actual experiment. It was decided to set the experiment up in this way so that each participant would have met the experimenter the day prior to the main experiment session, and would therefore be regulating the emotions of someone with whom they had a standardised level of familiarity with, but no close relationship. In experiments investigating interpersonal interactions such as interpersonal emotion regulation, it is important to establish that the participants are meaningfully engaging with each other. To this end, within this study, the person in the video had met with the participant on the day prior to the scan and conducted the practice session with them. This ensured that each of the participants had the same level of interaction and familiarity with the other person, and also increased the likelihood that participants would be motivated to regulate that person’s emotion. 2.2.3 Regulation instructions: Manipulation of inter- versus intra-personal emotion regulation The key manipulation of this current study was to vary the target of the emotion regulation process from the ‘self’ (intrapersonal) to the ‘other’ (interpersonal). The interpersonal emotion regulation condition therefore required an interaction to be made between the participant and the experimenter on the video link in order to constitute a valid form of interpersonal regulation (Totterdell, personal communication). The way in which this interaction occurred was for the participant to speak aloud to the other person, instructing them as to how they should regulate their emotional state. To ensure that the two versions of the paradigm (intra- and interpersonal) were matched (which was of paramount importance for the fMRI phase of the study in order to permit a direct comparison) the intrapersonal version also required participants to speak aloud a regulation strategy; participants were therefore required to say a short phrase that corresponded to how they were regulating their emotion according to the task instructions (e.g. it’s just a film). In the interpersonal version of the paradigm participants were required to speak during the same timeframe as the intrapersonal condition, but this time had to direct the other person as to how they should regulate their emotions according to the
Data analysis of SCR data was performed in the same manner as described in Chapter 3, section 3.4. The data from each individual video was averaged over the course of the video to give a single integrated skin conductance response (ISCR) value for each video. This can be taken as a measure of the overall electrodermal activity within a particular window of time. 4.8 Behavioural data Neuropsychological data and behavioural responses obtained during the paradigm were analyzed using SPSS (version 14.0) 4.9 Results 4.9.1 Baseline characteristics Table 4.1 – baseline characteristics of participants Study 1 (reappraise) (N=60) Study 2 (suppress) (N=60) Anodal (N=20) Cathodal (N=20) Sham (N=20) Anodal (N=20) Cathodal (N=20) Sham (N=20) Mean age (years) PANAS-X positive PANAS-X negative Mean disgust sensitivity 23 26 12 1.75 21 22 14 1.63 22 28 13 1.59 21 22 12 1.43 21 28 12 1.35 21 28 13 1.52
previously found that the grey matter volume of a similar area of dACC was positively correlated with an individual’s self reported typical use of cognitive reappraisal. When compared with Giuliani, Drabant & Gross (2011) it might seem counterintuitive that individuals with a more positive attitude towards emotion regulation would display reductions in grey matter volume of dACC, rather than an increase, given that cognitive reappraisal is generally seen as a highly adaptive emotion regulation strategy (Gross & John, 2003). However one explanation might be that individuals more likely to engage in automatic emotion regulation, might require less of an ‘alarm’ signal from the dACC to engage in voluntary emotion regulation, because of their tendency to engage in regulation on a more automatic basis. An alternative explanation might be that individuals with a smaller dACC volume adopt a more automatic style of emotion regulation given that they may be less efficient at engaging in ‘voluntary’ emotion regulation such as cognitive reappraisal, as is suggested by Giuliani, Drabant & Gross (2011). There is also an interesting related line of investigation about the role of the dACC in the regulation of autonomic factors such as heart rate. Critchley et al., (2003), suggest that the role of the dACC is to mediate context-driven modulation of bodily arousal. They found that activation of the dACC was related to control of heart rate during a paradigm involving cognitive and motor control, with the interpretation that dACC coordinates cardiovascular arousal during effortful motor or cognitive control. This is particularly interesting given that the ability to regulate emotion is also linked to an individual’s underlying cardiac tone (Pu, Schmeichel & Demaree, 2009). Pu and colleagues found that individuals with a higher respiratory sinus arrhythmia (RSA) (i.e. increased cardiac control) were judged to have expressed less emotion than those with a low RSA, even though the self reported emotion experience was similar. The authors suggest that cardiac vagal control may act as an internal marker of self-regulatory tendencies. Taken together this previous research and the current findings suggest that the dACC volume may act as an internal marker for emotion regulation tendency, as a result of its involvement in the regulation of bodily arousal. 5.10 Limitations
16. ______ sad 17. ______ calm 18. ______ afraid 19. ______ tired 20. ______ amazed 21. ______ shaky 22. ______ happy 23. ______ timid 24. ______ alone 25. ______ alert 26. ______ upset 27. ______ angry 28. ______ bold 29. ______ blue 30. ______ shy 31. ______active 32. ______guilty 33. ______ joyful 34._______nerous 35.______lonely 36_______sleepy 37______ excited 38.______ hostile 39.______ proud 40._____ jittery 41.______ lively 42.______ ashamed 43. ______ at ease 44.______ scared 45._____ drowsy 46. ______ angry at self 47.______ enthusiastic 48. ______ downhearted 49. ______ sheepish 50. ______ distressed 51. ____blameworthy 52. ______ determined 53. ______ frightened