Can we measure the human mind? In this work, Joosun Hwang transmits the data of viewers’ concentration measured by a brainwave-measuring device and thereby promotes the interaction between viewers and the computer. The data works as a parameter to modulate images and sound and when their concentration reaches a certain level, a telephone bell rings to announce the concentration ranking. This process brings viewers in the situation in which they have to control their mind. By paying attention to the ambiguous feedback of a brainwave-measuring device, Hwang discloses the fledgling seam between man and the computer and expresses a doubt about modern scientific technology or the social consensus in which the pattern of brainwaves transmitted as the form of data isdefined as the index of concentration, that is, the mind. Joosun Hwang, who considers the viewer’s decisionmaking and choice as an important element to determine the form and content of a work of art, puts the viewers in a strange situation and makes them aware of the gap. Their act of filling the very gap is reflected again in the work, which adds another gap, creating a cyclical structure. In this way, the artist examines the relationship between an artist, an artwork, and the viewer, as well as their roles.