بررسی مقطعی از عدم بازداری خصلتی و ارتباط آن با تمرکز حواس و تکانشگری
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|33953||2011||8 صفحه PDF||سفارش دهید||محاسبه نشده|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Appetite, Volume 56, Issue 2, April 2011, Pages 241–248
Two online surveys were conducted to assess the relationship between trait disinhibition, impulsivity, mindfulness and adverse psychological symptoms. In study 1 adult females (n = 196; mean age = 21 yrs) completed the Three-Factor Eating Questionnaire (TEFQ-R21), the Hospital Anxiety and Depression Scale and a measure of dispositional mindfulness. In study 2 adult females (n = 190; mean age = 26 yrs) completed the same measures as in study 1 with the addition of the Barratt Impulsivity Scale. In both studies it was predicted that mindfulness would be negatively related to trait disinhibition controlling for adverse psychological symptoms. The second study addressed the additional hypothesis that the relationship between mindfulness and trait disinhibition would be mediated by impulsivity. Regression analyses indicated that mindfulness was negatively related to and explained 11% of variation in trait disinhibition (study 1). This relationship was replicated and extended in study 2 whereby impulsivity mediated the relationship between mindfulness and trait disinhibition. The findings warrant experimental and in vivo investigations of the potential causal relationships between mindfulness, impulsivity and eating behaviours.
Trait disinhibition is a propensity to be over responsive to external food cues and to eat in response to negative affect. Due to its association with overeating it is considered a behavioural proxy for body weight variation (Bryant et al., 2007, Dykes et al., 2004 and Hays et al., 2002). Trait disinhibition also reflects a “tonic readiness to eat” thereby conferring an “enduring and constant vulnerability to be stimulated to eat” (Blundell et al., 2005, p. 621). This is reflected by research highlighting its association with binge eating and dietary relapse (Bryant et al., 2007), and its ability to predict weight regain following weight loss (Cuntz, Leibbrand, Ehrig, Shaw, & Fichter, 2001). This evidence indicates that trait disinhibition is characteristic of a susceptibility to gain weight. Therefore, if the behavioural aspects of trait disinhibition could be modified, this would potentially curb the impact of the trait on eating behaviour and by consequence body weight. Bryant et al. (2007) have reviewed physiological and psychological factors associated with trait disinhibition and conclude that it plays a “significant mediating role between the ‘person’ and the ‘environment’ …” (p. 416). Further evidence is required to identify the nature of psychological factors that mediate the behavioural expression of the trait. Empirical evidence highlights a positive relation between trait disinhibition and impulsivity (Yeomans, Leitch, & Mobini, 2008) and a negative relation between dispositional mindfulness and impulsivity (Brown & Ryan, 2003). The current investigation examined how mindfulness and impulsivity are associated with trait disinhibition. Trait disinhibition as measured by the Three-Factor Eating Questionnaire (Cappelleri et al., 2009, Karlsson et al., 2000 and Stunkard and Messick, 1985) chateracterises an habitual behavioural tendency to respond to the hedonic properties of food (Barkeling, King, Naslund, & Blundell, 2007). This notion is supported by evidence that obese individuals who exhibit high trait disinhibition report no relationship between hunger sensation and eating (Barkeling et al., 2007). Furthermore, obese individuals have been shown to have a weak satiety response to fatty meals, a strong preference for high-fat foods when sated and a strong hedonic attraction to palatable foods (Blundell et al., 2005). The apparent habitual responding associated with trait disinhibition is likely to be activated automatically by specific environmental cues. In general, automatic processes occur without intention or awareness and are difficult to terminate once initiated. In contrast, controlled processes can be initiated and terminated at will and people are usually aware of their action (Bargh, 1997). Self-awareness is important in determining whether an implicit motivation is expressed behaviourally and is central to effective self-regulation of motivation (Carver and Scheier, 1981 and Deci and Ryan, 1980), specifically the self-regulation of eating behaviour (Baumeister et al., 1994, Heatherton and Baumeister, 1991 and Lattimore and Maxwell, 2004). Awareness directed at psychological and behavioural processes is likely to serve a “de-automatization” function (Bargh, 1997) and therefore facilitate self-regulation. In this respect, the likelihood of habitual behaviour being expressed will depend to some extent upon how aware an individual is of his or her habitual responding and the external or internal cues that drive it. The behavioural expression of trait disinhibition could be characterised as an automatic response driven by cues which the individual may not always be aware, or in control of. This proposition is supported by evidence for an association between the trait disinhibition and personality dispositions such as impulsiveness. Specific personality dispositions are associated with disinhibition as measured by the TFEQ-51. Research provides evidence for positive associations with novelty seeking and negative associations with self-directedness – an ability to resist external cues (Gendall, Joyce, Sullivan, & Bulik, 1998). In addition the Barratt Impulsivity Scale (BIS-11) (Patton, Stanford, & Barratt, 1995), and behavioural measures of impulsivity (i.e., delayed discounting task) are positively associated with the TFEQ-51 disinhibition scale. The BIS-11 comprises three second order factors: motor impulsiveness, defined as acting without thinking; non-planning impulsiveness (a lack of forethought), and attentional impulsiveness (an inability to focus attention (Barratt, 1985 and Patton et al., 1995)). Women with higher scores on the TFEQ-51 disinhibition scale score higher on the BIS-11 total score, motor impulsiveness and non-planning factors (Yeomans et al., 2008). Additionally, women with higher scores on the TFEQ-51 disinhibition scale are more impulsive based on their delayed discounting task performance (Yeomans et al., 2008). This association is independent of level of cognitive restraint which has been widely considered as a predictor of overeating (Polivy, Herman, & Coelho, 2008). These findings are supported by experimental evidence showing that normal weight highly impulsive women eat more in laboratory taste tests compared to their low-impulsive counterparts (Guerrieri et al., 2007) and that impulsivity is a better predictor of relative overeating than cognitive restraint (Jansen et al., 2009). Jansen's research group have advanced our understanding of the relationship between impulsivity and eating by highlighting how impulsivity may be a more important predictor of overeating, and by consequence overweight, than cognitive restraint. In light of these developments and conceptual associations, investigations into the relationship between impulsivity and trait disinhibition are clearly warranted. The theoretical case for investigation is based on an evolutionary account of overweight in modern society (van den Bos & de Ridder, 2006) which is conceptually aligned with the thrifty genotype hypothesis (for discussion see Bryant et al., 2007). A full account of the evolutionary perspective is beyond the scope of this paper (see review in van den Bos & de Ridder, 2006). Central to the evolutionary account of being overweight is the question of the role of self-control under conditions of certainty and uncertainty in the food environment. A tendency to gratify immediate needs by eating more than is nutritionally required, especially when future food supply is uncertain, would have been potentially adaptive, whereas patience or waiting for better foods would have had limited adaptive benefit. Immediate gratification equates to impulsiveness and delayed gratification equates to self-control (Forzano & Corry, 1998); humans, like animals demonstrate difficulty maintaining self-control especially when the reward value of food is high (Stephens, Kerr, & Fernandez-Juricic, 2004). The foregoing theoretical perspective suggests that in the current environment where humans are exposed to a large variety of foods differing in reward value they will be susceptible to immediate gratification, and by consequence gain weight, due to inherent traits, such as disinhibition and impulsiveness, that historically may have had adaptive benefit. In this respect consideration of the nature of impulsiveness may shed light on how impulsive behaviour could me moderated. The conceptualisation of impulsivity advanced by Barratt has had considerable influence in a range of domains (see Stanford et al., 2009 for review) and arguably impulsivity represents a disposition to act without awareness. Indeed this notion is implicit in a widespread definition: “[impulsivity is] a predisposition toward rapid, unplanned reactions to internal or external stimuli without regard to the negative consequences of these reactions to the impulsive individuals or to others” (Stanford et al., 2009, p. 385). We would suggest that if ‘acting without awareness’, as a manifestation of impulsivity, is positively associated with trait disinhibition we should expect that its polar opposite, ‘acting with awareness’, is negatively associated with the same trait. Acting with awareness is a core component of dispositional mindfulness. As various techniques have been put forward to foster mindfulness ( Levesque & Brown, 2007), it will be of interest to investigate the potential links between dispositional mindfulness, impulsivity and trait disinhibition. If a tendency to be mindful reduces the likelihood of acting impulsively it would be expected that in turn that acting mindfully would reduce the likelihood of responding automatically to external and internal cues to eat. Mindfulness is distinct from other forms of dispositional awareness that facilitate self-regulation, as for instance cognitive activity that focuses on the self (Heatherton & Baumeister, 1991), private and public self-awareness (Heatherton, Polivy, Herman, & Baumeister, 1993) and reflection (Trapnell & Campbell, 1999). In contrast to these forms of ‘reflexive awareness’, mindfulness has been described as ‘pre-reflexive’ awareness (Levesque & Brown, 2007) that is characterised by receptive attention to and awareness of present events and experiences (Brown, Ryan, & Creswell, 2007). Mindfulness does not involve evaluation, contemplation, introspection, reflection or rumination. Instead it is characterised by awareness of thoughts, impulses, physical sensations etc., and their accompanying emotions as simply reactions to them, where the mind can be engaged and disengaged by choice (Chambers, Gullone, & Allen, 2009). While reflexive awareness operates within experiences mindfulness operates upon them. Accordingly, mindfulness has been proposed as a means to “de-automatize” habitual responding to facilitate more effective self-regulation ( Levesque & Brown, 2007) and several studies confirm a link between mindfulness and the de-automatization of cognitive functions ( Cahn and Polich, 2009, Chambers et al., 2008, Jha et al., 2007, Lutz et al., 2008 and Moore and Malinowski, 2009). Mindfulness is negatively related to impulsivity, depression and anxiety (Brown & Ryan, 2003) and there has been a proliferation of research into its nature and potential use in therapeutic interventions (Brown et al., 2007). Investigation of the nature of mindfulness is clearly positioned in the context of habitual and automatic processes (Levesque & Brown, 2007) whereas its potential as a therapeutic tool has been addressed in varied contexts (Allen, Blashki, & Gullone, 2006), for example: stress reduction and depression (Chiesa and Serretti, 2009 and Teasdale et al., 2002), eating disorders (Kristeller, 2007 and Nagata, 2009), and weight control (Barnes et al., 2008, Davis et al., 2008 and Tapper et al., 2009). Recently a mindfulness based intervention addressed food craving in people attempting weight loss (Alberts, Mulkens, Smeets, & Thewissen, 2010) using meditation techniques common to many mindfulness based interventions (Kristeller, 2007). Participants were taught how to use meditation exercises to facilitate awareness of thoughts and bodily sensations related to cravings without judging or identifying with the content of such thoughts. The intervention equipped participants to resist cravings by simply focusing on and accepting sensations and thoughts that accompany the urges to eat. This enabled increased awareness of the “automatic pattern that usually emerges in the case of food cravings” (Alberts et al., 2010, p. 161). The authors maintain that the use of such mindful mediation exercises resulted in a reduction in cravings in response to food cues and a reduction in the extent to which participants experienced loss of control when exposed to food cues. Although the concept of mindfulness has attracted increased attention in the intervention literature the mechanisms by which enhanced mindfulness influences outcomes in a range of domains has yet to be clearly identified (Malinowski, 2008). Initial evidence supports the notion that mindfulness serves a “de-automatization” function or an “undoing” of automatic habitual processes whereby mindfulness modulates a motivational tendency toward heteronomy (Levesque & Brown, 2007). In effect, mindfulness leads to ‘acting with awareness’. Although enhancement of dispositional mindfulness has been addressed in the eating disorder therapy literature there has, with the exception of Alberts et al. (2010), been no assessment of its relationship with measures that capture behavioural tendencies to overeat. This is an important issue to address because of the putative inverse relationship between mindfulness and impulsivity and the positive relationship between impulsivity and trait disinhibition. Indeed this proposition partly addresses the suggestion put forward by Jansen et al. (2009) to “study ways that promote inhibition or self-control in otherwise impulsive people” (p. 109). The aim of the current investigation was firstly to determine how dispositional mindfulness is related to trait disinhibition, and secondly, examine how impulsivity would influence the relationship between mindfulness and trait disinhibition. The revised version of the original TFEQ-51 (Cappelleri et al., 2009 and Karlsson et al., 2000) was used to assess disinhibition. The TFEQ-R21 includes two subscales, in addition to a cognitive restraint scale, that assess different components of trait disinhibition. Firstly, uncontrolled eating (TFEQ-UE) which combines items from the original hunger and disinhibition scales reflects a propensity to overeat in response to external food related stimuli. Secondly, emotional eating (TFEQ-EE) which comprises items solely from the original disinhibition scale reflects a propensity to overeat in response to negative emotional states. Trait disinhibition is associated with adverse psychological symptoms such as depression (Kensinger et al., 1998 and Provencher et al., 2007) and anxiety (Karlsson et al., 2000). Therefore, we included assessment of such symptoms to statistically control for their influence. Initially (study 1) we predicted that mindfulness would be negatively associated with trait disinhibition, that is, greater dispositional mindfulness would be associated with lower scores on the TFEQ-R21 uncontrolled and emotional eating scales after controlling for an association with adverse psychological symptoms. Subsequently (study 2) we re-tested the same hypotheses in a new sample where we also measured impulsivity using the BIS-11. We predicted that mindfulness would be inversely related to impulsivity and components of trait disinhibition, and that impulsivity would be positively associated with components of trait disinhibition after controlling for adverse psychological symptoms.