A surgical instrument having opposed jaws that can be selectively moved between open and closed positions. A ratio between signal levels of pixels that are adjacent to the defective pixel and that have a different color from the defective pixel, and signal levels of pixels that are adjacent to pixels being located along the determine direction with respect to the defective pixel and having the same color as the defective pixel and that have a different color from the defective pixel, is acquired. At least one of the holder constituting bodies moves in the vertical direction to change the positions of the holder constituting bodies relative to each other. When a second stage triggering event occurs, the gaming system initiates a second bonus game stage.