Loss of Spontaneous Blinking in a Patient With Balint's Syndrome

A patient with Balint's syndrome caused by bilateral parieto-occipital lesions lost spontaneous blinking, suggesting that humans, like nonhuman primates, have parietal lobe neurons that are important for blinking. Although the functions of spontaneous blinking are not known, they may help initiate some saccades and, like saccades, be involved in the cancellation of thalamic inhibitory postsynaptic potentials, thereby facilitating processing of new foveal targets. Spontaneous blinking may also facilitate sensory relay during sustained attention and, therefore, help prevent fading of a retinal image.