This resource is the fourth in a series of interactive simulations that help students make sense of human responses. In this activity, students are experimenting to see which of their senses (sight, sound, or touch) has the fastest response time. Students investigate the response time of each of these senses using the interactive simulations. This lesson is designed to be done individually and the teacher has the ability to edit and assign the activity through the ITSI portal ((https://itsi.portal.concord.org/) This link takes you to the landing page for the Innovative Technology in Science Inquiry portal. Teachers will need to register for free to access the reviewed resource.