Great Ideas from the Brain Sciences: How Stimuli Affect Learning and Why They Matter for Learning
By: Mirela C. C. Ramacciotti
Why do we care about sound, smell, light, temperature, and movement when teaching languages? How did we come to know that sensations affect perceptions and impact learning? If you have wondered about that, you should know that this idea dates back to Aristotle—the “father” of our five senses—but it was around two centuries ago that measures of sensations led to studies of perception thresholds that could be linked to how we learn.
And if you believe that experimental psychology deserves all the credit, think again! It’s true that the systematic study of mental processes began in 1879, in Leipzig, Germany, with the establishment of the first laboratory by Wilhelm Wundt. However, without the contributions of Gustav Fechner, outlined in his 1860 publication “Elements of Psychophysics,” we wouldn’t have had the fundamental tools to explore how the mind functions.
From that point on, countless experiments explored how stimuli may affect our senses differently. They all involved thresholds that may be subject to change according to genetics, emotional states, and contextual conditions. Nevertheless, we must acknowledge that it was by studying sensations in a controlled environment, like a lab, in an organized and systematic study, i.e., scientific, that experiments could be shaped and reproduced so that vague notions about how our minds work found acceptance or refutation. But how does that relate to the language classroom? Let us proceed carefully—and respectfully—for the road is indeed interesting.
Gustav Theodor Fechner was a trained biologist who connected science and philosophy especially because quantitative measurements appealed to him. It was such appeal that led to his interest in measuring how much stimulus (magnitude) is needed to create a response, that is, a sensation. This happened because Fechner could build his ideas upon the work of a fellow German, Ernst H. Weber, who discovered the “just noticeable difference,” or “the smallest difference perceivable between two similar stimuli.”
In simpler terms, Fechner led us to the notion that stimuli have to increase geometrically, or exponentially, for sensation to increase arithmetically (or linearly). That ratio (geometrical to arithmetical concerning stimulus and sensation) is called the Fechner-Weber Law. You might have noticed it when dealing with audio input in the classroom. If you want students to notice something, you must increase the volume exponentially. But when what you want is for them to shift their attention, you modulate your voice so that their focus gets turned to what you want them to perceive. That cunning ability that teachers dwell upon—to have students detect a difference between an original stimulus and a new stimulus—is physically possible following the Fechner-Weber Law.
So it was that Wundt could, in primary form, manipulate certain variables to observe—and measure—how mental processes could differ in how they operated. He was especially interested in how perceptions, such as sensations provoked by certain stimuli, would evoke an immediate experience that could be conscious or unconscious. Perhaps that was also a construct he was able to develop after having assisted Von Helmholtz in his quest to understand the “sensory veil” that turns perceptions into a form of induction inference. To Helmholtz, our brains are making—and constantly updating—predictions about the causes of the sensory signals we get. Therefore, perception would be akin to a conclusion arrived at via unconscious inferencing. This was a truly revolutionary idea—one that we will explore in more detail soon, in another article of our “Great Ideas in the Brain Sciences” series.
Back to the classroom–you might not want to draw students’ attention to how stimuli are presented or manipulated, for that could increase students’ cognitive load and create an overload. However, knowing that we do this today in managing classroom environments to improve learning is a must. Now we may give proper credit to the originators of such an idea.
Mirela C. C. Ramacciotti is presently engaged as an external lecturer on the topic of Mind, Brain, and Education at the Graduate Level Course with the Psychology Department at the University of São Paulo. She holds a PhD in Neuroscience and Behavior and another in Human Communication Disorders.