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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.
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.
The authors compared 12 pairs of cerebral [18F]-fluoro-deoxyglucose (FDG) 2D/3D image sets from a GE/Advance PET scanner, incorporating the actual corrections used on human subjects. Differences in resolution consistent with other published values were found. There is a significant difference in axial resolution between 2D and 3D, and the authors focused on this as it is a scanner feature that cannot be readily changed. Previously published values for spatial axial resolution in 2D and 3D modes were used to model the differential axial smoothing at each image voxel. This model was applied to the 2D FDG images, and the resulting smoothed data indicate the published differences in axial resolution between 2D and 3D modes can account for 30-40% of the differences between these image sets. The authors then investigated the effect this difference might have on analysis typically performed on human FDG data. A phantom containing spherical hot- and cool-spots in a warm background to mimic a typical human cerebral FDG PET scan was scanned for a variety of time durations (30, 15, 5, 1 min). Only for the 1-minute frame (total counts 2D:6M, 3D:30M) is there an advantage to using 3D mode; for the longer frames which are more typical of a human FDG protocol, the reliability for extracting regions-of-interest is the same for either mode while 2D mode shows better quantitative accuracy
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.
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.
Recent studies have identified a distributed network of brain regions thought to support cognitive reappraisal processes underlying emotion regulation in response to affective images, including parieto-temporal regions and lateral/medial regions of prefrontal cortex (PFC). A number of these commonly activated regions are also known to underlie visuospatial attention and oculomotor control, which raises the possibility that people use attentional redeployment rather than, or in addition to, reappraisal as a strategy to regulate emotion. We predicted that a significant portion of the observed variance in brain activation during emotion regulation tasks would be associated with differences in how participants visually scan the images while regulating their emotions. We recorded brain activation using fMRI and quantified patterns of gaze fixation while participants increased or decreased their affective response to a set of affective images. fMRI results replicated previous findings on emotion regulation with regulation differences reflected in regions of PFC and the amygdala. In addition, our gaze fixation data revealed that when regulating, individuals changed their gaze patterns relative to a control condition. Furthermore, this variation in gaze fixation accounted for substantial amounts of variance in brain activation. These data point to the importance of controlling for gaze fixation in studies of emotion regulation that use visual stimuli.
Recent years have seen an explosion of interest in using neural oscillations to characterize the mechanisms supporting cognition and emotion. Oftentimes, oscillatory activity is indexed by mean power density in predefined frequency bands. Some investigators use broad bands originally defined by prominent surface features of the spectrum. Others rely on narrower bands originally defined by spectral factor analysis (SFA). Presently, the robustness and sensitivity of these competing band definitions remains unclear. Here, a Monte Carlo-based SFA strategy was used to decompose the tonic ("resting" or "spontaneous") electroencephalogram (EEG) into five bands: delta (1-5Hz), alpha-low (6-9Hz), alpha-high (10-11Hz), beta (12-19Hz), and gamma (>21Hz). This pattern was consistent across SFA methods, artifact correction/rejection procedures, scalp regions, and samples. Subsequent analyses revealed that SFA failed to deliver enhanced sensitivity; narrow alpha sub-bands proved no more sensitive than the classical broadband to individual differences in temperament or mean differences in task-induced activation. Other analyses suggested that residual ocular and muscular artifact was the dominant source of activity during quiescence in the delta and gamma bands. This was observed following threshold-based artifact rejection or independent component analysis (ICA)-based artifact correction, indicating that such procedures do not necessarily confer adequate protection. Collectively, these findings highlight the limitations of several commonly used EEG procedures and underscore the necessity of routinely performing exploratory data analyses, particularly data visualization, prior to hypothesis testing. They also suggest the potential benefits of using techniques other than SFA for interrogating high-dimensional EEG datasets in the frequency or time-frequency (event-related spectral perturbation, event-related synchronization/desynchronization) domains.
In order to gain a deeper understanding of the mindfulness construct and the mental health benefits associated with mindfulness-based programmes, the relation between mindfulness and its proposed core component attention was studied. Buddhist and Western mindfulness meditators were compared with non-meditators on tasks of sustained (SART) and executive (the Stroop Task) attention. Relations between self-reported mindfulness (FFMQ) and sustained and executive attention were also analysed. No significant differences were found between meditators and non-meditators either in sustained or executive attention. High scores on the FFMQ total scale and on Describe were related to fewer SART errors. High scores on Describe were also related to low Stroop interference. Mindfulness meditators may have an increased awareness of internal processes and the ability to quickly attend to them but this type of refined attentional ability does not seem to be related to performance on attention tests requiring responses to external targets.
We present a new sparse shape modeling framework on the Laplace-Beltrami (LB) eigenfunctions. Traditionally, the LB-eigenfunctions are used as a basis for intrinsically representing surface shapes by forming a Fourier series expansion. To reduce high frequency noise, only the first few terms are used in the expansion and higher frequency terms are simply thrown away. However, some lower frequency terms may not necessarily contribute significantly in reconstructing the surfaces. Motivated by this idea, we propose to filter out only the significant eigenfunctions by imposing l1-penalty. The new sparse framework can further avoid additional surface-based smoothing often used in the field. The proposed approach is applied in investigating the influence of age (38-79 years) and gender on amygdala and hippocampus shapes in the normal population. In addition, we show how the emotional response is related to the anatomy of the subcortical structures.
Although tantrums are among the most common behavioral problems of young children and may predict future antisocial behavior, little is known about them. To develop a model of this important phenomenon of early childhood, behaviors reported in parental narratives of the tantrums of 335 children aged 18 to 60 months were encoded as present or absent in consecutive 30-second periods. Principal Component (PC) analysis identified Anger and Distress as major, independent emotional and behavioral tantrum constituents. Anger-related behaviors formed PCs at three levels of intensity. High-intensity anger decreased with age, and low-intensity anger increased. Distress, the fourth PC, consisted of whining, crying, and comfort-seeking. Coping Style, the fifth PC, had high but opposite loadings on dropping down and running away, possibly reflecting the tendency to either "submit" or "escape." Model validity was indicated by significant correlations of the PCs with tantrum variables that were, by design, not included in the PC analysis.
This article completes the analysis of parental narratives of tantrums had by 335 children aged 18 to 60 months. Modal tantrum durations were 0.5 to 1 minute; 75% of the tantrums lasted 5 minutes or less. If the child stamped or dropped to the floor in the first 30 seconds, the tantrum was likely to be shorter and the likelihood of parental intervention less. A novel analysis of behavior probabilities that permitted grouping of tantrums of different durations converged with our previous statistically independent results to yield a model of tantrums as the expression of two independent but partially overlapping emotional and behavioral processes: Anger and Distress. Anger rises quickly, has its peak at or near the beginning of the tantrum, and declines thereafter. Crying and comfort-seeking, components of Distress, slowly increase in probability across the tantrum. This model indicates that tantrums can provide a window on the intense emotional processes of childhood.