How the Blind Draw

Ifirst met Betty, a blind teenager inToronto, as I was interviewing par-ticipants for an upcoming study of

mine on touch perception in 1973. Bet-ty had lost her sight at age two, whenshe was too young to have learned howto draw. So I was astonished when shetold me that she liked to draw profilesof her family members. Before I beganworking with the blind, I had alwaysthought of pictures as copies of the visi-ble world. After all, we do not drawsounds, tastes or smells; we draw whatwe see. Thus, I had assumed that blindpeople would have little interest or tal-

ent in creating images. But as Betty’scomments revealed that day, I was verywrong. Relying on her imagination andsense of touch, Betty enjoyed tracingout the distinctive shape of an individu-al’s face on paper.

I was so intrigued by Betty’s ability

that I wanted to find out if other blindpeople could readily make useful illus-trations—and if these drawings wouldbe anything like the pictures sighted in-dividuals use. In addition, I hoped todiscover whether the blind could inter-pret the symbols commonly used by

76 Scientific American January 1997 How the Blind Draw

BLIND ARTISTS, such as Tracy (above), rely on their sense of touch to render familiarobjects. Tracy lost all sight to retinal cancer at the age of two, but by feeling the glass,she determines its shape. By rubbing the paper, placed on a piece of felt, she knowswhere her pen has scored the page and left a mark. Because the lines in most simpledrawings reveal surface edges—features that are discerned by touching as readily asthey are by sight—drawings by the blind are easily recognized by sighted people.

How the Blind DrawBlind and sighted people use many of the same

devices in sketching their surroundings, suggesting that vision and touch are closely linked

by John M. Kennedy

AB

RA

HA

M M

ENA

SHE

Copyright 1996 Scientific American, Inc.

sighted people. To bring the blind intothe flat, graphical world of the sighted,I turned to a number of tools, includingmodels, wire displays and, most often,raised-line drawing kits, made availableby the Swedish Organization for theBlind. These kits are basically stiff boardscovered with a layer of rubber and a thinplastic sheet. The pressure from any ball-point pen produces a raised line on theplastic sheet.

Thanks to this equipment, my col-leagues and I have made some remark-able findings over the past 20 years, andthis information has revised our under-standing of sensory perception. Mostsignificantly, we have learned that blindand sighted people share a form of pic-torial shorthand. That is, they adoptmany of the same devices in sketchingtheir surroundings: for example, bothgroups use lines to represent the edgesof surfaces. Both employ foreshortenedshapes and converging lines to conveydepth. Both typically portray scenesfrom a single vantage point. Both ren-der extended or irregular lines to con-note motion. And both use shapes thatare symbolic, though not always visual-ly correct, such as a heart or a star, to re-lay abstract messages. In sum, our workshows that even very basic pictures re-flect far more than meets the eye.

Outlines

After meeting Betty, I wondered whether all blind people could ap-

preciate facial profiles shown in outline.Over the years, I asked blind volunteersin North America and Europe to drawprofiles of several kinds of objects. Mostrecently, I undertook a series of studieswith Yvonne Eriksson of Linköping Uni-versity and the Swedish Library of Talk-ing Books and Braille. In 1993 we test-ed nine adults from Stockholm—threemen and six women. Four were con-genitally blind, three had lost their sightafter the age of three, and two had min-imal vision. Each subject examined fourraised profiles, which Hans-Joergen An-dersen, an undergraduate psychologystudent at Aarhus University in Den-mark, made by gluing thin, plastic-coat-ed wires to a flat metal board [see up-per illustration on next page].

Eriksson and I asked the volunteersto describe the most prominent featureon each display using one of four labels:smile, curly hair, beard or large nose.Five of them—including one man whohad been totally blind since birth—cor-

rectly identified all four pictures. Onlyone participant recognized none. On av-erage, the group labeled 2.8 of the fouroutlines accurately. In comparison, when18 sighted undergraduates in Torontowere blindfolded and given the sameraised-line profiles, they scored onlyslightly better, matching up a mean of3.1 out of four displays.

Many investigators in the U.S., Japan,Norway, Sweden, Spain and the U.K.have reported similar results, leaving lit-tle doubt that blind people can recognizethe outline shape of familiar objects. Atfirst, it may seem odd that even thosewho have never had any vision whatso-ever possess some intuitive sense of howfaces and other objects appear. But withfurther thought, the finding makes per-fect sense. The lines in most simpledrawings show one of two things: wheretwo surfaces overlap, called an occlud-ing edge, or where two surfaces meet ina corner. Neither feature need be seen tobe perceived. Both can be discerned bytouching.

Not all blind people read raised-linedrawings equally well, and these indi-vidual discrepancies can reflect the ageat which someone lost his or her sight.

How the Blind Draw

OUTLINE DRAWINGS, made by Kathy,totally blind since age three, demonstratethat blind artists use many of the samedevices as sighted illustrators do. Theyuse lines to represent surfaces, as Kathy’spicture of the eagle on her charm braceletshows (top). Blind people portray objects,such as a house, from a single vantagepoint (at right). Blind artists use shapes toconvey abstract messages: Kathy drew aheart surrounding a crib to describe thelove surrounding a child (at right). Andthey use foreshortening to suggest per-spective: Kathy drew the L-shaped blockand the cube to be the same size whenthey were side by side but made the cubesmaller when it was placed farther awayfrom her (bottom).

DR

AW

ING

S C

OU

RTE

SY O

F JO

HN

M. K

ENN

EDY

Scientific American January 1997 77Copyright 1996 Scientific American, Inc.

For example, people who have beenblind from birth or infancy—termed theearly blind—sometimes find raised-linedrawings challenging. But in 1993 Ya-tuka Shimizu of Tsukuba College ofTechnology in Japan, with colleaguesShinya Saida and Hiroshi Shimura,found that 60 percent of the early-blindsubjects they studied could recognize theoutline of common objects, such as afish or a bottle. Recognition rates weresomewhat higher for sighted, blindfold-ed subjects, who are more familiar withpictures in general.

Interestingly, subjects who lose visionlater in life—called the later blind—fre-quently interpret raised outlines morereadily than either sighted or early-blind individuals do, according to Mor-ton Heller of Winston-Salem University.One likely explanation is that the laterblind have a double advantage in these

tasks: they are typically more familiarwith pictures than are the early blind,and they have much better tactile skillsthan do the sighted.

Perspective

Just as Betty prompted me to studywhether the blind appreciate pro-files in outline, another amateur art-

ist, Kathy from Ottawa, led me to inves-tigate a different question. Kathy firstparticipated in my studies when she was30 years old. Because of retinal cancerdetected during her first year of life,Kathy had been totally blind since agethree and had never had detailed vision.Even so, she was quite good at makingraised-line drawings. On one occasionKathy sketched several different arrange-ments of a cube and an L-shaped blockthat I used to test how relative distancesappear in line art. When the blocks satside by side, she made them the samesize—as they were in actuality. But whenthe cube was farther from her than theother block, she made it smaller in herdrawing.

This second drawing revealed a fun-damental principle of perspective—name-

ly, that as an object becomes more dis-tant, it subtends a smaller angle. (Thinkabout viewing a picket fence at an angleand how its posts appear shorter closerto the horizon.) Kathy’s use of this basicrule suggested that some aspects of per-spective might be readily understood bythe blind. Again the proposition seemedreasonable, given some consideration.Just as we see objects from a particularvantage point, so, too, do we reach outfor them from a certain spot. For proofof the theory, I designed a study withPaul Gabias of Okanagan UniversityCollege in British Columbia, who wasthen at New York University.

We prepared five raised-line drawings:one of a table and four of a cube [see up-per illustration on opposite page]. Weshowed the drawings to 24 congenitallyblind volunteers and asked them a se-ries of questions. The table drawing hada central square and four legs, one pro-truding from each corner. The subjectswere told that a blind person had drawnthe table and had explained, “I’ve drawnit this way to show that it is symmetri-cal on all four sides.” They were thentold that another blind person haddrawn an identical table but had offereda different explanation: “I’ve shown itfrom underneath in order to show theshape of the top and all four legs. If youshow the table from above or from theside, you can’t really show the top andall four legs, too.”

Next we asked our volunteers to pickout the cube drawing that had mostlikely been made by the person whodrew the table from below. To answerconsistently, they needed to understandwhat strategy had been used in drawingthe table and each cube. One cube re-sembled a foldout of a box, showing thefront face of the cube in the middle,surrounded by its top, bottom, left andright faces. Another drawing showed

How the Blind Draw78 Scientific American January 1997

PROFILES, made from plastic-coatedwires mounted on a thin metal board,were given to nine blind subjects in Stock-holm. The subjects were asked to de-scribe each display using one of four la-bels: smile, curly hair, beard or large nose.On average, the group described 2.8 ofthe four displays accurately, showing thatblind people often recognize the outlineof simple objects. Blindfolded, sightedcontrol subjects given the same task didonly slightly better.

SOLIDS—a sphere, a cone and a cube—

arranged on a table are commonly usedto test spatial ability. The arrangement isshown from overhead at the far right.Which drawing at the near right showsthe solids from the edge of the table fac-ing the bottom of the page? Which draw-ing shows them from the opposite edge?From the edge facing left? Facing right?Blind and sighted individuals do equallywell on this task, proving that the blindcan determine how objects appear fromparticular vantage points.

CO

UR

TESY

OF

JOH

N M

. KEN

NED

Y

CO

UR

TESY

OF

JOH

N M

. KEN

NED

Y


two squares, representing the front andtop of the cube. A third picture depict-ed the front of the cube as a square andthe top as a rectangle—foreshortened be-cause it was receding away from the ob-server. A fourth illustrated two trapezi-ums joined along the longest line; theextra length of this line revealed that itwas the edge nearest to the observer.

Which cube do you think was drawnby the person who intended to show thetable from below? Most of the blind vol-unteers chose the drawing that showedtwo trapeziums. That is, they selectedthe illustration that made the most so-phisticated use of perspective. Accord-ingly, they picked as the least likely matchthe flat “foldout” drawing—the one thatused no perspective whatsoever. Thefoldout drawing was also the one theyjudged most likely to have been made bythe person who, in drawing the table,had hoped to highlight its symmetry.

Heller and I joined forces to prepareanother task for demonstrating that theblind understood the use of perspective.(You might like to try it, too; it appearsat the bottom of the opposite page.) Wearranged three solids—a sphere, a coneand a cube—on a rectangular tabletop.Our blind subjects sat on one side. Weasked them to draw the objects fromwhere they were sitting and then toimagine four different views: from theother three sides of the table and fromdirectly above as well. (Swiss child psy-chologist Jean Piaget called this exercisethe perspective-taking, or “three moun-tains,” task.) Many adults and childrenfind this problem quite difficult. On av-erage, however, our blind subjects per-formed as well as sighted control sub-jects, drawing 3.4 of the five imagescorrectly.

Next, we asked our subjects to name

the vantage point used in five separatedrawings of the three objects. We pre-sented the drawings to them twice, inrandom order, so that the highest possi-ble score was 10 correct. Of that total,the blind subjects named an average of6.7 correctly. Sighted subjects scoredonly a little higher, giving 7.5 correct an-swers on average. The nine later-blindsubjects in the study fared slightly bet-ter than the congenitally blind and thesighted, scoring 4.2 on the drawing taskand 8.3 on the recognition task. Again,the later blind probably scored so wellbecause they have a familiarity with pic-tures and enhanced tactile skills.

Metaphor

From the studies described above, itis clear that blind people can appre-

ciate the use of outlines and perspectiveto describe the arrangement of objectsand other surfaces in space. But picturesare more than literal representations.This fact was drawn to my attentiondramatically when a blind woman inone of my investigations decided on herown initiative to draw a wheel as it was

spinning. To show this mo-tion, she traced a curve in-side the circle. I was takenaback. Lines of motion, suchas the one she used, are avery recent invention in thehistory of illustration. Indeed,as art scholar David Kunzlenotes, Wilhelm Busch, atrendsetting 19th-centurycartoonist, used virtually nomotion lines in his popularfigures until about 1877.

When I asked several oth-er blind study subjects todraw a spinning wheel, oneparticularly clever renditionappeared repeatedly: several

subjects showed the wheel’s spokes ascurved lines. When asked about thesecurves, they all described them as meta-phorical ways of suggesting motion.Majority rule would argue that this de-vice somehow indicated motion verywell. But was it a better indicator than,say, broken or wavy lines—or any otherkind of line, for that matter? The an-swer was not clear. So I decided to testwhether various lines of motion were aptways of showing movement or if theywere merely idiosyncratic marks. More-over, I wanted to discover whether therewere differences in how the blind andthe sighted interpreted lines of motion.

To search out these answers, Gabiasand I created raised-line drawings offive different wheels, depicting spokes

How the Blind Draw Scientific American January 1997 79

MOTION can be suggested by irregularlines. When blind and sighted volunteerswere shown five diagrams of movingwheels (right), they generally interpretedthem in the same way. Most guessed thatthe curved spokes indicated that the wheelwas spinning steadily; the wavy spokes,they thought, suggested that the wheel waswobbling; and the bent spokes were takenas a sign that the wheel was jerking. Sub-jects assumed that spokes extending be-yond the wheel’s perimeter signified thatthe wheel had its brakes on and thatdashed spokes indicated that the wheelwas spinning quickly.

CO

UR

TESY

OF

JOH

N M

. KEN

NED

Y

CO

UR

TESY

OF

JOH

N M

. KEN

NED

Y

PERSPECTIVE is readily understood by the blind. To prove this point, the author and Paul Gabiasof Okanagan University College asked 24 congenitally blind volunteers to examine a drawing of atable (far left) and four drawings of a cube. They were told that one blind person drew the table ina star shape to show how it appeared from underneath and that another blind person drew anidentical table, intending to show its symmetry instead. The subjects were then asked which cubewas most likely drawn by the person who drew the table from underneath. Most chose the cubecomposed of two trapeziums (far right), the one that made the most sophisticated use of perspective.


with lines that curved, bent, waved,dashed and extended beyond the peri-meter of the wheel. We then asked 18blind volunteers to assign one of the fol-lowing motions to each wheel: wob-bling, spinning fast, spinning steadily,jerking or braking. Which wheel do youthink fits with each motion? Our con-trol group consisted of 18 sighted un-dergraduates from the University ofToronto.

All but one of the blind subjects as-signed distinctive motions to each wheel.In addition, the favored description forthe sighted was the favored descriptionfor the blind in every instance. What ismore, the consensus among the sightedwas barely higher than that among theblind. Because motion devices are unfa-miliar to the blind, the task we gavethem involved some problem solving.Evidently, however, the blind not onlyfigured out meanings for each line of

motion, but as a group they generallycame up with the same meaning—at leastas frequently as did sighted subjects.

We have found that the blind under-stand other kinds of visual metaphorsas well. Kathy once drew a child’s cribinside a heart—choosing that symbol,she said, to show that love surroundedthe child. With Chang Hong Liu, a doc-toral student from China, I have begunexploring how well blind people under-stand the symbolism behind shapes suchas hearts, which do not directly repre-sent their meaning. We gave a list of 20pairs of words to sighted subjects andasked them to pick from each pair theterm that best related to a circle and theterm that best related to a square. (Ifyou wish to try this yourself, the list ofwords can be found at the left.) For ex-ample, we asked: What goes with soft?A circle or a square? Which shape goeswith hard?

All our subjects deemed the circle softand the square hard. A full 94 percentascribed happy to the circle, instead ofsad. But other pairs revealed less agree-ment: 79 percent matched fast and slowto circle and square, respectively. Andonly 51 percent linked deep to circleand shallow to square. When we testedfour totally blind volunteers using thesame list, we found that their choicesclosely resembled those made by thesighted subjects. One man, who hadbeen blind since birth, scored extremelywell. He made only one match differingfrom the consensus, assigning “far” to

square and “near” to circle. In fact, onlya small majority of sighted subjects—53percent—had paired far and near to theopposite partners. Thus, we concludedthat the blind interpret abstract shapesas sighted people do.

Perception

We typically think of sight as theperceptual system by which

shapes and surfaces speak to the mind.But as the empirical evidence discussedabove demonstrates, touch can relaymuch of the same information. In someways, this finding is not so surprising.When we see something, we know moreor less how it will feel to the touch, andvice versa. Even so, touch and sight aretwo very different senses: one receivesinput in the form of pressure, and oneresponds to changes in light. How is itthat they can then interpret somethingas simple as a line in exactly the sameway? To answer this question, we mustconsider what kind of information it isthat outlines impart to our senses.

The most obvious theory is that eachborder in a basic drawing represents onephysical boundary around some surfaceor shape. But it is not that simple, be-cause all lines, no matter how thin, havetwo sides or contours—an inside and anoutside border, if you will. As a result,thick lines are perceived quite different-ly from thin ones. Consider a thick linetracing a profile. If it is thick enough, itappears to show two profiles, one peredge, gazing in the same direction [seeillustration below]. When the line is thinand its two borders are close together,though, an observer perceives only one

How the Blind Draw80 Scientific American January 1997

WORD PAIRS were used to test the sym-bolism in abstract shapes—and whetherblind and sighted people perceived suchmeanings in the same way. Subjects weretold that in each pair of words, one fit bestwith circle and the other with square. Forexample, which shape better describessoft? According to the number given afterthe soft-hard word pair, everyone thoughta circle did. These percentages show thelevel of consensus among sighted subjects.Blind volunteers made similar choices.

THICKNESS of these outlines determineswhether their two contours are viewed asone profile or two. The same ambiguityoccurs with touch. Blind subjects inter-pret raised edges placed near each otheras a single surface boundary and thoseplaced farther apart as two.

CO

UR

TESY

OF

JOH

N M

. KEN

NED

Y

WORDS ASSOCIATEDWITH CIRCLE-

SQUARE

AGREEMENTAMONG

SUBJECTS(PERCENT)

SOFT-HARD

MOTHER-FATHER

HAPPY-SAD

GOOD-EVIL

LOVE-HATE

ALIVE-DEAD

BRIGHT-DARK

LIGHT-HEAVY

WARM-COLD

SUMMER-WINTER

WEAK-STRONG

FAST-SLOW

CAT-DOG

SPRING-FALL

QUIET-LOUD

WALKING-STANDING

ODD-EVEN

FAR-NEAR

PLANT-ANIMAL

DEEP-SHALLOW

100

94

94

89

89

87

87

85

81

81

79

79

74

74

62

62

57

53

53

51


face. As it turns out, touch produces asimilar effect. I prepared a series of pro-file drawings in which both edges of thedefining line were raised. When the edg-es were only 0.1 centimeter apart, myblind volunteer, Sanne, a student at Aar-hus University, said they showed oneface. When they were 0.8 centimeterapart, she reported that they showedtwo faces.

Another theory of outline drawingssuggests that lines substitute for any per-ceptible boundary, including those thatare not tangible, such as shadows. Butthis theory, too, fails in a very tellingfashion. Look at the illustration at theright, which shows two pictures of theauthor. In one image, shadow patterns,defined by a single contour separatinglight and dark areas, cross my face. Inthe second image, a dark line having twocontours traces the same shadow pat-terns. Despite the fact that the shapes inthe second picture are identical to thosein the first, the perceptual results arevividly different. The first is easily rec-ognized as a face; the second is not.

Again, this example shows that ourvisual system, like our tactile system,does not read two contours of a line inthe same way as it interprets a singlecontour. The implication is that thebrain region responsible for interpret-ing contours in sensory input from busyenvironments is a general surface-per-ception system. As such, it does not dis-criminate on the basis of purely visualmatters, such as brightness and color.Rather it takes the two contours of adark line and treats them as indicatorsfor the location of a single edge of somesurface. Whereas sighted individualstreat brightness borders as indicators ofsurface edges, the blind treat pressureborders in the same way.

Because the principles at work hereare not just visual, the brain region thatperforms them could be called multi-modal or, as it is more commonlytermed, amodal. In one account, whichI have discussed in my book on draw-ings by the blind, such an amodal sys-tem receives input from both vision andtouch. The system considers the inputas information about such features asocclusion, foreground and background,flat and curved surfaces, and vantagepoints. In the case of the sighted, visualand tactile signals are coordinated bythis amodal system.

As we have found, the ability to inter-pret surface edges functions even when

it does not receive any visual signals. Itis for this very reason that the blind soreadily appreciate line drawings and oth-er graphic symbols. Knowing this factshould encourage scholars and educa-tors to prepare materials for the blindthat make vital use of pictures. Severalgroups around the world are doing justthat. For instance, Art Education for theBlind, an organization associated withthe Whitney Museum of American Artand the Museum of Modern Art inNew York City, has prepared raised-lineversions of Henri Matisse paintings andof cave art. It may not be long beforeraised pictures for the blind are as wellknown as Braille texts.

How the Blind Draw Scientific American January 1997 81

The Author

JOHN M. KENNEDY was born in Belfast in 1942and was raised in one of the few Unitarian families inNorthern Ireland. He attended the Royal Belfast Aca-demical Institution and Queen’s University of Belfast,where his interests included fencing and theater. Hecompleted his Ph.D. in perception at Cornell Universi-ty and began his research with the blind shortly there-after as an assistant professor at Harvard University.He currently lectures at the University of Toronto,Scarborough College, where he won his college’s teach-ing prize in 1994. Notes from his courses on percep-tion are available through the university’s World WideWeb site at http://citd.scar.utoronto.ca/Psychology/PSYC54/PSYC54.html

Further Reading

Picture and Pattern Perception in the Sighted and the Blind: The Ad-vantage of the Late Blind. M. A. Heller in Perception, Vol. 18, No. 3, pages379–389; 1989.

Drawing and the Blind: Pictures to Touch. J. M. Kennedy. Yale UniversityPress, 1993.

Profiles and Orientation of Tactile Pictures. J. M. Kennedy and Y. Eriks-son. Paper presented at the meeting of the European Psychology Society, Tam-pere, July 2–5, 1993.

Symbolic Forms and Cognition. C. H. Liu and J. M. Kennedy in Psyke & Lo-gos, Vol. 14, No. 2, pages 441–456; 1993.

Tactile Pattern Recognition by Graphic Display: Importance of 3-D In-formation for Haptic Perception of Familiar Objects. Y. Shimizu, S. Sai-da and H. Shimura in Perception and Psychophysics, Vol. 53, No. 1, pages43–48; January 1993.

CO

UR

TESY

OF

JOH

N M

. KEN

NED

Y

SA

SHADOWS, and other intangible boundaries, are not recognizable in outline—ex-plaining in part why the blind can understand most line drawings made by sighted peo-ple. In the picture of the author on the left, a single contour separates light and dark ar-eas of his face. In the picture on the right, a line, having two contours, makes the samedivision. Note that although the shapes are identical in both images, the perceptual re-sults are quite different. Only the image on the left clearly resembles a face.


Documents

How the Blind Draw