes to the effects of FLS beyond the effects of frequency alone, indicating that neural entrainment may drive the induced phenomenal experience.