Top-down processing involves perceiving things based on your prior experiences and knowledge. In other words, you use what you already know to make sense of the new information you encounter. It refers to how our brain utilizes existing knowledge and expectations to interpret new sensory information.
Instead of interpreting the world based solely on the information we gather from our senses, the brain uses pre-existing concepts, ideas, and knowledge to comprehend sensory input.
We are surrounded by an endless amount of sensory stimuli at any given time, but our attentional and processing resources are limited. Top-down processing is vital for perception since it lets us quickly interpret and understand our environment. In doing so, we can make decisions and respond quickly when needed.
This article explores top-down processing in greater depth and explores some of the factors that can influence how it works.
What Is Top-Down Processing?
"Traditionally, “top-down perception” refers to situations in which context, learning, or expectation alters a perceptual process," write researchers Nicholas Gaspelin, PhD, and Steven J. Luck, PhD, in an article in the Journal of Cognition.
In top-down processing, perceptions begin with the most general and move toward the more specific. Our expectations and prior knowledge heavily influence these perceptions.
Put simply; your brain applies what it knows to fill in the blanks and anticipate what's next.
For example, if half of a tree branch is covered, you usually have an idea of what it looks like, even though half is not being shown. This is because you know what trees look like from prior knowledge.
While this process relies on past learning, context, and expectations, it is an automatic process.
Processing information from the top down allows us to make sense of information that has already been brought in by the senses, working downward from initial impressions down to particular details.
Why We Use Top-Down Processing
In a world where we are surrounded by virtually limitless sensory experiences and information, top-down processing can help us quickly make sense of the environment. It allows us to use our perceptual and attentional resources more efficiently to interpret incoming sensory data and make decisions.
Top-down processing also helps us fill in gaps in ambiguous or incomplete situations.
Our senses are constantly taking in new information. At any given time, we're experiencing a never-ending stream of sights, sounds, smells, tastes, and physical sensations. If we had to focus equally on all of these sensations every second of every day, we would be overwhelmed.
Top-down processing helps simplify our understanding of the world. It allows us to quickly make sense of all the information our senses bring in to navigate the world more effectively, recognize patterns, and make decisions.
As you begin to take in more information about your environment, your initial impressions (based on previous experiences and patterns) influence how you interpret the finer details.
This type of processing can be useful when we are looking for patterns in our environment, but these predispositions can also hinder our ability to perceive things in new and different ways.
Influences on This Process
Several things can influence top-down processing, including context and motivation. Specific circ*mstances, how we feel about a certain topic, and even our emotional state while having an experience might affect top-down processing.
Context
The context, or circ*mstances, in which an event or object is perceived can affect what we expect to find in that particular situation. Context can provide clues that tell us how we should interpret something we encounter.
For example, if you are reading an article about food and nutrition, you might interpret a word you're unfamiliar with as something related to food.
Motivation
Motivation can also make you more likely to interpret something in a particular way. For example, if you were shown a series of ambiguous images, you might be more motivated to perceive them as food-related when hungry.
Expectations
What you expect to encounter in a situation can also affect how you ultimately interpret it. If you believe that you will experience something in a specific situation, it is going to influence how your brain processes what you encounter.
Knowledge
Your previously existing knowledge about a specific topic or situation will also have an effect on your you perceive new information. For example, a novice might process information differently than someone who holds expertise in the subject.
Ambiguity
In ambiguous situations, your brain is more likely to rely on top-down processing to fill in the gaps. For example, when interpreting a visual illusion, your brain often fills in missing visual information to help make sense of an ambiguous figure.
The Kanizsa triangle illusion is one example of how top-down processing can fill gaps to allow the brain to perceive a cohesive shape.
The illusion consists of three incomplete circles and triangles resulting in a white triangle in the center. The edges of the triangle do not exist in the image, but the brain uses top-down processing to perceive a familiar shape.
Examples of Top-Down Processing
In order to better understand how top-down processing works, it can be helpful to explore a few examples of this phenomenon in action.
The Stroop Effect
One classic example of top-down processing in action is a phenomenon known as the Stroop effect. In this task, people are shown a list of words printed in different colors. They’re then asked to name the ink color, rather than the word itself.
Interestingly, people are much slower and make more mistakes when the meaning of the word and the ink color doesn’t match. So, for example, people have a harder time when the word "red" is printed in green ink instead of red ink.
Top-down processing explains why this task is so difficult. People automatically recognize the word before they think about the specific features of that word (like what color it's written in). This makes it easier to read the word aloud rather than to say the color of the word.
Perceptual Set
A perceptual set refers to the tendency to perceive things in a certain way based on past experiences, emotions, cultural influences, and expectations. This tendency is an example of top-down processing.
Our existing mental frameworks play a role in guiding these perceptual sets. For example, people have a schema, or cognitive framework, for faces that makes it easier to recognize people who are familiar to us, even in a crowd.
This same schema, however, also leads us to sometimes see faces where there are none. This is why you might see faces in everyday objects, a phenomenon known as face pareidolia.
Typos
You type a message to your boss, proofread it, and hit 'Send.' Only after the message has gone into the nether sphere do you spot three typos in the first few sentences.
If you've experienced some version of this scenario, you're not alone. Most people find it difficult to catch their own typos. But it's not because they're unintelligent. According to psychologist Tom Stafford, it may actually be because you're smart!
"When you're writing, you're trying to convey meaning. It's a very high-level task... We don't catch every detail, we're not like computers or NSA databases. Rather, we take in sensory information and combine it with what we expect, and we extract meaning," he explained in an interview with Wired magazine.
Because writing is such a high-level task, your brain tricks you into reading what you think you should see on the page. It fills in missing details and corrects errors without you even noticing. This allows you to focus on the more complex task of turning sentences into complex ideas.
Reading Misspelled Text
The same principles apply to the ability to read text riddled with misspellings.
For example:
Yuo cna porbalby raed tihs esaliy desptie teh msispeillgns.
Passages like this have been bouncing around the internet for years. But how do we read them? How do our brains so quickly make sense of these jumbled letters? The answer is simple: top-down processing.
How Bottom-Up Processing Works
Potential Pitfalls of Top-Down Processing
While top-down processing has important benefits, it can sometimes have downsides. Basing our interpretations on past knowledge can lead to faster decision-making, but it can also lead to mistakes.
Top-down processing can also prevent us from seeing novel ways of thinking about a problem. This can prevent you from learning new things, considering alternative solutions, or overcoming biased thinking.
Functional Fixedness as a Cognitive Bias
