Perceptual precision

ABSTRACT

The standard view in philosophy of mind is that the way to understand the difference between perception and misperception is in terms of accuracy. On this view, perception is accurate while misperception is inaccurate. However, there is some evidence (albeit controversial evidence) that perceptual experience actually involves widespread inaccuracy. I add to that evidence in the paper. Then I point toward a way of understanding the difference between perception and misperception, not in terms of accuracy alone, but in terms of precision. That is, I argue that perceptual experience is designed to enable more fine-grained discrimination among the properties that are most useful for action, even if that involves inaccuracy. The view in this paper motivates a new account of illusion, on which illusions are imprecise as well as inaccurate. I call this the Precision Account of Illusion.

KEYWORDS:

• Perception
• illusion
• psychology
• philosophy of mind

Acknowledgements

I would like to thank the many people who have helped me to develop this paper through discussion and comments. I owe gratitude to the participants of the 2017 Minds Online session on Perceptual Precision, the 2014 Barnard-Columbia Perception Workshop, and the 2014 conference at Yonsei University, especially its co-organizer Timothy Fuller. For discussion of the ideas in this paper, I am indebted to Colin Chamberlain, Kevin Connolly, Gary Hatfield, Chris Hill, Todd Ganson, Joseph Levine, Brian McLaughlin, Alison Springle, and several anonymous reviewers.

Disclosure statement

No potential conflict of interest was reported by the author.

Notes

1. There are some exceptions. See McLaughlin (2016), as well as the discussion below of Akins (1996) and Simmons’ (2008) interpretation of Descartes and Malebranche.

2. This paper defends a way of distinguishing successful from unsuccessful perception in terms of precision, but there may be other ways of defining ‘success,’ depending on the domain of inquiry. For example, an epistemologist may be more interested in accuracy than precision if accurate perception tends to result in true beliefs. My view is also consistent with the possibility that inaccurate perception can be successful for other reasons in addition to precision. For example, inaccurate perception may be considered successful if it reduces false negatives, such as when a subject mistakes a stick in the woods for a snake. However, this does not involve an increase in precision. I am grateful to two anonymous reviewers for these suggestions and examples.

3. For readers who would like more information about the philosophical account of accuracy and the content of perception, see Siegel (2016).

4. One intuitive example that illustrates this idea is a caricature in drawing. Caricatures distort a subject’s features in ways that are arguably inaccurate, but this enables better recognition of the person depicted by the drawing. I am grateful to an anonymous reviewer for this example.

5. The subject is accurate insofar as the door really is taller than she is, but she may nonetheless be inaccurate with respect to the door’s height or the magnitude of the difference between her height and the door’s. I think that we represent properties like the door’s height in visual perception and not just relations such as “taller than.” For this reason, I call this a case of inaccurate representation. I am grateful to Chris Hill for discussion of this point.

6. For some time, it was thought that subjects could perform complicated actions because their visual system re-inverted the light hitting the retina, transforming the inverted image into a veridical representation of an upright world. When subjects describe their experience, however, the picture that emerges is not so straightforward. Harris (1965) and Linden et al. (1999) found that the world remained inverted following adaptation, though other reports suggest that inversion may be partial (Kohler, 1961). This evidence from subjective reports suggests that the world does not fully re-invert to a veridical representation following adaptation.

7. Some of Proffitt’s research has been contested, such as his finding that backpacks and sugary drinks influence distance judgments (see Durgin et al., 2009). In contrast, the finding that subjects exaggerate the slant of hills has been replicated and is widely accepted in the literature.

8. I am grateful to Chris Hill for raising this objection at the 2017 Minds Online conference session on perceptual precision.

9. For a review of the literature on vague predicates, see Hyde (2011).

10. Redacted.

Additional information

Notes on contributors

Adrienne Prettyman

Adrienne Prettyman is Assistant Professor of Philosophy at Bryn Mawr College. Her research explores the nature of perception, attention, and consciousness.