We studied four patients with acquired brain injury who were compelled to gaze at a moving object or the face of an individual who came into their sight, especially the person's eyes. The patients continued to gaze at the object or person until it disappeared from their sight. This behavior, referred to as forced gazing, is related to visual groping (part of the instinctive grasp reaction), and, together with a similar sign of visual grasping, constitutes a spectrum of visual stimulus-bound behaviors. In addition to forced gazing, the patients exhibited a primitive reflex such as a grasp or sucking reflex. Each of the patients had lesions in the bilateral frontal lobes of the brain. We considered forced gazing to be a stimulus-bound behavior, in which patients become extremely dependent on a specific external stimulus. As gaze-related communication is considered one of the bases of an infant's social development, forced gazing may have its basis in innate human behavior that might manifest itself under specific pathological circumstances such as bilateral frontal-lobe damage.
Michitaka Funayama, Taketo Takata