Structure-Function relations in physiology education: Where’s the mechanism?
Matthew Lira and Stephanie Gardner published a study in Advances in Physiology Education published June 1st, 2017 Vol. 41 no. 2, 270-278—a journal published by the American Physiological Society. In this study the authors call attention to the skill of mechanistic reasoning in students’ explanations of physiological phenomena. In particular, the article describes how students characterize the general idea of mechanisms in physiology and how students can fail to distinguish mechanisms from other critical ideas, such as physiological functions. Although instructors may spend an entire lecture or semester describing mechanisms in biology, that essential point may be lost on students as they and the instructor transition between characterizing mechanisms and functions iteratively. The authors’ analysis of students’ thinking was guided by the Structure-Behavior-Function framework, a framework that distinguishes explicitly between “behaviors” (i.e. mechanisms) and functions. The lessons learned from this initial study informed the design of new learning tasks the aimed to better support students in making these distinctions explicit—students’ characterizations of mechanisms and functions suggest that more explicit instruction should direct students’ attention to the difference between these two central ideas in physiology. Analyses are continuing through the summer and preliminary findings will be presented at the Society for the Advancement of Biology Education Research in Minneapolis, MN in July. Matthew Lira will complete his post-doctoral training this summer and will then join the University of Iowa’s Educational Psychology and Learning Sciences program as a clinical assistant professor. At Purdue University, Matthew works as a post-doctoral scholar in the Department of Biological Sciences. Stephanie Gardner is a physiologist and biology education researcher in the Department of Biological Sciences.
Figure 1—Relations between structures, mechanisms, and functions. The SBF framework calls attention to the idea that mechanisms (behaviors) and functions differ from one another. At the same time, it also constructs relations between the terms to support a meaningful understanding—a specific structure supports a specific mechanism of action that supports a specific biological function. In the example in the figure shows, neurons reflect structures residing at the cellular level. The ionic mechanism of depolarization occurs at the molecular level, whereas the communicative function occurs at the multi-cellular level. The framework therefore affords a causal or asymmetric syntax that in this case reads, “Neurons depolarize to support communication.”