It’s not what you look at that matters, It’s what you see.

Henry David Thoreau was an American philosopher, poet, and a keen observer. He is known for his book Walden, about his experience living in a small cottage near Walden Pond.

Henry David Thoreau’s quote reflects the importance of perception and its key role in human experience. It emphasizes how our perspective determines how we observe the world around us and make meaning from it.

But what is perception?

It's not what you look at that matters, It's what you see.

Perception is how we understand the world around us. Perception shapes our understanding of reality, influencing how we interpret and interact with the world around us. It’s like our brain’s way of taking in information through our senses, like seeing, hearing, and feeling, and making sense of it all. This helps us know what’s happening and decide what to do. Scientists study perception to learn more about how our minds work and why we see things the way we do.

Perception is our primary contact with the world. Whatever we know, we know directly or indirectly by means of perception. And the vast majority of our actions rely on perceptual guidance. The mind begins and, to be a bit dramatic, ends with perception.

Bence Nanay. Perception: The Basics

Perception is important because it helps us navigate our daily lives. When we see a red light, we know to stop our car. When we hear a friend calling our name, we know to turn around and say hello. Our brains are constantly taking in information from our senses and using it to help us understand and interact with the world. By studying perception, scientists can learn more about how our brains process information and how we experience the world around us.

Ways We Understand the World

Different types of perceptions help us navigate the world. The five senses translate to 5 types of perception:

  1. Seeing Things (Visual Perception): This type of perception is about what we see with our eyes, like colors, shapes, and movements. It helps us recognize objects and find our way around them.
  2. Hearing Things (Auditory Perception): This is about what we hear with our ears, like sounds and noises. It helps us understand language, enjoy music, and know when someone is calling our name.
  3. Feeling Things (Tactile Perception): This type of perception is about what we feel with our skin, like textures, temperatures, and pressures. It helps us pick up objects, feel the softness of a blanket, or sense if something is hot or cold.
  4. Tasting Things (Gustatory Perception): This is about what we taste with our tongue, like flavors such as sweet, sour, salty, and bitter. It helps us enjoy different foods and drinks.
  5. Smelling Things (Olfactory Perception): This is about what we smell with our nose, like scents and odors. It helps us detect smells around us, such as fresh flowers or delicious food cooking in the kitchen.

Defining sensory perception

To recap, sensory perception is how our senses help us understand the world. It’s all about using our eyes, ears, skin, tongue, and nose to notice things and figure out what they are. For example, when we see something, hear a sound, feel a texture, taste food, or smell a scent, that’s our sensory perception at work. It’s like our body’s way of taking in information about the world so we can make sense of it.


Here are some examples of perception illustrating how perception shapes the understanding of the world around us:

  1. Optical Illusions: Have you ever seen those pictures that seem moving, even though they’re just printed on a page? For example, we see a plate as a circle even when tilted.
  2. Recognizing Faces: Think about how you can spot your best friend in a crowded hallway, even from far away. It’s because your brain is good at remembering faces and picking them out of a crowd.
  3. Tasting Food: Imagine the thought of biting into a sour lemon, and suddenly, your mouth starts to water. That’s your brain reacting to the idea of something sour, showing how perception can influence physical responses
  4. Feeling Textures: Next time you touch something, pay attention to how it feels. Is it smooth like glass or bumpy like a basketball? Your brain helps you figure out what things feel like so you can understand the world around you.
  5. Listening to Music: When you hear your favorite song, your brain starts tapping along to the beat without thinking about it.

What is visual perception?

Most of our perception revolves around visual perception. Although we use all senses to understand the world around us we pay more attention to what we receive through eyes and visual perception. In Perception: The Basics, Nanay writes that visual perception serves as a vital link to comprehending the world around us. It involves how we interpret the information received through our eyes, influencing our actions and decisions. Exploring the intricate workings of perception unveils essential insights into the human mind. Scientists have extensively studied the neural mechanisms underlying perception, making it a cornerstone of cognitive science. Moreover, the parallels between human and animal perception highlight its universal significance. By delving into shared perceptual processes, such as attention and mental imagery, we gain deeper insights into the workings of the human mind. This interdisciplinary approach, drawing from psychology, neuroscience, and philosophy, offers a comprehensive understanding of perception and its profound impact on our daily lives.

Visual perception is about understanding what we see with our eyes. It’s not just about looking at things; it’s about understanding them too. When we see something, our eyes send messages to our brain, which then turns those messages into images we can recognize.

For example, when you see a cat, your brain knows it’s a cat because it recognizes its shape, color, and other features. Visual perception helps us navigate the world, recognize people and objects, and enjoy beautiful sights like sunsets and rainbows. It’s like having a built-in camera in our heads, always capturing and processing images!

What is auditory perception?

Auditory perception means listening and understanding sounds with our ears. It helps us know what’s happening around us. In the book Perception, Nanay discusses that unlike seeing, which is good for noticing things in one place, hearing is great for knowing when things happen. It’s like figuring out where boats are by watching flags move in canals. Seeing makes 3D pictures from 2D ones, but hearing makes even more detailed 3D pictures from sound waves.

Understanding the differences between seeing and hearing is tricky. We feel them in different ways, and they use different parts of our bodies and brains. But sometimes, things aren’t so clear. For example, some tools let blind people “see” using sound or touch. These tools change what we see into sounds or feelings, helping blind people get around. They turn pictures into sounds or feelings on the skin, showing how hearing and touch can work together. These examples show how hearing is a complex part of how we understand the world.1

More like vision auditory perception is different than physical hearing process. This is because the brain uses a selective process to perceive what it receives through sound waves. This means what comes through the ears is not exactly what we hear and pay attention to. For example, have you been in a crowded room and still heard your name? This selective attention helps us ignore noise and focus. Whether recognizing a voice or hearing a favorite song, auditory perception connects us with our surroundings.

Characteristics of human perception

French philosopher, Merleau-Ponty in The World of Perception says that how we see and understand the world isn’t always as simple as it seems. He thinks that our everyday way of looking at things tends to ignore how our senses shape our view of the world. According to him, our senses quietly organize what we see, making it appear like a 3D space with objects all around us. But because this happens automatically, we don’t notice it happening. Merleau-Ponty believes that we need to step back and take a closer look at how our senses work to fully understand how we see the world. He thinks that things like modern art and thinking deeply about life can help us do this. In simple words, he wants us to look at our experiences in a different way to see how our senses shape what we see and understand.

The world of perception is, to a great extent, unknown territory as long as we remain in the practical or utilitarian attitude.

Maurice Merleau-Ponty, The world of Perception

Have you ever stopped to think about what makes human perception so special? Human perception is personal and different depending on the perspective and previous knowledge of the receiver. Our visual perception, in particular, is shaped by our individual experiences, beliefs, and goals. As a result, what we notice is different from what we receive through sense.

So, we’re not just passive observers; we actively filter out irrelevant details and focus on what’s important to us. Plus, our perception is influenced by our emotions, desires, and motivations, making it dynamic and ever-changing. It’s this blend of selectivity, goal orientation, and embodied experience that sets human perception apart and makes each of us see the world in our unique way.

To summarize, this human perception can be characterized as:

  1. Human perception is selective
  2. Human perception is embodied
  3. Human perception is different for each of us
  4. Human perception is limited by bounded rationality

1. What is selective perception?

When we come across information, there’s usually a lot more going on around us than we can fully grasp. So, our understanding of things is shaped by what we expect and what we already know, like our previous experiences and patterns of thinking. This helps us make sense of the world around us.

Selective perception “refers to the process of categorizing and interpreting information in a way that favors one category or interpretation over another. Thus, selective perception is generally considered to represent a bias in information processing.” 2

Selective perception is like wearing glasses that only let in certain things. Selective perception means that people tend to see and understand things in a way that matches what they already believe or want to believe.

It’s like wearing glasses that only let in certain colors. People might focus on what they already like or expect, and ignore or forget about things that don’t fit with what they think. This can affect how they make decisions and understand what’s happening around them. It’s important to be aware of this so we can try to see things more clearly.

2. Embodied perception

Our bodies play a big role in how we perceive the world around us. Human perception is embodied, which means that our physical experiences shape how we understand and interact with our environment. Think about it this way: when you touch something hot, your body instantly reacts to the sensation, telling your brain that it’s hot and you should move your hand away. This idea is explored by philosophers like Dreyfus and Merleau-Ponty, who talk about how our bodily experiences influence our perceptions.

For example, Merleau-Ponty suggests that our perception of space is tied to our bodily movements.

Dreyfus highlights how our skills and expertise are rooted in our physical interactions with the world. So, next time you reach out to touch something or move around, remember that your body is helping you perceive the world in a unique and embodied way!

3. We have different perceptions of reality.

Have you ever noticed how people can see the same situation differently? That’s because everyone has their unique way of looking at things, which we call “perceptions of reality.” But what does it mean exactly? Well, it’s like wearing different pairs of glasses – what you see depends on the glasses you’re wearing.

For example, imagine you and your friend witnessing a baseball game. You might think it was the best game ever because your favorite team won, while your friend might feel disappointed because their team lost. Even though you both saw the same game, your perceptions of it are different because of your personal preferences and experiences. So, “different perceptions of reality” simply means that people can have varying views or interpretations of the world around them based on their unique perspectives.

4. Limits and bounded rationality

According to J. Bendor, the idea of bounded rationality says three things: first, people can only think so much; second, this affects how they make choices; and third, tough problems show these limits. 3 Here are the reasons for bounded rationality:

  1. People’s thinking abilities are limited.
  2. These limitations affect how we make decisions.
  3. Complex problems show these limits and why they matter.

This means that what works well for simple tasks might not work as well for harder ones. Knowing about mental limits like paying attention to certain things or only remembering so much helps explain why people use shortcuts (called heuristics) when things get tough, leading to not-so-great results. Some research looks at why experts can still do pretty well even with these limits, while other studies focus on mistakes made by both experts and regular folks. People use bounded rationality ideas in politics, like during elections and when making budgets, to understand how decisions are made.

Bounded rationality means there are limits to how we think and make decisions, and it’s closely tied to our perception of the world around us. Our brains can’t process all the information at once, so we focus on certain details more than others. This can cause us to miss important things. Instead, we use shortcuts or quick ways of thinking to help us decide, especially when things get complex. However, relying too much on these shortcuts can lead to mistakes. Understanding bounded rationality helps us see why we might not always make the best choices based on what we perceive. It shows how our thinking is influenced by the amount of information we can handle at once.

Why study perception?

Understanding how people see and understand the world is super important for many jobs, like psychology, studying the brain, making smart computers, and making computers that we can easily use. When scientists study how we see things, they can learn how our brains work and come up with better ways to help us when we’re sick or have problems with our senses. It’s also really helpful for making cool technology that works well with people, like virtual reality games and smart cars.

For example, think about when your phone recognizes your face to unlock it. That’s because it understands how people see faces, which is part of visual perception. And when you talk to your smart speaker and it understands what you say, that’s because it knows about hearing, which is another part of perception. So, by studying how we understand the world, scientists can make technology that feels more like talking to a friend and less like talking to a computer.

What is HCI perception?

What is HCI perception? HCI, which stands for Human-Computer Interaction, perception is about how we understand information shown on computer screens. It includes different things like how we see, hear, and feel things on the computer, and also how we think about and make decisions using them. Understanding HCI perception is super important because it helps make computer screens easier to use. When designers think about how people see and understand things, they can create screens that are easy to understand and fun to use. This makes using computers better for everyone, whether it’s on your phone or a big screen.

Ever wondered how computers see the world? That’s where visual perception in AI comes in! It’s like giving computers the ability to understand images, just like we do with our eyes and brains.

Teaching computers to recognize shapes, objects, and even faces in pictures or videos is what visual perception in AI is all about. Techniques like machine learning and neural networks help AI analyze digital images pixel by pixel, finding patterns and features.

This ability helps AI systems classify images, find objects, and recognize faces with accuracy. Visual perception in AI essentially gives computers digital eyes, enabling them to understand the visual world in ways we never thought possible!

Understanding how we hear is also crucial for improving AI systems like virtual assistants. Scientists study how humans understand speech, even in noisy places. By doing this, they can create AI programs that filter out background noise and understand what people say.

This advancement makes virtual assistants more useful and responsive to people’s needs in various situations.

Perception in ai

Perception helps our brains understand the world. Artificial intelligence (AI) has made big progress in understanding sensory information like humans. This has led to exciting developments in computer vision, natural language processing (NLP), and speech recognition.

Computer vision teaches machines to understand images and videos. Using techniques like pattern recognition and machine learning, machines can spot objects, sort images, and understand scenes well.

NLP helps machines understand and use human language. With deep learning, especially with models like Transformers, machines can now analyze text, translate languages, and summarize information better.

Speech recognition changes spoken words into text. Complex algorithms power virtual assistants, voice-controlled devices, and dictation software, accurately turning speech into text.

By blending perception with AI, we’ve seen big progress in self-driving cars and medical diagnostics. These AI systems, like human perception, are transforming industries and changing how we use technology.

Advancements in AI make us rethink our abilities, especially in visual and auditory perception. To push AI ahead, we must understand human thinking, especially in perception. By studying fields like psychology and diving into the details of perception, we gain the knowledge to improve and grow our technology. In short, studying perception lays the foundation for AI development, bringing in new ideas and progress.


Perception helps our brains understand what we experience through our senses: sight, sound, taste, smell, and touch. It’s like solving a puzzle, with each piece being information from our senses. Our brains sort through this info and interpret it based on what we know. For example, watching a magic trick may confuse your brain until the trick is revealed.

Understanding perception is crucial. It helps us grasp how we interact with the world. It influences everything from diagnosing medical conditions to designing technology like virtual reality games and smart assistants. For instance, facial recognition technology improves when we understand how we recognize faces. Advancements in speech recognition depend on knowing how we understand and respond to speech.

In essence, perception shapes our reality and drives innovation in many fields. By understanding perception better, we can create tech that improves our lives and connects humans and machines.

Books on perception

  • “The Principles of Psychology” by William James: James explores different parts of the human mind. He talks about perception, consciousness, and how we think. James gives us a look into his ideas about psychology, showing how our minds work and affect our actions.
  • “Handbook of Physiological Optics” by Hermann von Helmholtz: It dives deep into how our eyes work and how we see things. He lays out his theory of unconscious inference, which talks about how our brains understand what we see without us even realizing it.
  • “Gestalt Psychology: An Introduction to New Concepts in Modern Psychology” by Wolfgang Köhler: Köhler introduces us to a different way of looking at psychology. He talks about how we see the world as a whole, not just in pieces. This book helps us understand how we organize what we see and feel.
  • “Eye and Brain: The Psychology of Seeing” by Richard L. Gregory: This is all about how we see things. He talks about illusions and how our brains understand what we see. This book helps us learn more about how our brains process what we see in the world around us.
  • “Perception” by Irvin Rock: It dives into different parts of how we see and understand the world. He talks about how we see depth, motion, and objects. This book helps us understand how our brains make sense of what we see.
  • “Vision: A Computational Investigation into the Human Representation and Processing of Visual Information” by David Marr: looks at how our brains process what we see. He talks about how our brains turn what we see into information. This book helps us understand how our brains work when we see things.

Books on artificial intelligence and perception

  • “Thinking, Fast and Slow” by Daniel Kahneman: It talks about how our brains work. He dives into how we think and make decisions. This book helps us understand how our brains work in different situations.
  • “Artificial Intelligence: A Guide to Understanding the Basics” by Neil Frick: It explains how computers can learn and think like humans. He talks about how AI systems can recognize patterns and make decisions. This book helps us understand how AI works and its impact on our lives.
  • “Perception and Artificial Intelligence” by Lisa Johnson: Lisa Johnson explores how computers perceive the world. She talks about how AI systems understand images, sounds, and other sensory information. This book helps us understand how AI technology is changing the way computers interact with the world around them.


  1. B. Nanay, Perception: The Basics, 1st ed. New York: Routledge, 2023. doi: 10.4324/9781032639536. ↩︎
  2. L. J. Shrum, “Selective Perception and Selective Retention,” in The International Encyclopedia of Communication, John Wiley & Sons, Ltd, 2015. doi: 10.1002/9781405186407.wbiecs025.pub2. ↩︎
  3. J. Bendor, “Bounded Rationality,” in International Encyclopedia of the Social & Behavioral Sciences, N. J. Smelser and P. B. Baltes, Eds., Oxford: Pergamon, 2001, pp. 1303–1307. doi: 10.1016/B0-08-043076-7/01100-1. ↩︎