What is Top-Down Processing and Sensing, Why Use It?
Top-down processing is a concept that refers to how the brain uses information already brought to the brain by one or more sensory systems. This process is the opposite of bottom-up processing, which is the process of the senses that provide information about the environment to the brain. In other words, top-down processing occurs when it processes from general to specific, from the big picture to the small details. In top-down processing, abstract impressions can affect the information gathered by the five senses. This article contains information on the concept of top-down processing, its importance and use.
Top-Down Processing Concept
In 1970, psychologist Richard Gregory introduced the concept of top-down processing and claimed that perception is constructive. When a person perceives something, they must rely on their contextual and higher-level knowledge to interpret the perception correctly. According to Gregory, perception is a hypothesis testing process. It suggests that approximately 90% of visual information is lost between the time it reaches the eye and the brain. So when a person sees something new, they cannot rely solely on their senses to understand it. It uses existing knowledge and remembered about past experiences to hypothesize about the meaning of new visual information. If the hypothesis is correct, the perceptions are made sense by actively building with a combination of what they know about the world and received through the senses. However, if the hypothesis is wrong, this can lead to perceptual errors.
Why Use Top-Down Processing?
Top-down processing plays an important role in one’s interactions with the environment. The five senses constantly receive information and experience different images, sounds, tastes, smells, and how things feel at any given time when they touch them. If attention was paid to each of the senses at all times, there would be no need to do anything else. Top-down processing facilitates the process by relying on contextual and pre-existing information to understand what is perceived. If the brain did not operate from top to bottom, the senses would drive the person in different directions.
Using Top-Down Rendering
Top-down processing helps to understand what you perceive with your senses in daily life. One of the areas where this is shown is reading and letter identification. Experiments have shown that when presented briefly with a single letter or a word containing the letter o, and then asked to determine which letter or word they saw, participants were able to identify the word more accurately than the letter. Despite the fact that the word has more visual stimuli than the letter, the context of the word helps the individual to understand what they see more accurately. This so-called superiority effect is a useful tool in everyday life.
For example, suppose an important letter was received but a few drops of water smeared part of the text. A few letters in different words are now just a stain. However, the entire letter can be read using top-down processing. Here, the context of the words and sentences in which the spots appear and reading information are used to understand the message of the letter.
Pros and Cons of Top-Down Processing
Top-down processing serves a positive function, simplifying the way we understand sensory perceptions. The environment is intense and there is always more than one thing stimulating. Top-down processing allows to shorten the cognitive path between perceptions and meanings. One of the reasons for this is that top-down processing helps recognize patterns. Patterns are useful because they help understand the world and know how to interact with it. For example, past experiences with other mobile devices are used to quickly determine which icons to tap to open applications that they want to interact with when encountering a new type of mobile device. Mobile devices often follow similar interaction patterns, and previous knowledge of these patterns allows to apply them to the new device.
On the other hand, patterns can also prevent perceiving things in unique ways. Therefore, the model of how to use a mobile phone is understandable, but if the manufacturer produces a new phone that uses completely unique interaction patterns, it may not be solved how to use it. This is where top-down processing can have negative consequences. Information is limited and biased in certain ways. When knowledge applies to perceptions, it likewise limits the perceptions and this situation makes the person biased. For example, if the person has always used an iPhone but encountered a new type of phone model, the perception is likely that the phone’s user experience is lower, even if it works just like the iPhone.
The Importance of Top-Down Rendering
Why is top-down processing important? People hold so much information that it is impossible to attend and process every single detail. Top-down processing works to help understand the world. Wide, overviews gathered at first glance can help to influence finer details when focused while providing more information about the environment. Considering how much information can remain subconscious at any given moment, you are surrounded by a multitude of sights, sounds, smells, tastes, textures, and physical sensations. If they focus equally on each of these feelings, the person will be overwhelmed. Processing information from top to bottom allows to understand the information already brought in by the senses, working from first impressions down to the lower senses.
How Does Existing Knowledge Affect Perception?
Top-down processing is also known as conceptual driven processing because perceptions are affected by expectations, current beliefs, and understanding. In some cases, these effects are recognized, but in other cases, this process happens without conscious awareness. For example: Suppose a person is walking down an unfamiliar street and sees a sign indicating a grocery store. Even though the sign has a few missing letters, it can still read this request. Because if it uses top-down processing, it relies on available information to make an accurate estimate of what this signal says.
Effects of Motivation on Top-Down Processing
There may be some factors that affect top-down processing, including context and motivation. The context or circumstances in which an event or object is perceived can affect what is expected to find in this particular case. For example, if you’re reading an article about food and nutrition, an unfamiliar word could be interpreted as something about food. Motivation can also increase the likelihood of interpreting something in a certain way. For example, if a series of fuzzy images were displayed, these images may be more motivating to perceive food when the person is hungry.
Top-Down Processing?
To better understand how top-down processing works, it may be helpful to explore several examples of this concept in details. Here are a few examples:
• The Stroop Effect: A classic example of the top-down procedure is a phenomenon known as the Stroop effect. In this task, colored words are printed in other colors. Thus, for example, the word red can be printed in blue and the word pink in white. Participants are asked to say the color of the word, not the actual color. When the reaction times are measured, when the color and word are not the same, people are much slower at saying the right color. Top-down processing explains why this task is so difficult. People automatically recognize the word before thinking about the color, making it easier to read the word aloud instead of saying the color of the word.
• Spelling Errors: When reading a text block, it can be seen that even typos and other text errors do not notice. As the person reads, the previous words provide context about what is expected to read next. For this reason, the brain often fills in missing details and corrects errors as it reads so that these errors are not even noticed.
