University of Essex,
Colchester, UK
Predicting Discomfort from
Contemporary Art
Debbie Ayles, Dom Fernandez and Arnold J Wilkins
Supported by a Sciart Research and Development award from the
1
Introduction: visual angle
Hold out your index finger at arm’s length.
Your finger nail covers (subtends) about one
degree at your eye.
1 degree
2
Introduction: spatial frequency
The spatial frequency of a repetitive pattern is the
number of repetitions (cycles) of the pattern in one
degree visual angle.
Some people find patterns of stripes uncomfortable
to look at. The discomfort depends on the spatial
frequency of the stripes.
3
Discomfort from patterns
Some people find the centre pattern uncomfortable.
The centre pattern has a spatial frequency of about 3
cycles per degree from where you are looking.
4
Symptoms of visual stress
Uncomfortable patterns can provoke both visual
distortions (illusions of motion, shape, and colour) and
bodily symptoms (eye strain, nausea, headaches, even
seizures).
Discomfort depends on the susceptibility of the
individual. Migraine sufferers experience discomfort from
patterns that cause only mild aversion and illusions in
other people.
5
Aversive or exciting?
Contemporary art, particularly op
art, is often judged aversive.
The artist Debbie Ayles uses
phenomena experienced during
her migraine attacks as sources
of inspiration.
Some people have said they find
her paintings aversive; others
find them exciting.
6
Three Focus Groups
We gave an exhibition of Debbie Ayles’ art to 3 focus
groups: 4 - 9 people per group, one group exclusively
artists.
We identified two sources of discomfort and instability:
• repetitive linear elements
• juxtaposition of complementary colours.
7
Aversion/discomfort
The instability was sometimes seen as interesting and
attractive, but more often as aversive.
The aversion was expressed by phrases such as
“disturbing”, “eyes dart about”, “messes with the head”,
“likely to cause headaches”.
8
Ratings
The focus groups then observed a presentation
featuring 45 images, a mixture of original art
and computer-distorted art.
The images were rated for artistic merit
and aversiveness.
9
Results of Study 1
Some of the most “uncomfortable” images:
Some of the least “uncomfortable” images:
10
Fourier analysis of images
We can build any image mathematically by adding
together patterns of stripes with different spatial
frequencies and orientations (Fourier’s theorem).
We can do the reverse with Fourier analysis: break an
image down into its component stripes.
Fourier analysis tells us which spatial frequencies are
necessary and how strong they are (how much energy
they have).
11
Study 1 - Fourier analysis
9
The brightness
about 3 cycles/degree
was 3.2 times greater
in the uncomfortable
images.
luminance energy (log units)
(luminance energy) at
Comfortable
images
Uncomfortable
images
8
7
6
5
4
3
2
1
0
0.1
1
3
10
spatial frequency (cycles/degree)
100
12
Study 2
Images from other artists were included. Teenagers
rated them.
Some of the most “uncomfortable” images:
Some of the least “uncomfortable” images:
13
Study 2 - Fourier analysis
9
Luminance energy at
7.3 times greater in
uncomfortable
images.
luminance energy (log units)
3 cycles/degree was
Comfortable
images
Uncomfortable
images
8
7
6
5
4
3
2
1
0
0.1
1
3
10
spatial frequency (cycles/degree)
100
14
Study 3
New images. None inspired by migraine.
Some of the most “uncomfortable” images:
Some of the least “uncomfortable” images:
15
Study 3 - Fourier analysis
9
Comfortable
images
Uncomfortable
images
8
luminance power (log units)
Luminance energy at
3 cycles/degree was
1.7 times greater in
uncomfortable
images.
7
6
5
4
3
2
1
0
0.1
1
3
10
spatial frequency (cycles/degree)
100
16
Summary of results
Uncomfortable images show an ‘un-natural’
curved power spectrum.
They tend to have greater power at about
3 cycles/degree.
Stripes with a spatial frequency close to this:
¾ are uncomfortable to view
¾ give perceptual distortions
¾ can provoke eye strain, nausea, headaches,
even seizures.
17
Aversion and artistic merit
Unsurprisingly, uncomfortable paintings were judged to
have lower artistic merit.
Study 2
7
7
6
6
r =-0.59
Rated artistic merit
Rated artistic merit
Study 1
5
4
3
r=0.31
r =-0.31
5
4
3
2
2
1
1
1
2
3
4
Rated aversion
5
6
7
1
2
3
4
Rated aversion
5
6
7
18
Can we predict problems?
Look at this advert.
It has an unfortunate
health warning...
Daily
DailyTelegraph
TelegraphTuesday
Tuesday31
31Oct
Oct1989
1989
The prophesy made
headlines 5 days later!
th
The
TheObserver
ObserverSunday
Sunday55thNov
Nov1989
1989
19
Uncomfortable art?
Daily Telegraph 1971
Bridget Riley exhibition:
guards complained of
headaches and requested
dark glasses.
20
Uncomfortable art?
“A £35,000 mural at West London’s Hillingdon
Hospital was almost removed after staff
complained it was an eyesore....”
21
Predictions
We compared power at 3 cycles/degree relative to that
at 0.5 cycles/degree.
The relative power was abnormally high in art that has
led to complaints.
We can predict complaints before they occur.
22
Photographs of real scenes
J. Pretty, J. Peacock, M. Sellens, and M. Griffin (2005)
chose rural and urban scenes that were consistently rated
as pleasant or unpleasant. They kindly let us analyse their
images. Again, uncomfortable images had more energy at
3 cycles/degree.
Examples:
Urban
pleasant
Urban
unpleasant
Rural
pleasant
Rural
unpleasant
23
Urban vs. rural scenes
We calculated the relative power for 100 rural pictures
and 100 urban pictures sampled consecutively from the
BBC’s digital pictures of Britain.
24
Results
The urban images had
slightly more power at
about 3 cycles/degree.
Perhaps we have designed
an urban environment that
is visually more
uncomfortable than it needs
to be!
25
Future work
We are now extending these analyses to include colour.
We thank the artists:
Debbie Ayles
Marcel Brekelmans
Fred Casselman
Cliff Colman
Ernie Gerzabek
Karl Maenz
Wayne Riggs
N.J. Strother
Lynne Taetzsch
We also thank:
• The students and staff at St. Helena School, Colchester, UK.
• Drs P Bex and A F Clark for guidance with the programming.