Learning vs. Cognition
Learning is the process of acquiring knowledge or ability. Typically learning is done through experience, instruction, or study and practice. Although it is natural to think about the brain when considering learning, ironically not much consideration is given to cognition when instruction and study are constructed. Cognition is central to learning, as it is the way that the brain collects and organizes information and ultimately determines how much an individual can acquire and retain.
Assessing Cognitive Load in Educational Research
Before we can use our understanding of cognition to redesign teaching practices, we must first measure what’s known as cognitive load: the mental resources required to complete a task. Current research depends on self-reported scales, a subjective measure of cognitive load. At Lab 58, we are investigating the use of thermal imaging cameras to measure cognitive load based on skin temperature. Thermal imaging should be at the forefront of educational research. It gives us clear advantage with regard to measuring, estimating, and even anticipating cognitive load.
Cognitive Load Theory: Free Up Space to Learn More
The concept of cognitive load surrounds the appraised level of complexity or level of information processing resources that are mandatory for engagement in a particular learning experience. In other words, cognitive load is all about how difficult a task is and how many of our brains’ resources are required to complete the task. Cognitive load is connected to working memory, essentially the brain’s short-term memory bank. Working memory comes equipped with a limited capacity that varies from individual to individual. Once information enters our working memory, there is a short time before it is either discarded or begins its journey into long-term memory storage.
Cognitive load theory states that because our brain, particularly our working memory, is limited in capacity, we must be intentional about the way that we structure learning tasks and experiences so they are designed to reduce working memory load. Reducing working memory load encourages the production of new schema that will free up pathways to store new information.
Measuring Cognitive Load
Determining the most effective ways to measure cognitive load is significant. When cognitive load can be measured in a scalable way across varying tasks and people, knowledge and instruction can be shaped to encourage more constructive learning and comprehension. Measuring cognitive load has been a continuing challenge in experimental and educational research, partly because there are numerous ways to measure cognitive load, each with their own set of limitations. The two primary types of measures include self-report dual-task, and physiological parameters.
The Likert Scale
There are multiple self-report measures used in experimental research; however, the most widely used scale for measuring cognitive load is the rating scale developed by Paas et al. (1992). This Likert scale was designed for the purpose of measuring the difficulty of a particular learning task. Although this scale is widely used in research due to its low economic cost, it has its own set of limitations. Aside from the difficulty in distinguishing between true variance and measurement error, many researchers are deterred by the inconsistent wording, labels, and scale ranges. Additionally, like many self-reported scales, measures that require introspection from participants are typically unreliable, as the responses are subjective in nature. Often, participants may alter their responses based on situational attributes; as a result, their responses may not provide an adequate measure.
Dual-task measures are objective measures that require an individual to participate in two tasks simultaneously. The guiding assumption of this type of measure is that performance on a secondary task diminishes as the initial task becomes more and more complex. This assumption is acceptable in theory; however in practice, there are numerous disadvantages to this type of measure. The most salient limitation is that everyone has a unique working memory capacity. As a result, the complexity of a task and the utilization of cognitive resources among learners will differ as well.
Another disadvantage of dual-task measures is that it is difficult to determine whether the measured load is intrinsic, extraneous, or germane. Intrinsic load refers to the general difficulty of the learning task being performed. It is typically static, and unable to be adjusted by the instructional designer. Extraneous load has little to do with the learning task at hand. This type of measurement is also intrusive and therefore disrupts the natural learning process, adding to the amount of cognitive load experienced by the participant. Germane load refers to the mental resources allocated to programming schema into the brain’s long-term memory stores.
Measuring Cognitive Load via Physiological Parameters
Cognitive load can also be evaluated using measures of physiological parameters, as a wide range of them have been used as indicators of cognitive load. Some of these measures include heart rate, electroencephalography, hormone levels, fMRI, and pupil dilation. Pupillometry, or pupil dilation, is the most frequently evaluated physiological indicator. Individual differences in pupil diameter and blink rate represent noninvasive physiological indicators of attentional engagement. Typically, increased blink rate and dilation are correlated with greater cognitive load. Physiological assessments provide an objective and effective method of measurement, as they do not rely on the introspection of the learner.