Profile Photo Paul Linton

I'm a NOMIS Foundation Fellow at Columbia University at the Italian Academy for Advanced Studies, and an affiliate of Niko Kriegeskorte's Visual Inference Lab at the Zuckerman Mind Brain Behavior Institute. My work focuses on:

1. Developing a New Theory of Visual Experience,

2. Illustrating its Significance through 5 New Visual Illusions, and

3. Linking this Theory to Early Visual Processing in the Brain.

I am also leading a Generative Adversarial Collaboration on the Primary Visual Cortex (V1) and was the lead organizer of a Royal Society Scientific Meeting and Volume on New Approaches to 3D Vision.

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NOMIS Foundation Logo I'm extremely grateful to the NOMIS Foundation for supporting my work, as well as the Presidential Scholars in Society and Neuroscience and the Italian Academy for Advanced Studies at Columbia University.
New Theory of Visual Experience

In my book The Perception and Cognition of Visual Space (Palgrave, 2017), and in two articles, I develop a new low-level theory of visual experience:

Article Screenshot Linton, P. (2023). Minimal Theory of 3D Vision: New Approach to Visual Scale and Visual Shape. Philosophical Transactions of the Royal Society B

This paper argues that 3D Visual Shape is not attempting to estimate 3D geometry of the environment, but merely reflects the un-corrected "retinal disparities". It goes on to argue that Visual Scale uses these imperfections in 3D Visual Shape to estimate size and distance.
Article Screenshot Linton, P. (2021). V1 as an Egocentric Cognitive Map. Neuroscience of Consciousness

This paper argues that the Primary Visual Cortex (V1) acts as the neural basis for the Perception/Cognition distinction, exploring the different roles of layers in V1. Now part of the basis for a Generative Adversarial Collaboration on V1.
Book Cover Linton, P. (2017).The Perception and Cognition of Visual Space (Palgrave Macmillan), 162 pages.

Sole authored book arguing for a two stage theory of 3D vision, according to which depth from stereo vision is extracted first (at level of Perception), before cue-integration and visual scale are processed (at level of Cognition).

Email me for a copy for research purposes.
Article Screenshot Erkelens, C. (2018). Review of Linton, P. The Perception and Cognition of Visual Space (2017), Perception

Review of my book by Prof. Casper Erkelens in Perception:

"Paul Linton (2017) ... presents an overarching theory for visual space perception in his book The Perception and Cognition of Visual Space. ... it provides much food for thought for students of visual perception..."
Article Screenshot Linton, P. (2018). Brains Blog

My book was featured on the Brains Blog, the leading online forum for cognitive science:

1. Visual Space and the Perception / Cognition Divide

2. Perceptual Integration and Visual Illusions

3. Seeing Depth with One Eye and Pictorial Space

4. Perceptual Idealism and Phenomenal Geometry

5. Do We See Scale?

Five New Visual Illusions

Inspired by my theoretical work, I developed five new visual illusions that suggest that visual experience is much simpler than we previously thought.

VSS Poster Vision Sciences Society (2025) [abstract].

Preprint Linton, P. (2025). Five Illusions Challenge Our Understanding of Visual Experience. Preprint

Outlines five new visual illusions - covering 1. Visual Inference, 2. Visual Shape, 3. Visual Scale, 4. Size Constancy, and 5. Color Constancy - arguing that visual experience is much simpler than we previously thought.

Visual Inference

The Hollow Face Illusion is often appealed to as evidence that visual experience is the visual system's "inference" ("best guess") about what is out there in the world, since a hollow mask is percieved as inverted in depth.

However, in two illusions I question whether percieved depth is really inverted:

Linton, P. (2024). Depth Cue Integration is Cognitive Rather than Perceptual: Linton Un-Hollow Face Illusion and Linton Morphing Face Illusion. Applied Vision Association 2024 Christmas Meeting Abstract

LINTON UN-HOLLOW FACE ILLUSION

I show that if you add physical objects into the hollow of the Hollow Face Illusion - space that physically exists, but which is "impossible" according to the illusion - the illusion still persists (as evidenced by illusory motion), but you still see the true (non-inverted) depth ordering of the objects and mask in stereo depth.

LINTON MORPHING FACE ILLUSION

I show that if you add balls to the tip of the nose and the cheek, and morph back and forth from a receding to a protruding mask, the change in the ordinal depth of the balls (inverting back and forth) is apparent.

Visual Inference

If the Un-Hollow Face Illusion suggests that 3D Shape is governed solely by stereo vision, then the next question is how the visual system extracts 3D shape from disparity. Traditionally, it is thought that retinal disparities are "scaled" to transform them from retinal to world coordinates.

However, I argue there is no "depth constancy" (scaling into world coordinates):

Linton, P. (2024). Linton Stereo Illusion. Preprint

LINTON STEREO ILLUSION

Traditional accounts ask participants to make evaluative depth judgments. I simplify the question by testing which of two conditions appears to move rigidly in depth (with angular size controlled): a stimulus moving in depth with contant physical separation, or a stimulus moving in depth with contant disparity?

As you see below, the answer is "constant disparity" (right), suggesting that percieved stereo depth is simply a function of disparities on the retina.

Visual Inference

We know that increasing the separation between the eyes makes scenes seem miniature. Traditionally, this has been explained as due to "vergence" (eye rotation) making objects seems smaller and closer.

However, I argue that it instead rests on a purely cognitive association between accentuated stereo depth (from horizontal disparities) and closer distances given disparities fall off with distance squared:

Linton, P. (2024). Visual Scale is Governed by Horizontal Disparities: Linton Scale Illusion. Applied Vision Association 2024 Christmas Meeting Abstract

LINTON SCALE ILLUSION

I replicate the effect in VR (Condition 1), but show it disappears as soon as we control for changes in horizontal disparities (Condition 2).

Visual Scale

Switching between the two conditions we see a startling effect: the "scale" of the scene changes, even though all that has changed is the geometry of the scene, not the apparent distance of the scene itself.

Visual Inference

Size constancy is thought to change the percieved angular size of objects in images, for instance the apparent size of the cars in this image:

Size Constancy Illusion
(c) Alex Blouin / Reddit

However, I argue that size constancy does not affect perceived angular size:

Linton, P. (2025). Size and Shape Constancies Do Not Affect Perceived Angular Size: Linton Size Constancy and Shape Constancy Illusions. Applied Vision Association 2025 Spring Meeting Abstract

LINTON SIZE CONSTANCY ILLUSION

If we add frames to the cars, the cars appear more distorted than the frames, which is inconsistent with size constancy affecting perceived angular size.

Visual Inference
Visual Inference

Color constancy is thought to affect the percieved color of objects, so that the disk in this illusion by Akiyoshi Kitaoka (based on Anderson & Winawer, 2005) is perceived differently as yellow or blue:

Size Constancy Illusion
(c) Akiyoshi Kitaoka

However, I argue that color constancy does not affect perceptual appearance:

Linton, P. (2025). Lightness and Color Constancies Do Not Affect Perceptual Appearance: Linton Lightness and Color Constancy Illusions. Applied Vision Association 2025 Spring Meeting Abstract

LINTON COLOR CONSTANCY ILLUSION

I show that if we switch back and forth between the two interpretations of the disks, our judgement of the disk's color ("yellow" or "blue") changes without the disk's perceptual appearance changing.

© Paul Linton, 2025. Site based on Jon Barron's website.