Showing papers by "Richard J. Davidson published in 2008"
TL;DR: Meditation can be conceptualized as a family of complex emotional and attentional regulatory training regimes developed for various ends, including the cultivation of well-being and emotional balance, which could have a long-term impact on the brain and behavior.
1,961 citations
TL;DR: Data indicate that the mental expertise to cultivate positive emotion alters the activation of circuitries previously linked to empathy and theory of mind in response to emotional stimuli.
Abstract: Recent brain imaging studies using functional magnetic resonance imaging (fMRI) have implicated insula and anterior cingulate cortices in the empathic response to another's pain. However, virtually nothing is known about the impact of the voluntary generation of compassion on this network. To investigate these questions we assessed brain activity using fMRI while novice and expert meditation practitioners generated a loving-kindness-compassion meditation state. To probe affective reactivity, we presented emotional and neutral sounds during the meditation and comparison periods. Our main hypothesis was that the concern for others cultivated during this form of meditation enhances affective processing, in particular in response to sounds of distress, and that this response to emotional sounds is modulated by the degree of meditation training. The presentation of the emotional sounds was associated with increased pupil diameter and activation of limbic regions (insula and cingulate cortices) during meditation (versus rest). During meditation, activation in insula was greater during presentation of negative sounds than positive or neutral sounds in expert than it was in novice meditators. The strength of activation in insula was also associated with self-reported intensity of the meditation for both groups. These results support the role of the limbic circuitry in emotion sharing. The comparison between meditation vs. rest states between experts and novices also showed increased activation in amygdala, right temporo-parietal junction (TPJ), and right posterior superior temporal sulcus (pSTS) in response to all sounds, suggesting, greater detection of the emotional sounds, and enhanced mentation in response to emotional human vocalizations for experts than novices during meditation. Together these data indicate that the mental expertise to cultivate positive emotion alters the activation of circuitries previously linked to empathy and theory of mind in response to emotional stimuli.
803 citations
TL;DR: It is suggested that in humans, the PFC is activated in response to psychosocial stress and distinct prefrontal metabolic glucose patterns are linked to endocrine stress measures as well as subjective ratings on task stressfulness, controllability as as dispositional mood states.
237 citations
TL;DR: Compared to nonmeditators, meditators consistently rated their interoceptive performance as superior and the difficulty of the task as easier, which provides evidence against the notion that practicing attention to internal body sensations, a core feature of meditation, enhances the ability to sense the heartbeat at rest.
Abstract: Attention to internal body sensations is practiced in most meditation traditions. Many traditions state that this practice results in increased awareness of internal body sensations, but scientific studies evaluating this claim are lacking. We predicted that experienced meditators would display performance superior to that of nonmeditators on heartbeat detection, a standard noninvasive measure of resting interoceptive awareness. We compared two groups of meditators (Tibetan Buddhist and Kundalini) to an age- and body mass index-matched group of nonmeditators. Contrary to our prediction, we found no evidence that meditators were superior to nonmeditators in the heartbeat detection task, across several sessions and respiratory modulation conditions. Compared to nonmeditators, however, meditators consistently rated their interoceptive performance as superior and the difficulty of the task as easier. These results provide evidence against the notion that practicing attention to internal body sensations, a core feature of meditation, enhances the ability to sense the heartbeat at rest. Descriptors: Meditation, Interoception, Heartbeat detection, Awareness, Respiration
217 citations
TL;DR: The changes in the brain that occur during different styles of meditation practice are examined to describe the brain changes that occur in response to experience.
Abstract: The term neuroplasticity is used to describe the brain changes that occur in response to experience. This article examines the changes in the brain that occur during different styles of meditation practice.
217 citations
TL;DR: Findings show that this pattern of rACC-amygdala responsivity could prove useful as a predictor of venlafaxine treatment response in patients with GAD.
198 citations
TL;DR: The weighted-SPHARM is shown to be the least squares approximation to the solution of an isotropic heat diffusion on a unit sphere and to show how it can be used in the tensor-based morphometry.
Abstract: We present a new tensor-based morphometric framework that quantifies cortical shape variations using a local area element. The local area element is computed from the Riemannian metric tensors, which are obtained from the smooth functional parametrization of a cortical mesh. For the smooth parametrization, we have developed a novel weighted spherical harmonic (SPHARM) representation, which generalizes the traditional SPHARM as a special case. For a specific choice of weights, the weighted-SPHARM is shown to be the least squares approximation to the solution of an isotropic heat diffusion on a unit sphere. The main aims of this paper are to present the weighted-SPHARM and to show how it can be used in the tensor-based morphometry. As an illustration, the methodology has been applied in the problem of detecting abnormal cortical regions in the group of high functioning autistic subjects.
138 citations
TL;DR: It is suggested that increased activity of this circuit early in life mediates the childhood temperamental risk to develop anxiety and depression and provides an explanation for why individuals with anxious temperament have difficulty relaxing in environments that others perceive as non-stressful.
Abstract: Early theorists (Freud and Darwin) speculated that extremely shy children, or those with anxious temperament, were likely to have anxiety problems as adults. More recent studies demonstrate that these children have heightened responses to potentially threatening situations reacting with intense defensive responses that are characterized by behavioral inhibition (BI) (inhibited motor behavior and decreased vocalizations) and physiological arousal. Confirming the earlier impressions, data now demonstrate that children with this disposition are at increased risk to develop anxiety, depression, and comorbid substance abuse. Additional key features of anxious temperament are that it appears at a young age, it is a stable characteristic of individuals, and even in non-threatening environments it is associated with increased psychic anxiety and somatic tension. To understand the neural underpinnings of anxious temperament, we performed imaging studies with 18-fluoro-deoxyglucose (FDG) high-resolution Positron Emission Tomography (PET) in young rhesus monkeys. Rhesus monkeys were used because they provide a well validated model of anxious temperament for studies that cannot be performed in human children. Imaging the same animal in stressful and secure contexts, we examined the relation between regional metabolic brain activity and a trait-like measure of anxious temperament that encompasses measures of BI and pituitary-adrenal reactivity. Regardless of context, results demonstrated a trait-like pattern of brain activity (amygdala, bed nucleus of stria terminalis, hippocampus, and periaqueductal gray) that is predictive of individual phenotypic differences. Importantly, individuals with extreme anxious temperament also displayed increased activity of this circuit when assessed in the security of their home environment. These findings suggest that increased activity of this circuit early in life mediates the childhood temperamental risk to develop anxiety and depression. In addition, the findings provide an explanation for why individuals with anxious temperament have difficulty relaxing in environments that others perceive as non-stressful.
137 citations
TL;DR: Three perspectives on how developmental neurobiology constrains and enriches theories of ER are presented, illustrated with empirical results derived from both typical and atypical samples of children and adults.
Abstract: Because individual differences in emotion regulation are associated with risk for childhood behavioral problems, multidisciplinary investigation of the genetic and neural underpinnings of emotion regulation should be a research priority. This article summarizes research findings from 3 independent laboratories to demonstrate the ways in which a variety of developmental human neuroscience-based approaches can address critical conceptual issues in the emergence of emotion regulation. To do so, the authors present 3 perspectives on how developmental neurobiology constrains and enriches theories of emotion regulation. The 3 perspectives of (a) genetics, (b) brain structure and function, and (c) plasticity of development are illustrated with empirical results derived from both typical and atypical samples of children and adults. These perspectives are complementary and sometimes represent different levels of analysis of the same question.
100 citations
TL;DR: Findings demonstrate context-dependent intermediate phenotypes in s carriers that provide a framework for understanding the mechanisms underlying the vulnerabilities of s-allele carriers exposed to different types of stressors.
Abstract: A variant allele in the promoter region of the serotonin transporter gene, SLC6A4, the s allele, is associated with increased vulnerability to develop anxiety-related traits and depression. Furthermore, functional magnetic resonance imaging (fMRI) studies reveal that s carriers have increased amygdala reactivity in response to aversive stimuli, which is thought to be an intermediate phenotype mediating the influences of the s allele on emotionality. We used high-resolution microPET [18F]fluoro-2-deoxy-D-glucose (FDG) scanning to assess regional brain metabolic activity in rhesus monkeys to further explore s allele-related intermediate phenotypes. Rhesus monkeys provide an excellent model to understand mechanisms underlying human anxiety, and FDG microPET allows for the assessment of brain activity associated with naturalistic environments outside the scanner. During FDG uptake, monkeys were exposed to different ethologically relevant stressful situations (relocation and threat) as well as to the less stressful familiar environment of their home cage. The s carriers displayed increased orbitofrontal cortex activity in response to both relocation and threat. However, during relocation they displayed increased amygdala reactivity and in response to threat they displayed increased reactivity of the bed nucleus of the stria terminalis. No increase in the activity of any of these regions occurred when the animals were administered FDG in their home cages. These findings demonstrate context-dependent intermediate phenotypes in s carriers that provide a framework for understanding the mechanisms underlying the vulnerabilities of s-allele carriers exposed to different types of stressors.
89 citations
TL;DR: Group differences in brain activation are important as they suggest unique underlying face‐processing neural circuitry in FXS versus idiopathic ASD, largely supporting the hypothesis that ASD characteristics inFXS and idiopATHic ASD reflect partially divergent impairments at the neural level, at least in FXs individuals without a co‐morbid diagnosis of ASD.
Abstract: Fragile X syndrome (FXS) is the most commonly known genetic disorder associated with autism spectrum disorder (ASD). Overlapping features in these populations include gaze aversion, communication deficits, and social withdrawal. Although the association between FXS and ASD has been well documented at the behavioral level, the underlying neural mechanisms associated with the social/emotional deficits in these groups remain unclear. We collected functional brain images and eye-gaze fixations from 9 individuals with FXS and 14 individuals with idiopathic ASD, as well as 15 typically developing (TD) individuals, while they performed a facial-emotion discrimination task. The FXS group showed a similar yet less aberrant pattern of gaze fixations compared with the ASD group. The FXS group also showed fusiform gyrus (FG) hypoactivation compared with the TD control group. Activation in FG was strongly and positively associated with average eye fixation and negatively associated with ASD characteristics in the FXS group. The FXS group displayed significantly greater activation than both the TD control and ASD groups in the left hippocampus (HIPP), left superior temporal gyrus (STG), right insula (INS), and left postcentral gyrus (PCG). These group differences in brain activation are important as they suggest unique underlying face-processing neural circuitry in FXS versus idiopathic ASD, largely supporting the hypothesis that ASD characteristics in FXS and idiopathic ASD reflect partially divergent impairments at the neural level, at least in FXS individuals without a co-morbid diagnosis of ASD.
TL;DR: Compared to the control group, individuals with FXS exhibited decreased activation of prefrontal regions associated with complex social cognition, including the medial and superior frontal cortex, during successful face encoding, indicating that social anxiety in FXS may be related to the inability to successfully recruit higher level social cognition regions during the initial phases of memory formation.
Journal Article•
TL;DR: In this article, a novel weighted spherical harmonic representation of cortical surfaces is presented to parameterize cortical surfaces, establish the hemispheric correspondence, and normalize cortical surface in a unified mathematical framework.
Abstract: There is a lack of a unified statistical modeling framework for cerebral shape asymmetry analysis in the literature. Most previous approaches start with flipping the 3D magnetic resonance images (MRI). The anatomical correspondence across the hemispheres is then established by registering the original image to the flipped image. A difference of an anatomical index between these two images is used as a measure of cerebral asymmetry. We present a radically different asymmetry analysis that utilizes a novel weighted spherical harmonic representation of cortical surfaces. The weighted spherical harmonic representation is a surface smoothing technique given explicitly as a weighted linear combination of spherical harmonics. This new representation is used to parameterize cortical surfaces, establish the hemispheric correspondence, and normalize cortical surfaces in a unified mathematical framework. The methodology has been applied in characterizing the cortical asymmetry of a group of autistic subjects.
TL;DR: Cyclic AMP is a potentially useful biochemical marker to distinguish autism comorbid with FX from autism per se and the cAMP cascade may be a viable therapeutic target for both FX and autism.
TL;DR: Anhedonia may be characterized by disruptions of mPFC-mediated neuroendocrine regulation, which could constitute a vulnerability to the development of stress-related disorders.
Abstract: The medial prefrontal cortex (mPFC), hippocampus, and amygdala are implicated in the regulation of affect and physiological processes, including hypothalamic-pituitary-adrenal (HPA) axis function. Anhedonia is likely associated with dysregulation of these processes. Dense-array resting electroencephalographic and cortisol were obtained from healthy and anhedonic groups. Low-resolution electromagnetic tomography was used to compute intracerebral current density. For the control group, voxelwise analyses found a relationship between current density in beta and gamma bands and steeper cortisol slope (indicative of more adaptive HPA axis functioning) in regions of the hippocampus, parahippocampal gyrus, and mPFC. For the anhedonic group, the mPFC finding was absent. Anhedonia may be characterized by disruptions of mPFC-mediated neuroendocrine regulation, which could constitute a vulnerability to the development of stress-related disorders.
TL;DR: An open source, physiological signal processing program, called PhysioNoise, in the python language, which consistently identifies physiological fluctuations for fMRI noise correction and also generates covariates for subsequent analyses of brain activation and connectivity.
Abstract: Functional MRI resting state and connectivity studies of brain focus on neural fluctuations at low frequencies which share power with physiological fluctuations originating from lung and heart. Due to the lack of automated software to process physiological signals collected at high magnetic fields, a gap exists in the processing pathway between the acquisition of physiological data and its use in fMRI software for both physiological noise correction and functional analyses of brain activation and connectivity. To fill this gap, we developed an open source, physiological signal processing program, called PhysioNoise, in the python language. We tested its automated processing algorithms and dynamic signal visualization on resting monkey cardiac and respiratory waveforms. PhysioNoise consistently identifies physiological fluctuations for fMRI noise correction and also generates covariates for subsequent analyses of brain activation and connectivity.
TL;DR: The role of spiritual care at the end of life, a topic of critical importance for compassionate and humane treatment at this very sensitive period for the patient and his or her fam- ily, is explored.
Abstract: hree articles in the current issue of the Annals explore different aspects of the role of spiri- tuality in primary care. The article by Daale- man and colleagues explores the role of spiritual care at the end of life, a topic of critical importance for compassionate and humane treatment at this very sensitive period for the patient and his or her fam- ily. 1 The article by Anandarajah describes several conceptual models for understanding the spiritual dimension in medical care with an emphasis on mul- ticultural factors. 2 The article by Katerndahl reports on an empirical study of the impact of knowledge of spiritual symptoms assessed by a self-report measure that includes such items as "peaceful," "a reason for liv- ing," and "sense of purpose" on health-care utilization, extreme use of services, and life satisfaction among primary care patients. 3 Each article underscores the value of the primary care physician being attentive to the spiritual dimen- sion of a patient's life context and taking this dimen- sion into account in providing care. The body of work reviewed in these articles also draws attention to the importance of the primary care clinician embody- ing certain qualities that facilitate attention to the spiritual dimension of patients' care, including the notion of being present. This type of sensitive atten- tion conveyed by the clinician is marked by physical proximity and intentionality. 1 A central theme that cuts across all of these articles is that good medical care should include sensitivity to the spiritual dimension of patients' lives.
TL;DR: New methodologies that are important improvements not only to parametric but also to nonparametric estimation and hypothesis testing of the HRF are developed and reveal more meaningful findings than the popular methods offered by AFNI and FSL.
TL;DR: It is demonstrated that making a standardized pain face increases negative affect in response to nociceptive stimulation, even in the absence of social feedback, which suggests that exaggerated facial displays of pain, although often socially reinforced, may also have unintended aversive consequences.
01 Aug 2008
TL;DR: A systematic framework for modeling local amygdala shape variations is presented using a novel surface flattening technique and amygdala surfaces are parameterized as a weighted linear combination of smooth basis functions using the recently developed weighted spherical harmonic representation.
Abstract: Although there are numerous publications on amygdala volumetry, so far there has not been many studies on modeling local amygdala surface shape variations in a rigorous framework. This paper present a systematic framework for modeling local amygdala shape. Using a novel surface flattening technique, we obtain a smooth mapping from the amygdala surface to a sphere. Then taking the spherical coordinates as a reference frame, amygdala surfaces are parameterized as a weighted linear combination of smooth basis functions using the recently developed weighted spherical harmonic representation. This new representation is used for parameterizing, smoothing and nonlinearly registering a group of amygdala surfaces. The methodology has been applied in detecting abnormal local shape variations in 23 autistic subjects compared against 24 normal controls. We did not detect any statistically significant abnormal amygdala shape variations in autistic subjects. The complete amygdala surface modeling codes used in this study is available at http://www.stat.wisc.edu/~mchung/research/amygdala .
TL;DR: A nanoimaging, molecular imaging, and medical imaging teaching unit is incorporated into three 1-h class periods of an introductory course on ways of knowing biology, derived from NIH Roadmap initiatives in nanomedicine, regenerative medicine, and nuclear medicine.
Abstract: Imaging techniques provide ways of knowing structure and function in biology at different scales. The multidisciplinary nature and rapid advancement of imaging sciences requires imaging education to begin early in the biology curriculum. Guided by the National Institutes of Health (NIH) Roadmap initiatives, we incorporated a nanoimaging, molecular imaging, and medical imaging teaching unit into three 1-h class periods of an introductory course on ways of knowing biology. Activities were derived from NIH Roadmap initiatives in nanomedicine, regenerative medicine, and nuclear medicine. The course materials we describe contributed positively to student learning gains in quantifying and interpreting images, in characterizing imaging methods that provide ways of knowing biological structure and function, and in understanding scale in biology and imaging. The NIH Roadmap provides a useful context to educate students about the multidisciplinary imaging continuum.
Veterans Health Administration1, Yale University2, University of California, Davis3, University of California, Los Angeles4, National Institutes of Health5, Duke University6, University of Texas Southwestern Medical Center7, University of Michigan8, Icahn School of Medicine at Mount Sinai9, University of Pennsylvania10, Columbia University11, University of Washington12, University of North Carolina at Chapel Hill13, Cornell University14, University of California, San Francisco15, University of California, San Diego16, Harvard University17, University of Illinois at Chicago18, University of Wisconsin-Madison19, Emory University20, Massachusetts Institute of Technology21, State University of New York Upstate Medical University22, University of Colorado Denver23, University College London24, Washington University in St. Louis25, Trinity College, Dublin26, Princeton University27, University of Pittsburgh28, Scripps Research Institute29, Stanford University30, Vanderbilt University31, Indiana University32, Rockefeller University33, Cardiff University34, University of Cambridge35, Wayne State University36, Johns Hopkins University37
02 Oct 2008
TL;DR: In this paper, the authors present a relatively simpler method for constructing an orthonormal basis for an arbitrary anatomical manifold, which is based on the spherical harmonics and a smooth mapping from the manifold to the sphere, which can be obtained from various surface flattening techniques.
Abstract: One main obstacle in building a sophisticated parametric model along an arbitary anatomical manifold is the lack of an easily available orthonormal basis. Although there are at least two numerical techniques available for constructing an orhonormal basis such as the Laplacian eigenfunction approach and the Gram-Smidth orthogonaliza- tion, they are computationally not so trivial and costly. We present a relatively simpler method for constructing an orthonormal basis for an arbitrary anatomical manifold. On a unit sphere, a natural orthonormal basis is the spherical harmonics which can be easily computed. Assuming the manifold is topologically equivalent to the sphere, we can establish a smooth mapping from the manifold to the sphere. Such mapping can be obtained from various surface flattening techniques. If we project the spherical harmonics to the manifold, they are no longer orthonormal. However, we claim that there exists an orthonormal basis that is the function of spherical harmonics and the spherical mapping . The detailed step by step procedures for the construction is given along with the numerical validation using amygdala surfaces as an illustration. As an application, we propose the pullback representation that recon- structs surfaces using the orthonormal basis obtained from an average template. The pullback representation introduces less inter-subject vari- ability and thus requires far less number of coefficients than the tradi- tional spherical harmonic representation. The source code used in the study is freely available at http://www.stat.wisc.edu/ mchung/research/amygdala.