An exploration of electrodermal activity
during comprehension of a seductive scientific text
Michael C. Mensink, Jacob Achtemeier, & Paige Lysne
Introduction
Previous research has well documented the seductive details effect,
in which highly interesting anecdotes reduce memory for important
scientific content to be learned and enhance memory for irrelevant content,
compared to control readers (for a review, see Rey, 2012). Seductive
details also appear highly attractive during reading, as evidenced by online
measures (Peshkam, Mensink, Putnam, & Rapp, 2011).
Why do seductive details attract so much attention during reading?
One explanation is that seductive details appear as small narrativevignettes within expository texts, potentially evoking high levels of
emotional interest (Kintsch, 1980) compared to other content. However,
previous examinations regarding the interestingness of seductive details
have relied on offline Likert-type self-reports of emotional interest. In the
current experiment, we conducted an initial exploration into the feasibility of
using electrodermal activity (EDA) as an online measure of emotional
interest while reading a seductive scientific text. While previous research
studies have shown some promising results in predicting reading
comprehension outcomes using physiological arousal (i.e., Daley, Willett, &
Fischer, 2013); similar investigations into an effect that may be largely
driven by emotional response has not been undertaken. We considered
this study an initial examination of the feasibility of recording arousal in
conjunction with other standard online and offline measures of
comprehension.
In order to examine these aspects, participants in the current
experiment read a seductive scientific text on a computer while their
electrodermal activity was recorded and completed a free recall. In this
way, we hoped to best understand the contribution of arousal to online
processes and subsequent offline products while reading a seductive
scientific text. Our hypotheses were formulated around these measures:
We predicted that 1) participant reading times would be longer for
seductive details compared to important content, 2) participants would
recall a higher proportion of seductive details compared to important
content, and 3) that overall arousal would be higher for a seductive
scientific text compared to a non-seductive scientific text.
Method
Materials. Prior to the experiment, a dual-topic scientific text on
severe weather was created and normed that contained twelve paragraphs
on lightning and tornado formation (1132 words), constituting the important
content. Twelve seductive detail sentences were added throughout the text
(252 words).
Apparatus. Electrodermal activity was measured using a BIOPAC
MP35 4-channel physiological data acquisition system on a PC. Sentence
reading times were measured using EPRIME 2.0 on a second display PC.
Participants. Thirty-five students from the University of WisconsinStout (MAGE = 19.69, SDAGE = 2.90) participated in the experiment for
course credit.
Procedure. Participants read the text one sentence at a time on a
computer while electrodermal activity during reading was measured via two
sensors on their left hand palm. Participants used their right hand to press
the space bar and advance through the text at their own pace. After
reading, the electrodes were removed, and participants completed a math
distractor page, a free recall, and a short reading strategy inventory. Once
participants completed the experiment, they were debriefed and excused.
Table 1 - Mean Reading Times for
Seductive Details & Important Content
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Results
Table 1 – Reading Times: Reading times in milliseconds were averaged
for each sentence type and participant. Reading times greater than 2.5
standard deviations above the mean for each participant were removed, with
less than 2.5% of the data lost. A repeated-measures ANOVA was conducted
on mean sentence reading times, with sentence type repeated withinparticipants (Important Content, Seductive Details). We observed a significant
main effect of sentence type on reading times, F(1,34) = 20.22, MSe =
491,315.15, p < .001, η2 = .37, with participants spending longer reading
seductive detail sentences compared to important content, on average.
Table 2 – Proportional Recalls: A repeated-measures ANOVA was
conducted on the proportion of idea units recalled, with sentence type repeated
within-participants (Important Content, Seductive Details). We observed a
significant main effect of sentence type on recall, F(1,34) = 42.17, MSe = .005,
p < .001, η2 = .554, with participants recalling significantly more seductive
detail sentences compared to important content, on average.
Electrodermal Activity (EDA): Average EDAs for participant who read
the seductive scientific text (M = 14.86, SD = 9.11) were compared to a group
of control readers (M = 11.87, SD = 6.76); no significant differences in mean
EDA were observed between the two groups (p = .17).
Discussion
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Important Content
Seductive Details
Table 2 - Mean Proportional Recalls for
Seductive Details & Important Content
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While the experimental hypotheses were supported in regards to
increased reading times and recall of seductive details compared to important
content, we were unable to discriminate physiological arousal for participants
who read a seductive scientific text and participants who read the same text
without seductive details.
It may be the case that electrodermal activity, as a gross indicator of
emotional interest tied to physiological arousal, is simply not responsive
enough a measure during online comprehension. Indeed, current
investigations of physiological response and reading comprehension have
suggested the utility of a more sensitive arousal measure tied to respiratory
sinus arrhythmia (i.e., Daley et al., 2014). It may also be the case that the
control text used in this experiment is emotionally stimulating to readers even
when the seductive details are removed.
Future experiments in our laboratory will seek to utilize more sensitive
measures of arousal in conjunction with other widely utilized indicators of
online processes and offline products, in order to better understand the
relationship between interest, arousal, and comprehension of scientific texts.
References
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Important Content
Seductive Details
Daley, S. G., Willett, J. B., & Fischer, K. W. (2014). Emotional responses
during reading: Physiological responses predict real-time reading
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Harp, S. F., & Mayer, R. E. (1997). The role of interest in learning from
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Kintsch, W. (1980). Learning from text, levels of comprehension, or: Why
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Peshkam, A., Mensink, M. C., Putnam, A. L., & Rapp, D. N. (2011). Warning
readers to avoid irrelevant information: When being vague might be
valuable. Contemporary Educational Psychology, 36(3), 219-231.
Rey, G.D. (2012). A review of research and a meta-analysis of the seductive
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