Abstract

The menace reflex (blink reflex to visual threat) tests visual processing at the bedside in patients who cannot participate in normal visual field testing. We reviewed a collection of recently discovered historical movies showing the experiments of the Dutch physiologist Gysbertus Rademaker (1887–1957), exploring the anatomy of this reflex by making cerebral lesions in dogs. The experiments show not only that the menace reflex is cortically mediated, but also that lesions outside the visual cortex can abolish the reflex. Therefore, although often erroneously used in this way, an absent menace does not always indicate a visual field deficit.