Wiech, Farias, Kahane, Shackel, Tiede, & Tracey (2008)
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Transcript of Wiech, Farias, Kahane, Shackel, Tiede, & Tracey (2008)
Wiech, Farias, Kahane, Shackel, Tiede, & Tracey (2008)
An fMRI study measuring analgesia enhanced by religion as a belief system
Stories of diminished physical pain or pain tolerance due to religious belief
Research has shown that high-level cognitive processes such as placebo-induced analgesia, emotional detachment, and perceived control over pain can reduce pain intensity.
Religious individuals → positive framing
fMRI studies and the right ventrolateral prefrontal cortex (VLPFC)
Introduction
1. Can religious belief be shown to modulate pain in a controlled experimental setting?
2. Is such modulation of pain by religious belief mediated by the right VLPFC?
Research Questions
Subjects:
12 religious (Catholic) and 12 atheist/agnostic healthy individuals
Age 19-34
Questionnaire → All religious participants attended mass at least once/week and prayed everyday
QUESTION: Should atheists be used in the control group?
Design:
2 x 2 factorial design
GROUP (religious vs. non-religious) → between-subject
CONDITION (religious vs. non-religious) → within-subject
“Vergine Annunciate” by Sassoferrato
“Lady with an Ermine” by da Vinci
Methods
Visual stimuli:
(1) The religious image had to reliably evoke a religious mind set in believers and (2) the non-religious picture had to be sufficiently similar to the religious one in order to minimize the influence of confounding factors.
Image of Jesus may introduce confounding factors
Religious → evoked most powerful religious feelings
Non-religious → rated most similar to religious image
Procedure:
Electrical stimulation to the back of the left hand
fMRI session
Coping and familiarity rating using visual analog
Methods
Procedure:
Pain ratings:
Significant effects for CONDITION and GROUP x CONDITION
GROUP was not significant → Religious not less sensitive to pain
Atheist group rated pain same in both conditions
Results
Affectedness ratings:
Significant effects for GROUP and GROUP x CONDITION
Religious sample → more positive ratings for religious image
Atheist sample → more positive ratings for non-religious image
*Both groups indicated differences in preferred image but only religious group also indicated pain reduction when viewing preferred image
Results
Coping and familiarity ratings:
Both factors and interaction significant for coping
Religious → Virgin Mary more helpful in coping
Atheist → Both pictures equally helpful
Participants rated both pictures as equally familiar.
Neuroimaging data:
No significant differences between groups for pain-related brain activation
Religious group/ religious image → significant activation in right VLPFC and pons/ventral midbrain
*Support for 2nd research question
Results
*Religious group/ Religious image
Neuroimaging data:
Activation in right VLPFC not due to preferential liking
→ no activation for atheist group with preferred image
Pons/midbrain activation found in both groups
→ likely due to preferential liking
Results
Pons/midbrain area – most strongly associated with affectedness (positive)
Right VLPFC – most strongly associated with pain intensity (negative)
Results
Religious individuals are able to lessen the perceived pain intensity when they are presented with a religious image.
(1) Distraction effect
(2) Motivational priming
(3) Reappraisal – a process of reinterpreting the meaning of a stimulus leading to a change in one’s emotional response to it.
→ Supported by data
→ Distraction and motivational priming – preferential liking should have produced a reduction in pain
Discussion
Right VLPFC
Active for religious group/religious condition, leading to a decrease in perceived pain intensity
Active in previous studies of pain modulation
Pons/ventral midbrain
More strongly related to affectedness → active during preferred condition
Unknowns
Is the pain-reduction effect started by the VLPFC or is the VLPFC compelled by the dorsolateral prefrontal cortex?
QUESTION: Do you think similar pain-reduction effects can occur using stimuli that are not religious in nature but have similar cultural and nurturing influences?
Discussion
Catholic → familiar with image of Virgin Mary
Prayed the rosary every night → Hail Mary
Likely helped the survivors cope with the pain associated with injuries from crash, hunger, and the cold.
Andes Survivors