Parallel Processing: More complex than it may seem.


Parallel processing is a much more complex process than it sounds. It is the combined process of both top-down and bottom-up processing occurring simultaneously in the brain at all times. Bottom-up processing is the building up of complex processes in order to eventually perceive something. That is, taking into account the most basic aspects of a stimulus first and sequentially building up information in order to experience the entire thing fully. Top-down processing uses your experiences, expectations, and beliefs to guide your perception. An example of this is your ability to understand that a person’s legs are not actually missing if they are cut off of your field of view by, say, a desk that they are sitting behind. Parallel processing says that rather than doing one of these functions or the other, your brain does them unconsciously and simultaneously in order to create a full picture of whatever stimulus your brain is trying to process.¬†

A study was conducted in by Buetti, Cronin, Madison, Wang, and Lleras (2016) to better understand parallel processing in human vision. Observers were asked to find a specific object in a scene, and the researchers found the observers used the specific architecture from the scene to compare all locations in the world in parallel to the scene they were looking for. This allowed them to quickly reject the locations of the world that were unlikely to be the scene they were looking for. They found their hypotheses to be true: that the certain task which an observer performs on a very simple display can significantly alter the way that such a display is processed. In other words, when we are looking for something, we attentively process each individual item in our visual field, just not to the same extent.

The meme that I created above is a simplified version of the basic idea that neither top-down or bottom-up processing occurs on its own. Rather, the two occur simultaneously as parallel processing. The video is highlighting that it is not accurate to simply reduce processing to one type or the other. It is also pointing out that parallel processing is a very complex process, as described by the study above. This study showed that visual stimuli is not passively observed but actively processed in a parallel manner.

The evidence that is found in this study is compelling, but one issue with it is that the presented displays contained only two items and were not based on real-life objects and scenes. This would have been important to study because it would have allowed for a more direct application of the research.

Overall, I found the topic of parallel processing very interesting. It was hard to find recent research on it that was relevant, but when I found this research article discussing parallel processing in relation to visual processing, I was intrigued because we have been talking about visual processing in class. I thought that the research article was difficult to read but the findings were interesting because it was novel research that was conducted, rather than a replication study of information that we already know about parallel processing.

Buetti, S., Cronin, D. A., Madison, A. M., Wang, Z., & Lleras, A. (2016). Towards a better understanding of parallel visual processing in human vision: Evidence for exhaustive analysis of visual information. Journal of Experimental Psychology: General, 145(6), 672-707.