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Effect of Emotional Arousal
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Running Head: THE EFFECT OF EMOTIONAL AROUSAL ON RECALL
The Effect of Emotional Arousal and Valence on Memory Recall
500181765
Bangor University
Group 14, Thursday Afternoon
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Abstract
This study examined the effect of emotion on memory when recalling positive, negative and
neutral events. Four hundred and fourteen participants aged over 18 years were asked to read
stories that differed in emotional arousal and valence, and then performed a spatial distraction
task before they were asked to recall the details of the stories. Afterwards, participants rated
the stories on how emotional they found them, from ‘Very Negative’ to ‘Very Positive’. It
was found that the emotional stories were remembered significantly better than the neutral
story; however there was no significant difference in recall when a negative mood was
induced versus a positive mood. Therefore this research suggests that emotional valence does
not affect recall but emotional arousal affects recall to a large extent.
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Emotional arousal has often been found to influence an individual’s recall of past
events. It has been documented that highly emotional autobiographical memories tend to be
remembered in better detail than neutral events in a person’s life. Structures involved in
memory and emotions, the hippocampus and amygdala respectively, are joined in the limbic
system within the brain. Therefore, it would seem true that emotions and memory are linked.
Many studies have investigated this topic, finding that emotional arousal increases recall. For
instance, Kensinger and Corkin (2003) found that individuals remember emotionally arousing
words (such as swear words) more than they remember neutral words. This is supported by
Cahill and McGaugh (1995), who presented participants with either an emotionally arousing
story (concerning a car accident), or a neutral story. The findings showed that participants
who read the neutral story recalled less story elements than those who read the arousal one,
and memory was enhanced when the emotional element was introduced in the arousal story.
Thus, it would seem that emotions can significantly enhance memories. However, the studies
mentioned have only investigated memory using negative emotions and stimuli. Therefore, it
is difficult to say whether it is the emotional valence or arousal that is responsible for
enhanced recall.
There is considerable evidence to suggest that the emotional valence an individual
feels can affect recall of memories. Some argue that negative emotion makes one focus, and
thus one can remember details better (Kensinger, 2007). This idea is supported by Kensinger,
Garoff-Eaton and Schacter (2005), who found that negatively arousing content increases the
likelihood of remembering visual details about an object. However, this is disputed to some
extent by Yeung, Dalgleish, Golden and Schartau (2006) who found an induced negative
mood reduced the specificity of autobiographical memories. Gasper & Clore (2002) added to
this suggesting positive moods make people remember general information while negative
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moods make people focus on detail, thus recall of detail should be better when a negative
mood is induced.
Therefore, this study investigated the effect of emotional arousal on recall, and also
examined recall after negative and positive arousal was induced. It was a between subjects
experiment with four conditions. Participants were given two stories to read, one of which
contained emotional content. The first condition had participants read a negative story
followed by a neutral story, the second condition was a neutral story followed by a negative
one, the third condition was a positive story followed by a neutral one and the last was a
neutral story followed by a positive one. After reading each story once, participants were
asked to perform a distraction task before completing a free recall task about the information
in the stories. The hypotheses for this research was that recall of the stories with emotional
content will be higher than recall of the stories with neutral content, and that recall will be
higher when the neutral story is preceded by the negative story than when preceded by the
positive story.
Method
Participants
An opportunity sample of 414 male and female participants, over the age of 18, was
collected.
Measures
Recall was measured by giving participants a free recall task, to write down as much
information they could remember about each story (see Appendices A, B & C) on separate,
blank pieces of paper. One point was given for each correct phrase the participant recalled
that corresponded to the experimenters standardised mark scheme and the maximum amount
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for each story was 20 points (see Appendix D). Participants were given a scale for each story
they read after the experiment to rate how the story made them feel, from ‘Very Negative’ to
‘Very Positive’ with ‘Neutral’ in the middle (see Appendix E). This was used to find out if a
particular mood had been successfully induced in participants, and to see how they had
perceived the stories.
Stimuli and Apparatus
Three different stories were used as stimuli in this research. There was one negative
story (see Appendix A), one positive (see Appendix B) and one neutral (see Appendix C).
Two of the stories were presented to participants, one of which was always neutral and the
other contained emotional content. The neutral story was about dive watches, adapted from
Ellerby (2004) whereas the emotional stories were about a boy who had been taken to
hospital after a car accident (negative) or had been taken to hospital to visit a new sibling
(positive), adapted from Cahill & McGaugh (1995). Blank pieces of paper were used for the
participants to complete the distraction task of drawing a map, and the free recall tasks about
the stories. A rating scale concerning the mood of the participants after reading both stories
was also used (see Appendix E).
Design
The independent variables were the level of emotional content (either emotional or
neutral) in the first hypothesis, and the valence of emotional content (positive or negative) in
the second hypothesis. Participants were put into four different conditions, where they
received one of the following: the neutral story followed by the positive story, the neutral
story followed by the negative story, the positive story followed by the neutral story or the
negative story followed by the neutral story. This was a between-groups design because
participants could not be in more than one condition, in case rehearsal affected memory.
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Participants read the two stories they were given and were asked to complete a spatial
distraction task (drawing a map of their way to work or university) to prevent rehearsal. They
then freely recalled information about the stories on blank paper, and points were awarded
according to the mark scheme (see Appendix D). Thus, the dependent variable was how
much correct information participants recalled from the stories. To reduce experimenter bias,
standardised instructions were used (see Appendix F).
Procedure
Participants read the standardised instructions and signed the consent form (see
Appendix G) before reading the two stories presented to them. The stories were taken away
and participants completed a distraction task, consisting of drawing a map of their way to
work or university. Participants then were given two pieces of paper and asked to write down
any information they recalled from the stories on separate sheets. They were given a time
limit of five minutes for this free recall task so all participants had the same amount of time to
recall information. Afterwards, participants were asked to rate the stories depending on how
each story made them feel, e.g. Very Negative, Quite Positive, Neutral etc. Participants were
debriefed afterwards (see Appendix H), and the aims of the research and their right to
withdraw were explained.
Results
The results of the recall for the emotional stories and neutral stories are illustrated in
Figure 1. It was hypothesised that recall of the stories with emotional content will be higher
than recall of the stories with neutral content. The results showed recall for the emotional
stories was higher (M = 8.48, SD = 3.11) than that for the neutral story (M = 5.63, SD = 2.75)
but little difference between recall for stories presented first (M = 7.00, SD = 3.33) and
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second (M = 7.11, SD = 3.20).
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Figure 1. The mean percentage recall of the emotional stories when presented first
(n=104) and second (n=103) and neutral story when presented first (n=103) and second
(n=104). The error bars represent ± 1 SE of the mean.
A two-factor analysis of variance carried out on the results confirmed a main effect of
story F(1, 409) = 96.97, p < .001, 2 = .19 but no main effect of order F(1, 409) = 0.13, p =
.72, 2 = .01 and no significant interaction F(1, 409) = 0.69, p = .41, 2 = .01. An LSD test
carried out post-hoc shows the recall for the emotional stories were significantly higher than
that of the neutral story, p < .05. This will be used as evidence to support the claim that
emotional details are more likely to be remembered than neutral details.
The results of the recall after positive and negative mood induction are illustrated in
Figure 2. The hypothesis stated that recall will be higher when the neutral story is preceded
by the negative story than when preceded by the positive story. The results showed similar
recall for the neutral story when it followed the positive story (M= 6.24, SD=2.45) and the
negative story (M= 5.50, SD= 2.82).
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Figure 2. The mean recall of the neutral story after participants read the positive story
(n=43) and the negative story (n=61). The error bars represent ± 1 SE of the mean.
An independent samples t-test carried out on the data showed no significant difference
between recall for the neutral story when a positive mood or when negative mood was
induced, t(102) = 1.39, p = .17. This will be used as evidence to refute the claim that being in
a negative mood will improve memory for details more than being in a positive mood.
The story ratings from participants showed the positive story was rated most
positively, (M = 1.56, SD = 1.17) and the negative story was rated most negatively, (M = 1.93, SD = 0.87) but the neutral story was rated slightly negatively, (M = -0.13, SD = 0.52).
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Figure 3. The mean valence ratings for the positive, neutral and negative stories (n=
414). The error bars represent ±1 SE of the mean.
A one-way analysis of variance conducted on the story ratings showed a significant
difference between all three mean ratings. Post-hoc tests confirmed the positive story was
rated significantly more positive and the negative story was rated significantly more negative.
Discussion
The purpose of this research was to determine whether emotional content is
remembered better than neutral content, and to investigate whether inducing a negative mood
in participants would improve memory more than a positive mood. The results showed that
participants were significantly more likely to recall emotional content than neutral content;
however there was no difference in recall when a negative or positive mood was induced.
Therefore, the findings are consistent with the first hypothesis, but not the second. The
findings for the first hypothesis agree with previous research in this area. For instance,
Kensinger and Corkin (2003) found that individuals remember emotional stimuli more than
they remember neutral stimuli. However, the findings for the second hypothesis, concerning
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emotional valence, do not agree with previous research. Yeung, Dalgleish, Golden and
Schartau (2006) found an induced negative mood reduced the specificity of autobiographical
memories. Other research has also found significant differences when it comes to inducing
positive and negative moods. Kensinger, Garoff-Eaton and Schacter (2005) found that
negatively arousing content increases the likelihood of remembering details. Thus, our
findings for the second hypothesis are not consistent with previous results. Perhaps our
stimuli were not emotionally arousing enough, as results from ratings showed that most
participants found the emotional stories to be only ‘Quite Negative’ or ‘Quite Positive’.
There are several ways in which this study could be furthered. Firstly, the sample used
included older adults, and it has been found that the memory of older adults is not as good as
that of younger adults (Taylor, Miller & Tinklenberg, 1992). Therefore there may have been
a main effect of age that was never tested. To further this research, participants could be split
into groups of younger and older adults, thereby creating a three factor design when
investigating emotional versus neutral content. Another issue was the ratings of the emotional
stories. Results from the ratings showed that although the stories were rated how we
expected, participants did not consider the stories ‘Very Positive’ or ‘Very Negative’, thus we
may not have induced a strong enough mood in participants, therefore a pilot study should
have been used to test the emotionality of the stimuli, and if this study were replicated the
emotional stories should contain more emotional content.
There are theoretical and practical implications to this research. Firstly, these results
add to the literature in the area concerning memory and emotion, and fit partially with what
we already know. That is, that emotion enhances memory. Therefore we can apply the
findings of the first hypothesis to learning; attaching some emotion to information that needs
to be remembered could help one recall it, for instance in an exam setting. It also helps
explain Post Traumatic Stress Disorder, as this disorder comes about from emotion being
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involved with memory. Further research into this area could bring about treatments for this
particular disorder. The results for the second hypothesis imply that memory is just as good
when in a negative or positive mood, therefore we could apply this to autobiographical
memories and suggest that people will remember just as many negative as positive events in
their lives. This can also be used in education, like the results of the first hypothesis, as it
suggests we can remember information from subjects we dislike as well as information from
subjects we enjoy.
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References
Cahill, L. & McGaugh J. L. (1995). A novel demonstration of enhanced memory associated with
emotional arousal. Consciousness and Cognition, 4, 410-421.
Ellerby, D. (2004). The diving manual: An introduction to scuba diving. Richmond,
Surrey: Circle Books.
Gasper, K. & Clore, G. L. (2002). Attending to the big picture: mood and global versus local
processing of visual information. Psychological Science, 13, 34–40. doi: 10.1111/14679280.00406
Kensinger, E. A. (2007). Negative emotion enhances memory accuracy: Behavioural and
neuroimaging evidence. Current Directions in Psychological Science, 16 (4), 213-218. doi:
10.1111/j.1467-8721.2007.00506
Kensinger, E. A. & Corkin, S. (2003). Memory enhancement for emotional words: Are emotional
words more vividly remembered than neutral words? Memory & Cognition, 31 (8), 11691180. Retrieved from http://web.mit.edu/bnl/pdf/Kensinger_Corkin_MC03.pdf
Kensinger, E. A., Garoff-Eaton, R. J. & Schacter, D. L. (2007). Effects of emotion on memory
specificity in young and older adults. Psychological Sciences and Social Sciences, 62, 208215. Retrieved from http://psychsoc.gerontologyjournals.org/cgi/reprint/62/4/P208
Taylor, J. L., Miller, T. P. & Tinklenberg, J. R. (1992). Correlates of memory decline: a 4-year
longitudinal study of older adults with memory complaints. Psychol Aging., 7 (2), 185-193.
doi: 10.1037/0882-7974.7.2.185
Yeung, C., Dalgleish, T., Golden, A. & Schartau, P. (2005). Reduced specificity of autobiographical
memories following a negative mood induction. Behaviour Research and Therapy, 44 (10),
1481-1490.
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Appendices
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Appendix A
Negative Story
A father and his son were leaving home in the morning. He was taking him to visit his
mother. The mother was a laboratory technician at Victoria Memorial Hospital. They checked
before crossing a busy road. While crossing the road, the boy was caught in a terrible
accident, which critically injured him. At the hospital, staff prepared Accident & Emergency,
and the boy was rushed in. An image from a brain scan machine showed severe bleeding in
the boy’s brain. All morning, a surgical team struggled to save the boy’s life. Specialised
surgeons were able to re-attach the boy’s severed feet. After the surgery, while the mother
stayed with the boy, the father left to phone his other child’s nursery. Feeling distraught, he
phoned the nursery to tell them he would soon pick up his child. Heading to pick up his child,
he hailed a taxi at the number 9 bus stop.
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Appendix B
Positive Story
A father and his son were leaving home in the morning. He was taking him to visit his
mother. The mother was in the maternity ward at Victoria Memorial Hospital. They checked
before crossing a busy road. While walking along, the father received a phone-call to say the
mother had given birth. The father told his son that he had a new baby brother. The boy felt
very excited. At the hospital, the boy rushed to his mother’s bedside. The boy held his baby
brother for the first time. Staff in the ward took a photograph of the smiling boy and his
brother. After, while the boy stayed with his mother, the father left to phone his other child’s
nursery. Feeling elated, he phoned the nursery to tell them he would soon pick up his child.
Heading to pick up his child, he hailed a taxi at the number 9 bus stop.
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Appendix C
Neutral Story
Dive watches come in two basic forms. First, the traditional analogue type with a calibrated
bezel used to measure dive duration. Second the digital type, which is essentially a
sophisticated waterproof stopwatch. There is no doubt that the heavy analogue diver’s watch
is much more of an eye-catcher in the pub. However, with the best will in the world it is not
easy to read dive times from the bezel to anything like the accuracy of a digital watch or dive
computer. Many analogue divers have failed to correctly time their dive. Sometimes because
they have forgotten to correctly align the bezel at the start of the dive. Other times because
they have accidentally rotated the bezel during the dive. Of course, forgetting to start a digital
instrument can also result in inaccurate time measuring. However, most modern dive
computers are pressure-triggered and will start automatically at the beginning of the dive.
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Appendix D
Standardised Mark Scheme for Negative and Neutral Story Recall.
Rules:- Exact words are not needed, meaning must be intact. Allocate half points where
appropriate. If information is crosses, irrelevant or untrue, allocate zero points. Maximum of
20 points for each story.
Neutral Story:1. Two types of watch = 2 points
2. Analogue = 1 point
3. Calibrated bezel = 2 points
4. Digital = 1 point
5. Sophisticated waterproof stopwatch = 2 points
6. Analogue eye catching in pub = 1 point
7. Analogue not as easy to read = 1 point
8. As digital or dive computer = 2 points
9. Analogue incorrect dive time = 1 point
10. Forgotten to align bezel = 1 point
11. Accidentally rotated bezel = 1 point
12. Forget to start digital = 1 point
13. Inaccurate time measuring = 1 point
14. Modern dive computer = 1 point
15. Pressure triggered = 1 point
16. Automatic start = 1 point
Negative Story:1. Father and son = 1 point
2. Leaving home in morning = 1 point
3. Visit mum = 1 point
4. Lab technician = 1 point
5. Victoria Memorial Hospital = 2 point
6. Checked road = 1 point
7. Boy caught in accident = 1 point
8. A+E prepared and rushed in = 2 point
9. Brain scan and bleeding = 2 point
10. Surgical team struggle to save life = 2 point
11. Specialists reattach feet = 1 point
12. Mother stayed with boy = 1 point
13. Dad phoned nursery = 1 point
14. Distraught, soon to pick up child = 1 point
15. Taxi no. 9 bus stop = 2 points
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Positive Story: 1) Father & son - 1 point
2) Leaving home in morning - 1 point
3) Visit mother - 1 point
4) Maternity ward - 1 point
5) Victoria Memorial Hospital - 2 points
6) Phone call to father - 1 point
7) Mum given birth - 1 point
8) New baby brother - 1 point
9) Boy excited - 1 point
10) Boy rushed to mum’s bedside - 2 points
11) Held baby brother - 1 point
12) Staff photo of smiling boy & brother - 2 points
13) Boy stayed with mum - 1 point
14) Dad phoned nursery - 1 point
15) Elated soon pick up child - 1 point
16) Taxi at no. 9 bus stop - 2 points
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Appendix E
Story Rating Sheet
We would like to know how the stories you read made you feel. Please indicate on the
following scale how positive, neutral or negative you found:
The first story you read:
Very
negative
Quite
negative
A little
negative
Neutral
A little
positive
Quite
positive
Very
positive
A little
negative
Neutral
A little
positive
Quite
positive
Very
positive
The second story you read:
Very
negative
Quite
negative
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Appendix F
Standardised Instructions
During this experiment you will be presented with two stories. You will be required to read
each story once. Following this you will be asked to rate these stories. This experiment will
not take in excess of 30 minutes. If you decide to participate in this experiment you will be
required to complete a consent form. Thank you for considering taking part.
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Appendix G
Consent Form
This is to certify that I, ……………………………….. (print name in block capitals) hereby
agree to participate in a scientific experiment as an authorised part of the research
undertakings within the School of Psychology at the University of Wales, Bangor, under the
supervision of Dr Caroline Bowman.
The investigation and my part in the investigation have been explained fully to me by the
Experimenter, …………………………………. (print name in block capitals), and I
understand his/her explanation. I understand that some of the information that I will read
during the experiment might be distressing. The procedures of this investigation and their
risks have been answered to my satisfaction.
I understand that all data will remain confidential with regard to my identity.
I understand that I am free to withdraw my consent and terminate my participation at any
time without penalty.
I understand that I may request a summary of the results of the study.
………………………
…………………………………..
Date
Participant’s signature
I, the undersigned, have fully explained the investigation to the above individual.
………………………
…………………………………..
Date
Experimenter’s signature
Complaints about the conduct of this research should be addressed to Professor Oliver
Turnbull, Head of School of Psychology, University of Wales, Bangor, LL57 2DG.
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Appendix H
Debriefing Form
Thank you for your participation in the project.
It is expected that emotion will have a positive effect on memory recall. The results of this
investigation will allow our understanding of emotion based memory recall to develop.
As your participation was voluntary you therefore have the right to withdraw your results at
any time. Any results gathered from this experiment will remain anonymous.
Any queries or problems related to this study should be forwarded to Caroline Bowman.