Scientific Report on Bial Fellowship 36/08 Theoretical Background
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Scientific Report on Bial Fellowship 36/08 Theoretical background and study overview In sympathetic magical belief, objects are deemed to possess an affinity of power through their resemblance or connection to individuals by the ‘Law of Similarity’ (Frazer, 1922). Early belief in these laws underpin folk herbal remedies, alchemy and voodoo witchcraft, but also trigger magical notions in modern scientifically literate adults (e.g. Rozin & Nemeroff, 1990). One of the most dramatic examples of belief in sympathetic magic is the concern that damage to a representation can somehow harm the real-world person or object it is representing (Behrand, 2003). In our pilot studies, we have demonstrated that adults who do not think that they will be upset by cutting up a photograph of their childhood sentimental object will show significantly elevated arousal as measured by their galvanic skin response. Following the destruction they reported no awareness of increased arousal. This suggests that there may be latent emotional responses to perceived destruction that are suppressed. We predict that this reflects suppression of amygdala fear activation by inhibitory dorsal-lateral prefrontal cortex (DLPC) networks. The rationale for this frontal inhibitory effect is the recent demonstration that activation of the DLPC and anterior cingulate is associated with unwanted prejudicial responses to Black faces by White participants (Richeson et al, 2003; Cunningham et al, 2004). These studies on prejudice are consistent with the idea that it is possible to control spontaneously activated negative attitudes. The current body of work examined whether the same network might be implicated in sympathetic magical reasoning. Sixty-seventy percent of Western children form a strong emotional attachment to a specific toy which they then treat as invaluable and irreplaceable (Lehman et al., 1995). Many adults retain their childhood attachment objects soothing (Hood, 2009). To examine sympathetic magical belief in scientifically rational adults we focused on measuring participant’s explicit and implicit responses when destroying a photo of their childhood attachment object or watching a video of their attachment object being destroyed. Stage 1 Three experiments with 82 participants established that scientifically literate adults experience implicit arousal when cutting up photos of their childhood attachment objects relative to other objects they own or control objects. This was the case when they were and were not being observed by the experimenter and when the picture of their attachment object bore little resemblance to the object itself. These results are taken as evidence for a tacit acceptance of sympathetic magic even in those individuals who explicitly stated that they would not be upset. This suggests that sympathetic magical belief is an implicit reasoning bias that is suppressed. This work was accepted for publication in the Journal of Cognition and Culture (2010) and is attached in Appendix A. Stage 2 Having established an implicit response to destruction of a picture of an attachment object, it was necessary to change the protocol to make it appropriate for conducting an fMRI scanning experiment. Participants in the scanner cannot move to cut up the pictures, as they did in Stage 1, so a series of videos were created in which the participant saw their attachment object or a range of control objects (their phone, a toy that looked similar to their attachment object, an empty box), being placed in a box and then the box being destroyed in 6 different ways (burning, exploding, chain-sawing, being driven over, squashed and skewered). These were contrasted with a video in which the box was not harmed (it was stroked) to ensure participants did not become habituated to the destruction scenarios. Piloting with 10 participants revealed significantly greater electrodermal response 1 when presented with a destruction video involving their attachment objects relative to all of the other controls. The degree of electrodermal response was comparable to that shown in Stage 1 where participants themselves cut up pictures of their attachment objects and controls. Stage 3 A primary hypothesis was that the degree to which sympathetic magical beliefs are expressed would be modulated by individual differences in reasoning style, paranormal belief and attachment style. These were measured using the following instruments: The Rational-Experiential Reasoning Scale (Pacini & Epstein, 1999) – a 41-item scale that establishes along two orthogonal scales whether individuals prefer to reason experientially (e.g. in line with their gut reactions) or rationally (e.g. though conscious analysis). Revised Paranormal Beliefs Scale (Tobyack, 2004) – a 26-item questionnaire on which respondents score a range of common paranormal beliefs as true or false. Global Attachment Style Questionnaire (Fraley, Waller & Brennan, 2000) – a 36-item questionnaire to establish whether respondents form anxious or avoidant social attachments. Explicit measures In addition we also asked participants to rate how emotionally significant their attachment object was to them and, on a scale of 1-10, where 1 was the worst thing that could ever happen, how upset they thought they would be about watching a video of their attachment object being destroyed, knowing it was pretend. Participants Thirty-two adult participants (6 male) aged between 20 and 55 years (mean age = 27 years). All of the participants obtained their attachment object before 5 years of age and the majority (88%) obtained it in their first year of life. All of the attachment objects had a face (though in some cases the face was no longer visible due to wear and tear.) Results & Discussion Experiential reasoning correlated significantly with paranormal beliefs and anticipated distress seeing the destruction video. This suggests that individual differences in reasoning style predicts explicit sympathetic magical beliefs. Self-rated emotional significance of the attachment object also correlated significantly with how upset participants predicted that they would be which provides confirmation that the explicit measures are consistent. Attachment style did not correlate significantly with any of the other measures. Stage 4 All of the participants who had completed Stage 3 (N = 32) were then placed into an MRI scanner. The primary objective of this experiment was to establish whether the amygdala, associated with low-level threat detection (e.g. Whalen, 1998), is differentially activated when a representation of the participant’s attachment object is destroyed as compared to objects that have personal financial but no sentimental value. The second objective of this experiment was to determine whether those participants who claim they will be least distressed by destruction of a representation of their attachment object show significantly greater activation of dorso-lateral pre-frontal lobe networks associated in previous literature with inhibition of pre-potent responses. Correlations were explored between strength of frontal lobe response and participants’ scores on the Experiential-Rational Reasoning Scale (Pacini & Epstein, 1999), the Revised Paranormal Beliefs Scale (Tobacyk, 2004) and anticipated perceived distress. 2 Acquisition All data were acquired on a GE 3 Tesla HDx system. BOLD FMRI data were obtained using a gradient echo EPI sequence with the following parameters: Repetition time (TR) = 3000ms; echo time (TE) = 35ms; field of view = (240mm)2; data matrix = 64x64; 44 slices with thickness 2.8mm and 1.0mm gap; parallel imaging (ASSET) factor = 2. Slices were acquired with an oblique-axial angulation, aligned to the participants’ anterior commissure- posterior commissure line. A T1-weighted 3D structural scan (FSPGR) was acquired during the same session for registration purposes, with the following parameters; TR/TE=7.9/3.0 ms, TI=450ms, Flip angle=20deg, 1 average, data matrix 256x256x176, field of view 256x256x176 mm3 . Statistical Analysis Data preprocessing and analysis were performed using the Oxford Centre for Functional Magnetic Resonance Imaging of the Brain (FMRIB) Software Library (www.fmrib.ox.ac.uk/ fsl). Spatial smoothing was applied using a full-width half-maximum Gaussian kernel of 5 mm. Preprocessing and analysis was performed using FEAT (fMRI Expert Analysis Tool, version 5.63). To remove low- frequency artifacts, each functional run was temporally filtered using a high-pass cutoff of 100 s. FMRIB Brain Extraction Tool (Smith, 2002) was used to remove non- brain data, and motion correction was applied using 3-dimensional co-registration of each image to the middle image of the time series with MCFLIRT (Jenkinson, Bannister, Brady & Smith, 2002). Registration of the functional data followed a two-stage process using FLIRT, initially the EPI data were registered to the participant’s a high resolution T1-weighted FSPGR image (7 degrees of freedom), and then registered to the Montreal Neurological Institute (MNI) 152 standard template anatomical image (12 degrees of freedom). Each trial type (attachment object, AO; control object, CO; familiar object, FO; empty box, EB) was modeled as a 15s block, with onset time at the beginning of the video. For the first level analysis, four event types were modeled – the ‘destruction’ videos for attachment object, control object, familiar object (mobile phone) and empty box. Six contrasts were set up to investigate differences in neural activity when viewing the destruction of