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| 2. |
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| 3. |
- Björnsdotter, Annika, 1970-
(författare)
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Evaluation of Family Check-Up and iComet : Effectiveness as well as Psychometrics and Norms for Parent Rating Scales
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis compromise four studies, three regarding psychometrics and norms of parent rating scales, and one study regarding effectiveness of two different interventions. A normative sample consisting of 1443 parents with children aged 10 to 13 years old, was used in the Study I, II and III. In Study IV, 231 self-referred parents with children aged 10-13 years old with externalizing behavior problem (EBP) were randomized to either Family Check-Up (FCU) or iComet.The Strengths and Difficulties Questionnaire (SDQ) used in Study I proved to be a reliable and valid instrument with high internal consistency, clear factor structure and high correlation with other similar instruments. In addition, the results support the online use of SDQ as well as using norms obtained through traditional administration even when the SDQ has been administrated online. The Emotion Regulation Questionnaire (ERQ) investigated in Study II was shown to have adequate reliability and construct validity. The specific use of expressive suppression or cognitive reappraisal as a parental emotion regulation strategy was correlated as expected to the couple’s satisfaction, family warmth, and the employment of adequate discipline strategies. Swedish norms for self-rated ERQs are also presented. Study III investigated the Parental Knowledge and Monitoring Scale (PKMS), which was shown to be a useful instrument for assessing parental knowledge and its sources. Family climate appears to moderate important relationships between parental knowledge and conduct problems with implications for such things as family interventions. Finally, a person-oriented analysis was used in Study IV to subtype the children according to combinations of prosocial behavior and EBP, such as different levels of attention deficit hyperactivity disorder (ADHD) symptoms and/or oppositional defiant disorder (ODD) behaviors. Despite being a heterogeneous group of children with EBP, they were meaningfully grouped into significantly different profiles. Both FCU and iComet resulted in post-treatment measurement within non-clinical range for three of the five profiles. The two profiles that included high levels of ADHD behaviors at baseline assessment continued to have residual symptoms post intervention.
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| 4. |
- Björnsdotter, Malin, et al.
(författare)
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A Monte Carlo method for locally multivariate brain mapping.
- 2011
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Ingår i: NeuroImage. - : Elsevier BV. - 1095-9572 .- 1053-8119.
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Tidskriftsartikel (refereegranskat)abstract
- Locally multivariate approaches to functional brain mapping offer a highly appealing complement to conventional statistics, but require restrictive region-of-interest hypotheses, or, in exhaustive search forms (such as the "searchlight" algorithm; Kriegeskorte et al., 2006), are excessively computer intensive. We therefore propose a non-restrictive, comparatively fast yet highly sensitive method based on Monte Carlo approximation principles where locally multivariate maps are computed by averaging across voxelwise condition-discriminative information obtained from repeated stochastic sampling of fixed-size search volumes. On simulated data containing discriminative regions of varying size and contrast-to-noise ratio (CNR), the Monte Carlo method reduced the required computer resources by as much as 75% compared to the searchlight with no reduction in mapping performance. Notably, the Monte Carlo mapping approach not only outperformed the general linear method (GLM), but also produced higher discriminative voxel detection scores than the searchlight irrespective of classifier (linear or nonlinear support vector machine), discriminative region size or CNR. The improved performance was explained by the information-average procedure, and the Monte Carlo approach yielded mapping sensitivities of a few percent lower than an information-average exhaustive search. Finally, we demonstrate the utility of the algorithm on whole-brain, multi-subject functional magnetic resonance imaging (fMRI) data from a tactile study, revealing that the central representation of gentle touch is spatially distributed in somatosensory, insular and visual regions.
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| 5. |
- Björnsdotter, Malin
(författare)
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Brain Processing of CT-Targeted Stimulation
- 2016
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Ingår i: Affective Touch and the Neurophysiology of CT Afferents. Olausson, H., Wessberg, J., Morrison, I., McGlone, F. (Eds.). - New York, NY : Springer. - 9781493964185 ; , s. 187-194
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Bokkapitel (refereegranskat)
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| 6. |
- Björnsdotter, Malin, et al.
(författare)
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Clustered sampling improves random subspace brain mapping
- 2012
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Ingår i: Pattern recognition. - : Elsevier BV. - 0031-3203 .- 1873-5142. ; 45:6, s. 2035-2040
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Tidskriftsartikel (refereegranskat)abstract
- Intuitive and efficient, the random subspace ensemble approach provides an appealing solution to the problem of the vast dimensionality of functional magnetic resonance imaging (fMRI) data for maximal-accuracy brain state decoding. Recently, efforts to generate biologically plausible and interpretable maps of brain regions which contribute information to the ensemble decoding task have been made and two approaches have been introduced: globally multivariate random subsampling and locally multivariate Monte Carlo mapping. Both types of maps reflect voxel-wise decoding accuracies averaged across repeatedly randomly sampled voxel subsets, highlighting voxels which consistently participate in high-classification subsets. We compare the mapping sensitivities of the approaches on realistic simulated data containing both locally and globally multivariate information and demonstrate that utilizing the inherent volumetric nature of fMRI through clustered Monte Carlo mapping yields dramatically improved performances in terms of voxel detection sensitivity and efficiency. These results suggest that, unless a priori information specifically dictates a global search, variants of clustered sampling should be the priority for random subspace brain mapping.
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| 7. |
- Björnsdotter, Malin, et al.
(författare)
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Development of brain mechanisms for processing affective touch
- 2014
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Ingår i: Frontiers in Behavioral Neuroscience. - Lausanne, Switzerland : Frontiers Media SA. - 1662-5153. ; 8:FEB
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Tidskriftsartikel (refereegranskat)abstract
- Affective tactile stimulation plays a key role in the maturation of neural circuits, but the development of brain mechanisms processing touch is poorly understood. We therefore used functional magnetic resonance imaging (fMRI) to study brain responses to soft brush stroking of both glabrous (palm) and hairy (forearm) skin in healthy children (5-13 years), adolescents (14-17 years), and adults (25-35 years). Adult-defined regions-of-interests in the primary somatosensory cortex (SI), secondary somatosensory cortex (SII), insular cortex and right posterior superior temporal sulcus (pSTS) were significantly and similarly activated in all age groups. Whole-brain analyses revealed that responses in the ipsilateral SII were positively correlated with age in both genders, and that responses in bilateral regions near the pSTS correlated significantly and strongly with age in females but not in males. These results suggest that brain mechanisms associated with both sensory-discriminative and affective-motivational aspects of touch are largely established in school-aged children, and that there is a general continuing maturation of SII and a female-specific increase in pSTS sensitivity with age. Our work establishes a groundwork for future comparative studies of tactile processing in developmental disorders characterized by disrupted social perception such as autism. © 2014 Björnsdotter, Gordon, Pelphrey, Olausson and Kaiser.
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| 8. |
- Björnsdotter, Malin, et al.
(författare)
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Evaluation of Quantified Social Perception Circuit Activity as a Neurobiological Marker of Autism Spectrum Disorder.
- 2016
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Ingår i: JAMA psychiatry. - : American Medical Association (AMA). - 2168-6238 .- 2168-622X. ; 73:6, s. 614-621
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Tidskriftsartikel (refereegranskat)abstract
- Autism spectrum disorder (ASD) is marked by social disability and is associated with dysfunction in brain circuits supporting social cue perception. The degree to which neural functioning reflects individual-level behavioral phenotype is unclear, slowing the search for functional neuroimaging biomarkers of ASD.
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| 9. |
- Björnsdotter, Malin, et al.
(författare)
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Feeling good : on the role of C fiber mediated touch in interoception.
- 2010
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Ingår i: Experimental Brain Research. - : Springer. - 0014-4819 .- 1432-1106. ; 207:3, s. 149-155
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Tidskriftsartikel (refereegranskat)abstract
- The human skin is innervated by a network of thin, slow-conducting afferent (C and Aδ) fibers, transmitting a diverse range of information. Classically, these fibers are described as thermo-, noci- or chemoreceptive, whereas mechanoreception is attributed exclusively to thick, fast-conducting (Aβ) afferents. A growing body of evidence, however, supports the notion that C tactile afferents comprise a second anatomically and functionally distinct system signaling touch in humans. This review discusses established as well as recent findings which highlight fundamental differences in peripheral and central information coding and processing between Aβ and C mechanoreception. We conclude that from the skin through the brain, C touch shares more characteristics with interoceptive modalities (e.g. pain, temperature, and itch) than exteroceptive Aβ touch, vision or hearing. In this light, we discuss the motivational-affective role of C touch as an integral part of a thin-fiber afferent homeostatic network for the maintenance of physical and social well-being.
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| 10. |
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| 11. |
- Björnsdotter, Malin, et al.
(författare)
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Identification and localization of human brain activity patterns using particle swarm optimization.
- 2010
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Ingår i: The 2nd International Conference on Computer and Automation Engineering, Singapore.
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Konferensbidrag (refereegranskat)abstract
- Classifier-based multivariate pattern recognition techniques have in recent years enabled highly sensitive mapping of brain regions where mind states can be decoded from functional magnetic resonance imaging (fMRI) data. The “searchlight” mapping approach, where the brain volume is exhaustively scanned with a fixed-size search volume, is highly appealing in terms of sensitivity but also exceedingly time consuming [1]. We therefore propose an efficient, easily-implemented particle swarm optimization (PSO) brain mapping method, where fixed-size, fixed-shape (spherical) particles search the brain volume for informative regions where a classifier can decode the mind states. Particle positions and velocities are encoded in Cartesian coordinates, and niching techniques are used to identify multiple informative brain regions. We demonstrate the versatility of the algorithm in combination with linear discriminant analysis (LDA) and linear and non-linear support vector machines (SVMs) to decode brain states on simulated as well as authentic fMRI data. The PSO method outperformed the conventional general linear model (GLM) method in terms of mapping sensitivity, and compared favorably with the “searchlight” algorithm – for a dramatic reduction in time requirements (e.g. 6.7 min compared to 9 h for a minute reduction in mapping sensitivity). On the authentic fMRI dataset, expected brain regions were identified. The PSO algorithm is a promising highly efficient multivariate alternative for functional brain mapping and brain state decoding.
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| 12. |
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| 13. |
- Björnsdotter, Malin, et al.
(författare)
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Somatotopic organization of gentle touch processing in the posterior insular cortex.
- 2009
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Ingår i: The Journal of neuroscience : the official journal of the Society for Neuroscience. - Washington, DC, United States : Society for Neuroscience. - 1529-2401 .- 0270-6474. ; 29:29, s. 9314-20
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Tidskriftsartikel (refereegranskat)abstract
- A network of thin (C and A delta) afferents relays various signals related to the physiological condition of the body, including sensations of gentle touch, pain, and temperature changes. Such afferents project to the insular cortex, where a somatotopic organization of responses to noxious and cooling stimuli was recently observed. To explore the possibility of a corresponding body-map topography in relation to gentle touch mediated through C tactile (CT) fibers, we applied soft brush stimuli to the right forearm and thigh of a patient (GL) lacking A beta afferents, and six healthy subjects during functional magnetic resonance imaging (fMRI). For improved fMRI analysis, we used a highly sensitive multivariate voxel clustering approach. A somatotopic organization of the left (contralateral) posterior insular cortex was consistently demonstrated in all subjects, including GL, with forearm projecting anterior to thigh stimulation. Also, despite denying any sense of touch in daily life, GL correctly localized 97% of the stimuli to the forearm or thigh in a forced-choice paradigm. The consistency in activation patterns across GL and the healthy subjects suggests that the identified organization reflects the central projection of CT fibers. Moreover, substantial similarities of the presently observed insular activation with that described for noxious and cooling stimuli solidify the hypothesized sensory-affective role of the CT system in the maintenance of physical well-being as part of a thin-afferent homeostatic network.
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| 14. |
- Björnsdotter, Malin, et al.
(författare)
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Support Vector Machine Diagnosis of Acute Abdominal Pain
- 2010
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Ingår i: Communications in Computer and Information Science. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 1865-0929. ; 52:4, s. 347-355, s. 347-355
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Tidskriftsartikel (refereegranskat)abstract
- This study explores the feasibility of a decision-support system for patients seeking care for acute abdominal pain, and, specifically the diagnosis of acute diverticulitis. We used a linear support vector machine (SVM) to separate diverticulitis from all other reported cases of abdominal pain and from the important differential diagnosis non-specific abdominal pain (NSAP). On a database containing 3337 patients, the SVM obtained results comparable to those of the doctors in separating diverticulitis or NSAP from the remaining diseases. The distinction between diverticulitis and NSAP was, however, substantially improved by the SVM. For this patient group, the doctors achieved a sensitivity of 0.714 and a specificity of 0.963. When adjusted to the physicians’ results, the SVM sensitivity/specificity was higher at 0.714/0.985 and 0.786/0.963 respectively. Age was found as the most important discriminative variable, closely followed by C-reactive protein level and lower left side pain.
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| 15. |
- Björnsdotter Åberg, Malin, et al.
(författare)
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Grey matter correlates of autistic traits in women with anorexia nervosa
- 2018
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Ingår i: Journal of Psychiatry & Neuroscience. - : CMA-CANADIAN MEDICAL ASSOC. - 1180-4882 .- 1488-2434. ; 43:2, s. 79-86
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Tidskriftsartikel (refereegranskat)abstract
- Background: Patients with anorexia nervosa exhibit higher levels of behaviours typically associated with autism-spectrum disorder (ASD), but the neural basis is unclear. We sought to determine whether elevated autistic traits in women with anorexia nervosa may be reflected in cortical morphology. Methods: We used voxel-based morphometry (VBM) to examine regional grey matter volumes in high-resolution MRI structural brain scans in women with anorexia nervosa and matched healthy controls. The Autism-spectrum Quotient (AQ) scale was used to assess autistic traits. Results: Women with anorexia nervosa (n = 25) had higher AQ scores and lower bilateral superior temporal sulcus (STS) grey matter volumes than the control group (n = 25). The AQ scores correlated negatively with average left STS grey matter volume in women with anorexia nervosa. Limitations: We did not control for cognitive ability and examined only women with ongoing anorexia nervosa. Conclusion: Elevated autistic traits in women with anorexia nervosa are associated with morphometric alterations of brain areas linked to social cognition. This finding provides neurobiological support for the behavioural link between anorexia nervosa and ASD and emphasizes the importance of recognizing autistic traits in preventing and treating-anorexia nervosa.
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| 16. |
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| 17. |
- Björnsdotter Åberg, Malin, 1980
(författare)
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Machine learning for identification of brain activity patterns with applications in gentle touch processing
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Since the first mention of artificial intelligence in the 1950s, the field of machine learning has provided increasingly appealing tools for recognition of otherwise unintelligible pattern representations in complex data structures. Human brain activity, acquired using functional magnetic resonance imaging (fMRI), is a prime example of such complex data where the utility of pattern recognition has been demonstrated in a wide range of studies recently (Haynes et al., Nature Reviews Neuroscience, 2006, 7(7), pp. 523-34). In contrast to conventional methods, pattern recognition approaches exploit the distributed nature of fMRI activity to achieve superior sensitivities in detecting subtle differences in brain responses. The first objective of this thesis was to implement and empirically evaluate such novel machine learning algorithms for detection and, specifically, spatial localization of regional brain response patterns. Two complementary methods are proposed, namely a Monte Carlo approximation designed for coarse whole-brain mapping, and an evolutionary optimization scheme for refined identification of specific brain regions. As demonstrated on real and simulated data, both methods were more sensitive than conventional approaches in localizing differential brain activity patterns. The second objective was to utilize these methods to study brain processing of gentle touch mediated by a system of thin, unmyelinated mechanoreceptive C tactile (CT) afferents (Vallbo et al., Brain Research, 1993, 628(310), pp. 301-4). These afferents are thought to modulate affective aspects of tactile sensations, and to act in parallel with thick, myelinated Ab fibers which signal discriminative information (Löken et al., Nature Neuroscience, 2009, 12(5), pp. 547-8). First, the Monte Carlo algorithm identified differential response patterns due to C tactile and Ab activation in the posterior insular cortex. Second, the evolutionary scheme revealed a C tactile induced somatotopic insular activation pattern similar to that previously described in relation to other thin-fiber mediated sensations such as pain (Björnsdotter et al., Journal of Neuroscience, 2009, 29(29), pp. 9314-20). In addition to demonstrating the utility of brain response pattern analysis, the results have a number of implications. The findings support the hypothesis that parallel networks of C tactile and Ab fibers project affective and discriminative aspects of touch, respectively, and that C tactile afferents follow the projection path of other thin fibers. This further solidifies the hypothesized sensory-affective role of the C tactile system in the maintenance of physical well-being as part of a thin-afferent homeostatic network.
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| 18. |
- Björnsdotter Åberg, Malin, 1980, et al.
(författare)
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Towards an Automatic Diagnosis System for Acute Abdominal Pain - Support Vector Machines for the Diagnosis of Diverticulitis and Non-specific Abdominal Pain
- 2009
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Ingår i: Luís Azevedo, Ana Rita Londral (Eds.): Proceedings of the Second International Conference on Health Informatics, HEALTHINF 2009, Porto, Portugal, January 14-17, 2009. - 9789898111630 ; , s. 51-57
-
Konferensbidrag (refereegranskat)abstract
- This study explores the feasibility of a decision-support system for patients seeking care for acute abdominal pain, and, specifically the diagnosis of acute diverticulitis. We used a linear support vector machine (SVM) to separate diverticulitis from all other reported cases of abdominal pain and from the important differential diagnosis non-specific abdominal pain (NSAP). On a database containing 3337 patients, the SVM obtained results comparable to those of the doctors in separating diverticulitis or NSAP from the remaining diseases. The distinction between diverticulitis and NSAP was, however, substantially improved by the SVM. For this patient group, the doctors achieved a sensitivity of 0.714 and a specificity of 0.963. When adjusted to the physicians’ results, the SVM sensitivity/specificity was higher at 0.714/0.985 and 0.786/0.963 respectively. Age was found as the most important discriminative variable, closely followed by C-reactive protein level and lower left side pain.
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| 19. |
- Bunketorp Käll, Lina, 1975, et al.
(författare)
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Adaptive motor cortex plasticity following grip reconstruction in individuals with tetraplegia
- 2018
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Ingår i: Restorative Neurology and Neuroscience. - : IOS Press. - 0922-6028 .- 1878-3627. ; 36:1, s. 73-82
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Tidskriftsartikel (refereegranskat)abstract
- Background: Tendon transfer is a surgical technique for restoring upper limb motor control in patients with cervical spinal cord injuries (SCI), and offers a rare window into cortical neuroplasticity following regained arm and hand function. Objective: Here, we aimed to examine neuroplasticity mechanisms related to re-established voluntary motor control of thumb flexion following tendon transfer. Methods: We used functional Magnetic Resonance Imaging (fMRI) to test the hypothesis that restored limb control following tendon transfer is mediated by activation of that limb's area of the primary motor cortex. We examined six individuals with tetraplegia who underwent right-sided surgical grip reconstruction at Sahlgrenska University Hospital, Sweden. All were right-handed males, with a SCI at the C6 or C7 level, and a mean age of 40 years (range = 31-48). The average number of years elapsed since the SCI was 13 (range = 6-26). Six right-handed gender-and age-matched control subjects were included (mean age 39 years, range = 29-46). Restoration of active thumb flexion in patients was achieved by surgical transfer of one of the functioning elbow flexors (brachioradialis), to the paralyzed thumb flexor (flexor pollicis longus). We studied fMRI responses to isometric right-sided elbow flexion and key pinch, and examined the cortical representations within the left hemisphere somatomotor cortex a minimum of one year after surgery. Results: Cortical activations elicited by elbow flexion did not differ in topography between patients and control participants. However, in contrast to control participants, patients' cortical thumb flexion activations were not topographically distinct from their elbow flexion activations. Conclusion: This result speaks against a topographic reorganization in which the thumb region regains thumb control following surgical tendon transfer. Instead, our findings suggest a neuroplastic mechanism in which motor cortex resources previously dedicated to elbow flexion adapt to control the thumb.
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| 20. |
- Bunketorp Käll, Lina, 1975, et al.
(författare)
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Feasibility of using fNIRS to explore motor-related regional haemodynamic signal changes in patients with sensorimotor impairment and healthy controls: A pilot study
- 2023
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Ingår i: Restorative Neurology and Neuroscience. - 0922-6028 .- 1878-3627. ; 41:3-4, s. 91-101
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Tidskriftsartikel (refereegranskat)abstract
- Background: While functional near-infrared spectroscopy (fNIRS) can provide insight into cortical brain activity during motor tasks in healthy and diseased populations, the feasibility of using fNIRS to assess haemoglobin-evoked responses to reanimated upper limb motor function in patients with tetraplegia remains unknown. Objective: The primary objective of this pilot study is to determine the feasibility of using fNIRS to assess cortical signal intensity changes during upper limb motor tasks in individuals with surgically restored grip functions. The secondary objectives are: 1) to collect pilot data on individuals with tetraplegia to determine any trends in the cortical signal intensity changes as measured by fNIRS and 2) to compare cortical signal intensity changes in affected individuals versus age-appropriate healthy volunteers. Specifically, patients presented with tetraplegia, a type of paralysis resulting from a cervical spinal cord injury causing loss of movement and sensation in both lower and upper limbs. All patients have their grip functions restored by surgical tendon transfer, a procedure which constitutes a unique, focused stimulus for brain plasticity. Method: fNIRS is used to assess changes in cortical signal intensity during the performance of two motor tasks (isometric elbow and thumb flexion). Six individuals with tetraplegia and six healthy controls participate in the study. A block paradigm is utilized to assess contralateral and ipsilateral haemodynamic responses in the premotor cortex (PMC) and primary motor cortex (M1). We assess the amplitude of the optical signal and spatial features during the paradigms. The accuracy of channel locations is maximized through 3D digitizations of channel locations and co-registering these locations to template atlas brains. A general linear model approach, with short-separation regression, is used to extract haemodynamic response functions at the individual and group levels. Results: Peak oxyhaemoglobin (oxy-Hb) changes in PMC appear to be particularly bilateral in nature in the tetraplegia group during both pinch and elbow trials whereas for controls, a bilateral PMC response is not especially evident. In M1 / primary sensory cortex (S1), the oxy-Hb responses to the pinch task are mainly contralateral in both groups, while for the elbow flexion task, lateralization is not particularly clear. Conclusions: This pilot study shows that the experimental setup is feasible for assessing brain activation using fNIRS during volitional upper limb motor tasks in individuals with surgically restored grip functions. Cortical signal changes in brain regions associated with upper extremity sensorimotor processing appear to be larger and more bilateral in nature in the tetraplegia group than in the control group. The bilateral hemispheric response in the tetraplegia group may reflect a signature of adaptive brain plasticity mechanisms. Larger studies than this one are needed to confirm these findings and draw reliable conclusions.
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| 21. |
- Bunketorp Käll, Lina, 1975, et al.
(författare)
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Regional estimates of cortical thickness in brain areas involved in control of surgically restored limb movement in patients with tetraplegia.
- 2020
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Ingår i: The journal of spinal cord medicine. - : Informa UK Limited. - 2045-7723 .- 1079-0268. ; 43:4, s. 462-469
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Tidskriftsartikel (refereegranskat)abstract
- Spinal cord injury (SCI) causes atrophy of brain regions linked to motor function. We aimed to estimate cortical thickness in brain regions that control surgically restored limb movement in individuals with tetraplegia.Cross-sectional study.Sahlgrenska University hospital, Gothenburg, Sweden.Six individuals with tetraplegia who had undergone surgical restoration of grip function by surgical transfer of one elbow flexor (brachioradialis), to the paralyzed thumb flexor (flexor pollicis longus). All subjects were males, with a SCI at the C6 or C7 level, and a mean age of 40 years (range=31-48). The average number of years elapsed since the SCI was 13 (range=6-26).We used structural magnetic resonance imaging (MRI) to estimate the thickness of selected motor cortices and compared these measurements to those of six matched control subjects. The pinch grip control area was defined in a previous functional MRI study.Compared to controls, the cortical thickness in the functionally defined pinch grip control area was not significantly reduced (P=0.591), and thickness showed a non-significant but positive correlation with years since surgery in the individuals with tetraplegia. In contrast, the anatomically defined primary motor cortex as a whole exhibited substantial atrophy (P=0.013), with a weak negative correlation with years since surgery.Individuals with tetraplegia do not seem to have reduced cortical thickness in brain regions involved in control of surgically restored limb movement. However, the studied sample is very small and further studies with larger samples are required to establish these findings.
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| 22. |
- Davidovic, Monika, et al.
(författare)
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Abnormal brain processing of gentle touch in anorexia nervosa
- 2018
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Ingår i: Psychiatry Research : Neuroimaging. - : Elsevier BV. - 0925-4927 .- 1872-7506. ; 281, s. 53-60
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Tidskriftsartikel (refereegranskat)abstract
- Body image disturbance is a core symptom in anorexia nervosa (AN). Recent research suggests that abnormalities in touch perception may contribute to the disease mechanisms in AN. Here, we used functional magnetic resonance imaging (fMRI) to study possible abnormalities in cortical processing of affective touch in AN. Gentle skin strokes were applied to the right forearm during fMRI scanning in women diagnosed with AN (n=25) and in matched healthy controls (HC; n=25). Blocks of skin stroking were alternated with blocks of static skin indentation. Participants provided ratings of the pleasantness of skin stroking stimulation. AN participants perceived skin stroking as significantly less pleasant than HC. We observed no group differences for the contrast between skin stroking and skin indentation in primary tactile regions. We did find, however, significantly less activity in the AN group in areas including left caudate nucleus. Also, we found less activity in the AN group in bilateral lateral occipital cortex for the main effect of skin stroking. Our results suggest that abnormal functioning of the dorsal striatum could affect evaluation of pleasant tactile stimuli, and that abnormal functioning of the lateral occipital cortex might be related to disturbed body image perception.
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| 23. |
- Davidovic, Monika, et al.
(författare)
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Posterior Superior Temporal Sulcus Responses Predict Perceived Pleasantness of Skin Stroking
- 2016
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Ingår i: Frontiers in Human Neuroscience. - : Frontiers Media SA. - 1662-5161. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Love and affection is expressed through a range of physically intimate gestures, including caresses. Recent studies suggest that posterior temporal lobe areas typically associated with visual processing of social cues also respond to interpersonal touch. Here, we asked whether these areas are selective to caress-like skin stroking. We collected functional magnetic resonance imaging data from 23 healthy participants and compared brain responses to skin stroking and vibration. We did not find any significant differences between stroking and vibration in the posterior temporal lobe; however, right posterior superior temporal sulcus (pSTS) responses predicted healthy participants perceived pleasantness of skin stroking, but not vibration. These findings link right pSTS responses to individual variability in perceived pleasantness of caress-like tactile stimuli. We speculate that the right pSTS may play a role in the translation of tactile stimuli into positively valenced, socially relevant interpersonal touch and that this system may be affected in disorders associated with impaired attachment.
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| 24. |
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| 25. |
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| 26. |
- Delfin, Carl, et al.
(författare)
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Prolonged NoGo P3 latency as a possible neurobehavioral correlate of aggressive and antisocial behaviors : A Go/NoGo ERP study
- 2022
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Ingår i: Biological Psychology. - : Elsevier BV. - 0301-0511 .- 1873-6246. ; 168
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Tidskriftsartikel (refereegranskat)abstract
- Aggressive and antisocial behaviors are detrimental to society and constitute major challenges in forensic mental health settings, yet the associated neural circuitry remains poorly understood. Here, we investigated differences in aggressive and antisocial behaviors between healthy controls (n = 20) and violent mentally disordered offenders (MDOs; n = 26), and examined associations between aggressive and antisocial behaviors, behavioral inhibitory control, and neurophysiological activity across the whole sample (n = 46). Event-related potentials were obtained using EEG while participants completed a Go/NoGo response inhibition task, and aggressive and antisocial behaviors were assessed with the Life History of Aggression (LHA) instrument. Using a robust Bayesian linear regression approach, we found that MDOs scored substantially higher than healthy controls on LHA Aggression and Antisocial subscales. Using the whole sample and after adjusting for age, we found that scores on the LHA Aggression and Antisocial subscales were robustly associated with longer NoGo P3 latency, and less robustly with longer NoGo N2 latency. Post-hoc analyzes suggested that healthy controls and MDOs exhibited similar associations. With several limitations in mind, we suggest that prolonged NoGo P3 latency, reflecting decreased neural efficiency during the later stages of conflict monitoring or outcome evaluation, is a potential neurobehavioral correlate of aggressive and antisocial behaviors.
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| 27. |
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| 28. |
- Delfin, Carl, et al.
(författare)
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Structural Brain Correlates of the Externalizing Spectrum in Young Adults
- 2021
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Ingår i: Neuroscience. - : Elsevier BV. - 0306-4522. ; 463, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- The externalizing spectrum, including traits and behaviors such as aggression, reduced inhibitiory control and substance abuse, is associated with altered prefrontal brain morphology. However, the degree to which different manifestations of the externalizing spectrum are associated with distinct or overlapping variations in individual brain morphology is unclear. Here, we therefore used structural magnetic resonance imaging, self-report assessment, and a response inhibition task in a sample of 59 young adults to examine how cortical thickness in the anterior cingulate cortex (ACC), orbitofrontal cortex (OFC), and dorsolateral prefrontal cortex (DLPFC) relate to four different manifestations of the externalizing spectrum: disinhibition, callous aggression, substance abuse, and behavioral inhibitory control. Using Bayesian linear regression models controlling for age, gender, and years of education, we found that the different manifestations of the externalizing spectrum were associated with both distinct and overlapping morphology variations. Specifically, both callous aggression and inhibitory control was associated with increased cortical thickness of the OFC, a region involved in reward processing, decision-making, and regulation of anxiety and fear. Both disinhibition and substance abuse were associated with DLPFC thickness, although with opposite association patterns, possibly reflecting processes related to inhibitory control, working memory and attention. Moreover, disinhibition, but not callous aggression or substance abuse, was associated with behavioral inhibitory control. Our results provide further support for the link between externalizing behaviors and prefrontal brain morphology, while identifying distinct prefrontal areas associated with different clinically relevant manifestations. These findings may help guide further research aimed at developing novel treatment and intervention strategies for externalizing behaviors and disorders.
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| 29. |
- Delfin, Carl, et al.
(författare)
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Trait Disinhibition and NoGo Event-Related Potentials in Violent Mentally Disordered Offenders and Healthy Controls
- 2020
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Ingår i: Frontiers in Psychiatry. - : Frontiers Media SA. - 1664-0640. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Trait disinhibition may function as a dispositional liability toward maladaptive behaviors relevant in the treatment of mentally disordered offenders (MDOs). Reduced amplitude and prolonged latency of the NoGo N2 and P3 event-related potentials have emerged as promising candidates for transdiagnostic, biobehavioral markers of trait disinhibition, yet no study has specifically investigated these two components in violent, inpatient MDOs. Here, we examined self-reported trait disinhibition, experimentally assessed response inhibition, and NoGo N2 and P3 amplitude and latency in male, violent MDOs (N = 27) and healthy controls (N = 20). MDOs had a higher degree of trait disinhibition, reduced NoGo P3 amplitude, and delayed NoGo P3 latency compared to controls. The reduced NoGo P3 amplitude and delayed NoGo P3 latency in MDOs may stem from deficits during monitoring or evaluation of behavior. NoGo P3 latency was associated with increased trait disinhibition in the whole sample, suggesting that trait disinhibition may be associated with reduced neural efficiency during later stages of outcome monitoring or evaluation. Findings for NoGo N2 amplitude and latency were small and non-robust. With several limitations in mind, this is the first study to demonstrate attenuated NoGo P3 amplitude and delayed NoGo P3 latency in violent, inpatient MDOs compared to healthy controls.
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| 30. |
- Eklund, Anders
(författare)
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Signal Processing for Robust and Real-Time fMRI With Application to Brain Computer Interfaces
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- It is hard to find another research field than functional magnetic resonance imaging (fMRI) that combines so many different areas of research. Without the beautiful physics of MRI we would not have any images to look at in the first place. To get images with good quality it is necessary to fully understand the concepts of the frequency domain. The analysis of fMRI data requires understanding of signal processing and statistics and also knowledge about the anatomy and function of the human brain. The resulting brain activity maps are used by physicians and neurologists in order to plan surgery and to increase their understanding of how the brain works.This thesis presents methods for signal processing of fMRI data in real-time situations. Real-time fMRI puts higher demands on the signal processing, than conventional fMRI, since all the calculations have to be made in realtime and in more complex situations. The result from the real-time fMRI analysis can for example be used to look at the subjects brain activity in real-time, for interactive planning of surgery or understanding of brain functions. Another possibility is to use the result in order to change the stimulus that is given to the subject, such that the brain and the computer can work together to solve a given task. These kind of setups are often called brain computer interfaces (BCI).Two BCI are presented in this thesis. In the first BCI the subject was able to balance a virtual inverted pendulum by thinking of activating the left or right hand or resting. In the second BCI the subject in the MR scanner was able to communicate with a person outside the MR scanner, through a communication interface.Since head motion is common during fMRI experiments it is necessary to apply image registration to align the collected volumes. To do image registration in real-time can be a challenging task, therefore how to implement a volume registration algorithm on a graphics card is presented. The power of modern graphic cards can also be used to save time in the daily clinical work, an example of this is also given in the thesis.Finally a method for calculating and incorporating a structural based certainty in the analysis of the fMRI data is proposed. The results show that the structural certainty helps to remove false activity that can occur due to head motion, especially at the edge of the brain.
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| 31. |
- Guterstam, Arvid, et al.
(författare)
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Decoding illusory self-location from activity in the human hippocampus
- 2015
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Ingår i: Frontiers in Human Neuroscience. - : FRONTIERS MEDIA SA. - 1662-5161. ; 9:412
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Tidskriftsartikel (refereegranskat)abstract
- Decades of research have demonstrated a role for the hippocampus in spatial navigation and episodic and spatial memory. However, empirical evidence linking hippocampal activity to the perceptual experience of being physically located at a particular place in the environment is lacking. In this study, we used a multisensory out-of-body illusion to perceptually teleport six healthy participants between two different locations in the scanner room during high-resolution functional magnetic resonance imaging (fMRI). The participants were fitted with MRI-compatible head-mounted displays that changed their first-person visual perspective to that of a pair of cameras placed in one of two corners of the scanner room. To elicit the illusion of being physically located in this position, we delivered synchronous visuo-tactile stimulation in the form of an object moving toward the cameras coupled with touches applied to the participants chest. Asynchronous visuo-tactile stimulation did not induce the illusion and served as a control condition. We found that illusory self-location could be successfully decoded from patterns of activity in the hippocampus in all of the participants in the synchronous (P less than 0.05) but not in the asynchronous condition (Pgreater than 0.05). At the group-level, the decoding accuracy was significantly higher in the synchronous than in the asynchronous condition (P = 0.012). These findings associate hippocampal activity with the perceived location of the bodily self in space, which suggests that the human hippocampus is involved not only in spatial navigation and memory but also in the construction of our sense of bodily self-location.
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| 32. |
- Guterstam, Arvid, et al.
(författare)
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Posterior Cingulate Cortex Integrates the Senses of Self-Location and Body Ownership
- 2015
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Ingår i: Current Biology. - : Elsevier (Cell Press). - 0960-9822 .- 1879-0445. ; 25:11, s. 1416-1425
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Tidskriftsartikel (refereegranskat)abstract
- The senses of owning a body and being localized somewhere in space are two key components of human self-consciousness. Despite a wealth of neurophysiological and neuroimaging research on the representations of the spatial environment in the parietal and medial temporal cortices, the relationship between body ownership and self-location remains unexplored. To investigate this relationship, we used a multisensory out-of-body illusion to manipulate healthy participants perceived self-location, head direction, and sense of body ownership during high-resolution fMRI. Activity patterns in the hippocampus and the posterior cingulate, retrosplenial, and intraparietal cortices reflected the sense of self-location, whereas the sense of body ownership was associated with premotor-intraparietal activity. The functional interplay between these two sets of areas was mediated by the posterior cingulate cortex. These results extend our understanding of the role of the posterior parietal and medial temporal cortices in spatial cognition by demonstrating that these areas not only are important for ecological behaviors, such as navigation and perspective taking, but also support the perceptual representation of the bodily self in space. Our results further suggest that the posterior cingulate cortex has a key role in integrating the neural representations of self-location and body ownership.
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| 33. |
- Liljencrantz, Jaquette, et al.
(författare)
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Altered C-tactile processing in human dynamic tactile allodynia
- 2013
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Ingår i: Pain. - : Ovid Technologies (Wolters Kluwer Health). - 0304-3959 .- 1872-6623. ; 154:2, s. 227-234
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Tidskriftsartikel (refereegranskat)abstract
- Human unmyelinated (C) tactile afferents signal the pleasantness of gentle skin stroking on hairy (nonglabrous) skin. After neuronal injury, that same type of touch can elicit unpleasant sensations: tactile allodynia. The prevailing pathophysiological explanation is a spinal cord sensitization, triggered by nerve injury, which enables Aβ afferents to access pain pathways. However, a recent mouse knockout study demonstrates that C-tactile afferents are necessary for allodynia to develop, suggesting a role for not only Aβ but also C-tactile afferent signaling. To examine the contribution of C-tactile afferents to the allodynic condition in humans, we applied the heat/capsaicin model of tactile allodynia in 43 healthy subjects and in 2 sensory neuronopathy patients lacking Aβ afferents. Healthy subjects reported tactile-evoked pain, whereas the patients did not. Instead, patients reported their C-touch percept (faint sensation of pleasant touch) to be significantly weaker in the allodynic zone compared to untreated skin. Functional magnetic resonance imaging in 18 healthy subjects and in 1 scanned patient indicated that stroking in the allodynic and control zones evoked different responses in the primary cortical receiving area for thin fiber signaling, the posterior insular cortex. In addition, reduced activation in the medial prefrontal cortices, key areas for C-tactile hedonic processing, was identified. These findings suggest that dynamic tactile allodynia is associated with reduced C-tactile mediated hedonic touch processing. Nevertheless, because the patients did not develop allodynic pain, this seems dependent on Aβ signaling, at least under these experimental conditions.
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| 34. |
- Morrison, India, 1972, et al.
(författare)
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Vicarious responses to social touch in posterior insular cortex are tuned to pleasant caressing speeds.
- 2011
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Ingår i: The Journal of neuroscience : the official journal of the Society for Neuroscience. - Washington, DC, United States : Society for Neuroscience. - 1529-2401 .- 0270-6474. ; 31:26, s. 9554-62
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Tidskriftsartikel (refereegranskat)abstract
- Affective touch carries strong significance for social mammals, including humans. Gentle, dynamic touch of a kind that occurs during social interactions is preferentially encoded by a distinct neural pathway involving tactile C (CT) afferents, a type of unmyelinated afferent nerve found exclusively in hairy skin. CT afferents increase firing when the skin is stroked at a pleasant, caress-like speed of ∼3 cm/s, and their discharge frequency correlates with the subjective hedonic experience of the caress. In humans, the posterior insula is a cortical target for CT afferents. Since the potential social relevance of affective touch extends to the touch interactions of others, we postulated that information from CT afferents in posterior insular cortex provides a basis for encoding observed caresses.
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| 35. |
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| 36. |
- Petkova, Valeria I, et al.
(författare)
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From part- to whole-body ownership in the multisensory brain.
- 2011
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Ingår i: Current Biology. - Cambridge, MA, United States : Cell Press. - 0960-9822 .- 1879-0445. ; 21:13, s. 1118-1122
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Tidskriftsartikel (refereegranskat)abstract
- The question of how we experience ownership of an entire body distinct from the external world is a fundamental problem in psychology and neuroscience [1-6]. Earlier studies suggest that integration of visual, tactile, and proprioceptive information in multisensory areas [7-11] mediates self-attribution of single limbs. However, it is still unknown how ownership of individual body parts translates into the unitary experience of owning a whole body. Here, we used a "body-swap" illusion [12], in which people experienced an artificial body to be their own, in combination with functional magnetic resonance imaging to reveal a coupling between the experience of full-body ownership and neural responses in bilateral ventral premotor and left intraparietal cortices, and left putamen. Importantly, activity in the ventral premotor cortex reflected the construction of ownership of a whole body from the parts, because it was stronger when the stimulated body part was attached to a body, was present irrespective of whether the illusion was triggered by stimulation of the hand or the abdomen, and displayed multivoxel patterns carrying information about full-body ownership. These findings suggest that the unitary experience of owning an entire body is produced by neuronal populations that integrate multisensory information across body segments.
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| 37. |
- Tuulari, Jetro J., et al.
(författare)
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Neural correlates of gentle skin stroking in early infancy
- 2019
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Ingår i: Developmental Cognitive Neuroscience. - : Elsevier BV. - 1878-9293 .- 1878-9307. ; 35, s. 36-41
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Tidskriftsartikel (refereegranskat)abstract
- Physical expressions of affection play a foundational role in early brain development, but the neural correlates of affective touch processing in infancy remain unclear. We examined brain responses to gentle skin stroking, a type of tactile stimulus associated with affectionate touch, in young infants. Thirteen term-born infants aged 11-36. days, recruited through the FinnBrain Birth Cohort Study, were included in the study. Soft brush strokes, which activate brain regions linked to somatosensory as well as socio-affective processing in children and adults, were applied to the skin of the right leg during functional magnetic resonance imaging. We examined infant brain responses in two regions-of-interest (ROIs) known to process gentle skin stroking - the postcentral gyrus and posterior insular cortex - and found significant responses in both ROIs. These results suggest that the neonate brain is responsive to gentle skin stroking within the first weeks of age, and that regions linked to primary somatosensory as well as socio-affective processing are activated. Our findings support the notion that social touch may play an important role in early life sensory processing. Future research will elucidate the significance of these findings for human brain development.
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