Ricerc@Sapienza

An eye tracker is a tool that records and evaluates a person's eye movements, allowing us to understand where they are looking, what they are paying attention to and, conversely, what stimuli they are ignoring. It works using a system that exploits light with a frequency close to infrared. This frequency band is below our perception threshold, so we cannot see it with the naked eye, but when it is directed towards the eyes, it generates a physiological reflection of the cornea that is visible. This reflection is captured by cameras integrated into the device, which allow the direction of gaze to be reconstructed with great precision and accuracy. With eye-tracking technology, it is thought that the eye gives researchers a window into the mind. It is important to note that eye-tracking has significant advantages over traditional online processing measures: mainly because it allows for more “natural” processing, as it does not require a secondary task, and because it provides a very rich source of data moment by moment. Recognising the advantages of this technology, an increasing number of researchers in applied linguistics and second language research are beginning to use it.