20 research outputs found
Subjective Posture and Subjective Affluence: Chicago Field Theories in the U.S. Media and Political Systems
To further understanding of how individuals experience media and political systems, this article compares a project in the Chicago sociology tradition to concepts from Bourdieu\u27s field theory and practical reason. Limited life history documents from Chicago working-class and more-advantaged young adults illustrate two interactionist concepts, subjective posture, one\u27s stance toward media and politics, and subjective affluence, the range of empowerment the postures reveal. A stance as individual consumer, primarily in pursuit of entertainment, crossed over class lines, but elite participants had higher subjective affluence, with agency as political actors influencing others. The similarities illustrate an aspect of Bourdieu\u27s habitus, and their class differences illustrate distinctions in symbolic power. The results advance theory in the midrange between macrolevel structures and microlevel subjectivity
Do Mirror Glasses Have the Same Effect on Brain Activity as a Mirror Box? Evidence from a Functional Magnetic Resonance Imaging Study with Healthy Subjects
Milde C, Rance M, Kirsch P, et al. Do Mirror Glasses Have the Same Effect on Brain Activity as a Mirror Box? Evidence from a Functional Magnetic Resonance Imaging Study with Healthy Subjects. PLOS ONE. 2015;10(5): e0127694
The Lie Algebraic Significance of Symmetric Informationally Complete Measurements
Examples of symmetric informationally complete positive operator valued
measures (SIC-POVMs) have been constructed in every dimension less than or
equal to 67. However, it remains an open question whether they exist in all
finite dimensions. A SIC-POVM is usually thought of as a highly symmetric
structure in quantum state space. However, its elements can equally well be
regarded as a basis for the Lie algebra gl(d,C). In this paper we examine the
resulting structure constants, which are calculated from the traces of the
triple products of the SIC-POVM elements and which, it turns out, characterize
the SIC-POVM up to unitary equivalence. We show that the structure constants
have numerous remarkable properties. In particular we show that the existence
of a SIC-POVM in dimension d is equivalent to the existence of a certain
structure in the adjoint representation of gl(d,C). We hope that transforming
the problem in this way, from a question about quantum state space to a
question about Lie algebras, may help to make the existence problem tractable.Comment: 56 page
Assessment of cortical reorganization and preserved function in phantom limb pain: a methodological perspective.
Andoh J, Milde C, Diers M, et al. Assessment of cortical reorganization and preserved function in phantom limb pain: a methodological perspective. Scientific reports. 2020;10(1): 11504.Phantom limb pain (PLP) has been associated with reorganization in primary somatosensory cortex (S1) and preserved S1 function. Here we examined if methodological differences in the assessment of cortical representations might explain these findings. We used functional magnetic resonance imaging during a virtual reality movement task, analogous to the classical mirror box task, in twenty amputees with and without PLP and twenty matched healthy controls. We assessed the relationship between task-related activation maxima and PLP intensity in S1 and motor cortex (M1) in individually-defined or group-conjoint regions of interest (ROI) (overlap of task-related activation between the groups). We also measured cortical distances between both locations and correlated them with PLP intensity. Amputees compared to controls showed significantly increased activation in M1, S1 and S1M1 unrelated to PLP. Neural activity in M1 was positively related to PLP intensity in amputees with PLP when a group-conjoint ROI was chosen. The location of activation maxima differed between groups in S1 and M1. Cortical distance measures were unrelated to PLP. These findings suggest that sensory and motor maps differentially relate to PLP and that methodological differences might explain discrepant findings in the literature
The Prevalence and Characteristics of Phantom Limb Pain and Non-Painful Phantom Phenomena in a Nationwide Survey of 3,374 Unilateral Limb Amputees
The experience of phantom limb pain (PLP) is a common consequence of limb amputation, resulting in severe impairments of the affected person. Previous studies have shown that several factors such as age at or site of amputation are associated with the emergence and maintenance of PLP. In this cross-sectional study we assessed the presence of several phantom phenomena including PLP and other amputation-related information in a sample of 3,374 unilateral upper and lower limb amputees. Clinical and demographic variables (age at amputation, level of amputation) explained 10.6% of the variance in PLP and perceptual variables (intensity of phantom limb sensation [PLS], referred sensations, intensity of telescoping, residual limb pain [RLP] intensity) explained 16.9% of the variance. These variables were specific for PLP and not for RLP. These results suggest that distinct variables are associated with PLP (age at amputation, level of amputation, PLS intensity, referred sensations, intensity of telescoping, RLP intensity) and RLP (PLP intensity) and point at partly different mechanisms for the emergence and maintenance of PLP and RLP. PERSPECTIVE: Clinical/demographic variables as well as perceptual variables are 2 major components related to PLP and explain ∼11% and ∼17% of the variance. These results could potentially help clinicians to understand which factors may contribute to chronic phantom limb pain.
Keywords: Amputation; phantom limb pain; phantom limb sensations; residual limb pain; telescope
The prevalence and characteristics of phantom limb pain and non-painful phantom phenomena in a nationwide survey of 3374 unilateral limb amputees.
Diers M, Krumm B, Fuchs X, et al. The prevalence and characteristics of phantom limb pain and non-painful phantom phenomena in a nationwide survey of 3374 unilateral limb amputees. The journal of pain. 2021.The experience of phantom limb pain (PLP) is a common consequence of limb amputation, resulting in severe impairments of the affected person. Previous studies have shown that several factors such as age at or site of amputation are associated with the emergence and maintenance of PLP. In this cross-sectional study we assessed the presence of several phantom phenomena including PLP and other amputation-related information in a sample of 3,374 unilateral upper and lower limb amputees. Clinical and demographic variables (age at amputation, level of amputation) explained 10.6% of the variance in PLP and perceptual variables (intensity of phantom limb sensation (PLS), referred sensations, intensity of telescoping, residual limb pain (RLP) intensity) explained 16.9% of the variance. These variables were specific for PLP and not for RLP. These results suggest that distinct variables are associated with PLP (age at amputation, level of amputation, PLS intensity, referred sensations, intensity of telescoping, RLP intensity) and RLP (PLP intensity) and point at partly different mechanisms for the emergence and maintenance of PLP and RLP. PERSPECTIVE: Clinical/demographic variables as well as perceptual variables are two major components related to PLP and explain 11% and 17% of the variance. These results could potentially help clinicians to understand which factors may contribute to chronic phantom limb pain. Copyright © 2021. Published by Elsevier Inc
Phantom limb pain after unilateral arm amputation is associated with decreased heat pain thresholds in the face
BACKGROUND
The mechanisms underlying chronic phantom limb pain (PLP) are complex and insufficiently understood. Altered sensory thresholds are often associated with chronic pain but quantitative sensory testing (QST) in PLP has so far been inconclusive due to large methodological variation between studies and small sample sizes.
METHODS
In this study, we applied QST in 37 unilateral upper-limb amputees (23 with and 14 without PLP) and 19 healthy controls. We assessed heat pain (HPT), pressure pain, warmth detection and two-point discrimination thresholds at the residual limb, a homologous point and the thenar of the intact limb as well as both corners of the mouth.
RESULTS
We did not find significant differences in any of the thresholds between the groups. However, PLP intensity was negatively associated with HPT at all measured body sites except for the residual limb, indicating lower pain thresholds with higher PLP levels. Correlations between HPT and PLP were strongest in the contralateral face (r = -0.65, p < 0.001). Facial HPT were specifically associated with PLP, independent of residual limb pain (RLP) and various other covariates. HPT at the residual limb, however, were significantly associated with RLP, but not with PLP.
CONCLUSION
We conclude that the association between PLP and, especially facial, HPT could be related to central mechanisms.
SIGNIFICANCE
Phantom limb pain (PLP) is still poorly understood. We show that PLP intensity is associated with lower heat pain thresholds, especially in the face. This finding could be related to central nervous changes in PLP