Skip to main content Skip to search
Displaying 1 - 25 of 85

Pages

  • Page
  • of 4
Although the co-occurrence of negative affect and pain is well recognized, the mechanism underlying their association is unclear. To examine whether a common self-regulatory ability impacts the experience of both emotion and pain, we integrated neuroimaging, behavioral, and physiological measures obtained from three assessments separated by substantial temporal intervals. Our results demonstrated that individual differences in emotion regulation ability, as indexed by an objective measure of emotional state, corrugator electromyography, predicted self-reported success while regulating pain. In both emotion and pain paradigms, the amygdala reflected regulatory success. Notably, we found that greater emotion regulation success was associated with greater change of amygdalar activity following pain regulation. Furthermore, individual differences in degree of amygdalar change following emotion regulation were a strong predictor of pain regulation success, as well as of the degree of amygdalar engagement following pain regulation. These findings suggest that common individual differences in emotion and pain regulatory success are reflected in a neural structure known to contribute to appraisal processes.
Zotero Collections:

The amygdalae are important, if not critical, brain regions for many affective, attentional and memorial processes, and dysfunction of the amygdalae has been a consistent finding in the study of clinical depression. Theoretical models of the functional neuroanatomy of both normal and psychopathological affective processes which posit cortical hemispheric specialization of functions have been supported by both lesion and functional neuroimaging studies in humans. Results from human neuroimaging studies in support of amygdalar hemispheric specialization are inconsistent. However, recent results from human lesion studies are consistent with hemispheric specialization. An important, yet largely ignored, feature of the amygdalae in the primate brain--derived from both neuroanatomical and electrophysiological data--is that there are virtually no direct interhemispheric connections via the anterior commissure (AC). This feature stands in stark contrast to that of the rodent brain wherein virtually all amygdalar nuclei have direct interhemispheric connections. We propose this feature of the primate brain, in particular the human brain, is a result of influences from frontocortical hemispheric specialization which have developed over the course of primate brain evolution. Results consistent with this notion were obtained by examining the nature of human amygdalar interhemispheric connectivity using both functional magnetic resonance imaging (FMRI) and positron emission tomography (PET). We found modest evidence of amygdalar interhemispheric functional connectivity in the non-depressed brain, whereas there was strong evidence of functional connectivity in the depressed brain. We interpret and discuss the nature of this connectivity in the depressed brain in the context of dysfunctional frontocortical-amygdalar interactions which accompany clinical depression.
Zotero Collections:

This study compared the asymmetry of different features of brain electrical activity during the performance of a verbal task (word finding) and a spatial task (dot localization) that had been carefully matched on psychometric properties and accompanying motor activity. Nineteen right-handed subjects were tested. EEG was recorded from F3, F4, C3, C4, P3, and P4, referred to both CZ and computer-derived averaged-ears references, and Fourier transformed. Power in the delta, theta, alpha, and beta bands was computed. There were significant Task X Hemisphere effects in all bands for CZ-referenced data and for the alpha and beta bands for ears-referenced data. The effects were always either greater power suppression in the hemisphere putatively most engaged in task processing or greater power in the opposite hemisphere. Correlations between EEG and task performance indicated that CZ-referenced parietal alpha asymmetry accounted for the most variance in verbal task performance. Power within individual hemispheres or across hemispheres was unrelated to task performance. The findings indicate robust differences in asymmetrical brain physiology that are produced by well-matched verbal and spatial cognitive tasks.
Zotero Collections:

Thirty-two participants were tested for both resting electroencephalography (EEG) and neuropsychological function. Eight one-minute trials of resting EEG were recorded from 14 channels referenced to linked ears, which was rederived to an average reference. Neuropsychological tasks included Verbal Fluency, the Tower of London, and Corsi's Recurring Blocks. Asymmetries in EEG alpha activity were correlated with performance on these tasks. Similar patterns were obtained for delta and theta bands. Factor analyses of resting EEG asymmetries over particular regions suggested that asymmetries over anterior scalp regions may be partly independent from those over posterior scalp regions. These results support the notions that resting EEG asymmetries are specified by multiple mechanisms along the rostral/caudal plane, and that these asymmetries predict task performance in a manner consistent with lesion and neuroimaging studies.
Zotero Collections:

<p>Publisher's description: Buddha Mind in Contemporary Art documents the growing presence of Buddhist perspectives in contemporary culture. This shift began in the nineteenth century and is now pervasive in many aspects of everyday experience. In the arts especially, the increasing importance of process over product has promoted a profound change in the relationship between artist and audience. But while artists have been among the most perceptive interpreters of Buddhism in the West, art historians and critics have been slow to develop the intellectual tools to analyze the impact of Buddhist concepts. This timely, multi-faceted volume explores the relationships between Buddhist practice and the contemporary arts in lively essays by writers from a range of disciplines and in revealing interviews with some of the most influential artists of our time. Elucidating the common ground between the creative mind, the perceiving mind, and the meditative mind, the contributors tackle essential questions about the relationship of art and life. Among the writers are curators, art critics, educators, and Buddhist commentators in psychology, literature, and cognitive science. They consider the many Western artists today who recognize the Buddhist notion of emptiness, achieved through focused meditation, as a place of great creative potential for the making and experiencing of art. The artists featured in the interviews, all internationally recognized, include Maya Lin, Bill Viola, and Ann Hamilton. Extending earlier twentieth-century aesthetic interests in blurring the boundaries of art and life, the artists view art as a way of life, a daily practice, in ways parallel to that of the Buddhist practitioner. Their works, woven throughout the book, richly convey how Buddhism has been both a source for and a lens through which we now perceive art.</p>

The anterior medial prefrontal (AMPFC) and retrosplenial (RSC) cortices are active during self-referential decision-making tasks such as when participants appraise traits and abilities, or current affect. Other appraisal tasks requiring an evaluative decision or mental representation, such as theory of mind and perspective-taking tasks, also involve these regions. In many instances, these types of decisions involve a subjective opinion or preference, but also a degree of ambiguity in the decision, rather than a strictly veridical response. However, this ambiguity is generally not controlled for in studies that examine self-referential decision-making. In this functional magnetic resonance imaging experiment with 17 healthy adults, we examined neural processes associated with subjective decision-making with and without an overt self-referential component. The task required subjective decisions about colors-regarding self-preference (internal subjective decision) or color similarity (external subjective decision) under conditions where there was no objectively correct response. Results indicated greater activation in the AMPFC, RSC, and caudate nucleus during internal subjective decision-making. The findings suggest that self-referential processing, rather than subjective judgments among ambiguous response alternatives, accounted for the AMPFC and RSC response.
Zotero Collections:

Functional neuroimaging research has demonstrated that retrieving information about object-associated colors activates the left fusiform gyrus in posterior temporal cortex. Although regions near the fusiform have previously been implicated in color perception, it remains unclear whether color knowledge retrieval actually activates the color perception system. Evidence to this effect would be particularly strong if color perception cortex was activated by color knowledge retrieval triggered strictly with linguistic stimuli. To address this question, subjects performed two tasks while undergoing fMRI. First, subjects performed a property verification task using only words to assess conceptual knowledge. On each trial, subjects verified whether a named color or motor property was true of a named object (e.g., TAXI-yellow, HAIR-combed). Next, subjects performed a color perception task. A region of the left fusiform gyrus that was highly responsive during color perception also showed greater activity for retrieving color than motor property knowledge. These data provide the first evidence for a direct overlap in the neural bases of color perception and stored information about object-associated color, and they significantly add to accumulating evidence that conceptual knowledge is grounded in the brain's modality-specific systems.
Zotero Collections:

Motion correction of fMRI data is a widely used step prior to data analysis. In this study, a comparison of the motion correction tools provided by several leading fMRI analysis software packages was performed, including AFNI, AIR, BrainVoyager, FSL, and SPM2. Comparisons were performed using data from typical human studies as well as phantom data. The identical reconstruction, preprocessing, and analysis steps were used on every data set, except that motion correction was performed using various configurations from each software package. Each package was studied using default parameters, as well as parameters optimized for speed and accuracy. Forty subjects performed a Go/No-go task (an event-related design that investigates inhibitory motor response) and an N-back task (a block-design paradigm investigating working memory). The human data were analyzed by extracting a set of general linear model (GLM)-derived activation results and comparing the effect of motion correction on thresholded activation cluster size and maximum t value. In addition, a series of simulated phantom data sets were created with known activation locations, magnitudes, and realistic motion. Results from the phantom data indicate that AFNI and SPM2 yield the most accurate motion estimation parameters, while AFNI's interpolation algorithm introduces the least smoothing. AFNI is also the fastest of the packages tested. However, these advantages did not produce noticeably better activation results in motion-corrected data from typical human fMRI experiments. Although differences in performance between packages were apparent in the human data, no single software package produced dramatically better results than the others. The "accurate" parameters showed virtually no improvement in cluster t values compared to the standard parameters. While the "fast" parameters did not result in a substantial increase in speed, they did not degrade the cluster results very much either. The phantom and human data indicate that motion correction can be a valuable step in the data processing chain, yielding improvements of up to 20% in the magnitude and up to 100% in the cluster size of detected activations, but the choice of software package does not substantially affect this improvement.
Zotero Collections:

Psychological stress is a major provocative factor of symptoms in chronic inflammatory conditions. In recent years, interest in addressing stress responsivity through meditation training in health-related domains has increased astoundingly, despite a paucity of evidence that reported benefits are specific to meditation practice. We designed the present study to rigorously compare an 8-week Mindfulness-Based Stress Reduction (MBSR) intervention to a well-matched active control intervention, the Health Enhancement Program (HEP) in ability to reduce psychological stress and experimentally-induced inflammation. The Trier Social Stress Test (TSST) was used to induce psychological stress and inflammation was produced using topical application of capsaicin cream to forearm skin. Immune and endocrine measures of inflammation and stress were collected both before and after MBSR training. Results show those randomized to MBSR and HEP training had comparable post-training stress-evoked cortisol responses, as well as equivalent reductions in self-reported psychological distress and physical symptoms. However, MBSR training resulted in a significantly smaller post-stress inflammatory response compared to HEP, despite equivalent levels of stress hormones. These results suggest behavioral interventions designed to reduce emotional reactivity may be of therapeutic benefit in chronic inflammatory conditions. Moreover, mindfulness practice, in particular, may be more efficacious in symptom relief than the well-being promoting activities cultivated in the HEP program.

Psychological stress is a major provocative factor of symptoms in chronic inflammatory conditions. In recent years, interest in addressing stress responsivity through meditation training in health-related domains has increased astoundingly, despite a paucity of evidence that reported benefits are specific to meditation practice. We designed the present study to rigorously compare an 8-week Mindfulness-Based Stress Reduction (MBSR) intervention to a well-matched active control intervention, the Health Enhancement Program (HEP) in ability to reduce psychological stress and experimentally-induced inflammation. The Trier Social Stress Test (TSST) was used to induce psychological stress and inflammation was produced using topical application of capsaicin cream to forearm skin. Immune and endocrine measures of inflammation and stress were collected both before and after MBSR training. Results show those randomized to MBSR and HEP training had comparable post-training stress-evoked cortisol responses, as well as equivalent reductions in self-reported psychological distress and physical symptoms. However, MBSR training resulted in a significantly smaller post-stress inflammatory response compared to HEP, despite equivalent levels of stress hormones. These results suggest behavioral interventions designed to reduce emotional reactivity may be of therapeutic benefit in chronic inflammatory conditions. Moreover, mindfulness practice, in particular, may be more efficacious in symptom relief than the well-being promoting activities cultivated in the HEP program.
Zotero Collections:

<p>Divides the study of human attention into 3 components: alertness, selectivity, and processing capacity. Experimental techniques designed to separate these components and examine their interrelations within comparable tasks are outlined. It is shown that a stimulus may be used to increase alertness for processing all external information, to improve selection of particular stimuli, or to do both simultaneously. Development of alertness and selectivity are separable, but may go on together without interference. Moreover, encoding a stimulus may proceed without producing interference with other signals. Thus, the contact between an external stimulus and its representation in memory does not appear to require processing capacity. Limited capacity results are obtained when mental operations, E.g., response selection or rehearsal, must be performed on the encoded information. (45 ref.)</p>

This article examines the lay meditation movement occurring in contemporary Buddhism in Sri Lanka. The lay meditation movement represents a different perspective from the nationalistic Sinhala Buddhism that has dominated the discourse in the wake of the intractable ethnic conflict in the country. The lay meditation movement reflects the contemporary ferment in Buddhist discourse among the laity. One of the key themes in this movement is the privileging of experience because it gives the lay groups authority to challenge contemporary orthodoxy and it has empowered a new class of spiritual leaders, the lay gurus. Paraphrasing Stirrat, we can say that these lay gurus are leading the lay meditation movement towards ‘a series of different interpretations of what it means’ to be a Buddhist today. In its overall effect the lay meditation movement not only reconstructs what it means to be a Buddhist today but also points in the direction of establishing new forms of sectarianism that could be considered to be ‘new religious movements’ under the umbrella of Buddhism.

We present a novel data smoothing and analysis framework for cortical thickness data defined on the brain cortical manifold. Gaussian kernel smoothing, which weights neighboring observations according to their 3D Euclidean distance, has been widely used in 3D brain images to increase the signal-to-noise ratio. When the observations lie on a convoluted brain surface, however, it is more natural to assign the weights based on the geodesic distance along the surface. We therefore develop a framework for geodesic distance-based kernel smoothing and statistical analysis on the cortical manifolds. As an illustration, we apply our methods in detecting the regions of abnormal cortical thickness in 16 high functioning autistic children via random field based multiple comparison correction that utilizes the new smoothing technique.
Zotero Collections:

Many investigators have hypothesized that brain response to cortisol is altered in depression. However, neural activation in response to exogenously manipulated cortisol elevations has not yet been directly examined in depressed humans. Animal research shows that glucocorticoids have robust effects on hippocampal function, and can either enhance or suppress neuroplastic events in the hippocampus depending on a number of factors. We hypothesized that depressed individuals would show 1) altered hippocampal response to exogenous administration of cortisol, and 2) altered effects of cortisol on learning. In a repeated-measures design, 19 unmedicated depressed and 41 healthy individuals completed two fMRI scans. Fifteen mg oral hydrocortisone (i.e., cortisol) or placebo (order randomized and double-blind) was administered 1 h prior to encoding of emotional and neutral words during fMRI scans. Data analysis examined the effects of cortisol administration on 1) brain activation during encoding, and 2) subsequent free recall for words. Cortisol affected subsequent recall performance in depressed but not healthy individuals. We found alterations in hippocampal response to cortisol in depressed women, but not in depressed men (who showed altered response to cortisol in other regions, including subgenual prefrontal cortex). In both depressed men and women, cortisol's effects on hippocampal function were positively correlated with its effects on recall performance assessed days later. Our data provide evidence that in depressed compared to healthy women, cortisol's effects on hippocampal function are altered. Our data also show that in both depressed men and women, cortisol's effects on emotional memory formation and hippocampal function are related.
Zotero Collections:

How does language reliably evoke emotion, as it does when people read a favorite novel or listen to a skilled orator? Recent evidence suggests that comprehension involves a mental simulation of sentence content that calls on the same neural systems used in literal action, perception, and emotion. In this study, we demonstrated that involuntary facial expression plays a causal role in the processing of emotional language. Subcutaneous injections of botulinum toxin-A (BTX) were used to temporarily paralyze the facial muscle used in frowning. We found that BTX selectively slowed the reading of sentences that described situations that normally require the paralyzed muscle for expressing the emotions evoked by the sentences. This finding demonstrates that peripheral feedback plays a role in language processing, supports facial-feedback theories of emotional cognition, and raises questions about the effects of BTX on cognition and emotional reactivity. We account for the role of facial feedback in language processing by considering neurophysiological mechanisms and reinforcement-learning theory.
Zotero Collections:

In rodents, theta rhythm has been linked to the hippocampal formation, as well as other regions, including the anterior cingulate cortex (ACC). To test the role of the ACC in theta rhythm, concurrent measurements of brain electrical activity (EEG) and glucose metabolism (PET) were performed in 29 subjects at baseline. EEG data were analyzed with a source localization technique that enabled voxelwise correlations of EEG and PET data. For theta, but not other bands, the rostral ACC (Brodmann areas 24/32) was the largest cluster with positive correlations between current density and glucose metabolism. Positive correlations were also found in right fronto-temporal regions. In control but not depressed subjects, theta within ACC and prefrontal/orbitofrontal regions was positively correlated. The results reveal a link between theta and cerebral metabolism in the ACC as well as disruption of functional connectivity within frontocingulate pathways in depression.
Zotero Collections:

Sensitivity, specificity, and reproducibility are vital to interpret neuroscientific results from functional magnetic resonance imaging (fMRI) experiments. Here we examine the scan-rescan reliability of the percent signal change (PSC) and parameters estimated using Dynamic Causal Modeling (DCM) in scans taken in the same scan session, less than 5 min apart. We find fair to good reliability of PSC in regions that are involved with the task, and fair to excellent reliability with DCM. Also, the DCM analysis uncovers group differences that were not present in the analysis of PSC, which implies that DCM may be more sensitive to the nuances of signal changes in fMRI data.
Zotero Collections:

Individual variation in the experience and expression of pleasure may relate to differential patterns of lateral frontal activity. Brain electrical measures have been used to study the asymmetric involvement of lateral frontal cortex in positive emotion, but the excellent time resolution of these measures has not been used to capture second-by-second changes in ongoing emotion until now. The relationship between pleasure and second-by-second lateral frontal activity was examined with the use of hierarchical linear modeling in a sample of 128 children ages 6-10 years. Electroencephalographic activity was recorded during "pop-out toy," a standardized task that elicits pleasure. The task consisted of 3 epochs: an anticipation period sandwiched between 2 play periods. The amount of pleasure expressed during the task predicted the pattern of nonlinear change in lateral frontal activity. Children who expressed increasing amounts of pleasure during the task exhibited increasing left lateral frontal activity during the task, whereas children who expressed contentment exhibited increasing right/decreasing left activity. These findings indicate that task-dependent changes in pleasure relate to dynamic, nonlinear changes in lateral frontal activity as the task unfolds.
Zotero Collections:

Individuals who experience early adversity, such as child maltreatment, are at heightened risk for a broad array of social and health difficulties. However, little is known about how this behavioral risk is instantiated in the brain. Here we examine a neurobiological contribution to individual differences in human behavior using methodology appropriate for use with pediatric populations paired with an in-depth measure of social behavior. We show that alterations in the orbitofrontal cortex among individuals who experienced physical abuse are related to social difficulties. These data suggest a biological mechanism linking early social learning to later behavioral outcomes.
Zotero Collections:

OBJECTIVES: Randomized controlled studies on the effectiveness of body-oriented methods of treatment for children with attention-deficit hyperactivity disorder (ADHD) are lacking. Our aim was to compare the effectiveness of two methods of treatment (yoga for children vs. conventional motor exercises) in a randomized controlled pilot study. METHODS: Nineteen children with a clinical diagnosis of ADHD (according to ICD-10 criteria) were included and randomly assigned to treatment conditions according to a 2x2 cross-over design. Effects of treatment were analyzed by means of an analysis of variance for repeated measurements. RESULTS: For all outcome measures (test scores on an attention task, and parent ratings of ADHD symptoms) the yoga training was superior to the conventional motor training, with effect sizes in the medium-to-high range (0.60-0.97). All children showed sizable reductions in symptoms over time, and at the end of the study, the group means for the ADHD scales did not differ significantly from those for a representative control group. Furthermore, the training was particularly effective for children undergoing pharmacotherapy (MPH). CONCLUSIONS: The findings from this pilot study demonstrate that yoga can be an effective complementary or concomitant treatment for attention-deficit hyperactivity disorder. The study advocates further research into the impact of yoga or body-oriented therapies on the prevention and treatment of ADHD.
Zotero Collections:

This study describes the effects of an 8-week course in Mindfulness-Based Stress Reduction (MBSR; J. Kabat-Zinn, 1982, 1990) on affective symptoms (depression and anxiety), dysfunctional attitudes, and rumination. Given the focus of mindfulness meditation (MM) in modifying cognitive processes, it was hypothesized that the primary change in MM practice involves reductions in ruminative tendencies. We studied a sample of individuals with lifetime mood disorders who were assessed prior to and upon completion of an MBSR course. We also compared a waitlist sample matched with a subset of the MBSR completers. Overall, the results suggest that MM practice primarily leads to decreases in ruminative thinking, even after controlling for reductions in affective symptoms and dysfunctional beliefs.

OBJECTIVES: Previously it was shown that a brief yoga-based lifestyle intervention was efficacious in reducing oxidative stress and risk of chronic diseases even in a short duration. The objective of this study was to assess the efficacy of this intervention in reducing stress and inflammation in patients with chronic inflammatory diseases. DESIGN: This study reports preliminary results from a nonrandomized prospective ongoing study with pre-post design. SETTING/LOCATION: The study was conducted at the Integral Health Clinic, an outpatient facility conducting these yoga-based lifestyle intervention programs for prevention and management of chronic diseases. SUBJECTS: Patients with chronic inflammatory diseases and overweight/obese subjects were included while physically challenged, and those on other interventions were excluded from the study. INTERVENTION: A pretested intervention program included asanas (postures), pranayama (breathing exercises), stress management, group discussions, lectures, and individualized advice. OUTCOME MEASURES: There was a reduction in stress (plasma cortisol and β-endorphin) and inflammation (interleukin [IL]-6 and tumor necrosis factor [TNF]-α) at day 0 versus day 10. RESULTS: Eighty-six (86) patients (44 female, 42 male, 40.07 ± 13.91 years) attended this program. Overall, the mean level of cortisol decreased from baseline to day 10 (149.95 ± 46.07, 129.07 ± 33.30 ng/mL; p=0.001) while β-endorphins increased from baseline to day 10 (3.53 ± 0.88, 4.06 ± 0.79 ng/mL; p=0.024). Also, there was reduction from baseline to day 10 in mean levels of IL-6 (2.16 ± 0.42, 1.94 ± 0.10 pg/mL, p=0.036) and TNF-α (2.85 ± 0.59, 1.95 ± 0.32 pg/mL, p=0.002). CONCLUSIONS: This brief yoga-based lifestyle intervention reduced the markers of stress and inflammation as early as 10 days in patients with chronic diseases; however, complete results of this study will confirm whether this program has utility as complementary and alternative therapy.
Zotero Collections:

Muscle or electromyogenic (EMG) artifact poses a serious risk to inferential validity for any electroencephalography (EEG) investigation in the frequency-domain owing to its high amplitude, broad spectrum, and sensitivity to psychological processes of interest. Even weak EMG is detectable across the scalp in frequencies as low as the alpha band. Given these hazards, there is substantial interest in developing EMG correction tools. Unfortunately, most published techniques are subjected to only modest validation attempts, rendering their utility questionable. We review recent work by our laboratory quantitatively investigating the validity of two popular EMG correction techniques, one using the general linear model (GLM), the other using temporal independent component analysis (ICA). We show that intra-individual GLM-based methods represent a sensitive and specific tool for correcting on-going or induced, but not evoked (phase-locked) or source-localized, spectral changes. Preliminary work with ICA shows that it may not represent a panacea for EMG contamination, although further scrutiny is strongly warranted. We conclude by describing emerging methodological trends in this area that are likely to have substantial benefits for basic and applied EEG research.
Zotero Collections:

Pages

  • Page
  • of 4