From stroboscope to dream machine: a history of flicker-induced hallucinations.

When early neurophysiologists, like William Grey Walter (1910-1977), started using intermittent photic driving in electroencephalography, they were struck by a wide range of visual hallucinations that were reported. In current neuroscience, the phenomenon is used mainly to model hallucinations that are related to altered neuronal activity between the thalamus and the visual cortex, such as the Charles Bonnet syndrome. However, during the psychedelic 1960s, Brion Gysin (1916-1986), a painter and a poet, became interested in the hallucinations and designed his own stroboscope or dream machine, as a means for spiritual enlightenment. This article traces back the history of flicker-induced hallucinations from the early use of stroboscopes in neurophysiology to the dream machine.

[Methods of larynx phoniatory function measurement in the Poznan University Department of Ear, Throat, Nose and Larynx Diseases between 1922 and 1939]. / Metody badania czynnosci fonacyjnej krtani w Klinice Otolaryngologicznej Uniwersytetu Poznanskiego w latach 1922-1939.

INTRODUCTION: Indirect laryngoscopy development and progress initiated in 1854 by the autolaryngoscopy of the famous singing voice teacher Manuel Garcia in ENT speciality is connected with the names of L. Tuerck and J.N. Czermak, the last one being called the father of laryngoscopy. In 1878 M. Oertel used for the first time stroboscopic light in indirect laryngoscopy. The perception of stroboscopic picture is based on the Talbot principle. OBJECT OF THE PAPER: Two apparatuses used for the evaluation of larynx function in the Poznan ENT Department before the II World War are presented:--Polylaryngoscop enabling evaluation the indirect laryngoscopy simultaneously by several individuals.--Mechanical stroboscop of Oertel type with perforated disc moved by electrical engine. CONCLUSION: For 130 years laryngostroboscopy belongs to the basic examination methods of larynx phonatory function.