Handheld cellular phones restrict head movements and range of visual regard

► Holding a phone to one ear restricted the horizontal range of head and gaze position. ► Gaze restriction was greatest in people prone to move the head most widely. ► Readiness to move the head and range of visual regard are tightly linked. ► Range of visual regard may reflect balance of costs and benefits of head movement. ► Even minor impediments to head movement may alter the cost/benefit balance.