Monthly Archives: April 2019

Embracing the Instability of Positive Feedback Loops

Feedback loops are a physiology professor’s bread and butter.  From blood sugar to body temperature, negative feedback ensures that no physiological variable strays from its set point (or range) and that homeostasis is maintained.  Positive feedback loops, on the other hand, are inherently unstable.  In these loops, the response elicited by a stimulus drives the variable further from its set point, reinforcing the stimulus rather than reducing it, and continuing until some outside influence intervenes1.  The classic physiological example of positive feedback is childbirth – pressure from the baby on the mother’s uterus and cervix triggers the release of the hormone oxytocin, which triggers uterine muscle contractions that further push the baby toward the cervix.  This loop of pressure, oxytocin release, and contractions continues until an intervening event occurs – the delivery of the baby.

While physiological positive feedback loops are fascinating, they are greatly outnumbered by negative feedback loops; thus, they don’t usually get much attention in our physiology classrooms.  We usually tell students that the instability of positive feedback loops is what makes them so uncommon.  However, I’d like to use my platform here to argue for a larger place for positive feedback loops in not just our physiology courses, but all of our courses.

 

Positive Feedback Loop Learning

I mentioned above that positive feedback loops are inherently unstable because they drive variables further from their set points, so you may be thinking, “why would I ever want my classroom to be unstable?”  Imagine it this way:  in this feedback loop, the stimulus is an idea, concept, or problem posed by the instructor.  The response is the student’s own investigation of the stimulus, which hopefully sparks further curiosity in the student about the topic at hand, and drives him or her toward more investigation and questioning.  Granted, this system of learning could certainly introduce some instability and uncertainty to the classroom.  Once sparked, the instructor does not have control over the student’s curiosity, which may take the student outside of the instructor’s area of expertise.  However, I maintain that this instability actually enriches our classroom by giving students the space to think critically.

 

Why Encourage Positive Feedback Loops?

Though often misattributed (or even misquoted), Oliver Wendell Holmes, Sr. (poet, essayist, physician, and father of US Supreme Court Justice Oliver Wendell Holmes, Jr.) once wrote “Every now and then a man’s mind is stretched by a new idea or sensation, and never shrinks back to its former dimensions.”2 Neuroscience research supports this assertion.  In rodents, exposure to novel stimuli in enriched environments enhances neuronal long-term potentiation, the cellular correlate of learning and memory in the brain3.  Human brains both functionally and structurally reorganize upon learning new information.  A magnetic resonance imaging study examined gray matter volume in the brains of German medical students who were studying for their “Physikum,” an extensive exam covering biology, chemistry, biochemistry, physics, human anatomy, and physiology4.  Brain scans taken 1-2 days after the Physikum demonstrated significantly increased gray matter volume in the parietal cortex and hippocampus compared to baseline scans taken 3 months prior to the exam (and prior to extensive exposure to new information during the study period)4.  Thus, while the brain may not literally be “stretched” by new ideas, as Holmes proposed, the process of learning (acquisition, encoding, and retrieval of new information) certainly reshapes the brain.

In the model I’ve presented above, new ideas, concepts, and questions are the stimuli in our positive feedback loop.  These stimuli promote changes in our student’s brains.  And, if these stimuli spark curiosity, these brain changes (and thus learning) will be amplified as students respond – meaning, as they construct new ideas, concepts, and questions based on their own interests.  Thus, the loop feeds into itself.

 

Designing Stimuli That Elicit Positive Feedback

How can we structure our teaching so that the stimulus we present to our students is strong enough to elicit a response?  First, it is crucial that our stimuli elicit curiosity in our students. In his essay surveying recent research on the role of curiosity in academic success, David Barry Kaufman wrote, “Stimulating classroom activities are those that offer novelty, surprise, and complexity, allowing greater autonomy and student choice; they also encourage students to ask questions, question assumptions, and achieve mastery through revision rather than judgment-day-style testing.”5  Project-based learning, a teaching technique focused on extended engagement with a problem or task as a means of constructing knowledge, checks many of Kaufman’s boxes6.  As an example, in the past two iterations of my Physiology course, my students have participated in the “Superhero Physiology Project” in which they develop interactive lesson plans for middle school students.  Based on the work of E. Paul Zehr, Ph.D. (author of Becoming Batman: The Possibility of Superhero7 and multiple APS Advances in Physiology Education articles), my students choose a superhero to base their lesson upon, and work over the course of several weeks to create interactive, hands-on activities to teach kids about a physiological system.  While I give my students feedback on the plausibility of their ideas (within our time and budgetary constraints), I leave much of the structure of their lessons open so that they have the opportunity to work through the complexities that come with keeping 20 or more middle schoolers engaged.  Often, my students tell me that figuring out the best way to communicate physiological concepts for a young audience encouraged them to go beyond our textbook to search for new analogies and real-life examples of physiology to which middle schoolers could relate.

Another way to design stimuli that elicit curiosity and positive feedback learning is by capitalizing on a student’s naiveté.  In this approach, described by education expert Kimberly Van Orman of the University of Albany in The Chronicle of Higher Education8, “students don’t need to know everything before they can do anything” – meaning, curiosity is most easily sparked when possibilities aren’t limited by your existing knowledge, because you don’t have any!  For me, this approach is somewhat difficult.  Like all instructors, I regularly feel the pressure to ensure we “get through the material” and often plow through concepts too quickly.  However, my physiology students last fall showed me the power of the “naïve task” firsthand when I observed the Superhero Physiology lesson9 they gave at the middle school.  They decided that before teaching the middle schoolers any physiological terms or concepts didactically, they would present them with a hands-on experiment to introduce the concepts of stroke volume and vasoconstriction.  Their rationale and approach (below) illustrate their mastery of using naiveté to spark curiosity.

Rationale:

The students should be provided with very little, if any, background information on the heart models and the reasoning behind the varying sizes of the materials. By providing little information up front, we hope to intrigue their curiosity regarding the lesson and its significance. Students will be told what to do with the instruments; however, they will not receive any advice on which instruments to use.

The Experiment:

  1. Divide the class into two groups (within each group there should be 4-5 “holders” for the tubes and 4-5 “pumpers” managing water and pipets). Group 1 will be given large diameter tubing, a large funnel as well as 3 large volume pipettes. Group 2 will receive smaller tubing, a smaller funnel and only one smaller volume pipet.
  2. Instruct the students that they will be transporting the water from a large bucket into another bucket 8-10 feet across the room without moving the bucket.
  3. The groups will have 10 minutes to construct their apparatus, and 5 minutes for the actual head-to-head “race” in which the winner is determined by who moves the most amount of water in the allotted time.
  4. After the students have completed the first experiment they will return to their seats for the lecture portion of the lesson which will connect the different parts of the build to different portions of the cardiovascular system.

 

Not only did the middle school students have a fantastic time building their apparatus (and accidentally on purpose getting each other wet!), but as the experiment progressed, they began to get curious about why the other team was so behind or ahead.  Soon after, discussions between groups about tubing diameter and pipet size emerged organically among the middle schoolers, and they were able to easily apply these concepts to later discussions of blood flow and cardiac output.

 

Embracing Instability

While I think most educators aspire to elicit positive feedback learning in their students, there can be barriers to putting it into practice.  As I mentioned above, pressure to cover content results in some of us shying away from open-ended activities and projects.  Not all students in a given class will come in with the same motivations for learning (as discussed in Dr. Ryan Downey’s December 2018 PECOP Blog post10), nor will they all respond to the same stimuli with curiosity.  However, it just takes one stimulus to put a positive feedback loop into action – and once it gets going, it’s hard to stop.  Once a student’s curiosity is piqued, the classroom may feel a bit unstable as their interests move out of the realm of your expertise as an instructor.  But ultimately, we all as educators live for that moment when a connection crystallizes in a student’s mind and they discover a new question they can’t wait to answer.

 

Acknowledgements

The author is grateful to Wabash students James Eaton, Sam Hayes, Cheng Ge, and Hunter Jones for sharing an excerpt of their middle school lesson.

 

References

1 Silverthorn DU. (2013).  Human physiology, an integrated approach (6th Ed.). Pearson.

2 Holmes OW. (1858). The autocrat of the breakfast-table. Boston:  Phillips, Sampson and Company.

3 Hullinger R, O’Riordan K, Burger C.  (2015).  Environmental enrichment improves learning and memory and long-term potentiation in young adult rats through a mechanism requiring mGluR5 signaling and sustained activation of p70s6k.  Neurobiol Learn Mem 125:126-34.

4 Draganski B, Gaser C, Kempermann G, Kuhn HG, Winkler J, Büchel C, May A. (2006).  Temporal and spatial dynamics of brain structure changes during extensive learning.  J Neurosci 26(23):6314-17.

5  Kaufman,SB. (2017, July 24).  Schools are missing what matters about learning.  The Atlantic.  Retrieved from https://www.theatlantic.com/education/archive/2017/07/the-underrated-gift-of-curiosity/534573/

6 What is PBL? (n.d.) Retrieved from https://www.pblworks.org/what-is-pbl

7 Zehr, EP. (2008).  Becoming Batman: the possibility of a superhero.  Baltimore: Johns Hopkins University Press.

8 Supiano, B. (2018, June 7). How one teaching expert activates students’ curiosity. Retrieved from https://www.chronicle.com/article/How-One-Teaching-Expert/243609

9 Eaton J, Hayes S, Ge C, Jones H. (2018).  Superhero cardio: the effects of blood vessel diameter, stroke volume, and heart rate on cardiac output. Unpublished work, Wabash College, Crawfordsville, IN.

10 Downey, R.  (2018, December 13).  Affective teaching and motivational instruction: becoming more effective educators of science. [Blog post]. Retrieved from https://blog.lifescitrc.org/pecop/2018/12/13/affective-teaching-and-motivational-instruction-becoming-more-effective-educators-of-science/

 
Heidi Walsh has been an Assistant Professor of Biology at Wabash College since 2014. She received a B.S. in Neuroscience from Allegheny College, a Ph.D. in Neuroscience from the University of Virginia, and completed post-doctoral work in the Department of Metabolism & Aging at The Scripps Research Institute’s Florida campus.  Heidi’s research lab studies the impact of obesity-related stressors, including endoplasmic reticulum stress, on gonadotropin-releasing hormone (GnRH) neurons. She teaches courses in Cell Biology, Physiology, and Molecular Endocrinology, and enjoys collaborating with students on science outreach projects.
Engaging students in active learning via protocol development

Physiology, particularly metabolic physiology, covers the fundamentals of biophysics and biochemistry for nutrient absorption, transport, and metabolism. Engaging pre-health students in experimentation may facilitate students’ learning and their in-depth understanding of the mechanisms coordinating homeostatic control. In addition, it may promote critical thinking and problem-solving ability if students are engaged in active learning.

Traditionally, students are provided instructions that detail the stepwise procedures before an experiment or demonstration. Although students are encouraged to ask questions before and during the experiments, an in-depth discussion would not be possible until they understand each step and the underlying principles. This is particularly true nowadays when commercial kits come with stepwise instructions where no explanation can be found of principles behind the procedure. The outcomes may contrast in three ways: (1) students are happy with the perfect data they acquire by following the instructions provided by the manufacturer, but they miss the opportunity to chew on the key principles that are critical for students to develop creative thinking; (2) students are frustrated as they follow the instruction but fail the experiments, without knowing what is wrong and where to start for trouble shooting; and (3) driven by self-motivation, students dig into the details and interact intensively with the instructor to grasp the principles of the procedure. As such, the students can produce reliable data and interpret the procedure and data with confidence, and in addition, they may effectively diagnose operational errors for trouble shooting. Evidently, the 3rd scenario demonstrates an example of active learning, which is desirable but not common in a traditional model of experimentation.

To engage students in active learning, one of the strategies is to remove the ready-to-go procedure from the curricular setting but request the students to submit a working protocol of their own version at the end of an experiment. Instead of a stepwise procedure (i.e., a “recipe”), the students are provided with reading materials that discuss the key principles of the analytical procedures. When students show the competency in the understanding of the principles in a formative assessment (e.g., a 30-min quiz), they are ready to observe the demonstrations step by step, taking notes and asking questions. Based on their notes and inspiration from discussion, each student is requested to develop a protocol of their own version. Depending on how detail-oriented the protocols are, the instructor may approve it or ask students to recall the details and revise their protocols before moving forward. Once students show competency in the protocol development, they are ready to conduct the steps in groups under the instructor’s (or teaching assistant, TA’s) supervision. Assessment on precision and accuracy is the key to examine the competency of students’ operation, which also provides opportunities for students to go back to improve or update their protocols. In the case of unexpected results, the students are encouraged to interpret and justify their results in a physiological setting (e.g., fasting vs. feeding states) unless they choose not to. Regardless, students are asked to go back to recall and review their operation for trouble shooting under the instructor’s (or TA’s) supervision, till they show competency in the experiment with reproducible and biologically meaningful data. Trouble shooting under instructor’s or TA’s supervision and inspiration serves as an efficient platform for students to take the lead in critical thinking and problem solving, which prompts students to go back to improve or update their protocols showing special and practical notes about potential pitfalls and success tips.

Often with delight, students realize how much they have grown at the end of experimentation. However, frustration is not uncommon during the troubleshooting and learning, which has to be overcome through students’ persistence and instructor’s encouragement. Some students might feel like “jumping off a cliff” in the early stage of an experiment where a ready-to follow instruction is not available. Growing in experience and persistence, they become more confident and open to pursue “why” in addition to “what”.

Of note, logistic consideration is critical to ensure active learning by this strategy. A single experiment would take up to 3-fold more time for the instructor and students to work together to reach competency. To this end, the instructor needs to reduce the number of experiments for a semester, and carefully select and design the key experiments to maximally benefit students in terms of skill learning, critical thinking, and problem solving. Furthermore, group size should be kept small (e.g., less than 3 students per group) to maximize interactive learning if independent experimentation by individuals is not an option. Such a requirement can be met either by increasing TA support or reducing class size.

 

 
Zhiyong Cheng is an Assistant Professor of Nutritional Science at the Food Science and Human Nutrition Department, University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS). Dr. Cheng received his PhD in Analytical Biochemistry from Peking University. After completing his postdoctoral training at the University of Michigan (Ann Arbor) and Harvard Medical School, Dr. Cheng joined Virginia Tech as a faculty member, and recently he relocated to the University of Florida. Dr. Cheng has taught Nutrition and Metabolism, with a focus on substrate absorption, transport, and metabolism. As the principal investigator in a research lab studying metabolic diseases (obesity and type 2 diabetes), Dr. Cheng has been actively participating in undergraduate and graduate research training.
Where does general education fit into an undergraduate degree?

I am currently serving on a taskforce which has been given the job of revising our general education program. As a member of this taskforce, I have been reading, analyzing, and using data to design and implement a program that many faculty struggle to explain and that many students often question. This made me think. What do schools mean by general education?

If we look at definitions, most people would say this is the part of a student’s education which is meant to develop their personalities or provide skills and knowledge which will help students succeed not only in their chosen major but also in their careers and life. If we look at this more closely, many faculty members see general education as the place for students to develop some of those soft skills that are often talked about by employers. These soft skills include communication skills, listening skills, critical thinking/problem solving, and interpersonal skills to name a few.

If general education is the place for the learning of these skills, where do we as faculty fit into general education? After all, isn’t it my job to provide the knowledge for Biology classes? That is why I have my Ph.D. and the institution hired me. Surely, there are other members of the campus community that can also guide students on successful acquisition of these skills? For example, I was never taught how to teach writing so why should I teach writing? But is this statement true? I was taught how to write. In elementary, junior high, and high school, I was taught how to construct sentences to ensure that all verbs had a subject. I was taught how to put together an outline so that my thoughts were organized in a logical manner. In college, I was taught how to now take difficult concepts and use them to develop a hypothesis. I was taught how to present the methodology of my experiments. And finally, I was taught how to analyze and present data and then discuss what that data meant. Graduate school asked me to use these skills and bring them to a higher level. I could list similar instances and experiences for thinking and problem solving, collaboration, and other soft skills as well. Are these experiences enough for me to be able to teach writing in our general education program? That is the million dollar question our taskforce is trying to answer. There is a part of me, that says, “YES! I can teach students how to write.” I have had papers published. I write all the time for different committees, classes, and other activities. There is a second part of me that is terrified of the idea of teaching writing in a more general class. Those scary terms like logic and rhetoric seem overwhelming to this Biology professor. Can I even give an example of rhetoric? I know that if I stepped back and took a breath, I could give an example of rhetoric. But this raises another question. Do the students deserve someone better trained (and less afraid of these terms) to guide them while learning these skills? That question is still one our taskforce is trying to answer.

The other question our taskforce has had to face is, “How do we get students to buy into general education?” What can we as faculty and staff do to promote the importance of those skills learned in our institution’s general education programs? Are we so focused on the knowledge and skills of the major that we forget that those soft skills can make or break a successful employee? Knowledge and skills specific to a job can get the applicant to the interview. It is the soft skills that can get the applicant the job. If this is the case, then isn’t it our job as professors and teachers to not only help our students gain the knowledge but also to help them gain those skills that will help them to succeed in their careers and lives? And if that is our job, how do we as faculty support and allow for equal importance of both technical knowledge and skills and these so-called soft skills?

Let me preface, I am certainly not telling faculty that they need to get rid of their grading scales. And I am not telling students they should forget about their grades. But I am questioning how we measure success in today’s academic world and in our global society. If we look at surveys and reports that have been published, employers are having trouble finding students/potential employees with soft skills. Does this mean all of these higher education institutions are failing in their general education of students? I would like to think that we aren’t failing. But I am suggesting we might need to find a better way to illustrate the importance of the skills learned in general education classes. This could be in how we discuss general education to how we define successful completion of general education. Most teachers always ask how to assess soft skills. Is it possible that maybe a grading scale isn’t the only way to define success when it comes to learning some skills? Again, our taskforce hasn’t come up with the golden answer yet.

Serving on this taskforce has been eye opening and I have learned that putting together a successful general education program requires a great deal of guesswork. There have been questions raised that I truly do not have answers for, and I don’t know that answers are available for these questions. But these questions and this process have made me question what the future of general education looks like.  The current generation of students have access to technology and possess skills and talents that did not even exist when many faculty were students. As faculty we learned skills that helped us succeed back when we were graduating and looking to move to the next phase of life. And we have adapted as changes to the world have come. While I cannot say for sure what general education will look like in the future, I can say that we need to be training students for the requirements of today’s workforce and the ability to adapt for the future workforce. And unless we have a crystal ball which can predict the future, what that looks like will remain unknown.

 
Melissa A. Fleegal-DeMotta, Ph.D. earned her BS in Biology from Lebanon Valley College in Annville, PA. After working at Penn State’s College of Medicine, she then earned her PhD from the University of Florida in Gainesville, FL. Following postdoctoral fellowships at the University of Florida, University of Arizona, and Saint Louis University, she has been a professor at Clarke University in Dubuque, IA for over 10 years. During her time at Clarke, she has developed an interest in how the general education of a liberal arts university fits with the education of science majors.