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Supplemental Materials
Supplemental materials for Inhibition of attention for negative affective material: contributions
by HOMER1 gene variation.
Supplementary Figure 1. An example of an experimental trial pair (A) and a control trial pair (B)
for the negative affective priming task. Note that fixation and stimuli are not to scale.
A
terrible
+
+
friendly
Fixation
500 ms
Prime Trial
Until Response
ITI
500 ms
Fixation
500 ms
insecure
terrific
Probe Trial
Until Response
ITI
500 ms
Time
B
quick
+
Fixation
500 ms
Time
alone
+
quiet
Prime Trial
Until Response
ITI
500 ms
Fixation
500 ms
happy
Probe Trial
Until Response
ITI
500 ms
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Effects of endorsement on reaction time in the negative affective priming task
An anonymous reviewer raised the question as to whether endorsement or rejection of
target words might affect reaction time. To our knowledge, this has not been examined in prior
studies using the Negative Affective Priming (NAP) task. We report our analyses below, but the
results should be interpreted with caution. Many participants did not endorse any negative words
as self-descriptive and/or did not reject any positive words as self-descriptive. This resulted in a
reduced sample size for each study. In addition, even participants who did endorse negative
words and/or reject positive words tended to do so at a low rate. Thus, for many participants
there were very few trials to use to calculate a mean reaction time. With these caveats in mind,
we present results including endorsement below.
Study 1:
A 2 (Trial Type: prime, probe) x 2 (stimulus valence: negative, positive) x 2
(endorsement as self-descriptive: no, yes) repeated measures ANOVA revealed a significant
main effect of trial type on reaction time, F(1, 26) = 6.93, p = .014, ηp2 = .21, with participants
demonstrating faster reaction times in prime trials (M = 1301, SD = 550) compared to probe
trials (M = 1393, SD = 581).
There was also a significant interaction between valence and endorsement on reaction
time, F(1, 26) = 13.25, p = .001, ηp2 = .34. Participants were slower to endorse a negative word
as self-descriptive (M = 1416, SD = 734) compared to when they indicated that a negative word
was not self-descriptive (M = 1264, SD = 436), t(53) = 2.26, p = .028, Cohen’s d = .25. In
contrast, participants were faster to endorse a positive word as self-descriptive (M = 1219, SD =
452) compared to when they indicated that a positive word was not self-descriptive (M = 1488,
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SD = 565), t(53) = 4.77, p < .001, Cohen’s d = .53. Participants were also faster to reject a
negative word as self-descriptive compared to rejecting a positive word, t(53) = 4.01, p < .001,
Cohen’s d = .44, and faster to endorse a positive word as self-descriptive compared to a negative
word, t(53) = 2.90, p = .005, Cohen’s d = .32. See Supplementary Figure 2 below.
Supplementary Figure 2. Interaction between word valence and endorsement of target words on
reaction time in Study 1. Error bars represent the 95% confidence interval of the mean.
Main effects for valence, F(1, 26) < 1, p = .76, and endorsement, F(1, 26) = 1.87, p = .18,
were not statistically significant. Similarly, interactions of trial type by valence, F(1, 26) < 1, p =
.33, trial type by endorsement, F(1, 26) < 1, p = .91, and the three way interaction of trial type by
valence by endorsement, F(1, 26) = 1.12, p = .29, were not statistically significant.
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Study 2:
A 2 (Trial Type: prime, probe) x 2 (stimulus valence: negative, positive) x 2
(endorsement as self-descriptive: no, yes) repeated measures ANOVA revealed a significant
main effect of endorsement on reaction time, F(1, 37) = 7.27, p = .01, ηp2 = .16, with participants
demonstrating faster reaction times when endorsing a word as self-descriptive (M = 950, SD =
290) compared to when rejecting a word as self-descriptive (M = 1030, SD = 365).
There was also a significant interaction between valence and endorsement on reaction
time, F(1, 37) = 7.48, p = .01, ηp2 = .17. Participants were faster to endorse a positive word as
self-descriptive (M = 921, SD = 196) compared to when they indicated that a positive word was
not self-descriptive (M = 1100, SD = 464), t(75) = 4.49, p < .001, Cohen’s d = .50. Participants
were also faster to reject a negative word as self-descriptive (M = 960, SD = 205) compared to
rejecting a positive word, t(75) = 3.63, p = .001, Cohen’s d = .39. See Supplementary Figure 3
below.
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Supplementary Figure 3. Interaction between word valence and endorsement of target words on
reaction time in Study 2. Error bars represent the 95% confidence interval of the mean.
The interaction between trial type and endorsement on reaction time was also significant,
F(1, 37) = 4.71, p = .037, ηp2 = .11. This interaction was driven by faster reaction times to
endorse words as self-descriptive in prime trials (M = 930, SD = 289) compared to rejecting
words in prime trials (M = 1056, SD = 397), t(75) = 3.08, p = .003, Cohen’s d = .36. There was
also a marginally significant trend for participants to reject words in the probe condition (M =
1004, SD = 329) compared to the prime condition, t(75) = 1.85, p = .069, Cohen’s d = .14.
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Supplementary Figure 4. Interaction between trial type and endorsement of target words on
reaction time in Study 2. Error bars represent the 95% confidence interval of the mean.
Main effects for valence, F(1, 37) = 1.71, p = .20, and trial type, F(1, 37) < 1, p = .75,
were not statistically significant. Similarly, interactions of trial type by valence, F(1, 37) = 3.30,
p = .077, and the three way interaction of trial type by valence by endorsement, F(1, 37) = 1.11,
p = .30, were not statistically significant.
Effects of HOMER1 genotype variation on the NAP using the full ethnically heterogeneous
sample in Study 2
Using an ethnically heterogeneous sample of 46 GG, 71 GA, and 53 AA participants
there was a significant effect of genotype on inhibition of attention for negative material, F(2,
167) = 3.63, p = .029, ηp2 = .04. Post-hoc analyses revealed that differences between HOMER1
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genotype group in inhibition for negative words was driven by differences between the GG and
GA genotype groups, t(115) = 2.56, p = .012, Cohen’s d = .48. There were no significant
differences between GG and AA, t(97) = 1.63, p = .11, or GA and AA, t(122) = 1.21, p = .23,
groups. See Supplementary Figure 5 below.
Supplementary Figure 5. Inhibition of attention to negative material by HOMER1 genotype in
Study 2 using an ethnically heterogeneous sample. Error bars represent the 95% confidence
Inhibition of Attention to Negative Material
interval of the mean.
60
40
20
0
-20
-40
-60
-80
-100
GG
GA
AA
HOMER1 genotype
There were no effects of HOMER1 genotype group on inhibition of attention to positive
material, F(2, 167) < 1, p = .85. Similarly there were no effects of BDNF Val66Met genotype
group on inhibition of negative, F(1, 168) < 1, p = .81, or positive, F(1, 168) < 1, p = .39,
material.