The primary recommendation of the 2010 President's Council of Advisors on Science and Technology report on K-12 education was to inspire more students so that they are motivated to study science. Scientists' visits to classrooms are intended to inspire learners and increase their interest in science, but verifications of this impact are largely qualitative. Our primary goal was to evaluate the impact of a longstanding Brain Awareness classroom visit program focused on increasing learners understanding of their own brains. Educational psychologists have established that neuroscience training sessions can improve academic performance and shift attitudes of students from a fixed mindset to a growth mindset. Our secondary goal was to determine whether short interactive Brain Awareness scientist-in-the-classroom sessions could similarly alter learners' perceptions of their own potential to learn. Teacher and student surveys were administered in 4th-6th grade classrooms throughout Minnesota either before or after one-hour Brain Awareness sessions that engaged students in activities related to brain function. Teachers rated the Brain Awareness program as very valuable and said that the visits stimulated students' interest in the brain and in science. Student surveys probed general attitudes towards science and their knowledge of neuroscience concepts (particularly the ability of the brain to change). Significant favorable improvements were found on 10 of 18 survey statements. Factor analyses of 4805 responses demonstrated that Brain Awareness presentations increased positive attitudes toward science and improved agreement with statements related to growth mindset. Overall effect sizes were small, consistent with the short length of the presentations. Thus, the impact of Brain Awareness presentations was positive and proportional to the efforts expended, demonstrating that short, scientist-in-the-classroom visits can make a positive contribution to primary school students' attitudes toward science and learning.