The book takes as its opening target the representationalist orthodoxy in vision science — the view, developed by David Marr and others, that visual experience is produced by the brain's construction of increasingly sophisticated internal representations of the visual scene. Noë argues this picture is both empirically inadequate (it cannot explain change blindness, sensory substitution, or the active character of perception) and philosophically confused (it generates intractable problems about how the internal representation comes to be experienced).
The alternative Noë develops is that perceptual experience consists in the exercise of sensorimotor knowledge — practical mastery of how sensory appearances change with bodily movement. To see a tomato as having a back is not to construct an internal representation of the back but to implicitly know how the back would appear if one moved around it. This knowledge is bodily, skilled, and exercised in the act of perceiving itself. Seeing is enacted, not produced.
The book develops extensive arguments about color, spatial perception, perceptual presence, and the role of attention, each aimed at showing that the active, skilled, embodied character of perception is not an add-on to some more fundamental representational process but constitutive of perceptual experience itself. The brain is necessary for perception but not sufficient; the body and the environment are equally constitutive parts of the perceptual system.
For the AI revolution, Action in Perception's arguments have direct implications. If perception requires the exercise of sensorimotor skill in an embodied organism engaged with a world, then disembodied computational systems cannot perceive in the relevant sense — however sophisticated their information processing. The book became a key reference for critics of computational claims about AI consciousness and perception, and Noë has extended its arguments into the AI context in his recent work and in his 2024 Aeon essay.
Alva Noë, Action in Perception (MIT Press, 2004). Built on O'Regan and Noë's 2001 Behavioral and Brain Sciences paper and emerged from Noë's doctoral work at Harvard and subsequent faculty position at Berkeley.
Perception as enacted. Seeing is not the brain's construction of internal images but the perceiver's skilled engagement with a visual environment.
Sensorimotor knowledge is constitutive. Perceptual experience consists in the exercise of practical know-how about bodily movement.
The virtual presence. The back of the tomato is 'virtually present' in experience — available to further exploration, not currently represented.
Brain-body-world as perceptual system. The brain is necessary but not sufficient; perception emerges from the coupled system.
Against representationalism. The standard picture of vision as internal representation construction is rejected in favor of an enactive alternative.