Cognitive Loads

The first step to ensuring that we can properly absorb information is to look at the cognitive load that we place on our brains. There are three types of loads: intrinsic, extrinsic, and germane. They have to do with how difficult the information is, how the information is presented, and how difficult the information is to turn into something with personal significance.

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Have you ever had a really bad teacher or a textbook that felt like it was actively making you understand less? This is a classic example of high extrinsic load. Even if the intrinsic load of a task is low, a high intrinsic load can threaten your absorption and understanding of the material. Incompetent teachers can present concepts in a disordered or confusing way. Overly cluttered study notes and textbooks or material with loads of unnecessary and redundant information also have high extrinsic cognitive load.

What can you do in this case? Cut through it all by actively simplifying whenever you can, and you reduce this load. Where you can, change the “format.” For example, a student may be trying to learn a new math concept but finds that every read of the (outdated) textbook just makes matters more confusing. She may forego the textbook and turn to short online explainer videos, different “for dummies”-style study guides, or even notes and help from other students who understand the concept. This reduces potential grueling hours spent trying to understand poor materials and cuts to the chase.

Another tip to reducing extrinsic cognitive load is to be “goal-free” in your attitude. Focus only on your current state and how to get to the next state, and don’t stress too much about the final stage you’re meant to reach (i.e., the goal). This is great for multistage math or programming problems. Stay in a loose, nondirected state for a while and simply become curious about the space of potential options in front of you before trying to jump in and immediately solve the stated problem.

Explore the relevant components. Take a look at the different functions, ask a few questions about how they work, and take things step by step. When you’re stuck on a particular outcome, your view narrows considerably and you can close yourself off to avenues of understanding that would otherwise help you understand the problem from a new perspective. Being “goal-free” for a while takes pressure off you and clears your working memory somewhat.

If you’re trying to study something and feel like the material is difficult or complex, it is likely high intrinsic load. If you feel, on the other hand, that the explanations are confusing or don’t make sense, extrinsic load problems are likely the culprit. Knowing which one you’re dealing with will help you decide which approach to take—i.e., chunking and segmenting for high intrinsic load and goal-free working to reduce extrinsic load.

Finally, germane cognitive load, the third type, is the effort you’re required to make to consolidate the pieces of information you have into one larger concept (i.e., a schema). We’ll explore this third type in the next section on chunking.

This is all a roundabout way of saying that our memories, though amazing in some ways and capable of superhuman feats, are generally pretty fickle. In fact, they’re so fragile that sometimes even learning something new can cause us to forget what we previously knew (or thought we knew).

In a study published in the Journal of Experimental Psychology, Learning, Memory and Cognition, researchers found evidence that memory retrieval itself is a process that aids in “everyday forgetting.” But this is not necessarily anything to be alarmed about. There’s a very good reason your brain behaves this way. Old information is likely to interfere with newer, more useful information. As an example, consider the memory of an interesting person you may have met last week. Your brain likely remembered all the relevant information—their name, whether you liked them or not, their overall demeanor. But you probably didn’t bother to remember the color of their socks or the precise time of day you encountered them.
A study published in the journal Nature Neuroscience showed that when two ideas compete with each other, the brain has trouble with retrieval. To fix this interference, the brain uses several inhibitory mechanisms to help suppress one of the competing ideas, which usually means that old memories fade and new ones are reinforced. Every time you recall the “target memory,” you’re actually further suppressing the interfering one, essentially shaping the past as you remember it. Again, this is an adaptive process that you want to happen. In fact, the handful of people who suffer from the very rare hyperthymestic syndrome literally can’t forget—and their lives are complicated to say the least.
But forgetting something in this way doesn’t mean it’s gone forever. Have you ever been out and about and bumped into someone you recognized but couldn’t for the life of you remember who they were or how you knew them? Maybe with time you finally remembered but found it difficult because this person wasn’t in their usual “place.” Maybe they worked at your gym and you saw them every day behind the reception desk, and though you never had trouble remembering who they were when in that context, your mind drew a blank when you suddenly saw that person walking around in an unfamiliar place.
This shows that retrieval is very context-dependent. You may actually have a lot more mental storage space than you realize, only it’s accessed when you’re in the same mental place in which you made those memories. We’ll look more at how to use this knowledge a little later on.
Your brain is not like a computer, functioning in a linear, cause-and-effect fashion. It wasn’t programmed, but evolved, and is a living, fluid entity filled with quirks and idiosyncrasies. And yet, like anything biological, or flesh and blood, there are serious limitations that we must consider and cater to.
Another aspect of the cognitive load is just how long we can last. Despite the fact that classes in school can last for an hour or more, humans are not good at paying attention to one thing for an extended period of time. At the biological level, we are programmed to pay attention to multiple things for short periods of time instead of focusing on one object. Of course, we can attribute this to our propensity for staying alive by fleeing at the first sign of danger. This biologically leads to short attention spans, and we must learn to account for this in our learning endeavors.
Multiple studies have investigated exactly how long our attention spans are; in one early study, scientists noticed that the quality of the notes students took during a lecture declined in quality as the lecture went on. This led them to posit that human attention spans were 10–15 minutes long and that we have difficulty paying attention to information after that much time passes.

A different study utilized trained observers to watch students for lapses in attention during a lecture. They noticed peak inattention in three spots: during the initial settling-in period, 10–18 minutes into the lecture, and toward the end of the lecture. Indeed, by the final 10 minutes, they noticed students failing to pay attention as often as every three to four minutes. Their conclusion was that declines in attentiveness occur over time and that there is a certain acclimatization period at the beginning, during which we are particularly susceptible to losing focus.

A third study provided students with clickers to press when they found themselves being inattentive during class. This time, the researchers had students sit in on three different types of classes. Some students sat in on a lecture course, others needed to pay attention to a demonstration, and others were in a question-and-answer session. Each student, regardless of the type of class they attended, was provided a clicker with three different buttons. One was pressed to record a lapse in attention of a minute or less, one was pressed to indicate lapses of two to four minutes, and the other was meant to indicate lapses of attention of five minutes or more. This data was then mapped onto the lecture or demonstration people attended to observe how a lesson’s style impacted student attentiveness.

They discovered that lapses in attention were sooner than the 10-minute estimate previous studies would lead people to expect. Inattention spiked in the students 30 seconds after arriving to class, during the “settling-in” period, at 4.5–5.5 minutes into class, at seven to nine minutes into class, and at nine to ten minutes in. Attention of the class as a whole continued to wax and wane with this pattern as the class continued, though there were more lapses in attention toward the end of class, when spikes of inattention could be observed every two minutes.

Perhaps the most interesting finding of this study is that the scientists noted much fewer lapses in attention in the demonstration and question-based teaching styles (an important note for the next chapter). When students were more active participants in their classroom experience rather than passive listeners, they stayed engaged more often and for longer periods of time. Taking one of these classes before a lecture course even made that lecture course easier, and students in that position were found to pay attention for longer periods and lapse less frequently. It seems that active learning engages human attention and refreshes it for subsequent, more passive learning sessions.

In short, humans do indeed have almost laughably short attention spans. No matter how flawed the data or study might be, there is a clear consensus of it being only a matter of minutes. So sitting down for hours, or even all night, while trying to cram information into your brain just isn’t going to work. We need to work around this attentional limitation by taking more frequent breaks and simply having the expectation that you can’t work like a machine.