Background: To investigate whether usage of treatment-acquired regulatory skills is associated with prevention of depressive relapse/recurrence. Method: Remitted depressed outpatients entered a ...24-month clinical follow up after either 8 weekly group sessions of cognitive therapy (CT; N = 84) or mindfulness-based cognitive therapy (MBCT; N = 82). The primary outcome was symptom return meeting the criteria for major depression on Module A of the SCID. Results: Factor analysis identified three latent factors (53% of the variance): decentering (DC), distress tolerance (DT), and residual symptoms (RS), which were equivalent across CT and MBCT. Latent change score modeling of factor slopes over the follow up revealed positive slopes for DC (β = .177), and for DT (β = .259), but not for RS (β = −.017), indicating posttreatment growth in DC and DT, but no change in RS. Cox regression indicated that DC slope was a significant predictor of relapse/recurrence prophylaxis, Hazard Ratio (HR) = .232 90% Confidence Interval (CI) .067, .806, controlling for past depressive episodes, treatment group, and medication. The practice of therapy-acquired regulatory skills had no direct effect on relapse/recurrence (β = .028) but predicted relapse/recurrence through an indirect path (β = −.125), such that greater practice of regulatory skills following treatment promoted increases in DC (β = .462), which, in turn, predicted a reduced risk of relapse/recurrence over 24 months (β = −.270). Conclusions: Preventing major depressive disorder relapse/recurrence may depend upon developing DC in addition to managing residual symptoms. Following the acquisition of therapy skills during maintenance psychotherapies, DC is strengthened by continued skill utilization beyond treatment termination.
What is the public health significance of this article?
People receiving maintenance psychotherapies for depression are expected to utilize emotion regulation skills past the point of active treatment but receive little guidance regarding which skills are most effective. Our data suggest that resilience to episode return depends upon the development of metacognitive skills for the regulation of distressing thoughts and emotions.
Studies of emotional memory typically focus on the memory-enhancing effects of emotional dimensions such as arousal and valence. However, it is unclear to what extent different emotional categories ...could have distinct effects on memory over and above these dimensional influences. We tested this possibility by investigating the impact of two negative, highly arousing, and withdrawal-related emotions-disgust and fear-on attention and subsequent memory. To index differential attention during encoding, participants performed a speeded line discrimination task (LDT) while viewing disgusting and fearful photographs of similar valence and arousal, which were assessed for later memory. LDT performance was slower, and subsequent recall and recognition were greater, for disgusting compared to both fearful and neutral images. Disgust enhancement of memory remained significant even when controlling for attention at encoding and for arousal, visual salience, and conceptual distinctiveness. Receiver-operating curve analyses indicated that disgust enhancement of memory was due to increased sensitivity, rather than response bias. Thus, disgust appears to have a special salience in memory relative to certain other emotions, suggesting that a purely dimensional model of emotional influences on cognition is inadequate to account for their effects. We speculate that disgust enhancement of memory could arise from an origin in conditioned taste aversion, a highly enduring form of implicit memory.
•We develop a deep learning-based image registration method for 3D ASL image series.•It achieves superior registration accuracy and faster speed compared to SPM.•Its improved performance can be ...generalized to several ASL datasets.
Convolutional neural networks (CNN) have demonstrated good accuracy and speed in spatially registering high signal-to-noise ratio (SNR) structural magnetic resonance imaging (sMRI) images. However, some functional magnetic resonance imaging (fMRI) images, e.g., those acquired from arterial spin labeling (ASL) perfusion fMRI, are of intrinsically low SNR and therefore the quality of registering ASL images using CNN is not clear. In this work, we aimed to explore the feasibility of a CNN-based affine registration network (ARN) for registration of low-SNR three-dimensional ASL perfusion image time series and compare its performance with that from the state-of-the-art statistical parametric mapping (SPM) algorithm. The six affine parameters were learned from the ARN using both simulated motion and real acquisitions from ASL perfusion fMRI data and the registered images were generated by applying the transformation derived from the affine parameters. The speed and registration accuracy were compared between ARN and SPM. Several independent datasets, including meditation study (10 subjects × 2), bipolar disorder study (26 controls, 19 bipolar disorder subjects), and aging study (27 young subjects, 33 older subjects), were used to validate the generality of the trained ARN model. The ARN method achieves superior image affine registration accuracy (total translation/total rotation errors of ARN vs. SPM: 1.17 mm/1.23° vs. 6.09 mm/12.90° for simulated images and reduced MSE/L1/DSSIM/Total errors of 18.07% / 19.02% / 0.04% / 29.59% for real ASL test images) and 4.4 times (ARN vs. SPM: 0.50 s vs. 2.21 s) faster speed compared to SPM. The trained ARN can be generalized to align ASL perfusion image time series acquired with different scanners, and from different image resolutions, and from healthy or diseased populations. The results demonstrated that our ARN markedly outperforms the iteration-based SPM both for simulated motion and real acquisitions in terms of registration accuracy, speed, and generalization.
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It has been proposed that facial expression production originates in sensory regulation. Here we demonstrate that facial expressions of fear are configured to enhance sensory acquisition. A ...statistical model of expression appearance revealed that fear and disgust expressions have opposite shape and surface reflectance features. We hypothesized that this reflects a fundamental antagonism serving to augment versus diminish sensory exposure. In keeping with this hypothesis, when subjects posed expressions of fear, they had a subjectively larger visual field, faster eye movements during target localization and an increase in nasal volume and air velocity during inspiration. The opposite pattern was found for disgust. Fear may therefore work to enhance perception, whereas disgust dampens it. These convergent results provide support for the Darwinian hypothesis that facial expressions are not arbitrary configurations for social communication, but rather, expressions may have originated in altering the sensory interface with the physical world.
Abstract
Changes in brain resting-state functional connectivity (rsFC) were investigated using a longitudinal design by following a 2-month focused attention meditation (FAM) practice and analyzing ...their association with FAM practice time. Ten novice meditators were recruited from a university meditation course. Participants were scanned with a resting-state fMRI sequence with multi-echo EPI acquisition at baseline and at the 2-month follow-up. Total FAM practice time was calculated from the daily log of the participants. We observed significantly increased rsFC between the posterior cingulate cortex (PCC) and dorsal attention network (DAN), the right middle temporal (RMT) region and default mode network (DMN), the left and right superior parietal lobules (LSPL/RSPL) and DMN, and the LSPL/RSPL and DAN. Furthermore, the rsFC between the LSPL and medial prefrontal cortex was significantly associated with the FAM practice time. These results demonstrate increased connectivity within the DAN, between the DMN and DAN, and between the DMN and visual cortex. These findings demonstrate that FAM can enhance the brain connection among and within brain networks, especially DMN and DAN, indicating potential effect of FAM on fast switching between mind wandering and focused attention and maintaining attention once in the attentive state.
The diffusion MRI “b-vector” table describing the diffusion sensitization direction can be flipped and permuted in dimension due to different orientation conventions used in scanners and incorrect or ...improperly utilized file formats. This can lead to incorrect fiber orientation estimates and subsequent tractography failure. Here, we present an automated quality control procedure to detect when the b-table is flipped and/or permuted incorrectly.
We define a “fiber coherence index” to describe how well fibers are connected to each other, and use it to automatically detect the correct configuration of b-vectors. We examined the performance on 3981 research subject scans (Baltimore Longitudinal Study of Aging), 1065 normal subject scans of high image quality (Human Connectome Project), and 202 patient scans (Vanderbilt University Medical Center), as well as 9 in-vivo and 9 ex-vivo animal data.
The coherence index resulted in a 99.9% (3979/3981) and 100% (1065/1065) success rate in normal subject scans, 98% (198/202) in patient scans, and 100% (18/18) in both in-vivo and ex-vivo animal data in detecting the correct gradient table in datasets without severe image artifacts. The four failing cases (4/202) in patient scans, and two failures in healthy subject scans (2/3981), all showed prominent motion or signal dropout artifacts.
The fiber coherence measure can be used as an automatic quality assurance check in any diffusion analysis pipeline. Additionally, the success of this fiber coherence measure suggests potential broader applications, including evaluating data quality, or even providing diagnostic value as a biomarker of white matter integrity.
Minding One's Emotions Farb, Norman A. S; Anderson, Adam K; Mayberg, Helen ...
Emotion (Washington, D.C.),
02/2010, Letnik:
10, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Recovery from emotional challenge and increased tolerance of negative affect are both hallmarks of mental health. Mindfulness training (MT) has been shown to facilitate these outcomes, yet little is ...known about its mechanisms of action. The present study employed functional MRI (fMRI) to compare neural reactivity to sadness provocation in participants completing 8 weeks of MT and waitlisted controls. Sadness resulted in widespread recruitment of regions associated with self-referential processes along the cortical midline. Despite equivalent self-reported sadness, MT participants demonstrated a distinct neural response, with greater right-lateralized recruitment, including visceral and somatosensory areas associated with body sensation. The greater somatic recruitment observed in the MT group during evoked sadness was associated with decreased depression scores. Restoring balance between affective and sensory neural networks-supporting conceptual and body based representations of emotion-could be one path through which mindfulness reduces vulnerability to dysphoric reactivity.
Characterizing and understanding the limitations of diffusion MRI fiber tractography is a prerequisite for methodological advances and innovations which will allow these techniques to accurately map ...the connections of the human brain. The so‐called “crossing fiber problem” has received tremendous attention and has continuously triggered the community to develop novel approaches for disentangling distinctly oriented fiber populations. Perhaps an even greater challenge occurs when multiple white matter bundles converge within a single voxel, or throughout a single brain region, and share the same parallel orientation, before diverging and continuing towards their final cortical or sub‐cortical terminations. These so‐called “bottleneck” regions contribute to the ill‐posed nature of the tractography process, and lead to both false positive and false negative estimated connections. Yet, as opposed to the extent of crossing fibers, a thorough characterization of bottleneck regions has not been performed. The aim of this study is to quantify the prevalence of bottleneck regions. To do this, we use diffusion tractography to segment known white matter bundles of the brain, and assign each bundle to voxels they pass through and to specific orientations within those voxels (i.e. fixels). We demonstrate that bottlenecks occur in greater than 50‐70% of fixels in the white matter of the human brain. We find that all projection, association, and commissural fibers contribute to, and are affected by, this phenomenon, and show that even regions traditionally considered “single fiber voxels” often contain multiple fiber populations. Together, this study shows that a majority of white matter presents bottlenecks for tractography which may lead to incorrect or erroneous estimates of brain connectivity or quantitative tractography (i.e., tractometry), and underscores the need for a paradigm shift in the process of tractography and bundle segmentation for studying the fiber pathways of the human brain.
"Bottleneck" pose a challenge for diffusion tractography, and hinder our ability to accurately map the structural connections of the brain. We demonstrate that bottlenecks occur in greater than 50–70% of fixels in the human brain white matter, and find that all projection, association, and commissural fibers contribute to, and are affected by, this phenomenon. These results emphasize the use of caution when interpreting quantitative diffusion magnetic resonance imaging connectomics results, and underscore the need for a paradigm shift in the process of tractography for studying the fiber pathways of the human brain.
Functional MRI (fMRI) signals are robustly detectable in white matter (WM) but they have been largely ignored in the fMRI literature. Their nature, interpretation, and relevance as potential ...indicators of brain function remain under explored and even controversial. Blood oxygenation level dependent (BOLD) contrast has for over 25 years been exploited for detecting localized neural activity in the cortex using fMRI. While BOLD signals have been reliably detected in grey matter (GM) in a very large number of studies, such signals have rarely been reported from WM. However, it is clear from our own and other studies that although BOLD effects are weaker in WM, using appropriate detection and analysis methods they are robustly detectable both in response to stimuli and in a resting state. BOLD fluctuations in a resting state exhibit similar temporal and spectral profiles in both GM and WM, and their relative low frequency (0.01–0.1 Hz) signal powers are comparable. They also vary with baseline neural activity e.g. as induced by different levels of anesthesia, and alter in response to a stimulus. In previous work we reported that BOLD signals in WM in a resting state exhibit anisotropic temporal correlations with neighboring voxels. On the basis of these findings, we derived functional correlation tensors that quantify the correlational anisotropy in WM BOLD signals. We found that, along many WM tracts, the directional preferences of these functional correlation tensors in a resting state are grossly consistent with those revealed by diffusion tensors, and that external stimuli tend to enhance visualization of specific and relevant fiber pathways. These findings support the proposition that variations in WM BOLD signals represent tract-specific responses to neural activity. We have more recently shown that sensory stimulations induce explicit BOLD responses along parts of the projection fiber pathways, and that task-related BOLD changes in WM occur synchronously with the temporal pattern of stimuli. WM tracts also show a transient signal response following short stimuli analogous to but different from the hemodynamic response function (HRF) characteristic of GM. Thus there is converging and compelling evidence that WM exhibits both resting state fluctuations and stimulus-evoked BOLD signals very similar (albeit weaker) to those in GM. A number of studies from other laboratories have also reported reliable observations of WM activations. Detection of BOLD signals in WM has been enhanced by using specialized tasks or modified data analysis methods. In this mini-review we report summaries of some of our recent studies that provide evidence that BOLD signals in WM are related to brain functional activity and deserve greater attention by the neuroimaging community.
Emotional appraisal in humans is often considered a centrally mediated process by which sensory signals, void of emotional meaning, are assessed by integrative brain structures steps removed from raw ...sensation. We review emerging evidence that the emotional value of the environment is coded by nonvisual sensory systems as early as the sensory receptors and that these signals inform the emotional state of an organism independent of sensory cortical processes. We further present evidence for cross-species conservation of sensory projections to central emotion-processing brain regions. Based on this, we argue not only that emotional appraisal is a decentralized process, but that all human emotional experience may reflect the sensory experience of our ancestors.
Emotions function to motivate adaptive patterns of behavior and cognition, increasing the chance of an organism’s survival and reproduction by allowing it to compare objects, events, and cognitions in a modality-general manner.Current theories of human emotion appraisal as a centrally mediated process neglect evidence from nonvisual modalities, indicating that sensory afferents can reflect the adaptive value of external objects.In humans, valence-coded sensation informs modality-general representations of emotion and well-being independent of modality-specific processing.Whereas emotion processing in humans is predominantly informed by processed cortical signals, emotional processing in many non-human species is characterized by responsivity to raw sensation.We propose that centralized human emotion-processing structures are the evolutionary descendants of regions once dedicated to interpreting valenced-sensation, with valenced sensory inputs an artifact of this developmental history.
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