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Vol. 130, No. 3: Fall 2017
 
How You Measure Is What You Get: Differences in Self- and External Ratings of Emotional Experiences in Home Dreams
Pilleriin Sikka
University of Turku and University of Skövde
 
Diana Feilhauer
University of Skövde
 
Katja Valli and Antti Revonsuo
University of Turku and University of Skövde
 
Click to view the online article
 

Abstract

This study demonstrates that different methods for measuring emotional experiences in dreams—self-ratings of dreams using emotion rating scales versus external ratings in the form of content analysis of narrative dream reports—can lead to strikingly different results and contradicting conclusions about the emotional content of home dreams. During 3 consecutive weeks, every morning upon awakening, 44 participants (16 men, 28 women, average age 26.9 ± 5.1 years) reported their dreams and rated their emotional experiences in those dreams using the modified Differential Emotions Scale. Two external judges rated emotional experiences in the same 552 (M = 12.55 ± 5.72) home dream reports using the same scale. Comparison of the 2 methods showed that with self-ratings dreams were rated as more emotional and more positive than with external ratings. Moreover, whereas with self-ratings the majority of dreams was rated as positively valenced, with external ratings the majority of dream reports was rated as negatively valenced. Although self- and external ratings converge, at least partially, in the measurement of negative emotional experiences, they diverge greatly in the measurement of positive emotional experiences. On one hand, this discrepancy may result from different biases inherent in the 2 measurement methods highlighting the need to develop better methods for measuring emotional experiences. On the other hand, self- and external ratings may capture different phenomena and should thus be considered complementary and used concurrently. Nevertheless, results suggest that negative emotional experiences can be measured in a more valid and reliable manner than positive emotional experiences.

 

Supplementary Results

Changes Over Time

          To investigate whether the length of the study might explain differences in dream emotionality obtained with the two methods, data was analyzed separately for the first, last and intermediate periods of the study. For this, data was aggregated separately for week one, two, and three. Four participants who failed to fill in the dream diary on several days during the 3-week study period also continued to report dreams during week four of the study and these dream reports (n = 10) were combined with those from week three.

          Regarding dream recall frequency, there was a significant difference between the three weeks in the overall number of dream reports, N = 44, x2(2) = 43.40, p < .001, with a medium effect size (Kendall's W = .49). Post hoc analyses with Wilcoxon signed-rank tests with Bonferroni correction (adjusted p < .017) showed that participants reported significantly more dreams during week 1 (M = 5.75, SD = 2.51, Mdn = 5.00), as compared to week 2 (M = 3.41, SD = 2.41, Mdn = 3.00), Z = -5.20, p < .001, and week 3 (M = 3.39, SD = 1.93, Mdn = 3.50), Z = -4.82, p < .001. The number of dreams reported during week 2 and 3 was not significantly different, Z = -0.17, p = .867. Similar results were obtained when analyzing the number of days with dream recall. As these results are redundant with the findings presented above, they are not detailed here.

          To account for the different number of dream reports from the three weeks, the percentage (rather than the number) of emotionally valenced dreams was compared across the three weeks. The results showed no differences between the three weeks in the percentage of dreams rated as emotional, positive, or negative with either self- or external ratings (see Supplementary Table S1 for descriptive statistics and significance tests).

          In line with the decreased number of dream reports, participants rated and reported significantly less emotions per dream over the course of the three weeks. Specifically, regarding self-rated dream emotions, post hoc pairwise comparisons with Bonferroni correction showed that participants rated significantly less emotions in dreams during week 3, as compared to week 1, p = .004. Similar results were obtained with externally rated emotions in dream reports: post hoc Wilcoxon signed-rank tests with Bonferroni correction (adjusted p < .017) indicated that participants reported significantly less emotions in dream reports during week 3, as compared to week 1, Z = 2.63, p = .008. There were no differences in the ratings regarding the number of emotions per dream between week 1 and 2 (SR: p = .294; ER: Z = -1.23, p = .224) or between week 2 and 3 (SR: p = .565; ER: Z = -1.75, p = .08).

          Moreover, the smaller number of emotion ratings per dream occurred due to participants having given less positive emotion ratings per dream with self-ratings and reported less negative emotions per dream report (see Supplementary Table S1). Specifically, post hoc pairwise comparisons with Bonferroni correction showed that with self-ratings there were significantly less positive emotions per dream during week 3, as compared to week 1, p = .013 (with no significant difference between week 1 and 3, p = 1.000, or between week 2 and 3, p = .088). With external ratings, post hoc Wilcoxon signed-rank tests with Bonferroni correction (adjusted p < .017) showed that there were significantly less negative emotions per dream report during 3, as compared to week 1, Z = -2.45, p = .013 (with no significant difference between week 1 and 2, Z = -2.18, p = .028, or between week 2 and 3, Z = -0.44, p = .666).

          Thus, despite participants having reported less dream reports and less emotions per dream towards the end of the study, this change was not specific to the rating method or to the valence of emotions. Moreover, when directly comparing self- and external ratings of dream emotions separately for the three weeks, the pattern of results is the same as for the study overall (see Supplementary Table S2). The only notable aspect is that the difference in the amount of negative dreams between self- and external ratings occurs only towards the end of the study period (week 3) but not in the earlier periods of the study (week 1 and 2). Therefore, the length of the study and the changes occurring over the study period cannot explain the differences in overall emotionality and/or positivity between self- and external ratings.

Table S1

Differences in Dream Emotionality Between the Three Different Study Periods (N = 39)

 

 

Study period

 

 

Friedman test or paired-samples ANOVA

Effect size

 

Week 1

 

Week 2

 

Week 3

 

χ 2 or F

p

Kendall’s W or ηp 2

Self-ratings

% Emotional dreams

M

  98.24

 

  99.15

 

  95.90

 

χ 2(2) =2.96

=.267

W = .04

SD

    4.93

 

    5.34

 

  13.47

 

Mdn

100.00

 

100.00

 

100.00

 

% Positive dreams

M

  57.33

 

  65.09

 

  47.66

 

χ 2 (2) =5.29

=.069

W = .07

SD

  30.48

 

  34.58

 

  34.92

 

Mdn

  60.00

 

  66.67

 

  50.00

 

% Negative dreams

M

  33.72

 

  30.38

 

  42.85

 

χ 2 (2) =2.82

=.245

W = .04

SD

  29.69

 

  31.95

 

  34.79

 

Mdn

  33.33

 

  28.57

 

  50.00

 

Emotions per dream

M

    9.11

 

    8.30

 

    7.72

 

F(2,76) = 5.09

=.008

 

ηp2 = .12

 

SD

    3.17

 

    3.54

 

    3.53

 

Mdn

    9.00

 

    8.30

 

    8.00

 

Positive emotions per dream

M

    5.33

 

    5.11

 

    4.21

 

F(2,76) = 5.17

=.008

ηp2 = .20

SD

    2.21

 

    2.59

 

    2.64

 

Mdn

    5.25

 

    5.00

 

    4.75

 

Negative emotions per dream

M

    3.79

 

    3.19

 

    3.51

 

χ 2 (2) = 2.27

=.322

W = .03

SD

    2.24

 

    2.13

 

    2.27

 

Mdn

    3.00

 

    3.00

 

    3.20

 

External ratings

% Emotional dreams

M

  52.73

 

  51.51

 

  43.66

 

χ 2 (2) = 1.50

=.478

W = .02

SD

  29.05

 

  31.87

 

  34.93

 

Mdn

  50.00

 

  50.00

 

  50.00

 

% Positive dreams

M

  14.10

 

  17.86

 

    9.90

 

χ 2 (2) = 2.27

=.336

 

W = .03

SD

  16.55

 

  28.16

 

  20.12

 

Mdn

  11.11

 

    0.00

 

    0.00

 

% Negative dreams

M

  31.68

 

  22.49

 

  25.60

 

χ 2 (2) = 4.99

=.082

W = .06

SD

  24.39

 

  24.95

 

  27.74

 

Mdn

  28.57

 

  16.67

 

  20.00

 

Emotions per dream

M

    0.91

 

    0.78

 

    0.63

 

χ 2 (2) = 6.23

=.045

W = .08

SD

    0.89

 

    0.60

 

    0.63

 

Mdn

    0.67

 

    0.75

 

    0.50

 

Positive emotions per dream

M

    0.33

 

    0.33

 

    0.21

 

χ 2 (2) = 4.35

=.114

W = .06

SD

    0.46

 

    0.37

 

    0.36

 

Mdn

    0.22

 

    0.20

 

    0.00

 

Negative emotions per dream

M

    0.58

 

    0.45

 

    0.42

 

χ 2 (2) = 8.02

=.018

W =.10

SD

    0.54

 

    0.47

 

    0.43

 

Mdn

    0.40

 

    0.33

 

    0.33

 

 

 

Table S2

Differences Between Self-and External Ratings of Dream Emotional Experiences Separately for the Three Study Periods

 

Self-ratings

 

External ratings

 

Wilcoxon signed rank test

(two-tailed)

Effect size

 

M

SD

Mdn

 

M

SD

Mdn

 

Z

p

r

Week 1 (N = 44)

 

 

 

 

 

 

 

 

 

 

 

Emotional dreams

5.61

2.37

5.00

 

2.80

1.91

2.50

 

-5.54

<.001

.59

Positive dreams

3.14

2.02

3.00

 

0.68

0.86

0.50

 

-5.22

<.001

.56

Negative dreams

2.07

1.86

2.00

 

1.73

1.61

1.50

 

-1.49

=.138

.16

Balanced dreams

0.41

0.66

0.00

 

0.25

0.44

0.00

 

-1.40

=.231

.15

Undetermined a

N/A

N/A

N/A

 

0.14

0.41

0.00

 

N/A

N/A

N/A

Emotions per dream

9.00

3.25

8.88

 

0.88b

0.87b

0.67b

 

-5.78

<.001

.62

Positive emotions

5.22

2.22

5.25

 

0.32

0.44

0.24

 

-5.78

<.001

.62

Negative emotions

3.78

2.25

3.06

 

0.57

0.53

0.40

 

-5.71

<.001

.61

 

 

 

 

 

 

 

 

 

 

 

 

Week 2 (N = 40)

 

 

 

 

 

 

 

 

 

 

 

Emotional dreams

3.70

2.23

3.00

 

1.90

1.59

1.00

 

-4.98

<.001

.56

Positive dreams

2.32

1.87

2.00

 

0.55

0.75

0.00

 

-4.74

<.001

.53

Negative dreams

1.20

1.22

1.00

 

1.00

1.19

1.00

 

-1.05

=.327

.12

Balanced dreams

0.18

0.50

0.00

 

0.23

0.42

0.00

 

-0.41

=.827

.05

Undetermined a

N/A

N/A

N/A

 

0.13

0.40

0.00

 

N/A

N/A

N/A

Emotions per dream

8.26

3.49

8.28

 

0.78b

0.59b

0.78b

 

-5.49

<.001

.61

Positive emotions

5.04

2.59

5.00

 

0.32

0.37

0.18

 

-5.44

<.001

.61

Negative emotions

3.22

2.11

3.00

 

0.47

0.47

0.33

 

-5.21

<.001

.58

 

 

 

 

 

 

 

 

 

 

 

 

Week 3 (N = 42)

 

 

 

 

 

 

 

 

 

 

 

Emotional dreams

3.40

1.85

3.50

 

1.55

1.52

1.00

 

-5.22

<.001

.57

Positive dreams

1.83

1.75

1.50

 

0.40

0.86

0.00

 

-4.95

<.001

.54

Negative dreams

1.33

1.20

1.00

 

0.93

1.07

1.00

 

-2.29

=.022

.25

Balanced dreams

0.24

0.58

0.00

 

0.19

0.39

0.00

 

-0.54

=.795

.06

Undetermined a

N/A

N/A

N/A

 

0.02

0.15

0.00

 

N/A

N/A

N/A

Emotions per dream

7.85

3.44

8.53

 

0.59b

0.62b

0.50b

 

-5.65

<.001

.62

Positive emotions

4.41

2.71

4.75

 

0.19

0.35

0.00

 

-5.51

<.001

.60

Negative emotions

3.44

2.26

3.20

 

0.40

0.42

0.33

 

-5.44

<.001

.59

Note. a Dream reports containing only emotions classified by judges into the “Other” category (12 dreams of 8 participants). b Excludes emotions classified into the “Other” category8.

 

Table S3

Examples of Dream Reports (Translated from Swedish) Rated by External Judges (ER) and Participants Themselves (SR). The Scores for Positive Emotions (PE) and Negative Emotions (NE) Indicate the Number of Different Emotion Categories the Dream Has Been Rated With (min = 0; max = 10)

 

Emotional valence of dream

 

Emotions per dream

 

ER

SR

 

ER

SR

 

 

PE

NE

PE

NE

I was at some big industrial park. Everything was closed down and a criminal gang owned this place. The dream was generally "dark" in lighting. I stepped on glass and got a little scratch on my foot, but it was nothing dangerous. I then met my younger sister who had also stepped on glass, but she had a very deep wound on her foot that stretched from the toes to the heel. I never saw the criminal gang but had a strong feeling that my younger sister was stuck and could not get away from this area because of them + her injury (Male, 25).

Non-emotional

Non-emotional

 

0

0

0

0

I was in the desert. It was hot, but I was not feeling hot. It seemed like the sun was burning, and the sand was almost copper red. A girl dressed in a black skirt, with some glitter on, and a white jacket was there. She looked like one of my favorite bloggers. She was standing, waiting for a car, and talking on the mobile phone. Afterwards the car came and she left. I continued to walk, and ran into an island and a few trees that grew around it. It was shady there and two other girls, whom I did not know, were there. They were painting with a brush and white paint on each other's faces (Female, 37).

Non-emotional

Non-emotional

 

0

0

0

0

We were standing outside our old house and we were sorting out the garbage. We had some sort of motor device that would normally take care of everything, but it was broken, so we had to do it ourselves. No one wanted to help and someone suggested that we just threw everything in the same container instead, but then I became really angry and decided to invent something that could recycle everything so that there would never be any garbage left over (Female, 20).

Negative

Negative

 

0

1

1

5

I was in a beautiful house in a big forest, and I was there on behalf of the government with some important people. A boy, with his legs and arms tied, sat in a chair and seemed to show no emotions at all. I did not know who the boy was. I had been instructed to cut holes in two hoses that contained some liquid, both of which were steaming heavily. When these two met, a deadly gas was formed. I started cutting holes in the hoses and the people began to slowly move out of the house. I also went out when I was done, and someone closed the door from the outside after me. I looked in and saw how the toxic gas began to spread inside the house like a fog. I still had the knife in my hand that I held in my hand next to the forearm so that it would not be visible to people who walked past us outside the house. It felt as if everyone was very well dressed. I left from there fairly quickly and started running up steep stairs and was very remorseful and scared of what I had done, even if it was permitted by the government and the important persons who were there. I stopped on the stairs and wanted to save the boy, but I realized it would be too late. I continued to run up the steep stairs and wanted to find a good place to hide the knife which I never wanted to see again (Male, 40).

Negative

Negative

 

0

2

0

8

I was at my parents' home and sat in the kitchen. Then, suddenly, something happens out there, and when I look out the door, my mother has caught a big deer that was injured by gunshot, and was bleeding from the head. She stands by its side and holds the horns that are sticking out to the sides (in reality the horns are straight up). This deer was also unusually large and had a very round shape of the head, plus it had a long horn on its forehead, like a unicorn! I was happy that this happened and shouted to my boyfriend, who is a hunter, that he should come and kill the deer. I was happy because I thought now we get free meat. I also thought that it was a very special deer because of the horn on its forehead, which was awesome. All this happened during the day, and it was sunny outside, it felt like a spring day (Female, 28).

Positive

Positive

 

2

0

9

0

I was in a completely white room, floor, ceiling, walls, everything was white. A slight feeling of being in a big box, but it was not uncomfortable in any way. There was a door frame, without a door, hence an opening. Only light was coming from there. The feeling was that I was content. My cohabitant was present in some way, but I remember no interaction. It was like we were just there, we did nothing, I do not remember any direct visual input more than previously described. The presence of the partner was in the form of a feeling that he was there (Female, 24).

Positive

Positive

 

1

0

2

0

Out for a walk, me and my girlfriend saw an old classmate of mine who was putting out posters. On these it said that he was going to organize an expo. My girlfriend asked me if it was because he was unemployed, but I explained that it was because he was so successful nowadays, had his own company, and gladly agreed to undertake such tasks. The next thing I remember is that I looked around at the same expo, but not much more than that (Male, 28).

Non-emotional

Positive

 

0

0

10

0

I was in a room, maybe a kitchen again, with my partner. He was standing and talking on the phone with his big sister, I think. I stood and tinkered with some cabinet first and then I looked over his shoulder and grinned and began pulling up the edge of my panties (had only panties on I think), so that the edge slipped further and further up over the butt, to seduce him. (Female, 23).

Non-emotional

Positive

 

0

0

10

0

It was winter and a lot of snow outside. My wife and I were out playing in it, among other things, we jumped down from a big pile of snow. In the beginning of the dream, it was just the two of us, but then we had a small child with us, who we jumped and played with, but it was only a few months old so it was not particularly amused by the jumping so we took it easy in instead, until the child fell asleep (Male, 24).

Non-emotional

Positive

 

0

0

7

1

Me and my partner were of royal blood, and it was sometime around the 1800s because we were on a big wooden ship and we were wearing strange clothes, a lot of extravagant clothes. We were in the cabins and only a few people were allowed in there. We were going to get married so the priest tied a cloth around our hands so we would hold hands. The priest spoke in Latin for a long time, until we were supposed to promise each other to love each other in sickness and in health. Then the party broke loose on the ship, flute music began to play, and we were going to go out to the deck and dance. Before I was allowed to go out, I received a special scarf on the shoulders which would show that I was married. The party lasted until dawn and we danced and ate a lot of food (Female, 28).

Non-emotional

Positive

 

0

0

7

0

I was at a restaurant, a very nice one. Crystal chandeliers in the ceiling, dark wooden tables, white tablecloths, mint green drapes. I sat at a table and talked with a few people. I knew that I would enter into partnership with one of them. He knew that he was going to earn money from our cooperation, but I was looking for something different. The prospect of money did not interest me. Anyways, I was going to go to a place and pretend to work there, it was a company we were going to buy, but first we had to look up some information about it. All of a sudden I am in the back (I think) of the restaurant and jump into a pickup van that takes me to this place. I do not need to go on a job interview, it seems that I am already employed there. I walk in and there is some form of telemarketing company, anyways the primary work form are phones. I go up lots of stairs, pass by several people behind their back who are talking on the phone. At the top of the building I meet who I think is the boss. We discuss a little bit, then I start to notice that everyone around me has a mustache. Real bushy mustache that resembles half oval shapes under your nose. It looks terrible. I go through the building again to get to the end and everyone turns around and has these ugly mustaches. They look at me, but I do not meet their gazes. My view is fixed on the ugly mustaches, if anything. Once outside the building, I meet this person that I had a deal with at the restaurant. Somehow I have learned from my terrible experience with mustaches that my partner does not have what it takes to be part of a deal with me. I tell him that he must be ready to go the extra mile, because there is always someone else who is ready to go an extra mile (Male, 25).

Non-emotional

Positive

 

0

0

6

1

I meet two people at the beach because I am going to do a story and interview these two. We are going to the beach which is located in a beautiful valley, almost like in the Alps, it is not a lake, but more like a wide river or so. Suddenly, when we get there, all the people who were there start to pack up and go, all at once. The beach is emptied in less than a few minutes. I think it is me that has such an effect on the people, but they do not even look in our direction. I sit on the sand and dig my bare feet deep in the sand, it is a little wet. Suddenly, in the distance, we see ripples on the water or patterns on the water which indicate that something is traveling there with high speed.  Something that looks like a giant leech, as big as a tree log, in the water, swims by us, ugly teeth sitting in a circle in the mouth, many teeth. High-set eyes and nostrils that it holds above the surface when it swims, slightly crocodile-like. I have time to realize that this is the reason why everyone left the beach. According to those that I met there, it comes there the same time every day. I walked along the river and followed the beast, I saw that it followed me with the eyes as if I were an easy prey. When the beast opened its mouth close to my face, it flashed all its teeth in front of my eyes, but then, suddenly, someone was holding it and showed it, and suddenly I was standing at the other side of a window much like at the zoo (Female, 35).

Non-emotional

Positive

 

0

0

6

2

I had a motorcycle that I drove around with. My friend told me to be careful with how I sat on it, you were absolutely not allowed to sit on it carelessly. I drove around for a while with no problems, although I had never driven one before, and ended up in some place. At this place I accidentally met a guy that I had talked with through Tinder, we realized this while we were talking to each other. Then I went home to my brother and, once there, I panicked about whether I locked the motorcycle or not. When I went out and checked, it was not there. I wondered if I had put it somewhere where I did not remember. My brother and I talked about a party that some classmates of mine were going to have, I maybe wanted to go but was not sure. I got to see a list they had made for the party which I thought was really lame so I would probably not want to go after all. Then I know that something else happened in the dream but unfortunately I do not remember. The last thing I remember was that my father came home to mom and that he was drunk because he had been drinking at work (Female, 23).

Negative

Positive

 

0

1

10

2

I was in a big room and I was busy preparing a party with my mom and my dad. Simultaneously, as I was preparing the party, I was getting ready myself, and was looking for my high-heeled shoes. Outside sat a guy I have been dating once, in a car waiting for me, because we were together. I got in the car and we kissed. Suddenly, I was with my mother and father at a car park in the city, my three best friends were there too. Me, mom and dad found a lot of gold bars on the ground, we picked them up and walked along a long street. Two women came along and pulled my mother and father into an apartment house because they wanted to steal the gold bars, and I followed them. We were in a small apartment and that woman locked herself in the bathroom with my mom and dad. I tried to get in but the other woman tried to stop me, so I hit her in the head. When I managed to open the bathroom door, my mom, dad and the first woman were sitting in there and eating ribs. They shut the door again so I could not enter. I went to the living room and there was a baby, I looked at the baby but heard that the woman I had hit was beginning to wake up. I was going to pick up the baby because I thought that she would not dare to hurt me if I had a baby in my arms. But when I was about to pick up the baby, it turned out to be only a computer screen, filled with lots of pictures of the baby. I was really scared that the woman I had hit was angry and was going to kill me, so I went to the kitchen to get a knife I could defend myself with. She came towards me and yelled at me a lot, cannot remember what she said. She walked towards me and I stabbed her in the face and she just laughed, then I stabbed her in the stomach, and she fell to the floor, she was still laughing. I cried and cried a lot because I did not want to hurt her, but I had to (Female, 21).

Negative

Positive

 

0

1

6

1

 

 
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