NeuroImage
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Human empathy is an important component of social cognition that involves complex processes of emotional perspective taking and the issue of self/other distinction. Empathic perception enables us to experience negative emotions when someone else undergoes painful events. We investigated the influence of an extended time interval (10s) and subjective performance evaluation (following each trial) of perspective taking on the cortical and subcortical correlates of pain empathy in eighteen healthy subjects using functional magnetic resonance imaging (fMRI). ⋯ For Other, differential activations were mainly observed in the left pallidum, bilateral VLPFC, the right middle orbitofrontal cortex OFC and the middle cingulate cortex (MCC). These results suggest that trial-specific success ratings allow us to disentangle differences between effort-related and successful engagement in perspective taking. These two adjustments to the well-known paradigm showed new insight into the aspects of perspective taking during pain perception.
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The blood oxygenation level dependent (BOLD) response measured with functional magnetic resonance imaging (fMRI) depends on the evoked changes in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO(2)) in response to changes in neural activity. This response is strongly modulated by the CBF/CMRO(2) coupling relationship with activation, defined as n, the ratio of the fractional changes. The reliability of the BOLD signal as a quantitative reflection of underlying physiological changes depends on the stability of n in response to different stimuli. ⋯ Instead, this response ratio was significantly lower for the BOLD response (BOLD response: 0.23 ± 0.13, mean ± SD; CBF response: 0.42 ± 0.18; p=0.0054). This data is consistent with a reduced dynamic range (strongest/weakest response ratio) of the CMRO(2) response (~1.7-fold) compared to that of the CBF response (~2.4-fold) as luminance contrast increases, corresponding to an increase of n from 1.7 at the lowest contrast level to 2.3 at the highest contrast level. The implication of these results for fMRI studies is that the magnitude of the BOLD response does not accurately reflect the magnitude of underlying physiological processes.
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Experientially opening oneself to pain rather than avoiding it is said to reduce the mind's tendency toward avoidance or anxiety which can further exacerbate the experience of pain. This is a central feature of mindfulness-based therapies. Little is known about the neural mechanisms of mindfulness on pain. ⋯ The reduced baseline activation in left aI correlated with lifetime meditation experience. This pattern of low baseline activity coupled with high response in aIns and aMCC was associated with enhanced neural habituation in amygdala and pain-related regions before painful stimulation and in the pain-related regions during painful stimulation. These findings suggest that cultivating experiential openness down-regulates anticipatory representation of aversive events, and increases the recruitment of attentional resources during pain, which is associated with faster neural habituation.
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Noise in fMRI recordings creates uncertainty when mapping functional networks in the brain. Non-neural physiological processes can introduce correlated noise across much of the brain, altering the apparent strength and extent of intrinsic networks. In this work, a new data-driven noise correction, termed "APPLECOR" (for Affine Parameterization of Physiological Large-scale Error Correction), is introduced. ⋯ APPLECOR is shown to achieve greater consistency of the default mode network across time and across subjects than was achieved using global mean regression, respiratory volume and heart rate correction (RVHRCOR (Chang et al., 2009)), or no correction. Combining APPLECOR with RVHRCOR regressors attained greater consistency than either correction alone. Use of the proposed noise-reduction approach may help to better identify and delineate the structure of resting state networks.
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The earliest stages of osteoarthritis are characterized by peripheral pathology; however, during disease progression chronic pain emerges-a major symptom of osteoarthritis linked to neuroplasticity. Recent clinical imaging studies involving chronic pain patients, including osteoarthritis patients, have demonstrated that functional properties of the brain are altered, and these functional changes are correlated with subjective behavioral pain measures. Currently, preclinical osteoarthritis studies have not assessed if functional properties of supraspinal pain circuitry are altered, and if these functional properties can be modulated by pharmacological therapy either by direct or indirect action on brain systems. ⋯ Celecoxib was chosen as a comparator, given its clinical efficacy for alleviating pain in osteoarthritis patients and its peripheral and central pharmacological action. Relative to the vehicle condition, acute celecoxib treatment in MMT animals yielded decreased phMRI infusion responses and decreased functional connectivity, the latter observation being similar to what was detected following chronic MMPi treatment. These findings demonstrate that an assessment of brain function may provide an objective means by which to further evaluate the pathology of an osteoarthritis state as well as measure the pharmacodynamic effects of therapies with peripheral or peripheral and central pharmacological action.