There are patients with congenital insensitivity to pain (CIP) this is a rare condition. They don’t feel pain, cognition and sensation is otherwise normal; for instance they can still feel discriminative touch (though not always temperature), and there is no detectable physical abnormality. They offer a unique opportunity to test the model of empathy. Does the lack of self-pain representation influence the perception of others’ pain.
CIP patients globally underestimate the pain of others when emotional cues were lacking, and that their pain judgments, in contrast with those of control subjects, are strongly related to interindividual differences in empathy trait. More empathy better pain judgment.
Patients with CIP showed normal fMRI responses to observed pain. The same regions for observed pain in anterior mid-cingulate cortex and anterior insula, were activated. In contrast to healthy controls their empathy trait predicted ventromedial prefrontal responses to somatosensory representations of others’ pain and posterior cingulate responses to emotional representations of others’ pain. CIP patients can acknowledge the pain of others. The amount strongly correlates with their empathic capacity which mainly relies on the engagement of anterior the ventromedial prefrontal cortex (vmPFC) and posterior the ventral posterior cingulate cortex (vPCC) midline structures, which may in part compensate for the patients’ lack of automatic resonance mechanisms.
Why is this study important?
It provides insights into the brain’s ability to evaluate others’ feeling to observed pain without having a specific sensory experience of pain itself. These findings can elucidate the three components of pain processing.
It can be simplistically divided into three domains that are interconnected and/or influence each other through direct or indirect pathways. Most of the regions commonly activated in the CIP-group and C-group are shown in bold in the figure and include regions thought to be involved in emotional processing of pain
Some regions were active in both groups this suggests a generalized or common circuitry for emotional processing. Some regions differ in activation. These differences in activation in regions (medial frontal gyrus and posterior insula and caudate for body parts and the cingulate [mid and posterior]) noted in this study are of greater interest. These four regions are differentially activated in the CIP-group and not in the control group. These regions may provide some interesting insights into the processing of empathy.
How was this study done?
we used event-related functional magnetic resonance imaging (fMRI) to study the neural correlates of empathy for pain in a group of 13 CIP patients and a control group of 13 healthy subjects. Participants were scanned while observing body parts in painful situations (Experiment 1) or facial expressions of pain (Experiment 2), and were instructed to imagine how the person in the picture feels. We anticipated that CIP patients, deprived as they are of the depicted pain experiences, would show decreased activation in regions supposedly involved in automatic resonance to others’ pain, including the anterior insula (AI) and anterior mid-cingulate cortex (aMCC). In addition, we predicted that the patients’ effort to build a representation of others’ pain might engage brain areas known to be involved in emotional perspective taking, especially midline structures such as medial prefrontal and posterior cingulate cortices
Related post on this blog:
Patient doctor relationship: Neuroscience of empathy
N DANZIGER, I FAILLENOT, R PEYRON (2009). Can We Share a Pain We Never Felt? Neural Correlates of Empathy in Patients with Congenital Insensitivity to Pain Neuron, 61 (2), 203-212 DOI: 10.1016/j.neuron.2008.11.023
D BORSOOK, L BECERRA (2009). Emotional Pain without Sensory Pain—Dream On? Neuron, 61 (2), 153-155 DOI: 10.1016/j.neuron.2009.01.003