Freezing of Gaze in Anticipation of Avoidable Threat: A threat-specific proxy for freezing-like behavior in humans

A previous study demonstrated a freezing-like pattern of eye movements when participants could escape from aversive stimulation by a fast button press. Freezing of gaze was characterized by more centralized, fewer and longer fixations. Here, we aimed at examining whether 1) visual exploration is also reduced when a subsequent threat-reaction requires distributed attention and if so 2) whether this visual pattern is threat-specific. We measured gaze behavior while participants anticipated a certain, no or a potential aversive stimulation (study 1) or reward (study 2) that could be avoided or gained respectively via a fast joystick movement towards an indicated display side. In study 1, results replicated a centralization of gaze when participants expected an avoidable shock. In study 2, we did not find this pattern. These findings indicate that freezing of gaze is robust even when a subsequent reaction requires spatial attention. Furthermore, these visual dynamics seem to be threat-specific.