From sensation to perception

2025-02-13

Rick Gilmore

Prelude

MarvinGayeVEVO (2019)

https://x.com/cleans_letsrun/status/1847937360597578195

Overview

Announcements

Last time…

  • Light informs
    • Spatial perception: Where, how far, how big?
    • Object perception: What is it, what form, color, etc.
  • Eye
    • High resolution info only in center
    • Samples different categories of light wavelength
    • Moves to stablize retina, scan environment

Wade (2015)

Today

  • Wrap-up on sensation
  • From sensation to perception

Wrap-up on sensation

Color perception

  • Perceived color a function of activity in “R”, “G”, and “B” photoreceptors

Source: Wikipedia

Wavelengths are continuous, but are perceived colors?

https://rmit.pressbooks.pub/colourtheory1/part/2-colour-theory-the-visible-spectrum/

Perceived colors seem ordinal, but…

  • Color is a neuropsychological construct

What’s a reddish-green look like?

What’s a reddish-green look like?

Explanation

Color vision anomalies

  • Absence of or anomalies in photoreceptors

Wong (2011) Figure 1

Types

  • Protanopia (impaired R/long wavelength)
  • Deuteranopia (impaired G/medium wavelength)
  • Tritanopia (impaired B/short wavelength)

https://www.color-blindness.com/protanopia-red-green-color-blindness/

Color palettes

Wong (2011) Figure 2

Some consequences for data figures

  • Size of visual elements (symbols, including text)
  • Contrast (light/dark or color)
  • Textures of visual patterns
  • Some colors more visible than others
  • How much visual scanning (# of eye movements) required?

From sensation to perception

Visual brains love differences

Figure 6.1 Cairo (2013)

Especially …

  • Intensity (light/dark)
    • Contrast
  • Color
  • Position or size
  • Changes in…

Kahneman (2013)

Pre-attentive vision

  • Detect quickly, with minimal effort
  • Usually in a single glance/fixation
  • vs. attentive vision
    • Overt shifts of attention (eye movements)
    • Covert shifts (“mind’s eye” movements)

Figure 6.4 Cairo (2013)

Some features easier/faster to judge

Figure 1 Cleveland & McGill (1984)

Figure 6.12 Cairo (2013)

Figure 6.12 Cairo (2013)

Gestalt school

  • Gestalt: “whole form”
  • Can psychological phenomena be understood from their parts?
  • Or is the whole greater than the sum of the parts?

Reification

  • Perception is constructive

https://en.wikipedia.org/wiki/Gestalt_psychology

Figure 5.29 Few (2004)

Multistability

  • Perception is multistable

https://en.wikipedia.org/wiki/Gestalt_psychology

Invariance

  • And yet…
  • Perception is invariant

https://en.wikipedia.org/wiki/Gestalt_psychology

Gestalt “laws” of perceptual grouping

  • Proximity
  • Similarity
  • Connectedness
  • Closure
  • Continuity
  • Symmetry

Proximity

https://en.wikipedia.org/wiki/Gestalt_psychology

Figure 6.5 Cairo (2013)

Similarity

https://en.wikipedia.org/wiki/Gestalt_psychology

Figure 6.3 Cairo (2013)

Similar but not too similar

Closure

https://en.wikipedia.org/wiki/Gestalt_psychology

Continuity

https://en.wikipedia.org/wiki/Gestalt_psychology

Figure 6.9 Cairo (2013)

Figure 5.33 Few (2004)

Connectedness

Figure 6.8 Cairo (2013)

Few (2004)

Symmetry

https://en.wikipedia.org/wiki/Gestalt_psychology

Your turn

  • Find a compelling illustration of one of the Gestalt phenomena (non-data visualization-related)
  • Find an illustration of one of the Gestalt phenomena in a data visualization
  • Add findings (and URLs) here:

https://docs.google.com/spreadsheets/d/1G8U_IPMP0x17Sfl-FQfF37DN19bDQFm0GO_UmQQzv7Q/edit?usp=sharing

Putting it all together

Figure 6.20 Cairo (2013)

Figure 6.20 Cairo (2013)

Main points

  • Vision is reconstructive
  • Pre-attentive vs. attentive vision
  • Gestalt principles describe feature grouping

Next time

From cognition to understanding

Resources

References

Cairo, A. (2013). The functional art: An introduction to information graphics and visualization. Upper Saddle River, N: New Riders Publishing.
Cleveland, W. S., & McGill, R. (1984). Graphical perception: Theory, experimentation, and application to the development of graphical methods. Journal of the American Statistical Association, 79, 531–554. https://doi.org/10.1080/01621459.1984.10478080
Few, S. (2004). Show me the numbers: Designing tables and graphs to enlighten. Oakland, CA: Analytics Press.
Kahneman, D. (2013). Thinking, fast and slow (1st edition). Farrar, Straus; Giroux. Retrieved from https://www.amazon.com/Thinking-Fast-Slow-Daniel-Kahneman/dp/0374533555
MarvinGayeVEVO. (2019). Marvin gaye - what’s going on (official video 2019). Youtube. Retrieved from https://www.youtube.com/watch?v=o5TmORitlKk
Wade, N. J. (2015). How were eye movements recorded before yarbus? Perception, 44, 851–883. https://doi.org/10.1177/0301006615594947
Wong, B. (2011). Color blindness. Nature Methods, 8, 441. https://doi.org/10.1038/nmeth.1618