Quality of life, emotion regulation, and heart rate variability in individuals with intellectual disabilities and concomitant impaired vision
- Adrian Meule†1Email author,
- Katharina Fath†2,
- Ruben GL Real1,
- Stefan Sütterlin3, 4,
- Claus Vögele3, 4 and
- Andrea Kübler1, 5
© Meule et al.; licensee Springer. 2013
Received: 19 November 2012
Accepted: 21 March 2013
Published: 27 March 2013
Positive associations have been found between quality of life, emotion regulation strategies, and heart rate variability (HRV) in people without intellectual disabilities. However, emotion regulation and HRV have rarely been investigated in people with intellectual disabilities. Assessment of subjectively reported quality of life and emotion regulation strategies in this population is even more difficult when participants are also visually impaired.
Subjective and objective quality of life, emotion regulation strategies, and HRV at rest were measured in a sample of people with intellectual disabilities and concomitant impaired vision (N = 35). Heart rate was recorded during a 10 min resting period. For the assessment of quality of life and emotion regulation, custom made tactile versions of questionnaire-based instruments were used that enabled participants to grasp response categories.
The combined use of reappraisal and suppression as emotion regulation strategies was associated with higher HRV and quality of life. HRV was associated with objective quality of life only. Emotion regulation strategies partially mediated the relationship between HRV and quality of life.
Results replicate findings about associations between quality of life, emotion regulation, and HRV and extend them to individuals with intellectual disabilities. Furthermore, this study demonstrated that quality of life and emotion regulation could be assessed in such populations even with concomitant impaired vision with modified tactile versions of established questionnaires. HRV may be used as a physiological index to evaluate physical and affective conditions in this population.
Quality of life refers to the general well-being of an individual. While most humans can provide information about this quite easily, the assessment of quality of life in people with intellectual disabilities can be challenging. Research in people without intellectual disabilities shows that specific emotion regulation strategies are differentially related to quality of life and to physiological indices. In this paper, we first outline the concept of quality of life and its assessment in people with intellectual disabilities. Research on different emotion regulation strategies and their relationships with quality of life is then discussed. Finally, associations between cardiac autonomic regulation and both emotion regulation and quality of life are presented and findings integrated to explore whether emotion regulation (assessed by both subjective and physiological indices) was associated with quality of life in an intellectually and visually impaired adult population.
Quality of life
In 2006, the Convention on the Rights of Persons with Disabilities stated that people with disabilities should receive wide-ranging habilitation and rehabilitation services to achieve the highest level of independence, inclusion, participation, and abilities in the fields of health, employment, society and education (United Nations 2006). Since the 1980s, quality of life has become an important measure within intellectual disability research to measure these goals (Cummins 1997).
According to Cummins et al. (1994), quality of life can be divided into an objective and a subjective dimension. The subjective dimension comprises two components: importance and satisfaction. On all three parts of quality of life, i.e. objective quality of life and importance of and satisfaction with subjective quality of life, seven domains are represented. These domains are material well-being, health, productivity, intimacy, safety, place in community and emotional well-being (Cummins et al. 1994). Assessing quality of life – particularly its subjective components – in people with intellectual disabilities is difficult (McVilly et al. 2008) and many measures lack good psychometric properties (Townsend-White et al. 2012). The Comprehensive Quality of Life Scale for people with intellectual disabilities (Com-QOL-ID, Cummins et al. 1997) is one of the few measures that meet criteria of good psychometric properties and theoretical background. The Com-QOL-ID is the only instrument that measures objective and subjective quality of life on different axes as recommended in the literature (Townsend-White et al. 2012). Furthermore, it is the only standardized and sufficiently validated quality of life measure for people with intellectual disabilities available in German (Krüger 1998).
“Emotion regulation refers to the process by which we influence what emotions we experience, when we do so, and how we experience and express them“ (Gross 2002, p. 282). Two of the most often investigated emotion regulation strategies are cognitive reappraisal and expressive suppression (e.g. Webb et al. 2012). While cognitive reappraisal refers to a change of thoughts about a situation, expressive suppression implies the inhibition of emotional expression and behavior. Both strategies are differently associated with quality of life and psychopathology such that cognitive reappraisal has been found to be a rather adaptive emotion regulation strategy while suppression appears to be maladaptive. For example, infrequent use of emotional reappraisal strategies was associated with reduced quality of life in patients with multiple sclerosis in addition to the effects of disease severity (Phillips et al. 2009). In non-clinical samples, suppression was positively correlated with depressive symptoms and rumination while reappraisal was negatively related with rumination and neuroticism (Gross and John 2003; Abler and Kessler 2009). However, recent research has also emphasized that people have a repertoire of emotion regulation strategies that they use flexibly depending on circumstances (Bonanno et al. 2004). Furthermore, the use of adaptive emotion regulation strategies can compensate for the use of maladaptive strategies and, therefore, prevent psychopathology (Aldao and Nolen-Hoeksema 2012).
Research on emotion regulation in people with intellectual disabilities is rare (McClure et al. 2009). Wilson (1999) found that children with developmental delay apply less effective strategies of emotion regulation than children without developmental delay. Similarly, children with developmental delay had lower scores on the emotion regulation subscale of the Bayley Behavior Scales than those without developmental delay (Baker et al. 2002). Nevertheless, children with intellectual disabilities had no disadvantage in expressing or regulating their emotions compared to typically developing children in a study by Baurain and Nader-Grosbois (2012).
Heart rate variability
Heart rate variability (HRV) refers to the variation of heart beat intervals and is influenced by sympathetic and parasympathetic input to the sino-atrial node of the heart. Increased high-frequent parasympathetically (vagally) mediated modulations increase HRV while increased low-frequent sympathetic activation (sympathovagal imbalance) decreases HRV (Task Force of The European Society of Cardiology and The North American Society of Pacing and Electrophysiology 1996). Higher vagal-cardiac control or higher HRV reflects higher cardiovascular flexibility. This enables an organism to quickly adapt to changing environmental requirements. Moreover, the neurovisceral integration model provides a link between prefrontal and subcortical brain structures and the autonomic regulation of cardiac activity (Thayer and Lane 20002009; Thayer et al., 2012). Because of those associations, HRV has also been proposed as an index for self-regulatory strength (e.g. Segerstrom and Solberg Nes 2007; Smith et al. 2011). In line with this, higher HRV is associated with more adaptive emotion regulation (Appelhans and Luecken 2006). For instance, adolescents who reappraised an anger-inducing situation had higher resting HRV than those who ruminated about their anger (Vögele et al. 2010). In a study by Aldao and Mennin (2012), healthy controls had higher HRV when instructed to implement adaptive emotion regulation strategies, e.g. reappraisal, during an emotion-eliciting film clip. Besides those studies that investigated emotion regulation strategies in a specific situation in the lab, it has also been found that the habitual use of more adaptive emotion regulation strategies, e.g. reappraisal, is associated with higher HRV (Geisler et al. 2010).
HRV has rarely been investigated in people with intellectual disabilities. First evidence suggests cardiac autonomic dysregulation in adolescents with mental retardation (Gorbunov 2004) or individuals with Down syndrome (Baynard et al. 2004). Most recently, it has been reported that adults with intellectual disabilities had lower HRV than adults without intellectual disabilities (Chang et al. 2012).
Aims and hypotheses
As noted above, both HRV and quality of life are associated with distinct emotion regulation strategies. It appears that the habitual use of reappraisal in particular is related to higher HRV and higher quality of life. Recently, it could be shown that HRV is also indirectly associated with subjective well-being. Geisler et al. (2010) studied the relationships between HRV, satisfaction with life, and the habitual use of executive emotion regulation strategies which included refocusing, reappraisal, planning, putting into perspective, and distraction. They found that more frequent use of executive emotion regulation strategies was associated with higher HRV and higher satisfaction with life. A direct association between HRV and satisfaction with life, however, could not be found. Instead, they found an indirect relationship such that the impact of HRV on satisfaction with life was mediated by the use of executive emotion regulation strategies.
In the current study, we assessed quality of life, emotion regulation strategies, and HRV in a sample of individuals with intellectual disabilities and concomitant impaired vision. Due to their visual impairment, these individuals only receive restricted information through their visual modality and, therefore, the visual presentation of self-report measures is extremely difficult. Receiving information via the tactile or haptic modality is particularly important in those people (McLinden 2012). To accommodate the difficulties with visual perception and need for tactile information, we modified response categories of questionnaire-based instruments to three-dimensional objects.
We hypothesized positive relationships between all three variables. Specifically, as HRV has been (indirectly) associated with higher quality of life (e.g. Geisler et al. 2010) and with the habitual and situation-specific use of adaptive emotion regulation strategies, e.g. reappraisal (e.g. Geisler et al. 2010; Vögele et al. 2010), we expected that HRV would be (at least indirectly) positively related to quality of life and to the habitual use of reappraisal. Based on the fact that the use of adaptive emotion regulation strategies, e.g. reappraisal, is related to a higher quality of life (e.g. Geisler et al. 2010) and that adaptive emotion regulation strategies are particularly effective in reducing psychopathology when maladaptive strategies are also present (e.g. Aldao and Nolen-Hoeksema 2012), we expected that reappraisal would be positively correlated with quality of life, particularly in combination with high suppression. Subsequently, we tested whether the use of specific emotion regulation strategies mediated the relationship between HRV and quality of life.
This research was undertaken with the understanding and written consent of each participant and, where required, their legal representatives. The study protocol followed the Declaration of Helsinki (World Medical Association 2008). It was also independently reviewed and approved by the ethical board of the medical faculty at the University of Würzburg, Germany.
Participants (N = 35) were a convenience sample of residents of an institution for individuals with intellectual disabilities and concomitant visual impairment in Würzburg, Germany. Approximately half of the sample (54.29%) were women (n = 19). Mean age was M = 35.03 years (SD = 7.94) and mean body-mass-index (BMI) was M = 26.67 kg/m2 (SD = 5.44). Participants either had an amaurosis (n = 10) or had a maximum sight of 30% with visual aid. Four participants were on medication for hypertension.
Heart rate recording
Measurement of heart rate was performed at rest with the heart rate monitor Polar RS800CX (Polar Electro Oy, Kempele, Finland) for 10 min. For analysis and calculation of HRV the software Kubios HRV 2.0 (Tarvainen et al. 2009) was used. Only the last five minutes of the collected data were used for calculation of HRV to ensure that data reflected resting conditions. Inter-beat interval series were corrected for artifacts using the default settings of the program. Trend components were removed with the smoothness priors detrending method (λ = 500).We chose the root mean square of successive differences (RMSSD) as a measure of HRV. This parameter is recommended as a measure of vagal-cardiac outflow because of its robustness, e.g. against changes in breathing rate (Task Force of The European Society of Cardiology and The North American Society of Pacing and Electrophysiology 1996, Penttilä et al. 2001). As an additional index of parasympathetically mediated HRV, we performed a spectral analysis (Fast Fourier Transformation) and determined high frequency components (0.15-0.4 Hz) both as high frequency power (HF ms2) and normalized units (HF nu = HF ms2 / (total power ms2 - very low frequency ms2)). RMSSD and HF ms2 were log-transformed (ln) because of skewed distribution.
Comprehensive Quality of Life Scale – Intellectual Disability (Com-QOL-ID)
Emotion Regulation Questionnaire (ERQ)
Original and modified items of the Emotion Regulation Questionnaire
1. When I want to feel more positive emotion (such as joy or amusement), I change what I’m thinking about.
When I want to have more good feelings like joy or amusement, I think of something nice.
When I am sad and want to feel better, I think of something nice like eating ice cream in the sun or a happy celebration.
[Wenn ich mehr positive Gefühle (wie Freude oder Heiterkeit) empfinden möchte, ändere ich, woran ich denke.]
[Wenn ich mehr gute Gefühle, wie Freude oder Heiterkeit empfinden möchte, denke ich an etwas Schöneres.]
[Wenn ich traurig bin und mich besser fühlen möchte, stelle ich mir etwas Schönes vor, wie Eis essen im Sonnenschein oder ein lustiges Fest.]
2. I keep my emotions to myself.
I often do not show to others how I feel at the moment.
When I am in a very good or bad mood, I do not tell others.
[Ich behalte meine Gefühle für mich.]
[Ich zeige den anderen oft nicht, wie ich mich gerade fühle.]
[Wenn ich total gut oder total schlecht gelaunt bin, dann sage ich das nicht den anderen.]
3. When I want to feel less negative emotion (such as sadness or anger), I change what I’m thinking about.
When I want to have less bad feelings like sadness or anger, I think of something nice.
When I am sad and I do not want to feel so sad, I think of something nice like eating ice cream in the sun or a happy celebration.
[Wenn ich weniger negative Gefühle (wie Traurigkeit oder Ärger) empfinden möchte, ändere ich, woran ich denke.]
[Wenn ich weniger schlechte Gefühle, wie Traurigkeit oder Ärger empfinden möchte, denke ich an etwas Schöneres.]
[Wenn ich traurig bin und mich nicht so traurig fühlen möchte, stelle ich mir auch etwas Schönes vor, wie Eis essen im Sonnenschein oder ein lustiges Fest.]
4. When I am feeling positive emotions, I am careful not to express them.
When I am feeling good, I do not show this to others.
When I arrive at work in the morning feeling great, I do not show this and I am rather quiet or talk about something else.
[Wenn ich positive Gefühle empfinde, bemühe ich mich, sie nicht nach außen zu zeigen.]
[Wenn ich mich gut fühle, zeige ich das nicht den anderen.]
[Wenn ich morgens total gut gelaunt zur Arbeit komme, dann zeige ich das nicht und bin eher ganz still oder rede über etwas anderes.]
5. When I’m faced with a stressful situation, I make myself think about it in a way that helps me stay calm.
When I’m faced with a stressful situation, I make myself think about it in a way that helps me stay calm.
When I get home late from work and still have a doctor’s appointment or I am on duty in my group, I think that, although today is stressful, I will have my peace tomorrow.
[Wenn ich in eine stressige Situation gerate, ändere ich meine Gedanken über die Situation so, dass es mich beruhigt.]
[Wenn ich in eine stressige Situation gerate, ändere ich meine Gedanken über die Situation so, dass es mich beruhigt.]
[Wenn ich spät von der Werkstatt komme und noch einen Arzttermin oder Dienst in der Gruppe habe, dann denke ich daran, dass es heute zwar stressig ist, aber dafür habe ich morgen wieder meine Ruhe.]
6. I control my emotions by not expressing them.
When I do not show my feelings, I can control them better.
When I feel my anger rising, I do not show this to the others and as a result I am not getting so angry. Then, my anger wears off.
[Ich halte meine Gefühle unter Kontrolle, indem ich sie nicht nach außen zeige.]
[Wenn ich meine Gefühle nicht zeige, habe ich sie besser unter Kontrolle.]
[Wenn Ärger langsam in mir hochsteigt, dann zeige ich das nicht den anderen und dann werde ich auch nicht so wütend. Meine Wut vergeht dann wieder.]
7. When I want to feel more positive emotion, I change the way I’m thinking about the situation.
When I want to have more good feelings, I try to think differently about the situation.
When I made a mistake at work and I am angry about it and want to feel better, I remind myself that everyone makes a mistake sometimes and it is not so bad.
[Wenn ich mehr positive Gefühle empfinden möchte, versuche ich über die Situation anders zu denken.]
[Wenn ich mehr gute Gefühle empfinden möchte, versuche ich anders über die Situation zu denken.]
[Wenn ich einen Fehler in der Werkstatt gemacht habe, darüber verärgert bin und mich besser fühlen möchte, dann denke ich daran, dass jeder mal einen Fehler macht und dass das überhaupt nicht schlimm ist.]
8. I control my emotions by changing the way I think about the situation I’m in.
[Ich halte meine Gefühle unter Kontrolle, indem ich über meine aktuelle Situation anders nachdenke.]
9. When I am feeling negative emotions, I make sure not to express them.
When I feel bad, I do not show this to others.
When I arrive at work in the morning in a bad mood because I may have slept badly, I do not show this to others and I am rather quiet or talk about something else.
[Wenn ich negative Gefühle empfinde, sorge ich dafür, sie nicht nach außen zu zeigen.]
[Wenn ich mich schlecht fühle, zeige ich das nicht den anderen.]
[Wenn ich morgens schlecht gelaunt zur Arbeit komme, weil ich vielleicht schlecht geschlafen habe, dann zeige ich das nicht und bin eher ganz still oder rede über etwas anderes.]
10. When I want to feel less negative emotion, I change the way I’m thinking about the situation.
When I want to have less bad feelings, I try to think differently about the situation.
When I made a mistake at work and I am angry about it and do not want to feel so bad, I remind myself that everyone makes a mistake from time to time.
[Wenn ich weniger negative Gefühle empfinden möchte, versuche ich über die Situation anders zu denken.]
[Wenn ich weniger schlechte Gefühle empfinden möchte, versuche ich anders über die Situation zu denken.]
[Wenn ich einen Fehler in der Werkstatt gemacht habe, darüber verärgert bin und mich nicht so schlecht fühlen möchte, dann denke ich daran, dass jeder mal einen Fehler macht.]
A few days before the testing, participants became acquainted with the investigator. They were informed about the course of action and were familiarized with the instrument for heart rate monitoring. To ensure participants’ complete understanding of the study’s procedure, all steps were explained in full detail and any remaining questions answered. After a preliminary interview about demographic data, the interview on quality of life and emotion regulation followed. During a 10 min break, participants were asked to disengage from any negative thoughts and feelings they might have and to calm down and relax. After the break, heart rate was measured for 10 min. The session ended with a qualitative follow-up interview on well-being during the heart rate recording, and the participants’ debriefing.
Three participants were excluded because of missing data leaving n = 32 in the final sample. All variables used in the subsequent regression analyses were z-standardized. We first analyzed the association between emotion regulation strategies (i.e. reappraisal, suppression, and the interaction reappraisal × suppression) and quality of life. The variable with the highest β was chosen as mediating variable in subsequent mediation analyses (i.e., whether emotion regulation strategies mediated the effect of HRV on quality of life). In addition to regression analyses, the Goodman test (Goodman 1960) was used to test mediation effects. All statistical analyses were tested one-tailed because of our directed hypotheses.
Descriptive statistics and correlations between study variables
Emotion Regulation Questionnaire
Comprehensive Quality of Life Scale
3. Objective quality of life
4. Subjective quality of life
Heart rate variability
6. High frequency power (ms2)
7. High frequency power (n.u.)
Emotion regulation and quality of life
Emotion regulation strategies predicting quality of life
Objective quality of life
Reappraisal × suppression
Subjective quality of life
Reappraisal × suppression
Objective quality of life
Mediation testing steps for quality of life
HRV to objective quality of life
HRV to subjective quality of life
HRV to emotion regulation
Predicting objective quality of life
Predicting subjective quality of life
Subjective quality of life
HRV was not a significant predictor of subjective quality of life (F(1,32) = .18, p = .34, adj. R2 = -.03). The overall model including both HRV and emotion regulation as predictors was marginally significant (F(2,29) = 2.24, p = .06, adj. R2 = .07). While emotion regulation still was a significant predictor in this model, the influence of HRV was again not significant (Table 4). Testing of the mediating effect of emotion regulation between HRV and subjective quality of life was marginally significant (Goodman z = 1.45, p = .07).
In the current study, we assessed quality of life, emotion regulation strategies and HRV in a sample of individuals with intellectual disabilities and concomitant impaired vision. We modified existing questionnaires by using three-dimensional response categories to overcome restricted visual information processing in our participants. To our knowledge, this is the first study that (1) used such an assessment technique and (2) investigated emotion regulation and related it to quality of life and cardiac autonomic regulation in individuals with intellectual disabilities.
We found that higher scores of reappraisal were positively associated with subjective and objective quality of life, replicating prior findings in individuals without intellectual disabilities (Geisler et al. 2010). The interaction between reappraisal and suppression was also associated with high quality of life. The positive relationship between reappraisal and quality life was particularly pronounced when suppression was high or, vice versa, high suppression with concomitant low reappraisal was associated with lower quality of life (Figure 2). Hence, the use of reappraisal may compensate for the use of suppression and, therefore, contribute to higher quality of life. This finding is also consistent with a recent study in a sample of community residents, which found that the relationship between adaptive emotion regulation strategies and psychopathology is moderated by the level of maladaptive strategies. Specifically, the negative association between adaptive strategies and psychopathology was stronger at high levels of maladaptive strategies (Aldao and Nolen-Hoeksema 2012).
The combined use of emotion regulation strategies was also related to higher HRV. This finding is in accordance with HRV representing flexible adaptations of physiological processes, but also more adaptive emotion regulation (Appelhans and Luecken 2006, Thayer and Lane 2009). As a result, the current study further supports the use of physiological indices to evaluate affective conditions in people with intellectual disabilities (Vos et al. 2012).
There was a strong association between HRV and objective quality of life. As expected, this link was (partially) mediated via the flexible use of emotion regulation strategies. No evidence was found for an association between HRV and subjective quality of life. However, mediation analysis showed a trend toward mediation of HRV on subjective quality of life also via the combined use of emotion regulation strategies. Thus, subjective quality of life and HRV appear to be indirectly associated (refer to Zhao et al. 2010for rationale of exploring mediation effects in the absence of direct effects). The strong association between HRV and objective quality of life may be explained by the inclusion of items about physical health in this subscale2, a factor known to influence HRV (Thayer et al. 2010). Beyond this relationship, however, emotion regulation strategies partially mediated the relationship between HRV and quality of life, which is largely consistent with the results from the study by Geisler et al. (2010).
Several limitations of this study have to be mentioned. Firstly, the medium sample size may restrict generalization of our results. Secondly, there was no control group and, therefore, it cannot be evaluated if participants in our study had generally lower HRV than individuals without intellectual disabilities. However, it appears that HRV was comparable to individuals without intellectual disabilities (Sinnreich et al. 1998; Agelink et al. 2001; Nunan et al. 2010; Bertsch et al. 2012). Thirdly, we changed the response modality of the questionnaires from visual to visuo-tactile and modified the items of the ERQ. As a result, psychometric properties may have been affected. Yet, internal consistency was acceptable, at least for the reappraisal subscale. These caveats notwithstanding, we could demonstrate associations between emotion regulation, HRV and quality of life in a sample heterogeneous in age, gender, body mass and visual impairment which favors external validity of our results.
Our results support positive relationships between HRV, emotion regulation, and quality of life and the mediating role of emotion regulation between these variables. Importantly, we could demonstrate that these associations also extend to people with intellectual disabilities and concomitant impaired vision. The assessment of quality of life is complex in individuals with intellectual disabilities and requires more sophisticated approaches than simple interview, e.g. multi-modal methods (McVilly et al. 2008). Future studies may also make use of more recently developed quality of life measures, e.g. the Integral Quality of Life Scale (Verdugo et al. 2011). In addition, we presented new approaches for measuring emotion regulation and quality of life, namely questionnaires with visuo-tactile response modalities and assessment of HRV. The results may encourage further studies on quality of life that apply those techniques in individuals with intellectual disabilities. When both emotion regulation problems are present and HRV is low, intervention programs may be considered which have been shown to be beneficial in people without intellectual disabilities, e.g. HRV-biofeedback (Wheat and Larkin 2010). Such interventions may boost emotion regulation abilities and, thus, may indirectly enhance quality of life in people with intellectual disabilities.
1Note that we used the combined score for subjective quality of life (importance × satisfaction) as it is suggested in the questionnaire’s manual. Although this procedure has been criticized, it has been found that the combined score usually behaves like the satisfaction score alone and thus does not adversely affect outcomes (Cummins 2002). In the present study, the satisfaction score and the combined score were almost perfectly correlated (r = .99, p < .001). Accordingly, correlations when using the satisfaction score were similar to the combined score.
2Indeed, the largest correlation between objective quality of life dimensions and HRV was observed for health (health: r = .46, p < .01; emotional well-being: r = .38, p < .05; place in community: r = .34, p < .05; safety: r = .26, p < .07; productivity: r = .10, ns; intimacy: r = -.05, ns; material well-being: r = -.16, ns).
AM is supported by a grant of the research training group 1253/2 which is supported by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) by federal and Länder funds. This publication was funded by the DFG and the University of Wuerzburg in the funding program Open Access Publishing.
- Abler B, Kessler H: [Emotion Regulation Questionnaire - A German version of the ERQ by Gross and John]. Diagnostica 2009, 55: 144–152. 10.1026/0012-1922.214.171.124View ArticleGoogle Scholar
- Agelink MW, Malessa R, Baumann B, Majewski T, Akila F, Zeit T, Ziegler D: Standardized tests of heart rate variability: normal ranges obtained from 309 healthy humans, and effects of age, gender, and heart rate. Clinical Autonomic Research 2001, 11: 99–108. 10.1007/BF02322053View ArticlePubMedGoogle Scholar
- Aiken LS, West SG: Multiple regression: Testing and interpreting interactions. Thousand Oaks, CA: Sage; 1991.Google Scholar
- Aldao A, Mennin DS: Paradoxical cardiovascular effects of implementing adaptive emotion regulation strategies in generalized anxiety disorder. Behaviour Research and Therapy 2012, 50: 122–130. 10.1016/j.brat.2011.12.004View ArticlePubMedGoogle Scholar
- Aldao A, Nolen-Hoeksema S: When are adaptive strategies most predictive of psychopathology? Journal of Abnormal Psychology 2012, 121: 276–281.View ArticlePubMedGoogle Scholar
- Appelhans BM, Luecken LJ: Heart rate variability as an index of regulated emotional responding. Review of General Psychology 2006, 10: 229–240.View ArticleGoogle Scholar
- Baker BL, Blacher J, Crnic KA, Edelbrock C: Behavior problems and parenting stress in families of three-year-old children with and without developmental delays. American Journal of Mental Retardation 2002, 107: 433–444. 10.1352/0895-8017(2002)107<0433:BPAPSI>2.0.CO;2View ArticlePubMedGoogle Scholar
- Baurain C, Nader-Grosbois N: Socio-emotional regulation in children with intellectual disability and typically developing children in interactive contexts. ALTER – European Journal of Disability Research 2012, 6: 75–93. 10.1016/j.alter.2012.02.001View ArticleGoogle Scholar
- Baynard T, Pitetti KH, Guerra M, Fernhall B: Heart rate variability at rest and during exercise in persons with Down syndrome. Archives of Physical Medicine and Rehabilitation 2004, 85: 1285–1290. 10.1016/j.apmr.2003.11.023View ArticlePubMedGoogle Scholar
- Bertsch K, Hagemann D, Naumann E, Schachinger H, Schulz A: Stability of heart rate variability indices reflecting parasympathetic activity. Psychophysiology 2012, 49: 672–682. 10.1111/j.1469-8986.2011.01341.xView ArticlePubMedGoogle Scholar
- Bonanno GA, Papa A, Lalande K, Westphal M, Coifman K: The importance of being flexible - the ability to both enhance and suppress emotional expression predicts long-term adjustment. Psychological Science 2004, 15: 482–487. 10.1111/j.0956-7976.2004.00705.xView ArticlePubMedGoogle Scholar
- Chang Y-W, Lin J-D, Chen W-L, Yen C-F, Loh C-H, Fang W-H, Wu L-W: Metabolic syndrome and short-term heart rate variability in adults with intellectual disabilities. Research in Developmental Disabilities 2012, 33: 1701–1707. 10.1016/j.ridd.2012.04.005View ArticlePubMedGoogle Scholar
- Cummins RA: Self-rated quality of life scales for people with an intellectual disability: A review. Journal of Applied Research in Intellectual Disabilities 1997, 10: 199–216. 10.1111/j.1468-3148.1997.tb00017.xView ArticleGoogle Scholar
- Cummins RA: Vale ComQol: Caveats to using the Comprehensive Quality of Life Scale. 2002. Available at http://www.deakin.edu.au/research/acqol/instruments/comqol-scale Available atGoogle Scholar
- Cummins RA, McCabe MP, Romeo Y, Gullone E: The Comprehensive Quality of Life Scale (ComQol): Instrument development and psychometric evaluation on college staff and students. Educational and Psychological Measurement 1994, 54: 372–382. 10.1177/0013164494054002011View ArticleGoogle Scholar
- Cummins RA, McCabe MP, Romeo Y, Reid S, Waters L: An initial evaluation of the Comprehensive Quality of Life Scale - Intellectual Disability. International Journal of Disability, Development and Education 1997, 44: 7–19. 10.1080/0156655970440102View ArticleGoogle Scholar
- Geisler FCM, Vennewald N, Kubiak T, Weber H: The impact of heart rate variability on subjective well-being is mediated by emotion regulation. Personality and Individual Differences 2010, 49: 723–728. 10.1016/j.paid.2010.06.015View ArticleGoogle Scholar
- Goodman LA: On the exact variance of products. Journal of the American Statistical Association 1960, 55: 708–713. 10.1080/01621459.1960.10483369View ArticleGoogle Scholar
- Gorbunov NP: Changes in the heart rate parameters under the influence of academic school activities in adolescents with mental retardation. Human Physiology 2004, 30: 310–314.View ArticleGoogle Scholar
- Gross JJ: Emotion regulation: affective, cognitive, and social consequences. Psychophysiology 2002, 39: 281–291. 10.1017/S0048577201393198View ArticlePubMedGoogle Scholar
- Gross JJ, John OP: Individual differences in two emotion regulation processes: implications for affect, relationships, and well-being. Journal of Personality and Social Psychology 2003, 85: 348–362.View ArticlePubMedGoogle Scholar
- Krüger C: Comprehensive Quality of Life Scale - Intellectual/Cognitive Disability: German version. Hamburg: University of Hamburg; 1998.Google Scholar
- McClure KS, Halpern J, Wolper PA, Donahue JJ: Emotion regulation and intellectual disability. Journal on Developmental Disabilities 2009, 15: 38–44.Google Scholar
- McLinden M: Mediating haptic exploratory strategies in children who have visual impairment and intellectual disabilities. Journal of Intellectual Disability Research 2012, 56: 129–139. 10.1111/j.1365-2788.2011.01430.xView ArticlePubMedGoogle Scholar
- McVilly KR, Green AM, Hawthorne G, Cummins R, Hobbs J, Wong S: Developing a QOL measure: What (and what not) to ask and how (and how not) to ask it. Journal of Intellectual Disability Research 2008, 52: 779.View ArticleGoogle Scholar
- Nunan D, Sandercock GRH, Brodie DA: A quantitative systematic review of normal values for short-term heart rate variability in healthy adults. Pacing and Clinical Electrophysiology 2010, 33: 1407–1417. 10.1111/j.1540-8159.2010.02841.xView ArticlePubMedGoogle Scholar
- Penttilä J, Helminen A, Jartti T, Kuusela T, Huikuri HV, Tulppo MP, Coffeng R, Scheinin H: Time domain, geometrical and frequency domain analysis of cardiac vagal outflow: effects of various respiratory patterns. Clinical Physiology 2001, 21: 365–376. 10.1046/j.1365-2281.2001.00337.xView ArticlePubMedGoogle Scholar
- Phillips LH, Saldias A, McCarrey A, Henry JD, Scott C, Summers F, Whyte M: Attentional lapses, emotional regulation and quality of life in multiple sclerosis. British Journal of Clinical Psychology 2009, 48: 101–106. 10.1348/014466508X379566View ArticlePubMedGoogle Scholar
- Segerstrom SC, Solberg Nes L: Heart rate variability reflects self-regulatory strength, effort, and fatigue. Psychological Science 2007, 18: 275–281. 10.1111/j.1467-9280.2007.01888.xView ArticlePubMedGoogle Scholar
- Sinnreich R, Kark JD, Friedlander Y, Sapoznikov D, Luria MH: Five minute recordings of heart rate variability for population studies: repeatability and age-sex characteristics. Heart 1998, 80: 156–162.PubMed CentralView ArticlePubMedGoogle Scholar
- Smith TW, Cribbet MR, Nealey-Moore JB, Uchino BN, Williams PG, MacKenzie J, Thayer JF: Matters of the variable heart: respiratory sinus arrhythmia response to marital interaction and associations with marital quality. Journal of Personality and Social Psychology 2011, 100: 103–119.View ArticlePubMedGoogle Scholar
- Tarvainen MP, Niskanen J-P, Lipponen JA, Ranta-aho PO, Karjalainen PA: Kubios HRV - A software for advanced heart rate variability analysis. In J Vander Sloten, P Verdonck, M Nyssen, J Haueisen (Eds.), 4th European Conference of the International Federation for Medical and Biological Engineering (pp. 1022–1025). Antwerp, Belgium: Springer; 2009.Google Scholar
- Task Force of The European Society of Cardiology and The North American Society of Pacing and Electrophysiology: Heart rate variability - Standards of measurement, physiological interpretation, and clinical use. European Heart Journal 1996, 17: 354–381. 10.1093/oxfordjournals.eurheartj.a014868View ArticleGoogle Scholar
- Thayer JF, Åhs F, Fredrikson M, Sollers JJ 3rd, Wager TD: A meta-analysis of heart rate variability and neuroimaging studies: Implications for heart rate variability as a marker of stress and health. Neuroscience and Biobehavioral Reviews 2012, 36: 747–756. 10.1016/j.neubiorev.2011.11.009View ArticlePubMedGoogle Scholar
- Thayer JF, Lane RD: A model of neurovisceral integration in emotion regulation and dysregulation. Journal of Affective Disorders 2000, 61: 201–216. 10.1016/S0165-0327(00)00338-4View ArticlePubMedGoogle Scholar
- Thayer JF, Lane RD: Claude Bernard and the heart-brain connection: Further elaboration of a model of neurovisceral integration. Neuroscience and Biobehavioral Reviews 2009, 33: 81–88. 10.1016/j.neubiorev.2008.08.004View ArticlePubMedGoogle Scholar
- Thayer JF, Yamamoto SS, Brosschot JF: The relationship of autonomic imbalance, heart rate variability and cardiovascular disease risk factors. International Journal of Cardiology 2010, 141: 122–131. 10.1016/j.ijcard.2009.09.543View ArticlePubMedGoogle Scholar
- Townsend-White C, Pham AN, Vassos MV: A systematic review of quality of life measures for people with intellectual disabilities and challenging behaviours. Journal of Intellectual Disability Research 2012, 56: 270–284. 10.1111/j.1365-2788.2011.01427.xView ArticlePubMedGoogle Scholar
- United Nations: Convention on the rights of persons with disabilities and optional protocol. New York: United Nations; 2006.Google Scholar
- Verdugo MA, Gómez LE, Arias B, Schalock RL: The Integral Quality of Life Scale: development, validation, and use. In Enhancing the Quality of Life of People with Intellectual Disabilities. Edited by: Kober R. Dordrecht: Springer; 2011:47–60.Google Scholar
- Vögele C, Sorg S, Studtmann M, Weber H: Cardiac autonomic regulation and anger coping in adolescents. Biological Psychology 2010, 85: 465–471. 10.1016/j.biopsycho.2010.09.010View ArticlePubMedGoogle Scholar
- Vos P, De Cock P, Munde V, Petry K, Van den Noortgate W, Maes B: The tell-tale: What do heart rate, skin temperature and skin conductance reveal about emotions of people with severe and profound intellectual disabilities? Research in Developmental Disabilities 2012, 33: 1117–1127. 10.1016/j.ridd.2012.02.006View ArticlePubMedGoogle Scholar
- Webb TL, Miles E, Sheeran P: Dealing with feeling: a meta-analysis of the effectiveness of strategies derived from the process model of emotion regulation. Psychological Bulletin 2012, 138: 775–808.View ArticlePubMedGoogle Scholar
- Wheat AL, Larkin KT: Biofeedback of heart rate variability and related physiology: A critical review. Applied Psychophysiology and Biofeedback 2010, 35: 229–242. 10.1007/s10484-010-9133-yView ArticlePubMedGoogle Scholar
- Wilson BJ: Entry behavior and emotion regulation abilities of developmentally delayed boys. Developmental Psychology 1999, 35: 214–222.View ArticlePubMedGoogle Scholar
- World Medical Association: Declaration of Helsinki – Ethical Principles for Medical Research Involving Human Subjects. Seoul: 59th World Medical Association General Assembly; 2008.Google Scholar
- Zhao X, Lynch JG Jr, Chen Q: Reconsidering Baron and Kenny: myths and truths about mediation analysis. Journal of Consumer Research 2010, 37: 197–206. 10.1086/651257View ArticleGoogle Scholar
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