Instructions: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: The average curveball travels at 75mph (120km/h) in a smooth arc. While there's no sudden change in motion throughout its journey, this isn't what the batter sees as it nears the home plate. Instead, the ball creates an optical illusion that tricks the mind into thinking there is a 'break' in movement. And scientists say knowing this, could help the mind counteract the effect. Scientists at the University of Rochester say that our brains apply an algorithm, known as a Kalman filter, when tracking a baseball. In GPS devices, algorithms, including the Kalman filter, are used to estimate the location of your car based on its past position and speed.Our brains track moving objects using a similar algorithm to GPSThe algorithm estimates location based on its past position and speedWe do the same thing when perceiving position in our visual peripheryKnowing this can help us counteract the effect, the study claims 
 Question:This means you have a better chance of hitting a curveball by realising that our brains, like _, can lead us to 'see' changes in speed or direction that don't actually occur.
Output:
GPS