4 Life Lessons Learned from Training Monkeys

2421768035_809fde666e_oAs a PhD student I had the opportunity to work in a neuroprosthetics lab. My thesis was on decoding individuated finger movements from wireless electromyogram (EMG) recordings of the forearm and from the brain. The concept was that if we could show that these devices could predict desired finger movement based on physiological signals from residual muscles in the forearm or from the brain, then in theory those signals could likely be extracted from a human amputee to control a finger-dexterous prosthetic arm. The eventual application would essentially be Luke Skywalker’s prosthetic arm in Empire Strike’s Back.
darpa_arm_reaching<img class=”progressiveMedia-noscript js-progressiveMedia-inner” src=”https://cdn-images-1.medium.com/max/1600/1*K0VTzgmzl9NPK52XUm-qPA.jpeg”&gt;
HDT Global’s DARPA Prosthetic Arm

Medical devices are nearly always studied first in animals. For studies involving dexterous finger and thumb movements, the animal model is pretty much exclusively… monkeys. This meant that before I could obtain the data that I would need for my thesis, I would need to train a monkey to perform ON CUE various individual and combined finger flexions and extensions. It can’t be too bad, right? After all, monkeys are smart?

I wrote a program in LabVIEW that had a bar representing each finger. The bottom of each bar had a red circle representing flexion. From what I remember, it took me something like a year and a half to train the monkey fully. It looked somewhat like this….

 Task<img class=”progressiveMedia-noscript js-progressiveMedia-inner” src=”https://cdn-images-1.medium.com/max/1600/1*D_THIXzHeTcEiVuAgBaJig.png”&gt;

Starting out, I built a manipulandum with switches. The monkey placed his fingers between the flexion and extension switches of the manipulandum. To begin, I started with thumb flexion. I would go in with the monkey, sitting in his chair with his hand in the manipulandum and to begin I would slowly press the monkey’s thumb down onto the switch when the cue appeared on the computer screen. As soon as the program detected that the switch was successfully pressed, the monkey got his reward….Tang!

Tang<img class=”progressiveMedia-noscript js-progressiveMedia-inner” src=”https://cdn-images-1.medium.com/max/1600/1*4CoiiG8FABqSb_FwNT-uYg.jpeg”&gt;

So in a very real way, I owe my PhD to this sugary orange drink.

“Tang, the drink the astronauts took to the moon.” — Coneheads

#1: Create your purpose or motivation that pushes you forward

What’s your Tang? For the tasks, goals, dreams that you want to accomplish in life, have you created a purpose, motivation, or mission statement that pushes you forward? Like Stephen R. Covey taught in The 7 Habits of Highly Effective People, Habit 2: Begin with the end in mind! The more concrete and clear your vision, purpose, or mission, the more aware of it you will be and the more aware you are, the better your mind will be able to recognize patterns, people, and opportunities in your life and surroundings that can and will help you achieve that end.

#2: Repetition is the mother of all learning. Consistency is the father of results!

I would slowly try to push the monkey’s thumb less and less to see if the monkey would eventually flex his thumb all by himself to the cue. I would rotate times where I would go in and do a series of trials in which I would help the monkey to complete the task and then I would back off and see if the monkey would do it himself. I would then tried the 90–10 method, made famous in Hitch, where I would do 90% of the flexion movement and see if the monkey would come the other 10%. And I did this day in and day out. Consistently. It seemingly took forever until the lightbulb went off, but when it did… glory, glory hallelujah! Then the monkey would start crushing the task, just doing an awesome job flexing that thumb and getting all the tang that he wanted.

We need to do this in life as well. Sometimes we think, for example, if we exercise for 3 days in a row, we’ve got it all figured out! Repitition is the mother of all learning, and consistently working on those reps will ultimately, over time lead to the results you’re looking for. Keep going. Repeat, repeat, repeat! In consistency there’s power!

“It’s not what we do once in a while that shapes our lives. It’s what we do consistently.” — Anthony Robbins

Consistency leads to habit. 

“Motivation is what gets you started. Habit is what keeps you going.” — Jim Ryun

After the monkey figured out thumb flexion, I’d let him bask in his success for a couple days, I didn’t change anything up, just let him keep doing the thumb flexion and getting his reward.

#3: Reward yourself when you figure it out!

When you accomplish a goal you’ve set, be sure to reward yourself! Just make sure that your reward keeps you moving in the direction of your original goal. For example, if your goal was to lose 2o lbs. and you did, don’t reward yourself by going out and cramming down a big cinnamon roll or a box of cupcakes, instead align your reward with something that pushes you in the direction of your goal (e.g., buy yourself some new workout clothes!) 

But I didn’t let the monkey just settle into complacency, I mean a data set of just thumb flexions isn’t all that interesting. So, as always happens in life, there’s change.

I started cueing the monkey’s index finger to flex. And just like before, I had to go in and do hundreds or thousands of index finger flexions with the monkey to slowly get him to perform index finger flexion. HOWEVER, as soon as the monkey had learned how to do index finger flexion, I had to go back and interleave thumb flexions with index finger flexions so that the monkey wouldn’t forget what he had already learned.

#4: Interleave or go back and review

This hints back somewhat to lesson #2 regarding repetition. This is because interleaving and reviewing is all about helping us not forget what we have already learned. Interleaving is about applying and doing what we’ve just learned to what we already know. This helps cement both what we’ve newly learned as well as what we’ve learned in the past into long-term memory. I have heard it said often that remember is the most important word in the English language. 

In a famous study, H.F. Spitzer (1939) studied how quickly students forgot material from a textbook:

After 1 day — — —  54% was remembered.

After 7 days — — —  35% was remembered.

After 14 days — — —  21% was remembered.

After 21 days — — —  18% was remembered.

After 28 days — — — 19% was remembered.

After 63 days — — —  17% was remembered.

Without interleaving and review, what you’ve read or learned will soon be forgotten. So, if you liked this article or something that you’ve learned, bookmark it and come back later and re-read it. Highlight things that you read so that your later review is easier and faster. Take notes in the margins or in a notebook, the act of writing helps you to remember as well. I generally use the public library to read books, but occasionally I’ll read one that I know that I’ll want to come back and review, and I’ll buy it and add it to my library so that I can highlight, take notes, and read it next year for review.


Eventually, I trained the monkey in thumb flexion, index finger flexion, middle finger flexion, thumb and index finger combined flexion, thumb and middle finger combined flexion, and individual extension of the thumb, index, and middle finger. In some regard, I was lucky and blessed — the monkey I trained wasn’t the alpha of the group, so he was much more teachable and humble and he ended up becoming quite a smart monkey when it came to moving his fingers to get Tang!

It was extremely rewarding, as part of the DARPA Revolutionizing Prosthetics Program, to perform the first real-time decode of individuated finger movements based on the wireless EMG recording devices (known as IMES) using decode algorithms that my collaborators and I wrote.

So, if you want to be a “smart monkey” find out what is your Tang. Use repetition and consistency in your favor. Reward yourself when you figure it out, and don’t forget to go back and review!

Resonate & Align

If this resonates or aligns with you and you like what you read, subscribe to my blog, and share this with your friends who might feel the same way. Thanks! Justin.


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