Enhanced Response Inhibition During Intensive Meditation Training Predicts Improvements in Self-Reported Adaptive Socioemotional Functioning
Author: Baljinder Sahdra, Emilio Ferre, Katherine A Maclea, Phillip R Shave Publisher: https://www.researchgate.net/publication/51058702_Enhanced_Response_Inhibition_During_Intensive_Meditation_Training_Predicts_Improvements_in_Self-Reported_Adaptive_Socioemotional_Functioning Publish Date: 2011-4 Review Date: Status:š„
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We examined the impact of training-induced improvements in self-regulation, operationalized in terms
of response inhibition, on longitudinal changes in self-reported adaptive socioemotional functioning.
Data were collected from participants undergoing 3 months of intensive meditation training in an isolated
retreat setting (Retreat 1) and a wait-list control group that later underwent identical training (Retreat 2).
A 32-min response inhibition task (RIT) was designed to assess sustained self-regulatory control.
Adaptive functioning (AF) was operationalized as a single latent factor underlying self-report measures
of anxious and avoidant attachment, mindfulness, ego resilience, empathy, the five major personality
traits (extroversion, agreeableness, conscientiousness, neuroticism, and openness to experience), diffi-culties in emotion regulation, depression, anxiety, and psychological well-being. Participants in Retreat
1 improved in RIT performance and AF over time whereas the controls did not. The control participants
later also improved on both dimensions during their own retreat (Retreat 2). These improved levels of
RIT performance and AF were sustained in follow-up assessments conducted approximately 5 months
after the training. Longitudinal dynamic models with combined data from both retreats showed that
improvement in RIT performance during training influenced the change in AF over time, which is
consistent with a key claim in the Buddhist literature that enhanced capacity for self-regulation is an
important precursor of changes in emotional well-being.
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The benefits of certain kinds of meditation may stem in part
from their emphasis on using attentional skills to regulate emotions
and actions. A key feature of various kinds of meditation is
observing oneās experiences (e.g., thoughts, emotions, or behav-ioral inclinations) while refraining from either obsessively follow-ing them or actively pushing them away (e.g., Asanga, 4th to 5th
century BCE/1950; Bodhi, 2000; Lingpa, unknown publication
date, as referenced in Wallace, 2006; Padmasambhava, 9th century
BCE/1997; Shantideva, 7th century BCE/2006).
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Training in recognizing and inhibiting
oneās automatic tendencies during meditation (such as not scratch-ing an itch, not wiggling, and not following a trail of anxious or
depressing rumination) is thought to increase emotional balance in
daily life (Wallace & Shapiro, 2006) and enhance oneās general
capacity to direct attention at will to oneās goals, values, and
aspirations without being distracted or derailed by lifeās ups and
downs (Chƶdrƶn, 2006; Wallace, 2006).
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Furthermore, the ability to
control attention and habitual behavioral responses in the labora-tory has been shown to predict successful executive control outside
the laboratory, especially in tasks involving response inhibition,
the voluntary withholding of a habitual or impulsive response. For
instance, response inhibition errors in the laboratory predict atten-tional lapses and action slips in everyday life (Robertson, Manly,
Andrade, Baddeley, & Yiend, 1997).
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Recent diary studies of participants at-tempting to control bad habits in daily life shows that āvigilant
monitoringā (thinking ādonāt do itā or carefully watching for
slipups in daily life) helped in controlling unhealthy habits by
increasing inhibitory cognitive control (Quinn et al., 2010).
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Based on an integration of this diverse literature, we hypothesize
that meditation practice benefits socioemotional functioning by
enhancing executive control, which can be indexed, at least in part,
by laboratory assessments of the ability to inhibit undesired re-sponses. To test the hypothesis that meditation-induced changes in
response inhibition affect changes in adaptive socioemotional
functioning, we collected longitudinal data from adults engaged in
3 months of intensive meditation training in an isolated retreat
setting (Retreat 1) and from a wait-list control group that later
engaged in identical training (Retreat 2). The training involved
meditation techniques designed to improve sustained attention, and
attentional and emotional regulation (Wallace, 2006). We tracked
changes in response inhibition using a task that required partici-pants to respond quickly to frequently occurring stimuli (90%
probability) and not to respond to infrequently occurring stimuli
(10% probability).
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Despite the seemingly simple nature of the task, errors in re-sponding to the infrequent stimulus are common (Helton, 2009).
The task places high processing demands on executive attention,
requiring a person to monitor his or her performance to avoid
making the habitual motor response when the low-frequency stim-ulus appears. Further, the task implicitly involves making behav-ioral adjustments (via increased executive control) when response
errors occur (Carter, Botvinick, & Cohen, 1999; Ridderinkhof, van
den Wildenberg, Segalowitz, & Carter, 2004). When people per-form response inhibition tasks for extended periods (e.g., ?3
0min), accuracy notably decreases over time (Grier et al., 2003;
Helton et al., 2005), and people find the task stressful (Grier et al.,
2003). Informed by these findings, we designed a 32-min sustained
response inhibition task (RIT) that combined the effort associated
with sustained performance (see review in Warm, Parasuraman, &
Matthews, 2008) and the challenge of avoiding impulsive behav-ioral responses.
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P
articipant
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ence,
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-ence, and were likely to adhere to the intensive training schedule
and complete the retreat.
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Results1
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Response Inhibition Task (RIT):
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Retreat 1. Of the 60 participants in the period that included
Retreat 1 (n ?30 in each group), three participants were left-handed (1 retreat participant and 2 waitlist control participants).
Separate analyses including and excluding these participants
yielded virtually identical results. Thus left-handed participants are
included in the analyses reported below. We removed participants
who were outliers (3 S Dbelow the grand mean) in change in
accuracy (M ?. 07,S D?.07) on the RIT. One retreat participant
was an outlier on change in accuracy. Thus, the RIT analyses
included 59 individuals.
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RIT threshold. As mentioned before, the purpose of the
threshold procedure at the beginning of the RIT was to keep task
difficulty constant across participants and across testing times.
Calibrating task difficulty in this way allowed us to interpret any
training-related changes in RIT accuracy. First, to determine if
threshold itself changed over the course of training, we used
analysis of variance (ANOVA) to test the between-subjects effect
o fg roup(retreat v. control) and the within-subjects effect of
a ssessment(pre-, mid- and postretreat) on threshold. A main effect
of assessment (F(2, 56) ?4 5.0,p ?. 0001,?p
2 ?.62) revealed that
thresholds decreased (i.e., improved) across assessments in both
groups (Retreat: M ?1.0Ā° at preretreat, 0.71Ā° at midretreat, and
0.65Ā° at postretreat; Control: M ?1.2Ā° at preretreat, 0.87Ā° at
midretreat, and 0.76Ā° at postretreat). The main effect of group was
also significant (F(1, 57) ?4 .25,p ?. 04,?p
2 ?.07). Importantly,
there were no group differences in threshold at preretreat, t(
57)?1 .55,p ?.12, indicating that the groups were matched at the
beginning of training. Although thresholds were significantly
lower in the retreat group at midretreat, t( 57)?2 .06,p ?.04, the
group difference was not significant at postretreat, t( 57)?1
.60,p ?.11 and the interaction between group and assessment was not
significant ( p ?. 75,?p
2 ?.01). Taken together, these findings are
consistent with general practice effects and not with training-related change. Because we set the length of the target line in the
RIT to the threshold value obtained at each assessment for each
individual, individual differences in threshold change may have
influenced RIT performance. Thus, we statistically controlled for
the influence of threshold in all models of RIT performance
reported next.
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RIT accuracy. We modeled changes in RIT performance
during Retreat 1 using hierarchical linear regression. Analyses
were conducted in SAS using the proc mixed function (Singer,
1998). We first tested a baseline model with fixed effects of b
lock(centered to the first block), a ssessment(preretreat, midretreat and
postretreat centered to the first assessment), g roup(retreat and
control; retreat group membership was coded as 1 and control
group membership as 0) and t hreshold(centered to the grand
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mean). We included random effects on the intercept to allow for
individual differences in initial performance (Aā during the first
block). This model revealed a significant effect of block (
???. 009,p ?.0001), a significant effect of threshold (???.
044,p ??.0001) and a nonsignificant effect of group ( p ?.
52).Importantly, the effect of assessment was significant ( ??.
046,p ?.0001), indicating increases in average accuracy. To test the
prediction that increases in accuracy would be greater for retreat
participants, we next tested a model that included the interaction
between group and assessment. This model also included the
interaction between threshold and assessment, to control for indi-vidual differences in threshold change. Consistent with our pre-diction, the interaction between group and assessment was signif-icant ( ??. 011,p ?.02). Moreover, the Bayesan Information
Criterion (BIC; smaller values indicate a better model fit) indicated
that this model fit the data better (BIC ??3092) than the baseline
model (BIC ??3049). Finally, the addition of 2-way and 3-way
interaction effects (e.g., the interaction between block and assess-ment) did not improve the model fit. Thus, the findings demon-strate training-related increases in average response inhibition ac-c
urac
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Retreat 2
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RIT threshold. In the model of RIT performance in Retreat
1, we found that individual differences in threshold improvement
influenced accuracy on the RIT ( p ?.0001). In Retreat 2, we
addressed this issue by fixing the length of the target line for each
participant to the threshold achieved at the beginning of training.
A repeated-measures ANOVA across four assessments (postretreat
1, preretreat 2, midretreat 2 and postretreat 2) confirmed that
thresholds did not change significantly after the end of Retreat 1
(F(3, 26) ?1 .06,p ?. 38,?p
2 ?.
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RIT accuracy. As in Retreat 1, we modeled RIT performance
using hierarchical linear regression. We tested the fixed effects of
block, assessment (preretreat, midretreat and postretreat), and the
interaction between block and assessment. We again included
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random effects on the intercept to allow for individual differences
in initial accuracy. This model revealed a significant effect of
block (???. 011,p ?.0001), a significant effect of assessment
( ??. 011,p ?.02), and a significant interaction between assess-ment and block ( ??. 003,p ?.02). The significant effect of
assessment confirmed the result from Retreat 1 of improvements in
average response inhibition accuracy with training. Further, the
significant interaction between block and assessment demonstrated
that training led to improvements in sustained response inhibition
accuracy (i.e., a more positive slope across blocks) when task
difficulty and target parameters were held constant.