Category Archives: Outreach

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.

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.
Graduate Student Ambassadors: An APS Effort to Increase Involvement in Professional Societies

The Graduate Student Ambassador (GSA) program was organized by the American Physiological Society’s (APS) Trainee Advisory Committee in 2015. The goal of the program is to train graduate students to act as liaisons between APS and local undergraduate and graduate students. GSAs visit schools in their local area to share their experiences as graduate students, discuss physiology careers and the benefits of an APS membership, and encourage students to consider becoming a member of APS. The program has a unique, symbiotic relationship in that GSAs learn valuable outreach, public speaking, and leadership skills, while APS receives promotion of their awards, programs, and memberships. One particular goal of the GSA program is to recruit and retain individuals from under-represented communities. This is the aim that attracted me to the program.

 

As a first-generation college student, I was raised in a very low socioeconomic background. My exposure to careers was limited and like countless other young girls, I grew up with a short supply of role models who looked like me. While most of my public school teachers were female, the science labs and principal’s offices were considered masculine domains. In my mind, a scientist was that image we all remember of the mad chemist brewing his potions in a lab, hair all in disarray. Although I got the messy hair right, I couldn’t picture myself as this version of a scientist. I didn’t know anything about college because nobody in my life had ever been to one. I certainly didn’t know what a Ph.D. was at the time. By luck and happenstance, I wound up at the University of Kentucky for my undergraduate studies as a nontraditional student following community college. UK is a Research 1 institution, so I was exposed to the scientific method from the start. However, looking back, I’ve always wondered what if I had attended a different university? Would I have ever found my niche in research? And, thus, is the goal of the GSA program: to expose students to careers in research and promulgate the ways in which APS can assist them in these pursuits.

 

When I first got wind of the new GSA program, I was quick to apply. From the beginning, I was excited by the prospect of sharing my experiences as a graduate student with undergraduates. I knew I wanted to visit less research-intensive universities and try to reach under-represented students, first-generation college students, and students from low socioeconomic backgrounds. I recognized the need for diversity in STEM and wanted to contribute to efforts being made to increase it. According to the National Science Foundation, while blacks and Hispanics constitute 36% of the US resident population ages 18-24, they only represent 17% of enrolled graduate students. There is even less representation at the level of doctorate holders (Figure 3). Ethnic and cultural representations in science do not match their share in the US population. However, it is absolutely essential to the growth of STEM to sample from all groups of people.

 

Science is meant to be an objective process, but much of science has been shaped by individuals of a similar background. This not only halts progress but can actually hurt it. For example, the standard medical treatment for breast cancer used to be radical mastectomies. It wasn’t until female voices were welcomed that alternative treatments were implemented—treatments that allowed women to keep their breasts and have been shown to be just as, if not more, effective. Progress was made because of a different perspective. The same is true of drug development, our understanding of sex differences in cardiovascular disease, even air-bag design which was initially tailored to a man’s height and thus not as effective for women. A diverse and inclusive program can promote widely applicable and lifelong learning so that historically under-represented groups can contribute to future breakthroughs with a new perspective. If fields are not diverse and inclusive, we are not cultivating potential but instead losing talent.

 

Berea College, the first coeducational and interracial college in the south, is an example of an ongoing effort to increase inclusion. This school, located in Berea, Kentucky, is a 4-year university that offers a tuition-free education to every single student. They enroll academically promising, economically challenged students from every state in the U.S. and 60 other countries. Over one third of their student population are of color, 8% are international, and 70% are from the Appalachian region and Kentucky. They are inclusive regardless of sexual orientation, gender identity, disability, race, citizenship status, etc. Despite not being a research intensive university, they have an excellent science program with a newly built Natural Sciences and Health building featuring state-of-the-art teaching laboratory equipment. They also encourage students to participate in the Kentucky Biomedical Research Infrastructure Network, a program designed to support undergraduate students in biomedical research, promote collaboration, and improve access to biomedical facilities.

 

I wanted to visit Berea to share my experiences as a graduate student, discuss the different career paths within physiology, and provide interested students with information about beneficial awards and programs offered through APS. Many of the students I spoke with didn’t know much about graduate school or obtaining a Ph.D. They seemed intrigued by my experience as a teaching assistant to fund my program. Berea College offers a unique work program at their school where students work as part of their tuition-free enrollment. Some act as teaching assistants in their courses, giving these students the experience they need to enter a funded graduate program with a teaching component. A lot of the students didn’t realize, though, that you could simply apply to a doctoral program with a bachelor’s degree—they thought you needed to obtain a master’s degree first. Most of the students were particularly interested in the undergraduate summer research programs offered through APS, such as the STRIDE fellowship. They wanted to know more about the Porter Physiology Development Fellowship for graduate students. I was also very excited to share with them the Martin Frank Diversity Travel Fellowship Award to attend the Experimental Biology conference.

 

I had a meaningful and productive visit to Berea College. My next step will be visiting a local community college, another area where efforts to promote diversity and inclusion are progressing. Community colleges are also an excellent place to reach nontraditional students, such as myself. These students sometimes transfer to larger universities to finish their bachelor’s degree, but being a transfer student often doesn’t allow for exposure to research as an undergraduate. I hope to encourage these students to pursue careers in physiology.

 

If you’re interested in contributing to this mission, consider applying to become a GSA. The position is a 2 year term and requires you to attend Experimental Biology each year of your term. The applications for 2019 are currently under review.

 

References

National Science Foundation, National Center for Science and Engineering Statistics. 2017. Women, Minorities, and Persons with Disabilities in Science and Engineering: 2017. Special Report NSF 17-310. Arlington, VA. Available at www.nsf.gov/statistics/wmpd/.

 

Chelsea C. Weaver is a fourth year PhD candidate at the University of Kentucky where she studies hypertensive pregnancy disorders in African Green Monkeys. She has served as a teaching assistant for Principles of Genetics and Animal Physiology for undergraduates. She also guest-lectured for graduate level Advanced Physiology courses. Chelsea is interested in pursuing a postdoctoral position in STEM education research in K-16 upon graduation.
Scientific Literacy: A Challenge, a Task, a Poem

Scientific literacy allows citizens to get involved in issues and ideas related to science as a reflective citizen[1]. A scientifically literate person can:

  1. Recognize, offer and evaluate explanations for a variety of scientific and technological phenomena
  2. Describe and evaluate scientific research and propose ways to answer questions and solve problems following the scientific method
  3. Analyze and evaluate data, concepts and arguments in a variety of contexts, reaching appropriate conclusions for the data received[1]

 

The challenge

Quality education is the key to achieving literate societies. Unfortunately, scientific literacy is generally very low in most developing countries. Results of the PISA tests, for example, reveal that competencies in mathematics and sciences in developing countries are below the average of the countries evaluated[2]. This has enormous consequences for the communities by negatively impacting their political, economic and social decision-making.

 

Figure 1. Performance in mathematics and science of different countries in the 2015 Pisa tests. Images Taken from http://www.oecd.org/pisa/.[2]

The task

It is very important to open spaces for the general community in developing countries to learn about the practice of science. Many scientific organizations develop training activities that are usually directed at specialized audiences. For this reason, it is important to highlight the task of scientific associations that are concerned with bringing science to the general community such as the American Physiological Society through events such as PhUn week. In the particular case of Colombia, the Colombian Association for the Advancement of Science (ACAC) organizes every two years a very large science fair “Expociencia” that is visited by more than 40,000 elementary, middle and high school students.

 

These science fairs have several objectives:

  1. Allow students to present the results of scientific projects. Students are exposed to an essential component of science, sharing and communicating research. In addition, they have the opportunity to learn from their peers and receive feedback from more experienced researchers.
  2. Open the doors of academic, governmental or industry laboratories to the community. Visitors have the opportunity to know what scientists do, interact with them, expose their visions about science. In addition, visitors can express doubts they have about different concepts, and sometimes they can find answers to their questions.
  3. Generate academic spaces so that researchers can discuss how to work with the community, address their most pressing needs and communicate their results to the public.

Figure 2. Participation of students in academic activities at Expociencia 2018. Images courtesy of Deiryn Reyes, ACAC.

Recently with the support of the Faculty of Medicine of the Universidad de los Andes, I had the opportunity to participate in Expociencia[3]. It was gratifying to see how the children ran from one side to the other having the opportunity to learn about electronics, physics, programming, biology, medicine and anthropology. These children are like sponges that quickly absorb the information they receive and are willing to ask questions without filtering them through mechanisms that adults have learned. In addition, Expociencia promotes spaces for university students to share their experiences and for a moment to be role models for school students. I believe that many lives are changed thanks to the experience of living science.

 

The poem

In the nineteenth century lived a poet who wrote and translated from other languages several of the best-known stories that are known by children and adults in Colombia. His influence on Colombian literature is similar to that of the Grimm brothers in Europe. The name of this writer was Rafael Pombo. A few weeks ago, thanks to my son, I had the opportunity to learn that he also wrote about the importance of knowledge and science. On this occasion I want to share a personal translation of one of Rafael Pombo´s poems, that can be used to discuss with small children and adults the importance of science in our lives.

 

THE CHILD AND THE OX

Rafael Pombo (1833-1912)

The boy

 

-What do you think about all day

Lying on the grass?

You seem to me a great doctor

Enraptured in his science.

 

The ox

-The science, dear child

It is not what feeds me;

That is the fruit of study,

With what God gives humans.

 

Out thinking for me,

Poor animal, hard enterprise;

I prefer to make thirty furrows

Before learning two letters.

 

Chewing well, I care more

that a lesson at school.

With the teeth, I chew,

You, child, with your head.

 

But if you want to be wise

Hopefully seeing me you´ll learn

To ruminate, and ruminate a lot,

Every bit of science.

 

Digesting, not eating,

It is what the body takes advantage of,

And the soul, invisible body,

has to follow such a rule.

 

Without ruminating it well, do not swallow

Not a line, not a letter;

The one who learns like a parrot,

Ignorant parrot stays.

 

References

  1. National Academies of Sciences, E., and Medicine., Science Literacy: Concepts, Contexts, and Consequence. 2016.
  2. OECD. Results by Country. [cited 2018 November 4th]; Available from: http://www.oecd.org/pisa/.
  3. Ciencia, A.C.p.e.A.d.l. Expociencia 2018. 2018 [cited 2018 October 31st]; Available from: https://expociencia.co/home/.
Ricardo A. Peña-Silva M.D., PhD is an associate professor at the Universidad de los Andes, School of Medicine in Bogota, Colombia, where he is the coordinator of the physiology and pharmacology courses for second-year medical students. He received his doctorate in Pharmacology from The University of Iowa in Iowa City. His research interests are in aging, hypertension, cerebrovascular disease and medical education. He works in incorporation and evaluation of educational technology in biomedical education.

He enjoys spending time with his kids. Outside the office he likes running and riding his bicycle in the Colombian mountains.