One of the ideas I introduce with middle school and (especially) high school biology students is that our sensory organs and brain work together to create our perception of the world around us… but our perceptions are limited by our equipment and may not always fully or accurately reflect reality. Diving deep into this topic is generally outside the scope of the courses I teach, but it has important ties to both data collection (because sometimes measuring tools are more reliable than our senses) and evolution (because looking into strange quirks of our biology can sometimes give interesting insights into how we evolved), so I like to bring it up at least once during a year of biology class.
Having students find their blind spots and study the anatomy of they eye that causes blind spots is a classic for a reason. It’s a good classroom activity and a great way to talk about the limits of human sensory perception. However, I’ve discovered something that’s tremendously more fun.
Synsepalum dulcificum, also known as miracle fruit, is a small fruit that dramatically changes taste perception in most people. I first learned about it from a New York Times article. (But if you read this article, do try to contain yourself. In my experience miracle fruit is fun, but not as dramatic as the article makes it sound.)
When I can, I like to have a miracle fruit tasting in the classroom on a day when it might be difficult to get more serious work done (i.e., the day before winter break) or when students have been working particularly hard (i.e., the day students turn in a big project).
The big problem with experimenting with miracle fruit is that it is somewhat expensive and sometimes difficult to order. Also, the experiments it’s practical to do in class are qualitative, rather than quantitative. The fun and excitement are significant, though – I’ve had students tell me that it’s an experience they still think about years later.