In medical product design, Cognitive Load is an important concept to be aware of. Visual complexity is an enemy because it overloads our ability to mentally process all the information we are taking in. Not only is it difficult to process a lot of information at once, having too much information to choose from inhibits decision-making.
The environments in which medical devices are used are often visually stimulating, with a plethora of monitors, display screens, status and warning lights, etc. Previous posts in this series have discussed how we’re able to filter out a lot of extraneous information that we deem unnecessary for the task at hand. Designing complexity out of the device in the first place reduces the need to filter. Visual simplicity makes devices more usable.
In processing information, our brains are subject to three types of demands, or loads: cognitive (including memory), visual and motor. Each load requires a different amount of mental energy. Research has shown that it takes more mental energy to find something on a computer screen (a visual demand) than it does to decide to press a button or move a mouse (motor demands). Trying to remember something or do a mental calculation – both cognitive loads – requires the most mental energy. Using icons or symbols on a device serve as aids to memory, thereby reducing cognitive load. Also, we can process icons and symbols much quicker than we can read text.
As we use up mental energy, our attention and willpower lapse. If it takes a lot of mental energy to change something, we tend to want to keep things as they are. This bias for the status-quo can be utilized in medical product design by designing systems that provide either an opt-out option or an opt-in option, depending on the behavior you want to encourage. If you want to encourage people to participate, design the system so that participation is automatic unless the user chooses to opt-out. If you want to discourage participation, require an opt-in option.
Interestingly, we’re bored by things that are too plain. We have a fundamental drive to seek out information. This would suggest that there is a balance to be found between simplicity and complexity. Skillful medical industrial design can achieve that balance, which will in turn enhance the usability of the product. Finding the balance begins with understanding the concept of cognitive load.