The range of human perceptual experiences (with Anil Seth)
Spencer Greenberg speaks with Anil Seth about how our perception of reality and self is a brain-based construction, not a direct reflection of the world. They discuss perceptual diversity, the utility-driven nature of experience, and the deep connections between art and science as creative enterprises.
Deep Dive Analysis
16 Topic Outline
Introduction to Perception and Reality
The Nature and Location of Color Perception
Optical Illusions as Brain Constructions
The Virtual Reality Analogy for Perception
The Self as a Brain-Constructed Experience
Different Aspects of Selfhood and Their Construction
Why Understanding Perception Matters
The Perception Census: Mapping Inner Worlds
Perceptual Diversity Beyond Neurodivergence
Synesthesia and Hidden Perceptual Differences
Hearing Voices as a Normal Perceptual Variation
Aphantasia: The Absence of Mental Imagery
The Creative Overlap Between Art and Science
Historical Examples of Art and Science Synergy
The Dreamachine Project: An Art-Science Collaboration
The Dreamachine Experience and Its Mechanisms
8 Key Concepts
Noumenon
In philosophy, particularly by Kant, this refers to objective reality as it truly is, which is always hidden behind a sensory veil and inaccessible to direct human perception. Our experienced world is a construction, not the noumenon itself.
Color as Interaction
Color is not an inherent property of objects in the world nor solely a mental phenomenon. Instead, it is an interaction where the brain infers how surfaces reflect light, taking into account specific wavelengths and the ambient lighting of the environment.
Controlled Hallucination
This term describes normal perception, emphasizing that our experience of the world is a brain-based construction. However, it is 'controlled' because it is finely tuned and calibrated by objective reality, making it functional and useful for survival.
Bundle Theory of Self
An old philosophical idea, notably by David Hume, which posits that the self is not a single, essential entity or soul. Rather, it is a collection of different experiences and perceptions (e.g., body, mood, agency, narrative, social self) that tend to go together.
Perceptual Diversity
This concept suggests that all humans likely experience things quite differently on the inside, extending beyond specific neurodivergent conditions. These inner differences are often hidden by common language and shared behavior, making them hard to detect.
Secondary Qualities (Locke)
These are properties of objects that are not mind-independent and require a mind for their existence, such as color. They contrast with primary qualities like solidity, which are considered to have an existence independent of perception.
Aphantasia
A recently described phenomenon characterized by the complete absence of internal mental imagery. Individuals with aphantasia cannot 'visualize' things in their mind's eye, though this often has little impact on their functional capacity.
Beholder's Share
An art historical concept by Ernst Gombrich, which states that a significant part of the experience of viewing or experiencing an artwork is contributed by the observer, rather than being solely inherent in the artwork itself. This aligns with the idea that perception involves the brain making predictions and interpreting sensory data.
10 Questions Answered
Our eyes are only sensitive to a tiny slice of electromagnetic radiation, and the brain constructs our entire visual experience. This experience is always an interpretation and not a direct reflection of objective reality.
Redness is not in the berry itself (which only reflects certain wavelengths) nor solely in the mind. It's an interaction, an inference the brain makes about how surfaces reflect light in the context of their environment.
Optical illusions demonstrate the brain's constructive process, but in a broader sense, all perception is a 'brain-based construction' or 'controlled hallucination.' Our experience is always an interpretation, not a direct reflection of reality.
Yes, the experience of the self is a construction, not a single essence. It's a collection of different perceptions, including body awareness, emotions, agency, and a continuous narrative, all interpreted by the brain.
It provides insight into mental health conditions, fosters humility about our own perceptions, and helps us understand that others may have different experiences, leading to greater empathy and informing social and policy implications.
Our perception is not designed for accuracy in mirroring objective reality, but for utility. Evolution has shaped our perceptual systems to be 'systematically inaccurate' or different from what's there in ways that are most useful for our survival and effective behavior.
People likely experience things quite differently on the inside, even if they use the same words and behave similarly. This 'perceptual diversity' is a continuum, not just limited to recognized neurodivergent conditions.
Yes, it is not uncommon for people to hear voices in their head when nobody is speaking, and these voices are often not distressing or indicative of psychosis, highlighting a continuum of perceptual experiences.
Aphantasia is the complete absence of internal mental imagery, meaning individuals cannot visualize things in their mind's eye. Despite this, it generally has little or no impact on functional capacity, as people simply find different ways to solve problems.
Both are fundamentally creative enterprises driven by imagination and a desire to understand our place in nature. They can inform each other, with art sometimes reverse-engineering perceptual systems and science often valuing aesthetic criteria in theories.
13 Actionable Insights
1. Meditate for Self-Awareness
Engage in meditation to gain distance from your mental processes, observe how thoughts and attention unfold, and recognize that selfhood is part of a continuous flow of experiences, not a fixed entity.
2. Challenge the ‘Essential Self’
Question the intuitive feeling that there is a single, unchanging essence of ‘you’ deep within, understanding instead that the self is a collection of perceptions and experiences that can be teased apart.
3. Perception as Controlled Hallucination
Adopt the mental model that perception is a ‘controlled hallucination,’ recognizing that your brain constructs your reality not for accuracy, but for utility and survival in the world.
4. Understand Perceptual Diversity
Cultivate humility about your own perceptual experience by realizing that what you experience is dependent on your unique mind and brain, leading to an understanding that others may see, experience, and believe different things.
5. Use Optical Illusions for Insight
Engage with optical illusions to observe how your brain actively constructs reality, reinforcing the understanding that all experience is a brain-based construction, not a direct reflection of external reality.
6. Reframe Perception’s Goal
Shift your understanding of perception’s purpose from accuracy to utility, recognizing that your brain constructs reality in ways that are useful for survival and effective behavior, even if systematically different from what’s objectively there.
7. Participate in Perception Census
Contribute to scientific research on perceptual diversity by participating in the online Perception Census (anilseth.com or search ‘perception census’) to help map how different our inner worlds are across various sensory experiences.
8. Normalize Hearing Voices
Recognize that hearing voices in one’s head is not uncommon and often not distressing, which can help normalize the experience and prevent quick diagnoses of difference as deficit, avoiding unnecessary fear or stigma.
9. Recognize Imagery Variation
Understand that people vary widely in their capacity for internal mental imagery (from vivid to aphantasia), and that these differences typically have little to no impact on functional capacity, only on the diverse ways problems are solved.
10. View Art & Science as Complementary
Appreciate art and science as deeply intertwined, creative enterprises that both seek to understand our place in nature, recognizing how artistic aptitude can inform scientific discovery and how art can reveal insights into perceptual systems.
11. Reflect on Social Media’s Impact
Consider how prolonged engagement with highly stimulating, short-form social media content (e.g., TikTok) might cultivate ADHD-like behaviors or mindsets, potentially influencing attention and information processing.
12. Utilize ThoughtSaver for Recall
Use the free tool ThoughtSaver.com to strengthen your recall of important ideas by receiving daily flashcard quizzes, either from ready-made decks or by creating your own to remember valuable information.
13. Seek Mind-Expanding Experiences
Engage in experiences (like the ‘dream machine’ described) that highlight the mind’s power to generate experience, fostering a profound appreciation for the complexity, wonder, and potential of your own brain and its unique processes.
7 Key Quotes
Color is the place where the brain and the universe meet.
Cezanne
Perception as a kind of controlled hallucination.
Anil Seth
It's not only our experience of the world that is a construction, it's also the experience of the self.
Anil Seth
We see things as they are useful for us, not as they actually are.
Anil Seth
Neurodiversity... this idea that everybody is different and that differences are not deficits.
Anil Seth
Science isn't just about cranking a wheel and facts come out. Science is about imagination.
Anil Seth
The more crosstalk we can get between art and science, I think the better.
Anil Seth
2 Protocols
Testing Grapheme-Color Synesthesia
Anil Seth- Ask individuals to pick a specific color from a large palette that they associate with a given letter.
- Request them to repeat this process for the same letter five minutes or half an hour later.
- Observe that genuinely synesthetic individuals will pick very close to the exact same color consistently, which is difficult or impossible for non-synesthetes to fake.
Dreamachine Experience
Anil Seth- Enter a comfortable, welcoming space and remove shoes.
- Go into the Dreamachine structure, which accommodates about 30 people sitting in a circle on comfy seating.
- Lie down and engage in a breathing exercise.
- Close eyes as flashing white lights and music begin.
- Experience a visual journey of colors, shapes, patterns, geometries, movement, and sometimes complex imagery for approximately 30 minutes.
- Exit the Dreamachine and engage in opportunities to discuss the experience, draw pictures, and fill out surveys.