Top-Down vs Bottom-Up Processing

Both bottom-up and top-down processing play a crucial role in helping humans comprehend the environment and make decisions. Which plays a more important role has also been a long debate amongst psychologists. Some evidence demonstrates that both processes are, in fact, mutually interdependent (Rauss & Pourtois, 2013). However, if I had to choose one to prioritize in developing a visual display, it is more beneficial to consider bottom-up processing first when designing. 

Bottom-up processing is based on raw data, acting as the first contact point for people and the environment. Bottom-up attention acts first, and then top-down attention takes over after 100 milliseconds (Connor, Egeth & Yantis, 2004). Therefore, a human factor professional has the initial control of grabbing the user’s attention with their designs. It is found that a “high local feature” object attracts more initial attention even if it is not relevant to the task. Additionally, an object that is relevant to the task is found more noticeable than an irrelevant object (Nordfang, Dyrholm, & Bundesen, 2013). An example would be an AED device. An ideal AED device should allow immediate visibility of pads, and instructions should be as detailed as possible. Correct pad placement (the task)  is found more adequate when the device has detailed voice instructions (Mosesso Jr et al., 2009). Therefore, when designing a visual display, it is best to state a clear goal or task and use the correct stimuli and loud sensory cues to attract the user’s attention to a visual interface quickly.

Top-down processing utilizes prediction and knowledge based on prior experience and enables people to rapidly identify objects and determine their surroundings (Goldstein, 2019, p. 67). While top-down processing may be appropriate in a small number of fields where all potential users are well-educated on the field and the interface. In cases such as using an AED device where users are mostly untrained, designs utilizing users’ prior knowledge may significantly delay completing a task. Even if users are trained, it is still difficult for human factor professionals to design a visual display that prioritizes top-down processing and ensuring every user is “on the same page” while using the display. Therefore, rather than trying to achieve efficiency, it is better to consider bottom-up processing and ensure all possible cues are present, thereby eliminating potential errors b.

References

Callejas, S., Barry, A., Demertsidis, E., Jorgenson, D., & Becker, L. B. (2004). Human factors impact successful lay person automated external defibrillator use during simulated cardiac arrest. Critical Care Medicine, 32(Supplement), 1285-1289. http://doi.org/10.1097/01.ccm.0000139948.46663.3a

Connor, C. E., Egeth, H. E., & Yantis, S. (2004). Visual Attention: Bottom-Up Versus Top-Down. Current Biology, 14(19), R850-R852. http://doi.org/10.1016/j.cub.2004.09.041

Goldstein, E. B. (2019). Cognitive psychology: Connecting mind, research, and everyday experience. Boston, MA: Cengage.

Nordfang, M., Dyrholm, M., & Bundesen, C. (2013). Identifying bottom-up and top-down components of attentional weight by experimental analysis and computational modeling. Journal of Experimental Psychology: General, 142(2), 510-535. http://doi.org/10.1037/a0029631

Rauss, K., & Pourtois, G. (2013). What is Bottom-Up and What is Top-Down in Predictive Coding? Frontiers in Psychology,4, 1-8. http://doi.org/10.3389/fpsyg.2013.00276