SAMPLE SIZE & SAMPLE DEMOGRAPHICS We used the software G-Power 3.1.6 (Faul, Erdfelder, Lang, & Buchner, 2007) to calculate a-priori-Power for our experiment. Presuming a small to medium effect size of f(U) = 0.3, coupled with a critical alpha of .05 and seeking for a high Power-level of (1-β) = 0.95 the analysis for a repeated measures ANOVA with within factors with 1 group and 4 measurements indicated a total sample size of 57 participants to be needed. In inattentional blindness studies we can expect an exclusion rate of up to 30 % (see Schnuerch et al., 2016). To ascertain a sufficient level of Power we decided to collect 80 participants. The sample will be recruited in courses, on campus and via online networks of the German Sports University Cologne and, thus, will mostly comprise university students. MATERIALS Detailed information about the materials can be found under the “Methods and Measures” node. PROCEDURE Declaration of consent Inattentional Blindness Task Full-Attention Trial Task Visual Acuity Task Debriefing TESTING LOCATION AND LAB SETUP The study will be conducted at the German Sports University. All participants are tested alone or in groups of two people in a designated lab room with two identical work spaces. Each work space is made up of a desk with a computer, a screen, a keyboard, and a mouse. Participants have a standardized distance of 60 cm from the screen, which is secured by using a chin-rest. The two work spaces are separated by a room divider, so participants cannot see each other. There is an additional desk for the experimenter in the lab. It is placed in a way that the participants cannot see the experimenter, even not in the reflection of their screen. We use screens with a size of 24" and a resolution of 1920 x 1080 pixels. Also, participants are routinely instructed to work quietly. DATA COLLECTION Recruiting will take place in classes, on campus and via facebook groups of the university. Participants will receive 5€ for participation. The registration call will not contain any information about the study other than that it is a study about speed of response. The experimental instructions will be delivered to the participants on the screen before each test. Participants are additionally encouraged to ask questions if not clear about the instructions. The test will be shown on a computer display. Participants will be unaware that they are participating in an inattentional blindness study. To prevent task knowledge spilling over from tested participants to still-to-be-tested participants, the debriefing text will ask participants to avoid sharing information about the experimental procedure with their fellow students. DATA EXCLUSION Detailed information about the exclusion criteria can be found under the “Analysis Plan” node.