what do you see? a hat? an elephant? a snake? an elephant and a snake?

The Interface Theory of Perception

What do you see?

A hat? An elephant?

A snake? An elephant and a snake?

If you have seen this image before….

How about out in the World? In Real Life. What do we see? What is it that we perceive?

The Conventional view of perception

“A primary goal of perception is to recover, or estimate, objective properties of the physical

world. A primary goal of perceptual categorization is to recover, or estimate, the objective statistical structure of the physical

world.”

Bayes’ Theorem

Which object is casting the shadow?

Bayes’ Circle“We can only see the world through our

posteriors. When we measure priors and

likelihoods in the world, our

measurements are necessarily altered

through our posteriors. Using our

measurements of priors and likelihoods to

justify our posteriors thus leads to a

vicious circle.”

Bayes’ CircleThis essentially means that in order to know or

perceive the world, we must have a prior knowledge or perception of it to compare to.

HMMMMMM

Maybe not a reconstruction

?

Let’s examine a perceptual mistake

Somewhere in Australia

Shiny – checkDimpled – checkYellow brown –check

Desirable female ?It must be …..Oh no, not really

What’s wrong with this picture?

The Interface Theory of Perception

The perceptions of an organism are a

user interface between that

organism and the objective world

An interface

An interface

Do I really want or need to know all this?

Where is my

file????

An interface is

helpful!

Conventional TheoryReconstruction Thesis

“Perception reconstructs certain properties and categories of the objective world” (Hoffman). In essence, what you see is what you literally get. There are infinitely many and infinitely complex

possibilities in the objective reality.

Interface TheoryConstruction Thesis

“Perception constructs the properties and categories of an organism’s perceptual world” (Hoffman). In a sense, we perceive only the necessary qualities

of the objective reality. Our perceptual systems instead display relevant

representations of more complex phenomena in a simpler form, much like icons on a computer.

Interface Theory of Perception predicts that

Each species has its own interfaceAlmost surely, no interface performs reconstructionEach interface is tailored to guide adaptive behavior in a

relevant niche Much of the competition between and within species

exploits the strength and limitations of interfacesSuch competition can lead to arms races between

interfaces and critically influence their adaptive evolution.

Reconstruction? Model? Need for Isomorphism?Perception is indeed qualitatively different from the

represented physical reality: here Hoffman is right Perception is not a reconstruction but it is a

representationIs Hoffman correct in maintaining that perception

doesn’t even need an ‘isomorphism’ with reality?2D retinotopic neural maps as an example of

isomorphismGiven isomorphism, can we think of perception as a

model of reality, hence constructed if not reconstructed?

ReferencesD. Hoffman.

The interface theory of perception: Natural selection drives true perception to swift extinction. In Object categorization: Computer and human vision perspectives, S. Dickinson, M. Tarr, A. Leonardis, B. Schiele (Eds.) Cambridge, UK: Cambridge University Press, 2009, 148–165.

J.P. Frisby and J.V. Stone Seeing The Computational Approach to Biological Vision, 2nd Edition, The MIT Press 2010