Those who can improvise, do; those who cannot, teach
April 19, 2018This blog occasionally alludes to my fondness for improv comedy.
It’s mostly wrong to think of a classroom lecture as a “show,” and I mostly avoid pre-planned jokes. Every so often, though, a classroom discussion will take a spontaneous turn toward the delightfully bizarre.
Earlier this week, I was trying to explain how post-synaptic neurons “decide” whether to conduct action potentials based on the aggregated input of multiple pre-synaptic neurons, some excitatory and some inhibitory. In the heat of the moment, I attempted an unplanned analogy.
“It’s like, you’re trying to decide whether to go out with this guy,” I began. “One friend is whispering in your ear that you should stay away from him — and another friend is whispering in your other ear that you should totally date him!”
“But,” a student pressed, “Why are these ‘friends’ saying different things?”
“Well…” I paused. The analogy was quite possibly outliving its usefulness, but I forged on. “It’s because these friends heard different things from THEIR friends! Somebody told your first friend, ‘Hey, I saw that guy SMOKING CRACK the other day! He’s bad news!’ And somebody else told your second friend, ‘That guy is the best. I just saw him SAVE A PUPPY!'”
It wasn’t necessarily a moment of great teaching, or great comedy, or great anything. But, at a minimum, it was fun to see what my subconscious came up with when pressed for traits that make men desirable or undesirable as romantic prospects.
In invoking puppies, I reminded myself of another memorable moment, four years earlier. A student was trying to imagine a research study that wouldn’t get funded due to ethical concerns and/or bad publicity. “No government agency would want to be known as the office that supported a study on…” She sputtered for a second while her mental search engine churned. “…A study on, say, kicking puppies.”
A study on kicking puppies? Had I heard that right? Yes, she said. She seemed embarrassed, but I cracked up. Kicking puppies is not funny, but the idea of a committee debating the merits and risks of puppy-kicking research? Brilliant!
I congratulated the student on her vivid example, and then reluctantly returned to the day’s agenda.
My Track Record 
What a great moment teaching about summation! I don’t think your students will easily forget about neurons gossiping about a guy smoking crack and saving puppies.
Somewhat similar to your example, I modified a strategy that I saw my colleague try in class once. I briefly describe IPSPs, EPSPs, and convergence. Then, I select one student who has to decide whether they’re going to go to the San Diego Comic-Con (with a brief description of it – but most have heard about the SDCC). Then I ask other students to offer up reasons why they should or shouldn’t go. Finally, I ask the original student, “Based on the input, what’s your decision?” They go? BOOM! Action potential. No? Okay, threshold not reached.
Great example, John! Yours is better than mine because you explicitly related the various inputs to the ultimate decision/outcome.