The phrase "fixes attention" means to focus or concentrate on something intensely. There are several synonyms that can be used interchangeably such as captivates, engrosses, absorbs, rivets, hooks, enthralls, enchants, mesmerizes, hypnotizes, and spellbinds. When describing an activity or object that requires a person's undivided attention, these synonyms can be used to convey the intensity of the experience. For example, "the captivating movie held the audience's attention for the entire duration" or "the mesmerizing performance had the crowd spellbound". Using synonyms for "fixes attention" can add variety and depth to your writing, making it more interesting and engaging for the reader.