Changing the brain through instruction

I attended my second Transforming Online Pedagogy and Practices Symposium (TOPPS) this past May. The event is sponsored and hosted by UNCG's University Teaching and Learning Commons (UTLC). Like the 2018 symposium, this event was well worth it.

This year's theme was "Science and the Art of Changing the Brain through Instruction and Instructional Design," and the UTLC brought in Dr. Kristen Betts as the event's keynote speaker. Dr. Betts is a Clinical Professor in the School of Education at Drexel University and specializes, among other things, in how we can harness brain science to improve teaching. Her presentations, which revolved around the theme "Leveraging Psychology to Create Compelling Learning Experiences," was spread across two morning sessions on May 13th and 14th.

The first session was entitled "Neuropedagogy: Changing the Brain through Instruction and Instructional Design." Dr. Betts first asked us to go through a list of statements about learning and the brain and mark whether we thought the statement was correct or incorrect. Here they are:

1. Listening to classical music increases reasoning ability. 
2. Individuals learn better when they receive information in their preferred learning styles (e.g., auditory, visual, kinesthetic) 
3. Some of us are "left-brained" and some are "right-brained" due to hemispheric dominance and this helps explains differences in how we learn 
4. We only use 10% of our brain 
5. Normal development of the human brain involves the birth and death of brain cells 
6. Learning is due to the addition of new cells to the brain 
7. There are critical periods in human development after which certain skills can no longer be learned 
8. Learning occurs through changes to the connections between brain cells
9. The left and right hemispheres of the brain work together
10. Production of new connections in the brain can continue into old age

Now, this screamed "top 10 myths about the brain and learning," so my guard was up immediately. Nevertheless, I was sure that 1-4 were incorrect since I had discovered previously that these, including approaches based on "learning styles" and "left hemisphere/right hemisphere," are among the most commonly debunked myths, and the 10% fallacy is also well-known. What is interesting, though, is that when an instructor invokes a "learning style" approach and, in doing so, validates a student's preconceived notions about their own learning style, they create a fixed mindset in the learner--"well, I'm a visual learner, so that's the only way I can learn." The other list she had us look at included statements that highlighted how emotions can affect cognitive processes and the fact that human memory does not operate like a recording device.

With learning myths suitably punctured and learning truths duly identified, Dr. Betts then moved on to a discussion of feedback. I think we all know how important meaningful feedback is--the peer-review process in academia is an excellent example--but I never really thought deeply about why it is so important. It turns out that feedback, when it is done right, helps us to identify and reduce the gap between our current performance and some desired goal, be it an A on a research paper or a scientifically legitimate research study. Dr. Betts asked the audience to define feedback and its relationship to assessment. Our group described feedback as a response that allow students to see the difference between what they do and what they are trying to do (or, at least, what we as instructors are trying to get them to do). We also argued that feedback helps students identify biases, incorrect statements, and their overall strengths and weaknesses. It also quickly became clear that, for us, feedback and assessment are very distinct processes. While for former tracks the development of a skill, the latter evaluates whether a skill has been attained or not. We wrapped up the discussion by identifying the challenges of giving feedback. The most commonly cited one is time: do we have enough of it to provide substantive feedback? Others included the question of whether or not learners take the feedback into account (if not, why waste the time giving it?) and whether or not instructors are able to craft an assignment that can produce meaningful feedback in the first place. (One suggestion to ensure that students heed instructor feedback is to require it as part of an assignment's rubric.) Dr. Betts then outlined best practices for instructor feedback, which should be:

• Understandable. Use language that the student can understand.
• Selective. Choose two or three issues that the student can do something about without feeling overwhelmed.
• Specific. Point out the areas in the student's work to which the feedback applies.
• Timely. It should be provided so that the student has enough time to improve for the next assignment. Students need time to reflect, address misunderstandings, and seek support from the instructor and/or academic services. A lack of feedback, or even delayed feedback, often leads to (di)stress, which in turn creates anxiety and poorer performance. 
• Contextualized. Comments should be framed in reference to the assignment's learning outcomes and/or rubric. 
• Non-judgmental. The focus should be on learning goals rather than just performance and comments should be descriptive rather than evaluative. Even the terms we use can impact the way that students perceive, and thus react, to our feedback: give "feedback" rather than "criticism"; provide "constructive" rather than "critical" feedback; areas of "weakness" can become areas "to develop"; and "rewrites" turn into "revisions." 
• Balanced. Point out both the strengths and weaknesses.
• Forward-looking. Provide suggestions for how future work can be improved.
• Transferable. The focus should be on the process and skills, not just the knowledge content.
• Personal. Refer to what is already known about the student based on previous assignments.

The problem for many students is that they have not received thoughtful feedback in an educational context. As instructors, we'd of course love to provide this for everyone, and we should strive to do so within the constraints set by our class sizes and learning objectives. This workshop was designed specifically for online instruction, and one practice that Dr. Betts engages in, and one that I never thought about, was recording her feedback and sending the video to students. It turns out that this can be accomplished in two to three minutes and might take less time than red-marking a paper.

Dr. Betts went on to share some basic principles of learning science during the second day:

• Human brains are as unique as human faces.
• Everyone's brain is also uniquely prepared, based on their personal experiences, to learn different tasks. This is significantly influenced by one's developmental environment. It has been shown, for instance, that chronic toxic stress can affect the ability of the prefrontal cortex to process information. Of particular importance to us as instructors is students' prior educational experience: while some students have had extensive feedback and have been held accountable, others have had little or no feedback and have not been held accountable; while some students have been held to high standards, others have not been held to high standards. This sets an individual's "default mode network," which projects that experience into the future (e.g., "I've never been held to high standards, so I won't ever be held to high standards.")
• The brain changes in light of new experience, so neuroplasticity occurs throughout one's lifetime. Every time a new fact or skill is learned, the brain creates new neural pathways and, possibly, about 700 new neurons a day. Practice actually thickens the myelin sheaths surrounding the brain's axons, which in turn permits more efficient signal (that is, information) transfer. 
• Learning cannot occur without some form of attention and memory.
• The brain seeks novelty and patterns.
• Repeated practice and rehearsal of learned material across multiple modalities helps to consolidate information in long-term memory.

The overall take-home message is that because the brain physically changes every time learning happens, we, as instructors, are quite literally brain changers. A powerful thought indeed.

Shopping for rocks in the Olduvai Basin

The invention and proliferation of stone tool technology was one of the most significant events in human evolution--the ability to use stones as tools and, eventually, the wherewithal to modify them into sharp-edged knives and other implements enabled our early ancestors to access foods that would have been difficult or impossible to obtain and consume with their relatively small, unspecialized teeth. If you spend some time working with stones, it eventually becomes apparent that not all of them are created equal: some break easily, others are tough to fracture; some produce razor-sharp edges, others generate dull ones; some are close by and/or easy to get a hold of, others are far away and/or difficult to access; some are durable and last a long time, others are brittle and must be discarded after a single use.

Now, we know that a modern human can learn to recognize these attributes and, what is more, they can (not to say that they necessarily do) plan their days with them in mind ("well, let's see...there are two ways to get to the pond for fresh water, Path #1 and Path #2, but only Path #1 has an outcrop of durable rocks on the way, so I'll kill two birds with one stone and take Path #1"). The question, then, is this: to what degree did our early human ancestors appreciate the sometimes subtle differences among rocks, and what can this tell us about their cognitive capacities?

Before we can even answer this very interesting question, however, we need to figure out a way to (1) rank rocks in terms of their usefulness, and (2) determine where on the landscape early humans were getting their rocks in the first place. There is a long history of research on these topics in Paleolithic archaeology, and my colleagues and I added some data to the debate in a recently published paper in Quaternary International. My interest in the topic goes back to the late 2000s, when David Braun wrote a couple of really interesting papers on the stone tools from Kanjera South, a two-million-year-old site in Kenya. Most studies on rock "usefulness" are based on rather subjective and imprecise categories. These categories, and the studies that utilize them, have provided key insights, including the fact that rock selection by early humans was not random. Braun, however, explored the possibility that the material sciences might provide some useful tools to help archaeologists objectively describe the characteristics of rocks.

As I mentioned above, there are a host of features that one might consider when selecting a rock. We chose to concentrate on fracture predictability, largely because the creation of many types of stone tools involves breaking a rock into smaller (and hopefully useful) pieces. If a rock breaks differently every time you hit it, there is no way to predict what you're going to end up with. Sure, it might be useful, but, then again, it might not. With a rock that fractures predictably, though, you can be reasonably sure that the time and energy you've expended will pay off with the production of a useful tool. Flint knappers have known for a long time that homogenous rocks break more predictably than do heterogeneous rocks because they are stronger (they can resist strain) and more elastic (they can resist deformation) when impacted by an outside force. Thankfully, a rock's strength and elasticity are highly correlated with its hardness, something that can be quickly assessed with a rebound hammer. These nifty handheld devices, which were originally designed for use on concrete, fire a spring-loaded plunger onto the surface of a stone. The plunger then bounces back, or "rebounds," after impact. The distance of that rebound reflects the hardness of the stone. Braun and others have used this technique to estimate fracture predictability for the rocks available to early humans at several Pleistocene archaeological sites in Kenya.   

In 2014, we set out to produce comparable data in our neck of the woods, the Olduvai Basin of northern Tanzania. What is today a deep gorge surrounded by open grasslands was, about two million years ago, a stream-fed soda lake surrounded by lush vegetation. Largely unchanged, however, are the volcanic highlands that border the basin to the south and east and the numerous hills--remnants of Archean-aged metamorphosed bedrock--that rise above the plains. Importantly, both the volcanos and the hills are made up of rocks from which stone tools can (and, in the past, could) be made.

A view of Olduvai Gorge in the foreground and, in the background, Naibor Soit, a granulite outcrop from which quartz could be procured (photo: Amy Schnell).

With the help of students from the UNCG Olduvai Gorge Paleoanthropology Field School and Earlham College's Summer Collaborative Research Program, I and my good friends and colleagues Cynthia Fadem and Ryan Byerly have been traipsing around the Olduvai Basin hammering as many rocks as we can get a hold of. Since 2014, we've accumulated a database of 110 specimens, and some interesting patterns have emerged. It turns out that the volcanic rocks that occur as rounded cobbles within the seasonal streams that drain the volcanic highlands have high rebound values and, thus, high fracture predictability, while the metamorphic rocks from the hills show either intermediate or low rebound values. Now, if early humans were selecting their rocks based on fracture predictability, we might expect that most of the artifacts from the archaeological sites would be made from volcanic sources. It turns out, however, that among Olduvai's artifact assemblages, volcanic rocks tend to be very rare, while metamorphic rocks, especially those made largely of quartz, are very common, which implies that fracture predictability was not a major concern. But why not? We might interpret this pattern to mean that early humans in the Olduvai Basin were not clever enough to recognize the value of predictably fractured volcanic rocks. We're skeptical of this hypothesis, though, because experimental work indicates that there are good reasons not to select volcanic rocks, since they:

• usually occur as rounded cobbles, which are tough to flake because they don't have very many of the acute angles that make flake removal possible;
• require more raw muscle power to flake; and
• may not be as durable as other rock types.

What is more, the quartz-rich rocks in the Olduvai Basin:

• are readily available from conspicuous landscape features that are very close to most of the archaeological sites; and 
• are very friable, which, although reducing their fracture predictability, makes them relatively easy to smash into lots of small chunks, among which are typically a handful of useable tools.  

Finally, it's not like volcanic rocks were not utilized at all. In fact, early humans appear in some cases to have selected them over metamorphic rocks when they wanted to create handaxes rather than simple flakes. This makes sense given that the more complex production sequence of a handaxe probably requires a more predictably fractured rock. Unfortunately, you can't subject fragile artifacts to the impact of a rebound hammer. However, if you can tell where the artifact originally came from, we can correlate the hardness of our geological specimens with their archaeological counterparts without subjecting the latter to any damage. Well, in addition to hammering rocks, we also subjected them to X-ray fluorescence, which can help identify their chemical composition. The volcanic rocks are easily distinguished from the metamorphic rocks just by looking at them, but the metamorphic rocks themselves, even those from different hills, can look very similar to each other. Luckily, the chemical signatures of each metamorphic hill are distinct enough for statistical algorithms to correctly match chunks of rock to the correct hill with 75-80% accuracy.

In the future, we should be able to match Olduvai's metamorphic artifacts to the hills from which they were being collected, which in turn will give us an idea of how far early humans travelled when shopping for their rocks.

References:

Egeland, CP, Fadem, CM, Byerly, RM, Henderson, C, Fitzgerald, C, Mabulla, AZP, Baquedano, E, Gidna, A (2019). Geochemical and physical characterization of lithic raw materials in the Olduvai Basin, Tanzania. Quaternary International. doi.org/10.1016/j.quaint.2019.09.036