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Facial Expressions of Emotion Stimuli and Tests (FEEST). Psychology manual v 1.0 Thames Valley Test Company January 2002. Contents: page 1 of 4

Facial Expressions ofEmotion Stimuli andTests (FEEST)Psychology manual v1.0Thames Valley Test Company


Facial Expressions of Emotion Stimuli and Tests (FEEST)

Psychology manual v1.0

Andrew Young, University of York, EnglandDavid Perrett, University of St. Andrews, ScotlandAndrew Calder, MRC CBU, Cambidge, EnglandReiner Sprengelmeyer, University of St. Andrews, ScotlandPaul Ekman, University of California, USA

Thames Valley Test Company 2002Bury St Edmunds, England.http://www.tvtc.com

ISBN: 1 874261 96 2

Designed and produced by Boag Associates,34 Bartholomew Place, London EC1A 7NJ.http://www.boag.co.uk


Contents

Overview ................................................................................................................2About the FEEST...................................................................................................2The FEEST facial expression recognition tests ....................................................4

The Ekman 60 Faces test...................................................................................5The Emotion Hexagon test ................................................................................6

The FEEST stimuli ................................................................................................7Emotion Megamixes ..........................................................................................7Caricatures and anti-caricatures .......................................................................8Morphed and caricatured Continua..................................................................9

Uses of the FEEST...............................................................................................10References ............................................................................................................11

Section 1: The Ekman 60 Faces test......................................................................2Stimuli ...................................................................................................................2Procedure .............................................................................................................4Performance norms...............................................................................................6

Overall scores.....................................................................................................6Scores for each emotion.....................................................................................8

Validity and reliability.........................................................................................10Previous use of the Ekman 60 Faces test ........................................................... 12References ........................................................................................................... 14

Appendix 1: Files used in the Ekman 60 Faces test .............................................. 15Filenames ............................................................................................................ 15

Test files ........................................................................................................... 15Duplicate files .................................................................................................. 17

Section 2: The Emotion Hexagon test...................................................................2Stimuli ...................................................................................................................2Procedure ..............................................................................................................7Performance norms...............................................................................................8

Graphical representation of results...................................................................8Overall scores...................................................................................................10Scores for each emotion................................................................................... 12

Validity and reliability......................................................................................... 14Previous use of the Emotion Hexagon test......................................................... 16References ........................................................................................................... 19

Appendix 2: Files used in the Emotion Hexagon test ........................................... 19Filenames ............................................................................................................ 19

Test files .......................................................................................................... 20Duplicate files .................................................................................................. 21

Section 3: Emotion Megamixes.............................................................................2The Emotion Megamix stimuli .............................................................................2Properties of the Emotion Megamix images ........................................................6References ........................................................................................................... 14

Appendix 3: Organisation of the Emotion Megamix images on the CD-ROM .... 15

Section 4: Caricatures and anti-caricatures..........................................................2The Caricature stimuli ..........................................................................................2Properties of the Caricature images .....................................................................5


References .............................................................................................................9Appendix 4: Organisation of the Caricature images on the CD-ROM....................9

Section 5: Morphed and caricatured Continua.....................................................2The Continua.........................................................................................................2Properties of the Continua....................................................................................4References .............................................................................................................6

Appendix 5: Organisation of the Continua on the CD-ROM ..................................6

Section 6: Origin of the photographs in FEEST ...................................................2References .............................................................................................................8

Section 7: Computer morphing and caricaturing procedures..............................2Caricaturing...........................................................................................................2Morphing...............................................................................................................4References .............................................................................................................7

Facial Expressions of Emotion Stimuli and Tests (FEEST). Psychology manual v 1.0 Thames Valley Test Company January 2002. Overview: page 1 of 11

Overview .............................................................................................................................2About the FEEST ............................................................................................................2The FEEST facial expression recognition tests..............................................................4

The Ekman 60 Faces test............................................................................................5The Emotion Hexagon test .........................................................................................6

The FEEST stimuli.......................................................................................................... 7Emotion Megamixes ................................................................................................... 7Caricatures and anti-caricatures ................................................................................8Morphed and caricatured Continua ...........................................................................9

Uses of the FEEST ........................................................................................................ 10References......................................................................................................................11


Overview

The ability to interpret the moods and feelings of other people is an important socialskill. Misinterpretation of affect can lead to misunderstanding and inappropriatesocial behaviour.

For humans, facial expressions provide important indicators of emotion. Basicemotions are expressed and recognised in similar ways throughout the world.Functional imaging studies have uncovered some of the mechanisms involved inneural responses to perceived emotion, and impaired recognition of facial expressionshas been documented after a number of types of brain disease.

The Facial Expressions of Emotion: Stimuli and Tests (FEEST) makes available arange of high-quality materials for testing recognition of facial expressions ofemotion, including standard tasks with data for comparison groups andsupplementary stimuli which can be used to create new tests and experiments. Thestimuli include the six basic emotions from the Ekman and Friesen (1976) series(anger, disgust, fear, happiness, sadness, and surprise) and neutral expressions.Computer-morphing and computer-caricaturing procedures are used to createcontinua varying from one expression to another, or differing in intensity. Cliniciansand researchers can therefore create tasks which can be graded in difficulty rangingfrom subtle to intensely expressed emotions.

About the FEEST

The FEEST comprises the FEEST facial expression recognition tests (the Ekman 60Faces test and the Emotion Hexagon test), and the FEEST stimuli (EmotionMegamixes, Caricatures, and Continua).

All of the images used in FEEST are derived from pictures of facial expressions in theEkman and Friesen (1976) series of Pictures of Facial Affect, which has been the mostwidely used and validated series of photographs in facial expression research. Fromthis series, 10 models (6 female, 4 male) were chosen, using the criterion that well-recognised expressions corresponding to each of six basic emotions (anger, disgust,fear, happiness, sadness, and surprise) were available, as well as a neutral pose. Inthis Manual, we refer to these pictures from the Ekman and Friesen series asprototype expressions, because they form the basis from which the computer-manipulated expression images were created.


Figure 0.1: Photographs of facial expressions from the Ekman and Friesen (1976)Pictures of Facial Affect used in FEEST. There are emotional expressions of anger(A), disgust (D), fear (F), happiness (H), sadness (S) and surprise (U), and a neutral(N) pose for 6 female and 4 male models. The labels used to identify each of themodels locate them in the Ekman and Friesen series (F2 = second female model inthe series, M1 = first male model, etc.).

The prototype expressions used in FEEST are shown in Figure 0.1. The identifiers ofthe facial expressions in the Ekman and Friesen (1976) series are given in Tables 0.1aand 0.1b.


F2 F4 F5 F6 F7 F8

Anger 10 C-2-12 53 MF-2-07 61 MO-2-11 69 NR-2-07 89 PF-2-04 96 SW-4-09

Disgust 12 C-1-04 55 MF-2-13 64 MO-2-18 71 NR-3-29 91 PF-1-24 98 SW-1-30

Fear 9 C-1-23 50 MF-1-26 59 MO-1-23 68 NR-1-19 88 PF-2-30 95 SW-2-30

Happiness 7 C-2-18 48 MF-1-06 57 MO-1-04 66 NR-1-06 85 PF-1-06 93 SW-3-09

Sadness 8 C-1-18 49 MF-1-30 58 MO-1-30 67 NR-2-15 86 PF-2-12 94 SW-2-16

Surprise 11 C-1-10 54 MF-1-09 63 MO-1-14 70 NR-1-14 90 PF-1-16 97 SW-1-16

Neutral 13 C-2-03 56 MF-1-02 65 MO-1-05 72 NR-1-03 92 PF-1-02 99 SW-3-03

Table 0.1a: Identifiers from the Ekman and Friesen (1976) series for the facialexpressions of the 6 female models shown in Figure 0.1.

M1 M4 M5 M6

Anger 18 EM-5-14 38 JJ-3-12 80 PE-2-21 105 WF-3-01

Disgust 20 EM-4-17 40 JJ-3-20 82 PE-4-05 108 WF-3-11

Fear 16 EM-5-21 37 JJ-5-13 79 PE-3-21 104 WF-3-16

Happiness 14 EM-4-07 34 JJ-4-07 74 PE-2-12 101 WF-2-12

Sadness 15 EM-4-24 36 JJ-5-05 75 PE-2-31 102 WF-3-28

Surprise 19 EM-2-11 39 JJ-4-13 81 PE-6-02 107 WF-2-16

Neutral 21 EM-2-04 41 JJ-3-04 83 PE-2-04 110 WF-2-05

Table 0.1b: Identifiers from the Ekman and Friesen (1976) series for the facialexpressions of the 4 male models shown in Figure 0.1.

The origins of the photographs in the Ekman and Friesen series are described inSection 6 of this Manual, which lists the Action Units (facial muscle movements) foreach picture. The computer image-manipulation techniques used to createcaricatured and morphed variants of each expression are described in Section 7.

The FEEST facial expression recognition tests

Two tests of facial expression recognition are included in FEEST, each using adifferent procedure. The tests can be run from software included on the FEEST CD-ROM.


Testing of facial expression recognition is notoriously tricky. Stimulus sets thatpredated the Ekman and Friesen (1976) series often led to very variable responses byhuman perceivers (see Woodworth and Schlosberg, 1954). Our vocabulary of emotionwords is rich and to some extent personal, so that some emotion words can meanslightly different things to different people, which makes it hard to interpret resultsfrom tasks in which perceivers are simply asked to describe a person's feelings on thebasis of their facial expressions.

The procedure adopted in many modern studies of facial expression recognition hastherefore been to restrict stimuli to basic emotions which are likely to have significantevolutionary histories, and to use a forced-choice procedure in which participantsassign expressions to a limited range of categories. Both tests developed for FEESTare of this type.

The Ekman 60 Faces test

The Ekman 60 Faces test is described in detail in Section 1 of the FEEST Manual. Ituses a range of photographs from the Ekman and Friesen series (the top 6 rows ofFigure 0.1) to test recognition of facial expressions of basic emotions (anger, disgust,fear, happiness, sadness, and surprise). The test yields a score out of a maximum of60 correct for recognition of all six emotions, or scores out of 10 for recognition ofeach basic emotion. The computer software on the CD-ROM presents the stimuli inrandom order for 5 seconds each, records responses made from mouse clicks to on-screen buttons or user-defined key presses, and summarises these as test scores.

Comparison data are available for 227 individuals aged 2070 years with IQs of 90and above. Full details of the scores of the comparison group are given in Section 1 ofthe FEEST Manual, but for convenience mean correct recognition rates and cut-offscores defining the border between normal-range and impaired performance (p = .05)for the entire group and for sub-groupings based on age are reproduced in Table 0.2.


Totalscore

Anger Disgust Fear Happiness Sadness Surprise

Entire group Mean 50.64 7.86 8.59 7.19 9.87 8.33 8.55

Cut-off 42 5 6 4 9 6 6

Age 2040 Mean 51.43 8.21 8.38 7.82 9.90 8.59 8.54

Cut-off 45 5 6 4 9 6 6

Age 4160 Mean 51.20 8.17 8.77 7.23 9.84 8.53 8.61

Cut-off 43 5 6 4 9 6 6

Age 6170 Mean 49.41 7.33 9.00 6.47 9.93 8.03 8.66

Cut-off 41 4 6 3 9 5 6

Table 0.2: Mean correct recognition rates and cut-off scores indicating theboundary between normal-range and impaired total scores (max = 60) and scoresfor recognition of each emotion (max = 10) in the Ekman 60 Faces test.

The Emotion Hexagon test

Whereas the Ekman 60 Faces test involves recognition of a number of facialexpressions of each emotion, the Emotion Hexagon uses computer imagemanipulation techniques to test facial expression recognition with stimuli of gradeddifficulty.

The Emotion Hexagon test is described in detail in Section 2 of the FEEST Manual. Ituses 30 computer-manipulated images of faces from the Ekman and Friesen series totest recognition of basic emotions (anger, disgust, fear, happiness, sadness, andsurprise). The test's results can be shown as performance graphs, or converted to ascore out of a maximum of 120 correct for recognition of all six emotions, or scoresout of 20 for recognition of each basic emotion. The computer software on the CD-ROM presents the stimuli in random order for 5 seconds each across one practice and5 test blocks of 30 trials each, records responses made from mouse clicks to on-screenbuttons or user-defined key presses, and summarises these as test scores.

Comparison data are available for 125 individuals aged 2075 years with IQs of 90and above. Full details of the comparison group scores are given in Section 2 of theManual. Mean correct recognition rates and cut-off scores defining the borderbetween normal-range and impaired performance (p = .05) for the entire group andfor sub-groupings based on age are reproduced in Table 0.3.


Totalscore


Entire group Mean 107.97 17.84 18.01 16.56 19.64 18.38 17.69

Cut-off 92 13 12 10 18 13 14

Age 2040 Mean 109.16 18.38 16.88 17.74 19.74 18.66 18.10

Cut-off 94 14 11 12 18 13 15

Age 4160 Mean 108.10 17.63 18.71 16.15 19.63 18.31 17.65

Cut-off 92 13 13 10 18 13 14

Age 6175 Mean 105.09 17.13 18.83 14.91 19.43 17.91 16.87

Cut-off 90 13 13 9 18 12 13

Table 0.3: Mean correct recognition rates and cut-off scores indicating theboundary between normal-range and impaired total scores (max = 120) and scoresfor recognition of each emotion (max = 20) in the Emotion Hexagon test.

The FEEST stimuli

The FEEST stimuli comprise more than 1,000 images of faces derived fromphotographs in the Ekman and Friesen (1976) series. The stimuli include prototype(unmodified) facial expressions and computer-manipulated versions. In thecomputer-manipulated images, morphing and caricaturing techniques (described inSection 7 of the FEEST Manual) are used to systematically change the images in waysthat allow the creation of novel tests and experiments suited to a wide range ofpurposes. Morphing is used to create images that fall along regularly gradedtransitions from one prototype expression to another, whereas caricaturing is used toincrease or decrease the intensity of a particular expression.

The FEEST stimuli are arranged in directories on the CD-ROM. The filenames of theindividual images have been created in a way that will sort the images and allow animage to be returned to its correct directory if it is accidentally moved.

The image files are encrypted on the CD-ROM, but can be copied to a hard disk usingthe software supplied. Instructions for locating files are given as appendices to therelevant sections of the FEEST Manual.

Emotion Megamixes

The Emotion Megamixes use computer morphing to blend the shapes and surfacetone (regional brightness values) of prototype expressions from the Ekman andFriesen (1976) series, creating continua showing transitions between one expressionand another. The Emotion Megamix stimuli include continua between all possiblepairs of expressions (anger, disgust, fear, happiness, sadness, surprise, and neutral)for two separate models (F5 and M4 in Figure 0.1; these are models MO and JJ in the


Ekman and Friesen series). Examples of these morphed continua are given in Figure0.2, which shows the continua for pairwise transitions between three basic emotions(happiness, fear, and disgust). There are 21 such continua for each model in theEmotion Megamix series, with 9 images in each continuum.

Figure 0.2: Examples of continua of morphed facial expressions for three basicemotions (happiness, fear, and disgust) with model F5/MO. The top row shows thehappiness fear continuum, the centre row fear disgust, and the bottom rowdisgust happiness. The prototype expressions from the Ekman and Friesen (1976)series are not shown in this Figure (they can be seen in Figure 0.1); all of the stimuliare morphed to a greater or lesser degree.

The Emotion Megamix stimuli are described in detail in Section 3 of the FEESTManual, where the full set of 21 continua is illustrated for M4/JJ's face (Figures 3.1a,3.1b, and 3.2). The use of computer morphing creates a smooth transition from oneprototype expression to another, but the perception of such continua is not linear,and tends to show clearly demarcated category boundaries (Young, Rowland, Calder,Etcoff, Seth and Perrett, 1997).

Caricatures and anti-caricatures

Computer caricaturing procedures can be used to change the underlying shape of afacial expression away from a reference norm, exaggerating any differences in shapeto create a caricatured expression that is seen as more intense and is easier torecognise. It is also possible to create an anti-caricatured representation that is closerto the norm. Anti-caricatures are less intense and less easy to recognise.

In the FEEST Caricature stimuli (described in Section 4 of this Manual), theemotional expressions of models F5/MO and M4/JJ are caricatured and anti-caricatured relative to a Neutral expression norm or to an Average expression norm.Examples of Caricature series for expressions of happiness, fear, and disgust usingmodel F5/MO's face relative to a Neutral norm are shown in Figure 0.3. Each series(represented as a row in Figure 0.3) uses 4 levels of anti-caricature and 4 levels ofcaricature which, together with the prototype expression, creates a continuum of 9images of increasing intensity of expressed emotion.


Figure 0.3: Use of anti-caricature (left of the centre column) and caricature (right ofcentre column) methods to modify the apparent intensity of happiness (top row),fear (centre row), and disgust (bottom row) in prototype (unmodified) facialexpressions (centre column) of model F5/MO. The caricatures shown here wereprepared relative to a Neutral expression norm.

The FEEST Caricature stimuli include six continua for each model (one series of 9images for each of anger, disgust, fear, happiness, sadness, and surprise) preparedrelative to a Neutral expression norm, and a further six continua for each modelprepared relative to an Average expression norm. The full set of images for M4/JJ'sface using an Average expression norm is shown in Figure 4.2, and using a Neutralexpression norm in Figure 4.3.

Whereas the morphed stimuli from the Emotion Megamixes change from oneemotional expression to another (see Figure 0.2), in each Caricature series there is achange in the expressed intensity of a particular emotion rather than a shift in theemotion itself.

Morphed and caricatured Continua

The morphed and caricatured Continua are described in detail in Section 5 of theFEEST Manual. They use a combination of morphing and caricaturing methods tocreate Continua from a neutral pose to an intensely expressed emotion. Examples forF5/MO's face and the emotions of happiness, fear, and disgust are shown in Figure0.4.


Figure 0.4: Morphed and caricatured Continua for neutral happiness (top row),neutral fear (centre row), and neutral disgust (bottom row), with model F5/MO.In each continuum, the neutral expression is shown at the left of the row (firstcolumn), and the prototype expression in the fifth column. The images in the secondto fourth columns are morphed, and the images in the sixth and seventh columns arecaricatured. The combination of image manipulation techniques creates Continuaranging from a neutral pose to an intensely expressed emotion.

Morphed and caricatured Continua of 7 images are available for all of the 10 modelsshown in Figure 0.1, and all six basic emotions (anger, disgust, fear, happiness,sadness, and surprise), yielding 60 Continua in total. A full set of Continua for faceF2/C is shown in Figure 5.1.

The Continua are useful in circumstances requiring more than one or two models or aset of expressions that cover a range of intensities from neutral through to highlyemotional, provided that it is not essential that a consistent method (morphing orcaricature) was used to create the changes in expression. The hairlines are masked tomake it necessary to base any decision about the model's sex on facial features. Thisallows an incidental task of classifying the faces as female or male to be used ifneeded; for example, this is a common requirement in functional imaging studies(Morris, Frith, Perrett, Rowland, Young, Calder and Dolan, 1996).

Uses of the FEEST

The FEEST has a wide range of potential applications.

Testing of facial expression recognition is important in many neuropsychological andclinical contexts. The Ekman 60 Faces test and the Emotion Hexagon test can each beused on its own, or alongside the other test. The Ekman 60 Faces test uses a range ofexpressions and is shorter to administer than the Emotion Hexagon test, but theEmotion Hexagon usually has better reliability. Taken together, the two tests canpoint strongly to the existence of deficits affecting facial expression recognition, andallow examination of whether such deficits affect recognition of all emotions or


have a differentially severe impact on the recognition of certain emotions (seeSections 1 and 2 of the FEEST manual).

The FEEST stimuli can be used to create supplementary tests for specific purposes.For example, it is possible to explore emotion recognition deficits in detail by seeingwhether a person who does not recognise certain emotional expressions can matchdifferent pictures as representations of the same underlying emotion, perceivechanges in the intensity of an unrecognised expression, and so on.

A particular application where the stimuli have already been regularly used (seeSection 5 of this Manual) involves functional imaging studies to investigate the neuralresponses of the brain to different emotions. The ability to vary the level of intensityof an expression whilst keeping other factors tightly controlled is very useful in thistype of research.

The FEEST stimuli are also well-suited for creating psychological experiments toexamine the basis of facial expression perception. They can be used to investigatedimensional and category-based accounts, priming effects from expressions ofdifferent intensities, interference from distractor expressions on incidental tasks, andmany other questions.

The information about the Action Units (AUs) underlying each prototype expression(Section 6) offers added scope for authoritative studies investigating how AUs areinvolved in facial expression perception, in neuropsychological deficits, and indifferent types of neural response all possibilities that have yet to be systematicallyexplored.

ReferencesEkman, P. and Friesen, W.V. (1976). Pictures of facial affect. Palo Alto, California:

Consulting Psychologists Press.Morris, J.S., Frith, C.D., Perrett, D.I., Rowland, D., Young, A.W., Calder, A.J. and

Dolan, R.J. (1996). A differential neural response in the human amygdala tofearful and happy facial expressions. Nature, 383, 812815.

Woodworth, R.S. and Schlosberg, H. (1954). Experimental psychology: revisededition. New York: Henry Holt.

Young, A.W., Rowland, D., Calder, A.J., Etcoff, N.L., Seth, A. and Perrett, D.I. (1997).Facial expression megamix: tests of dimensional and category accounts of emotionrecognition. Cognition, 63, 271313

Facial Expressions of Emotion Stimuli and Tests (FEEST). Psychology manual v 1.0 Thames Valley Test Company January 2002. Section 1: page 1 of 20

Section 1: The Ekman 60 Faces test...................................................................................2Stimuli.............................................................................................................................2Procedure........................................................................................................................4Performance norms ........................................................................................................6

Overall scores ..............................................................................................................6Scores for each emotion..............................................................................................8

Validity and reliability .................................................................................................. 10Previous use of the Ekman 60 Faces test..................................................................... 12References..................................................................................................................... 14

Appendix 1: Files used in the Ekman 60 Faces test ........................................................ 15Filenames...................................................................................................................... 15

Test files .................................................................................................................... 15Duplicate files............................................................................................................ 17


Section 1: The Ekman 60 Faces test

The Ekman 60 Faces test uses a range of faces from the Ekman and Friesen (1976)series to test recognition of facial expressions of emotion. The Ekman and Friesen(1976) faces have been the most widely used and extensively validated set of facialexpressions in research studies, but have not previously been used in published testsof facial expression recognition.

The test involves recognition of facial expressions of six basic emotions anger,disgust, fear, happiness, sadness, and surprise. There are ten examples of facialexpressions of each emotion, leading to a score out of a maximum of 60 for overallperformance, or scores out of 10 for recognition of the six emotions.

The FEEST CD includes a computer program for presenting the test, recording andscoring responses, and saving these as an Excel-compatible spreadsheet file.Comparison data are available for a group of 227 participants.

Stimuli

Photographs of the faces of 10 people (6 female, 4 male) have been selected from theEkman and Friesen (1976) series. For each face, there are poses corresponding toeach of 6 emotions (anger, disgust, fear, happiness, sadness, and surprise), giving atotal of 60 photographs. The 10 models were chosen so that each emotion was as wellrecognised as possible in Ekman and Friesen's (1976) norms. Mean percentagerecognition rates across all 10 faces for Ekman and Friesen's (1976) participants, andstandard deviations, are shown in Table 1.1, which also lists the picture numbers andthe faces' identifiers in the Ekman and Friesen (1976) series. Details of the musclemovements (Action Units) involved in each expression can be found in Section 6 ofthis Manual.


Mean SD Picture numbers and identifiers used by Ekman andFriesen (1976)

Anger 89.50 11.39Female 10 C-2-12; 53 MF-2-07; 61 MO-2-11; 69 NR-2-07; 89 PF-

2-04; 96 SW-4-09Male 18 EM-5-14; 38 JJ-3-12; 80 PE-2-21; 105 WF-3-01

Disgust 93.10 5.20Female 12 C-1-04; 55 MF-2-13; 64 MO-2-18; 71 NR-3-29; 91 PF-1-

24; 98 SW-1-30Male 20 EM-4-17; 40 JJ-3-20; 82 PE-4-05; 108 WF-3-11

Fear 89.50 5.91Female 9 C-1-23; 50 MF-1-26; 59 MO-1-23; 68 NR-1-19; 88 PF-2-

30; 95 SW-2-30Male 16 EM-5-21; 37 JJ-5-13; 79 PE-3-21; 104 WF-3-16

Happiness 99.10 2.51Female 7 C-2-18; 48 MF-1-06; 57 MO-1-04; 66 NR-1-06; 85 PF-1-

06; 93 SW-3-09Male 14 EM-4-07; 34 JJ-4-07; 74 PE-2-12; 101 WF-2-12

Sadness 89.70 7.87Female 8 C-1-18; 49 MF-1-30; 58 MO-1-30; 67 NR-2-15; 86 PF-2-

12; 94 SW-2-16Male 15 EM-4-24; 36 JJ-5-05; 75 PE-2-31; 102 WF-3-28

Surprise 90.70 7.78Female 11 C-1-10; 54 MF-1-09; 63 MO-1-14; 70 NR-1-14; 90 PF-1-

16; 97 SW-1-16Male 19 EM-2-11; 39 JJ-4-13; 81 PE-6-02; 107 WF-2-16

Table 1.1: Faces used in the Ekman 60 Faces test. There are 6 female and 4 femalemodels expressing each emotion. The final column in the table lists each face'snumber and identifier in the Ekman and Friesen (1976) series. Means and standarddeviations calculated from Ekman and Friesen's (1976) data for percentagerecognition as each emotion across the 10 models are shown in the second and thirdcolumns.

An additional set of 6 expressions posed by a single model is used for practice, tointroduce the test.

The complete set of faces used in the Ekman 60 Faces Test is shown in Figure 1.1.Further details concerning the origin of these pictures and the different facial musclemovements (Action Units) seen in each picture can be found in Section 6 of thisManual.


Figure 1.1: Photographs of facial expressions used in the Ekman 60 Faces Test. Theleftmost column shows practice (P) stimuli. Columns in the main matrix show the 6female (F) and 4 male (M) models used in the test, numbered to reflect their positionin the Ekman and Friesen (1976) Pictures of Facial Affect series (F2 = second femalemodel in the series, etc.). Rows show facial expressions of anger (A), disgust (D),fear (F), happiness (H), sadness (S), and surprise (U).

Procedure

A computer program for running the Ekman 60 Faces Test is included on the FEESTCD-ROM, and separate instructions are provided for this software. The faces arepresented one at a time for 5 seconds each, followed by a blank screen. Theparticipant is asked to decide which of the emotion names (anger, disgust, fear,happiness, sadness, and surprise) best describes the facial expression shown. Thenames of these six emotions are visible on the computer screen throughout the test,with the order in which the emotion names are shown on the screen randomised eachtime the test is given. Before commencing the test, you should satisfy yourself thatyour participant understands the meanings of these emotion words sufficientlyaccurately for the results to be meaningful (for example, by asking for examples of


circumstances in which people would experience anger, disgust, fear, etc.). Responsescan be recorded from mouse-clicks to the on-screen buttons, or via the computerkeyboard. The test is not timed participants can take as long as they wish to decideon the emotion.

The 6 practice trials are followed by 60 test trials. The software randomises the orderof presentation of trials within each block, and allows responses to be saved to anExcel-compatible spreadsheet file that records the trial number, the stimulusfilename, and the response made.

The 60 test trials (one for each of the 6 emotions across the 10 models) can be used toderive an overall total score out of a possible maximum of 60 expressions correctlyrecognised, or accuracy scores out of a possible maximum of 10 for each of the sixemotions. The CD-ROM software will do this automatically.

When performance is impaired, it may also be desirable to examine the nature of theerrors made. The filenames for the stimuli used in the Ekman 60 Faces test containthe information needed to interpret responses to particular expressions. Eachfilename is constructed in the following way:

ET_emoxx_nnn_id_ekid_per.jpg

where ET designates that this is an image from the Ekman 60 Faces test, emoindicates the emotion (Ang = anger, Dis = disgust, Fea = fear, Hap = happiness,Sur = surprise), xx is used to order the pictures of each emotion from 01 to 10, nnnis the picture number in the Ekman and Friesen (1976) series, id gives theidentifier for each model used at the top of Figure 1.1, ekid is the identifier in theEkman and Friesen series, and per is the percentage recognition as the intendedemotion in Ekman and Friesen's data.

For example, the filename ET_Dis08_040_M4_JJ-3-20_088.jpg shows the 8thpicture of disgust in the appropriate row of Figure 1.1. The model is identified as M4in Figure 1.1. The picture is number 40 in the Ekman and Friesen series, where it hasthe identifier JJ-3-20. It was recognised as disgust by 88% of Ekman and Friesen'sparticipants.

The filename and participant's response for each stimulus is recorded by the programsoftware. This information can be combined with the information from Table 6.2 inSection 6 of the FEEST Manual, allowing the user to explore: whether errors are mainly to expressions that are not so easily recognised by

controls (this can also be done by using the percentage recognition rate at the endof each filename)

whether errors are of the same type as those made by normal perceivers whether errors consistently involve certain Action Units.

A complete list of filenames for the stimuli used in the Ekman 60 Faces test is givenas an Appendix to the present Section of the FEEST Manual. These files cannot beremoved from the CD-ROM, but the Appendix gives the location of a duplicate set offiles suitable for use by those who prefer to program their own version of the test. Thiscan be useful if it is necessary to adjust the procedure for example, to get moredetailed information by recording reaction times as well as accuracy.


Performance norms

We tested an opportunity sample of 241 individuals aged 2070. Where intelligencetest scores were not known from existing records, the NART-R (Nelson, 1991) wasused to estimate intelligence.

Data for 14 people with IQs less than 90 were omitted because the sample did notcontain sufficient numbers to estimate performance reliably for this sub-grouping.This left 227 people with IQs of 90 and above in the main sample.

As already noted the Ekman 60 Faces test yields an overall score out of a possiblemaximum of 60 expressions correctly recognised, or accuracy scores out of a possiblemaximum of 10 for each of the six emotions. We will consider these in turn.

Overall scores

An overall (total) score out of a maximum possible of 60 can be derived by summingcorrect responses across the 60 test trials.

To determine the effects of age, intelligence and sex on total score, participants weredivided into sub-groups based on five age bands (2030 years, 3140 years, 4150years, 5160 years, and 6170 years), four levels of intelligence (IQ 90100, IQ101110, IQ 111120, and IQ over 120), and female or male sex. Means and standarddeviations of total scores across age, IQ, and sex are shown in Table 1.2, together withthe numbers of participants in each sub-grouping.


Mean SD N

Entire group 50.64 5.04 227

Age 2030 51.52 3.83 73

Age 3140 51.22 4.48 32

Age 4150 51.48 4.80 29

Age 5160 50.89 5.03 35

Age 6170 49.41 4.88 58

IQ 90100 49.38 5.83 27

IQ 101110 50.81 4.45 68

IQ 111120 49.65 5.61 85

IQ > 120 51.80 4.22 47

Female 49.98 5.33 124

Male 50.81 4.85 103

Table 1.2: Means and standard deviations (SD) of total scores (Max = 60) on theEkman 60 Faces Test for the entire comparison group of 227 individuals, and forsub-groupings based on age, intelligence and sex. Numbers (N) of participants ineach group are also shown.

A three-factor analysis of variance of the effects of Age (5 levels), Intelligence (4levels) and Sex (female or male) revealed a borderline effect of Age (F = 2.39, df 4,190, p = .052). There were no other significant main effects or interactions (all otherprobabilities > .1).

Because of the borderline effect of age, it was considered prudent to subdivide thecontrol participants by age for the purpose of establishing cut-off scores. Table 1.2shows that age did not have any dramatic effect on overall means, so to achievereasonable numbers in each group, the data were subdivided into age bands of 2040years, 4160 years, and 6170 years, as shown in Table 1.3.


Mean SD N cut-off score

Entire group 50.64 5.04 227 42

Age 2040 51.43 4.02 105 45

Age 4160 51.20 4.90 64 43

Age 6170 49.41 4.88 58 41

Table 1.3: Means and standard deviations (SD) of total scores (Max = 60) on theEkman 60 Faces Test for the entire comparison group of 227 individuals, and forsub-groupings based on age. Numbers (N) of participants in each sub-group areshown. A level of performance falling 1.65 SDs below the mean has been used toderive a cut-off score indicating the boundary between normal-range and impairedperformance for each group.

Cut-off scores to define the border between normal-range and impaired performancefor each sub-group were established using the nearest integer score to a z value of 1.65(p = .05). These cut-off scores are shown in Table 1.3. They are also reproduced inTable 0.2, which may be an easier place to find them if they need to be consultedfrequently.

Scores for each emotion

The Ekman 60 Faces test also yields scores out of a maximum possible 10 correctresponses for recognition of each of the 6 emotions (anger, disgust, fear, happiness,sadness, surprise).

Because of the borderline effect of age on overall scores, a two-factor analysis ofvariance was used to investigate the effects of Age (5 levels: 2030 years, 3140years, 4150 years, 5160 years, and 6170 years) and Emotion (6 levels: anger,disgust, fear, happiness, sadness, surprise). Mauchly's test of sphericity showed asignificant violation of the assumption of sphericity (W = .532, Chi-square = 138.99,df 14, p < .001), due in large part to the near-ceiling performance for recognition ofhappiness, so degrees of freedom for tests involving the Emotion factor were adjustedusing the Greenhouse-Geisser correction.

The analysis of variance showed a significant main effect of Emotion (F = 69.67, df 4,933, p < .001), with some emotions being easier to recognise than others (as would beexpected from Ekman and Friesen's original data). The main effect of Age was againborderline (F = 2.07, df 4, 222, p = .085).

Both of these main effects were qualified by a significant Age x Emotion interaction (F= 2.75, df 17, 933, p < .001). This interaction is shown in Figure 1.2, which makesclear that recognition of some emotions (especially fear) declines across age. The datain Figure 1.2 are given as percentages, to facilitate comparison with Figure 2.4(Section 2), which charts the equivalent interaction for the Emotion Hexagon test.


Figure 1.2: Ekman 60 Faces test: Mean percent correct recognition of facialexpressions of anger, disgust, fear, happiness, sadness and surprise at differentages.

Because of the Age x Emotion interaction, data for recognition of each emotion in theEkman 60 Faces test were subdivided into age bands of 2040 years, 4160 years, and6170 years, as had been done with the overall total scores. Table 1.4 gives means andstandard deviations of scores for recognition of each emotion for the entire comparisongroup of 227 individuals, and mean scores for the sub-groupings based on age.


Entire group Mean 7.86 8.59 7.19 9.87 8.33 8.55

SD 1.90 1.62 2.03 0.42 1.66 1.44

Age 2040 Mean 8.21 8.38 7.82 9.90 8.59 8.54

Age 4160 Mean 8.17 8.77 7.23 9.84 8.53 8.61

Age 6170 Mean 7.33 9.00 6.47 9.93 8.03 8.66

Table 1.4: Means and standard deviations (SD) of scores for recognition of eachemotion (Max = 10) in the Ekman 60 Faces test for the entire comparison group of227 individuals, and means for sub-groupings based on age.

Cut-off scores to define the border between normal-range and impaired performancefor each sub-group were established at the nearest integer score to a z value of 1.65 (p= .05), using the standard deviation of the entire group to estimate the degree ofvariability of recognition of each emotion. These cut-off scores are shown in Table 1.5,and reproduced in Table 0.2.

Ekman 60 Faces test

020406080

100

Age 20-30 Age 31-40 Age 41-50 Age 51-60 Age 61-70

Perc

ent

corr

ect

reco

gniti

on

AngerDisgustFearHappinessSadnessSurprise



Entire group 5 6 4 9 6 6

Age 2040 5 6 4 9 6 6

Age 4160 5 6 4 9 6 6

Age 6170 4 6 3 9 5 6

Table 1.5: Cut-off scores indicating the boundary between normal-range andimpaired recognition of each emotion in the Ekman 60 Faces test.

Validity and reliability

Reliability of items in the Ekman 60 Faces test was assessed with split-halfreliabilities, using data from 50 participants. The 10 models whose facial expressionsare used as test items were arbitrarily assigned to one of two groups, each comprising3 female and 2 male models. The scores of the 50 participants were then subdividedinto scores out of 5 for recognition of each of the 6 emotions from the photographsposed by models in each group, and overall total scores out of 30 across the 6emotions.

Correlations between participants' recognition of expressions posed by models fromeach group are shown in Table 1.6. These split-half reliabilities are statisticallysignificant for total scores and for recognition of anger, disgust, fear, sadness, andsurprise. Recognition of happiness does not correlate significantly across the two setsof faces because scores are at ceiling.

Total score Anger Disgust Fear Happiness Sadness Surprise

r 0.62 0.62 0.66 0.53 0.21 0.60 0.61

t 5.47 5.46 6.12 4.38 1.50 5.22 5.31

df 48 48 48 48 48 48 48

p < .001 < .001 < .001 < .001 > .1 < .001 < .001

Table 1.6: Split-half reliabilities for scores on the Ekman 60 Faces test (r =correlation, t = equivalent t-value, df = degrees of freedom, p = probability).

The validity of the items used in the Ekman 60 Faces test does not need to beestablished here, since the Ekman and Friesen (1976) series has been the mostextensively used set of stimuli in research on recognition of facial expressions. Wedid, however, examine the relation between our performance norms and Ekman andFriesen's (1976) data.


To compare recognition rates for different emotions from the performance normscollected for the FEEST to Ekman and Friesen's (1976) data, we converted scores inthe Ekman 60 Faces test to percentage recognition rates. Figure 1.3 shows the meanpercentage correct recognition for the six different emotions by Ekman and Friesen's(1976) American college student participants and for FEEST control participants aged2030 years.

Figure 1.3: Mean percentage recognition rates for different emotions by Ekman andFriesen's (1976) participants and FEEST control participants aged 2030 years.

The FEEST data show good recognition of all emotions (over 80% correct in 6-wayforced-choice for all emotions except fear, whose recognition rate is 78% correct). Thepatterns of relative difficulty of the different emotions are comparable across FEESTand Ekman and Friesen's (1976) results, with happiness being the most easilyrecognised. The overall level of performance is slightly higher in the Ekman andFriesen (1976) data, but this observation should be qualified by noting that Ekmanand Friesen used a different procedure to establish recognition rates for eachphotograph (see Section 6 of this Manual). In addition, the expressions used in theEkman 60 Faces test were initially selected to have high recognition rates. Choosingstimuli in this way means that retesting will always be likely to lead to some degree ofdownward performance regression due to any error variance in the original data. Themost important observation is that recognition rates are good in both sets of data.

Looking at recognition rates for each of the 60 photographs used as test items in theEkman 60 Faces test, there was a strong correlation between recognition rates fromthe FEEST performance norms and the recognition rates reported by Ekman andFriesen (r = 0.81, t = 10.35, df 58, p < .001).

Further evidence of the validity of the Ekman 60 Faces test as a test of facialexpression recognition comes from its proven usefulness in previous research (seebelow).

0

20

40

60

80

100

Happiness Surprise Fear Sadness Disgust Anger

Ekman and Friesen (1976)FEEST age


Previous use of the Ekman 60 Faces test

A number of previously published studies have made use of variants of the Ekman 60Faces test. In some studies the faces were presented for 3 seconds each(Sprengelmeyer, Young, Calder, Karnat, Lange, Hmberg, Perrett and Rowland,1996) or for unlimited time (Calder, Young, Rowland, Perrett, Hodges and Etcoff,1996), rather than the 5 seconds used in the computer software version of the task onthe FEEST CD-ROM. Timing of control participants' responses has shown that morethan 99.5% of responses are made within 3 seconds, so the 5 seconds duration of eachstimulus is equivalent to unlimited presentation for neurologically normalindividuals.

The Ekman 60 Faces test has been used in group studies (Sprengelmeyer, Young,Pundt, Sprengelmeyer, Calder, Berrios, et al., 1997; Evangeli and Broks, 2000) and instudies of individual cases. We will provide some examples of case studies.

Table 1.7 illustrates two of the different ways of using overall scores on the Ekman 60faces test, taken from studies of Mbius syndrome (Calder, Keane, Cole, Campbelland Young, 2000a) and frontal variant frontotemporal dementia (Keane, Calder,Hodges and Young, 2002).

Aetiology Case Age Overall score

Mbius syndrome (Calder et al., 2000a)

BC 23 47LP 36 47NC 27 46

Frontal variant frontotemporal dementia (Keane et al., in press)

Case K2 59 17Case K3 55 30Case K4 54 30

Table 1.7: Overall total scores on the Ekman 60 Faces test for three participantswith Mbius syndrome and three with frontal variant frontotemporal dementia.Scores marked in bold type are at or below the cut-off for the appropriate agegroup.

Mbius syndrome is a rare congenital disorder that produces paralysis of the facialmuscles sufferers have an immobile, mask-like face. The research questionaddressed in Calder et al.'s (2000a) study concerned whether individuals who areunable to produce facial expressions themselves would none the less be able torecognise the facial expressions made by other people. Although none of the threeparticipants with Mbius syndrome was particularly good at recognising facialexpressions, they all scored above the appropriate cut-off on the Ekman 60 Faces test,demonstrating that inability to produce facial expressions does not result in completeinability to recognise them.

Frontal variant frontotemporal dementia (fvFTD) is a progressive disorder in whichthe typical focus of pathology appears to be the ventromedial frontal lobe. Patients are


typically brought to medical attention by their close relatives because of changes inpersonality and social behaviour, of which the patients themselves appear to beunaware. In some cases of fvFTD, testing with standard 'frontal' tests does not revealevidence of intellectual deterioration during the early stages of the disease. Table 1.7shows the performance of three participants with fvFTD from Keane et al.'s (2002)case series who showed severely impaired ability to recognise communicative signalsof emotion. In such circumstances, testing of facial expression recognition canprovide information pertinent to understanding deficits in everyday behaviour.

Table 1.8 shows how scores for recognising each of the six basic emotions in theEkman 60 Faces test can be used to separate emotion-specific forms of impairment inwhich the recognition of certain emotions is differentially severely affected.

Aetiology Case Age Anger Disgust Fear Happiness Sadness Surprise

Post-encephalitic without amygdala damage (Broks et al., 1998)

RS 48 6 8 9 10 9 9

Post-encephalitic with amygdala damage (Broks et al., 1998)

SE 64 10 10 3 10 8 9YW 53 7 7 4 10 7 10RB 61 6 9 5 10 8 9

Selective amygdala damage (Calder et al., 1996; Sprengelmeyer et al., 1999)

DR early 50s 7 8 5 10 9 9NM 50 7 10 2 10 5 9

Insula and basal ganglia lesion (Calder et al. 2000b)

NK 25 9 5 7 10 8 8

OCD cases (Sprengelmeyer et al., 1997)

Case S5 34 10 4 8 10 9 8Case S7 40 8 0 10 10 10 8

Table 1.8: Scores for recognition of emotion in the Ekman 60 Faces test forparticipants with brain dysfunction linked to different aetiologies. Scores marked inbold type are at or below the cut-off for the appropriate age group.

Five of the research participants tabulated in Table 1.8 suffered amygdala damage(SE, YW, RB, DR, and NM). In three cases (SE, YW, RB) this was associated withmedial temporal lobe pathology resulting from viral encephalitis (Broks, Young,Maratos, Coffey, Calder, et al., 1998), but in two other cases (DR and NM) the lesionswere relatively circumscribed (Calder et al., 1996; Sprengelmeyer, Young, Schroeder,Grossenbacher, Federlein, Bttner and Przuntek, 1999). For three of the five peoplewith amygdala damage, scores for the recognition of fear are at or below the


appropriate cut-off in the FEEST norms, and for the other two cases (DR and RB) thescores for fear recognition are low even though they do not enter the region that canbe regarded as significantly impaired on the basis of this test alone.

These examples of poor recognition of fear after amygdala damage can be contrastedwith case RS (Broks et al., 1998), whose viral encephalitis spared the region of theamygdala. RS showed good recognition of fear and the other basic emotions,strengthening the putative link between amygdala function and fear recognition.

Table 1.8 contrasts the cases with amygdala damage and poor recognition of fear withthree research participants who showed impaired recognition of disgust (NK, Case S5,Case S7).

NK (Calder, Keane, Manes, Antoun and Young, 2000b) was selected for testingbecause his lesions involved the insula and part of the basal ganglia regionsidentified in fMRI studies of neurologically normal participants as important forprocessing facial expressions of disgust (Phillips, Young, Scott, Calder, Andrew,Giampetro, et al., 1998; Phillips, Young, Senior, Brammer, Andrew, Calder, Bullmoreand Perrett, 1997). The Ekman 60 Faces Test data show selectively impairedrecognition of disgust.

The two cases of obsessive-compulsive disorder (OCD Case S5 and Case S7) aretaken from a group study in which people with OCD were recruited as participantsbecause neurophysiological and neuropsychological studies of OCD have highlightedabnormalities in fronto-striatal regions (Sprengelmeyer et al., 1997). These two casesalso show clear selective deficits of disgust recognition.

These examples show some of the ways in which the Ekman 60 Faces test has alreadybeen used, but there are many other circumstances in which testing of facialexpression recognition may provide useful information.

ReferencesBroks, P., Young, A.W., Maratos, E.J., Coffey, P.J., Calder, A.J., Isaac, C.L., Mayes,

A.R., Hodges, J.R., Montaldi, D., Cezayirli, E., Roberts, N. and Hadley, D. (1998).Face processing impairments after encephalitis: amygdala damage andrecognition of fear. Neuropsychologia, 36, 5970.

Calder, A.J., Keane, J., Cole, J., Campbell, R. and Young, A.W. (2000a). Facialexpression recognition by people with Mbius syndrome. CognitiveNeuropsychology, 17, 7387.

Calder, A.J., Keane, J., Manes, F., Antoun, N. and Young, A.W. (2000b). Impairedrecognition and experience of disgust following brain injury. NatureNeuroscience, 3, 10771078.

Calder, A.J., Young, A.W., Rowland, D., Perrett, D.I., Hodges, J.R. and Etcoff, N.L.(1996). Facial emotion recognition after bilateral amygdala damage: differentiallysevere impairment of fear. Cognitive Neuropsychology, 13, 699745.

Ekman, P. and Friesen, W.V. (1976). Pictures of facial affect. Palo Alto, California:Consulting Psychologists Press.

Evangeli, M. and Broks, P. (2000). Face processing in schizophrenia: parallels withthe effects of amygdala damage. Cognitive Neuropsychiatry, 5, 81104.

Keane, J., Calder, A.J., Hodges, J.R. and Young, A.W. (2002). Face and emotionprocessing in frontal variant frontotemporal dementia. Neuropsychologia, 40,655665.


Nelson, H.E. (1991). National Adult Reading Test (NART): test manual (revised).Windsor: NFER-Nelson.

Phillips, M.L., Young, A.W., Scott, S.K., Calder, A.J., Andrew, C., Giampetro, V.,Williams, S.C.R., Bullmore, E.T., Brammer, M. and Gray, J.A. (1998). Neuralresponses to facial and vocal expressions of fear and disgust. Proceedings of theRoyal Society: Biological Sciences, 265, 18091817.

Phillips, M.L., Young, A.W., Senior, C., Brammer, M., Andrew, C., Calder, A.J.,Bullmore, E.T., Perrett, D.I., Rowland, D., Williams, S.C.R., Gray, J.A. and David,A.S. (1997). A specific neural substrate for perceiving facial expressions of disgust.Nature, 389, 495498.

Sprengelmeyer, R., Young, A.W., Calder, A.J., Karnat, A., Lange, H.W., Hmberg, V.,Perrett, D.I. and Rowland, D. (1996). Loss of disgust: perception of faces andemotions in Huntington's disease. Brain, 119, 16471665.

Sprengelmeyer, R., Young, A.W., Pundt, I., Sprengelmeyer, A., Calder, A.J., Berrios,G., Winkel, R., Vollmoeller, W., Kuhn, W., Sartory, G. and Przuntek, H. (1997).Disgust implicated in obsessive-compulsive disorder. Proceedings of the RoyalSociety: Biological Sciences, B264, 17671773.

Sprengelmeyer, R., Young, A.W., Schroeder, U., Grossenbacher, P.G., Federlein, J.,Bttner, T. and Przuntek, H. (1999). Knowing no fear. Proceedings of the RoyalSociety: Biological Sciences, 266, 24512456.

Appendix 1: Files used in the Ekman 60 Faces test

This Appendix explains the system used to create names for the JPEG image filesused in the Ekman 60 Faces test, and how to locate files needed for the test on theFEEST CD-ROM.

Filenames

Each filename is constructed in the following way:

ET_emoxx_nnn_id_ekid_per.jpg

where the ET prefix designates that this is an image from the Ekman 60 Faces test(Practice images are prefixed ETP), emo indicates the emotion (Ang = anger, Dis =disgust, Fea = fear, Hap = happiness, Sur = surprise), xx is used to order thepictures of each emotion from 01 to 10, nnn is the picture number in the Ekmanand Friesen (1976) series, id gives the identifier for each model used at the top ofFigure 1.1, ekid is the identifier in the Ekman and Friesen series, and per is thepercentage recognition as the intended emotion in Ekman and Friesen's data.

Test files

The test begins with 6 practice trials. Files for these are:ETP_Ang_025_M2_GS-2-08_070.jpgETP_Dis_027_M2_GS-2-25_084.jpgETP_Fea_024_M2_GS-1-25_077.jpgETP_Hap_022_M2_GS-1-08_096.jpgETP_Sad_023_M2_GS-2-01_071.jpgETP_Sur_026_M2_GS-1-16_100.jpg

The complete set of 60 files used for the test trials, and correct responses, is asfollows:


Filename Correct response

ET_Ang01_010_F2_C-2-12_074.jpg AngerET_Ang02_053_F4_MF-2-07_100.jpg AngerET_Ang03_061_F5_MO-2-11_100.jpg AngerET_Ang04_069_F6_NR-2-07_100.jpg AngerET_Ang05_089_F7_PF-2-04_079.jpg AngerET_Ang06_096_F8_SW-4-09_100.jpg AngerET_Ang07_018_M1_EM-5-14_083.jpg AngerET_Ang08_038_M4_JJ-3-12_076.jpg AngerET_Ang09_080_M5_PE-2-21_083.jpg AngerET_Ang10_105_M6_WF-3-01_100.jpg AngerET_Dis01_012_F2_C-1-04_096.jpg DisgustET_Dis02_055_F4_MF-2-13_090.jpg DisgustET_Dis03_064_F5_MO-2-18_100.jpg DisgustET_Dis04_071_F6_NR-3-29_083.jpg DisgustET_Dis05_091_F7_PF-1-24_096.jpg DisgustET_Dis06_098_F8_SW-1-30_094.jpg DisgustET_Dis07_020_M1_EM-4-17_097.jpg DisgustET_Dis08_040_M4_JJ-3-20_088.jpg DisgustET_Dis09_082_M5_PE-4-05_090.jpg DisgustET_Dis10_108_M6_WF-3-11_097.jpg DisgustET_Fea01_009_F2_C-1-23_088.jpg FearET_Fea02_050_F4_MF-1-26_088.jpg FearET_Fea03_059_F5_MO-1-23_088.jpg FearET_Fea04_068_F6_NR-1-19_084.jpg FearET_Fea05_088_F7_PF-2-30_100.jpg FearET_Fea06_095_F8_SW-2-30_079.jpg FearET_Fea07_016_M1_EM-5-21_092.jpg FearET_Fea08_037_M4_JJ-5-13_096.jpg FearET_Fea09_079_M5_PE-3-21_092.jpg FearET_Fea10_104_M6_WF-3-16_088.jpg FearET_Hap01_007_F2_C-2-18_099.jpg HappinessET_Hap02_048_F4_MF-1-06_100.jpg HappinessET_Hap03_057_F5_MO-1-04_100.jpg HappinessET_Hap04_066_F6_NR-1-06_092.jpg HappinessET_Hap05_085_F7_PF-1-06_100.jpg HappinessET_Hap06_093_F8_SW-3-09_100.jpg HappinessET_Hap07_014_M1_EM-4-07_100.jpg HappinessET_Hap08_034_M4_JJ-4-07_100.jpg HappinessET_Hap09_074_M5_PE-2-12_100.jpg HappinessET_Hap10_101_M6_WF-2-12_100.jpg HappinessET_Sad01_008_F2_C-1-18_090.jpg SadnessET_Sad02_049_F4_MF-1-30_090.jpg SadnessET_Sad03_058_F5_MO-1-30_088.jpg SadnessET_Sad04_067_F6_NR-2-15_094.jpg SadnessET_Sad05_086_F7_PF-2-12_100.jpg SadnessET_Sad06_094_F8_SW-2-16_092.jpg SadnessET_Sad07_015_M1_EM-4-24_097.jpg SadnessET_Sad08_036_M4_JJ-5-05_093.jpg Sadness


ET_Sad09_075_M5_PE-2-31_074.jpg SadnessET_Sad10_102_M6_WF-3-28_079.jpg SadnessET_Sur01_011_F2_C-1-10_094.jpg SurpriseET_Sur02_054_F4_MF-1-09_096.jpg SurpriseET_Sur03_063_F5_MO-1-14_090.jpg SurpriseET_Sur04_070_F6_NR-1-14_081.jpg SurpriseET_Sur05_090_F7_PF-1-16_093.jpg SurpriseET_Sur06_097_F8_SW-1-16_100.jpg SurpriseET_Sur07_019_M1_EM-2-11_091.jpg SurpriseET_Sur08_039_M4_JJ-4-13_097.jpg SurpriseET_Sur09_081_M5_PE-6-02_074.jpg SurpriseET_Sur10_107_M6_WF-2-16_091.jpg Surprise

On each of the test trials, participants score 0 if they make the wrong response, 1 forthe correct response. The 6 practice trials are not scored.

The 60 test trials yield seven scores, which are automatically totalled by the softwaresupplied with the CD-ROM:

Anger a score from 010 for the number of anger faces correctly identified.Disgust a score from 010 for the number of disgust faces correctly identified.Fear a score from 010 for the number of fear faces correctly identified.Happiness a score from 010 for the number of happiness faces correctlyidentified.Sadness a score from 010 for the number of sadness faces correctly identified.Surprise a score from 010 for the number of surprise faces correctly identified.Total the sum of the above 6 scores.

Duplicate files

The image files listed above are only available to the program supplied with the CD-ROM, and cannot be copied from the CD. However, a duplicate set is provided forthose who wish to program their own test. These images are encrypted on the CD-ROM, but can be copied to a hard disk using the software supplied. Their filenamesare the same as those used by the Ekman 60 Faces test program software, except thatthey begin with the prefix Ek instead of ET.

The path to the image directory is:

FEEST_Stimuli/Images/Section_1_Ekman_60_faces_test/ Ekman_60_images/

The image directory has seven subdirectories:

Ek60P_Practice imagesThis directory contains the six practice images:EkP_Ang_025_M2_GS-2-08_070.jpgEkP_Dis_027_M2_GS-2-25_084.jpgEkP_Fea_024_M2_GS-1-25_077.jpgEkP_Hap_022_M2_GS-1-08_096.jpgEkP_Sad_023_M2_GS-2-01_071.jpgEkP_Sur_026_M2_GS-1-16_100.jpg

Ek60T_AngerThis directory contains the ten anger images:Ek_Ang01_010_F2_C-2-12_074.jpgEk_Ang02_053_F4_MF-2-07_100.jpg


Ek_Ang03_061_F5_MO-2-11_100.jpgEk_Ang04_069_F6_NR-2-07_100.jpgEk_Ang05_089_F7_PF-2-04_079.jpgEk_Ang06_096_F8_SW-4-09_100.jpgEk_Ang07_018_M1_EM-5-14_083.jpgEk_Ang08_038_M4_JJ-3-12_076.jpgEk_Ang09_080_M5_PE-2-21_083.jpgEk_Ang10_105_M6_WF-3-01_100.jpg

Ek60T_DisgustThis directory contains the ten disgust images:Ek_Dis01_012_F2_C-1-04_096.jpgEk_Dis02_055_F4_MF-2-13_090.jpgEk_Dis03_064_F5_MO-2-18_100.jpgEk_Dis04_071_F6_NR-3-29_083.jpgEk_Dis05_091_F7_PF-1-24_096.jpgEk_Dis06_098_F8_SW-1-30_094.jpgEk_Dis07_020_M1_EM-4-17_097.jpgEk_Dis08_040_M4_JJ-3-20_088.jpgEk_Dis09_082_M5_PE-4-05_090.jpgEk_Dis10_108_M6_WF-3-11_097.jpg

Ek60T_FearThis directory contains the ten fear images:Ek_Fea01_009_F2_C-1-23_088.jpgEk_Fea02_050_F4_MF-1-26_088.jpgEk_Fea03_059_F5_MO-1-23_088.jpgEk_Fea04_068_F6_NR-1-19_084.jpgEk_Fea05_088_F7_PF-2-30_100.jpgEk_Fea06_095_F8_SW-2-30_079.jpgEk_Fea07_016_M1_EM-5-21_092.jpgEk_Fea08_037_M4_JJ-5-13_096.jpgEk_Fea09_079_M5_PE-3-21_092.jpgEk_Fea10_104_M6_WF-3-16_088.jpg

Ek60T_HappinessThis directory contains the ten happiness images:Ek_Hap01_007_F2_C-2-18_099.jpgEk_Hap02_048_F4_MF-1-06_100.jpgEk_Hap03_057_F5_MO-1-04_100.jpgEk_Hap04_066_F6_NR-1-06_092.jpgEk_Hap05_085_F7_PF-1-06_100.jpgEk_Hap06_093_F8_SW-3-09_100.jpgEk_Hap07_014_M1_EM-4-07_100.jpgEk_Hap08_034_M4_JJ-4-07_100.jpgEk_Hap09_074_M5_PE-2-12_100.jpgEk_Hap10_101_M6_WF-2-12_100.jpg

Ek60T_SadnessThis directory contains the ten sadness images:Ek_Sad01_008_F2_C-1-18_090.jpgEk_Sad02_049_F4_MF-1-30_090.jpgEk_Sad03_058_F5_MO-1-30_088.jpg


Ek_Sad04_067_F6_NR-2-15_094.jpgEk_Sad05_086_F7_PF-2-12_100.jpgEk_Sad06_094_F8_SW-2-16_092.jpgEk_Sad07_015_M1_EM-4-24_097.jpgEk_Sad08_036_M4_JJ-5-05_093.jpgEk_Sad09_075_M5_PE-2-31_074.jpgEk_Sad10_102_M6_WF-3-28_079.jpg

Ek60T_SurpriseThis directory contains the ten surprise images:Ek_Sur01_011_F2_C-1-10_094.jpgEk_Sur02_054_F4_MF-1-09_096.jpgEk_Sur03_063_F5_MO-1-14_090.jpgEk_Sur04_070_F6_NR-1-14_081.jpgEk_Sur05_090_F7_PF-1-16_093.jpgEk_Sur06_097_F8_SW-1-16_100.jpgEk_Sur07_019_M1_EM-2-11_091.jpgEk_Sur08_039_M4_JJ-4-13_097.jpgEk_Sur09_081_M5_PE-6-02_074.jpgEk_Sur10_107_M6_WF-2-16_091.jpg

Facial Expressions of Emotion Stimuli and Tests (FEEST). Psychology manual v 1.0 Thames Valley Test Company January 2002. Section 2 page 1 of 22

Section 2: The Emotion Hexagon test ...............................................................................2Stimuli.............................................................................................................................2Procedure........................................................................................................................ 7Performance norms ........................................................................................................8

Graphical representation of results............................................................................8Overall scores ............................................................................................................ 10Scores for each emotion............................................................................................ 12

Validity and reliability .................................................................................................. 14Previous use of the Emotion Hexagon test .................................................................. 16References..................................................................................................................... 19

Appendix 2: Files used in the Emotion Hexagon test ..................................................... 19Filenames...................................................................................................................... 19

Test files ....................................................................................................................20Duplicate files............................................................................................................ 21


Section 2: The Emotion Hexagon test

The Emotion Hexagon test uses stimuli of graded difficulty, created using computerimage manipulation techniques. The rationale underlying the Emotion Hexagon isthat whereas the Ekman and Friesen (1976) faces were developed to provide relativelyunambiguous examples of each emotion, in some circumstances it is useful to be ableto test recognition of less clear-cut expressions. In the Emotion Hexagon test,computer morphing is used to modify photographs from the Ekman and Friesen(1976) series, creating examples that lie close to or more distant from the prototypeexpression.

The test involves recognition of six basic emotions; anger, disgust, fear, happiness,sadness, and surprise. Results can be represented in graphical form, or converted toscores out of a maximum of 120 for overall performance and scores out of 20 forrecognition of the six emotions.

The FEEST CD-ROM includes a computer program for presenting the EmotionHexagon test, recording and scoring responses, and saving these as an Excel-compatible spreadsheet file. Comparison data are available for a group of 125participants.

Stimuli

The Ekman and Friesen (1976) series contains examples of facial expressions of sixdifferent basic emotions (anger, disgust, fear, happiness, sadness, and surprise).Using Ekman and Friesen's (1976) norms, we plotted a confusion matrix for thedifferent emotions, and then ordered them in a series based on their maximumconfusabilities placing each emotion adjacent to the one it was most likely to beconfused with. The result ran happiness surprise fear sadness disgust anger, with mean percentage confusabilities for each pair of expressions in thissequence being happiness and surprise 0.8%, surprise and fear 5.8%, fear andsadness 2.4%, sadness and disgust 2.7%, disgust and anger 6.4%. The ends of thesequence (anger and happiness) were then joined to create a hexagonalrepresentation, as shown in Figure 2.1.


Figure 2.1: Hexagonal representation of confusabilities of basic emotions. Emotionsmost likely to have their facial expressions mistaken for each other are placed atadjacent points on the perimeter.

This hexagonal representation is related to the schemas used in two-dimensionalaccounts of facial expression perception. For example, a similar representation of theconfusability of facial expressions was developed by Woodworth and Schlosberg(1954), though it reverses the relative positions of anger and disgust. However, we donot wish to imply here that the hexagonal representation directly reflects theprocesses used in perceiving facial expressions it is simply a convenient way ofshowing what tends to be confused with what.

Morphed images were created for the six continua that lie around the perimeter ofthis hexagon (happiness surprise, surprise fear, fear sadness, sadness disgust,disgust anger, anger happiness). These continua therefore include those betweenmaximally confusable emotions.

Face JJ from the Ekman and Friesen (1976) series was chosen for morphing becausethe photographs of all six emotional facial expressions (happiness, surprise, fear,sadness, disgust, and anger) were of consistent quality, with reasonably standardisedpose and lighting. To describe the morphing procedure, we refer to these pictures asthe prototype expressions of Happiness, Surprise, Fear, Sadness, Disgust, and Anger.The numbers and identifiers of the selected prototype expression images in theEkman and Friesen (1976) series are given in Table 2.1, which also shows percentagerecognition rates for these six expressions by Ekman and Friesen's (1976) collegestudent sample. Details of the muscle movements (Action Units) involved in eachprototype expression can be found in Section 6 of this Manual.


Number E&F id Intendedemotion

Percentage recognition rates N

Happiness Surprise Fear Sadness Disgust Anger

34 JJ-4-07 Happiness 100 0 0 0 0 0 31

39 JJ-4-13 Surprise 0 97 3 0 0 0 30

37 JJ-5-13 Fear 0 0 96 4 0 0 25

36 JJ-5-05 Sadness 3 0 0 93 0 3 30

40 JJ-3-20 Disgust 0 0 0 12 88 0 33

38 JJ-3-12 Anger 0 3 15 0 6 76 33

Table 2.1: Numbers and identifiers (E&F id) in the Ekman and Friesen (1976) seriesfor the prototype images used to create the Emotion Hexagon, with percentagerecognition rates for these six expressions by Ekman and Friesen's (1976) collegestudent sample (N = number of judges for each face).

Photographic-quality continua were made, with five morphed images for eachcontinuum. These were prepared by blending between two prototype expressionsposed by JJ (e.g., Happiness and Surprise) in proportions 90:10 (i.e., 90% Happiness10% Surprise for the happiness surprise continuum), 70:30 (70% Happiness 30%Surprise), 50:50 (50% Happiness 50% Surprise), 30:70 (30% Happiness 70%Surprise), and 10:90 (10% Happiness 90% Surprise). These correspond to 90%, 70%,50%, 30%, and 10% morphs along the appropriate continuum (in our example,happiness surprise).

The preparation of each continuum was done in the same way. Preparation of thehappiness surprise continuum will be described, to illustrate the process. Theprocedure involved three stages. Further technical details can be found in Section 7 ofthis Manual.

Stage 1: delineation: One hundred and eighty six reference points were positionedmanually onto a digitised image of the Happiness prototype expression photograph ofJJ's face from the Ekman and Friesen (1976) series. The locations of these referencepoints were specified in terms of anatomical landmarks, with each facial featurerepresented by a set number of points; for example, the mouth was represented by 22points, and each eyebrow by 8 points. These reference points were then joined toproduce a delineated representation comprising 50 feature contours. Exactly thesame method was applied to a digitised image of JJ's Surprise prototype photograph.Hence, across the two prototype expressions (Happiness and Surprise) there wasconformity with respect to the anatomical positioning of the 186 reference points oneach face, but not always their exact spatial positions; for example, the eyebrows wereraised in the Surprise but not the Happiness prototype, whereas the shape of thehairline was the same in both.

Stage 2: shape interpolation: A continuum of face shapes was generated between thetwo delineated prototype face shapes (in our example, JJ Happiness and JJ Surprise).This was achieved by taking the delineation data for the two prototype images andcalculating the vector difference for each landmark. For example, consider thereference point positioned at the tip of the nose; this has a location on the JJ


Happiness prototype of (x1,y1) and a location on the JJ Surprise prototype of (x2,y2).Equations describing the vector from (x1,y1) to (x2,y2) were used to obtain positionsfor the point at the tip of the nose which moved 10%, 30%, 50%, 70%, and 90% alonga straight line from the location of that reference point in JJ's Happiness prototype(x1,y1) to the location of that reference point in JJ's Surprise prototype (x2,y2). Thisprocess was repeated for each of the 186 feature reference points, to generate the 5face shapes which would interpolate at 10%, 30%, 50%, 70%, and 90% distancesbetween the two original prototype face shapes.

Stage 3: producing a continuous-tone image: The final stage created a continuous-tone (photographic quality) image for each of these interpolated face shapes. This wasachieved by taking both of the prototype faces and 'warping' or 'stretching' them (as ifthey were printed on a rubber sheet) to the new shape, so that all points representingthe same feature were aligned across images. The two faces, now with the sameintermediary face shape, were then blended with the appropriate weight. For example,in the 90% Happiness 10% Surprise morph, the pixel intensities in each tessellationwere arrived at by deforming the Happiness prototype face 10% toward the Surpriseprototype, and the Surprise prototype face 90% toward the Happiness prototype, andthen blending the grey levels in these two contributory images in the ratio nine partsfrom the Happiness prototype to one part from the Surprise prototype.


Figure 2.2: Expression continua used in the Emotion Hexagon test. From left toright, the columns show 90%, 70%, 50%, 30% and 10% morphs along eachcontinuum. In each case, information from the prototype (Ekman and Friesenseries) expression of the emotion at each end of the continuum is blended in theproportions shown at the top of the Figure. From top to bottom, the continua shownin each row are happiness (H) surprise (U), surprise (U) fear (F), fear (F) sadness (S), sadness (S) disgust (D), disgust (D) anger (A), and anger (A) happiness (H).

The resulting morphed faces are shown in Figure 2.2. In total, there are 30 images (5from each of 6 continua). Moving from left to right in Figure 2.2, the columns show90%, 70%, 50%, 30% and 10% morphs along each continuum. Note that a 90%morph on the happiness surprise continuum would be the same as a 10% morph ona surprise happiness continuum, and that the prototype expressions are not shownin Figure 2.2. Moving from top to bottom of Figure 2.2, the rows show the happiness surprise continuum (top row), surprise fear (second row), fear sadness (thirdrow), sadness disgust (fourth row), disgust anger (fifth row), and anger happiness (bottom row).

Procedure

A computer program for running the Emotion Hexagon Test is included on theFEEST CD-ROM, and separate instructions are provided for this software. The facesare presented one at a time for 5 seconds each, followed by a blank screen. Theparticipant is asked to decide which of the emotion names (happiness, sadness,surprise, disgust, anger, and fear) best describes the facial expression shown. Thenames of these six emotions are visible on the computer screen throughout the test,with the order in which the emotion names are shown on the screen randomised eachtime the test is given. Before commencing the test, you should satisfy yourself thatyour participant understands the meanings of these emotion words sufficientlyaccurately for the results to be meaningful (for example, by asking for examples ofcircumstances in which people would experience fear, anger, disgust, etc.). Responsescan be recorded from mouse-clicks to the on-screen buttons, or via the computerkeyboard. The test is not timed participants can take as long as they wish to decideon the emotion.

The test involves a practice block of 30 trials, followed by 5 test blocks of 30 trialseach. In each block of trials the 30 images shown in Figure 2.2 are presented onceeach, in random order. The software allows responses to be saved to an Excel-compatible spreadsheet file that records the trial number, the stimulus filename(spreadsheet column C), an identifier that allows the results to be sorted (column D),and the response made.

Data from the practice block of trials are not analysed. This leaves data for 5 blocks of30 trials. These can be represented in graph form, or analysed numerically usingprocedures described below (Performance norms).

The filenames for the stimuli used in the Emotion Hexagon test number the picturesin Figure 2.2 from 01 to 30, proceeding from left to right and top to bottom of theFigure. This is equivalent to numbering them from 1 to 30 starting at 12 o'clock(happiness) and proceeding clockwise around the perimeter of Figure 2.1. Eachfilename is constructed in the following way:

HTxx_M4_JJ_ex1_pp1_ex2_pp2.jpg

where HT designates that this is an image from the Emotion Hexagon test, xx isused to order the pictures from 01 to 30, M4 is the identifier for the model (JJ)


used at the top of Figure 1.1, JJ designates the model in the Ekman and Friesenseries, ex1 and ex2 indicate the blended prototype expressions (Ang = Anger, Dis =Disgust, Fea = Fear, Hap = Happiness, Sad = Sadness, Sur = Surprise), and pp1and pp2 indicate the percentages of each prototype expression in the blend.

For example: the filename HT20_M4_JJ_Sad_10%_Dis_90%.jpg designates the20th picture in Figure 2.2 (the image in the 5th column of the 4th row). The model isidentified as M4 in Figure 1.1, who is JJ in the Ekman and Friesen series. The pictureis a blend of 10% Sadness and 90% Disgust prototypes.

A complete list of filenames for the stimuli used in the Emotion Hexagon test is givenas an Appendix to the present Section of the FEEST Manual. These files cannot beremoved from the CD-ROM, but the Appendix gives the location of a duplicate set offiles suitable for use by those who prefer to program their own version of the test. Thiscan be useful if it is considered necessary to adjust the procedure for example, to getmore detailed information by recording reaction times as well as accuracy, or to add amasking stimulus to the end of each trial to inhibit time-consuming strategies (seebelow Previous use of the Emotion Hexagon test).

Performance norms

Note that the prototype face for each expression is never shown in the EmotionHexagon test; all the stimuli are morphs. Note too that the morphs are presented inrandom order in each block of trials; they are not grouped into the underlyingcontinua.

Data from the Emotion Hexagon test can be represented in graph form, or analysednumerically using overall total scores or scores for recognition of each emotion. Wewill describe these methods in turn.

Graphical representation of results

The 5 blocks of 30 test trials can be used to derive a score out of a maximum possible5 for a participant's recognition of each of the 30 test images as each of the 6emotions. For example, if we consider the top left image in Figure 2.2 (image 01 in theEmotion Hexagon series, filename HT01_M4_JJ_Hap_90%_Sur_10%.jpg), we canlook at how many times a participant classifies it as anger, disgust, fear, happiness,sadness, or surprise across its 5 presentations (one presentation in each block of testtrials). Then we can do the same with the next image along the top row of Figure 2.2(image 02 in the Emotion Hexagon series, filenameHT02_M4_JJ_Hap_70%_Sur_30%.jpg), and so on until the data for all 30 imageshave been tabulated. To facilitate this, the filenames are constructed so that selectingthe data in columns AE of the output file and then sorting these by Column C(filenames) will group together responses to each image.

The data can then be represented as a graph in which the 30 images used in the testare located along the horizontal axis, as if lying along a continuum that traverses theperimeter of Figure 2.1 (happiness surprise fear sadness disgust anger happiness), and the vertical axis shows how often these 30 images are identified aseach of the 6 emotions (happiness, surprise, fear, sadness, disgust, or anger) acrossthe 5 presentations of each image.


Figure 2.3: Graph representing performance of the Emotion Hexagon test by 40participants aged 2060 years. The 30 images used in the test (as read from left toright and top to bottom of Figure 2.2) are located along the horizontal axis, as iflying along a continuum that traverses the perimeter of Figure 2.1 (Happiness Surprise Fear Sadness Disgust Anger Happiness). Because of the numberof images lying along the horizontal axis, not a

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