Evidence from satellite altimetry for small-scale convection in the mantle

Small scale convection can be defined as that part of the mantle circulation in which upwellings and downwellings can occur beneath the lithosphere within the interiors of plates, in contrast to the large scale flow associated with plate motions where upwellings and downwellings occur at ridges and trenches. The two scales of convection will interact so that the form of the small scale convection will depend on how it arises within the large scale flow. Observations based on GEOS-3 and SEASAT altimetry suggest that small scale convection occurs in at least two different ways

Graded Representations of Emotional Expressions in the Left Superior Temporal Sulcus

Perceptual categorization is a fundamental cognitive process that gives meaning to an often graded sensory environment. Previous research has subdivided the visual pathway into posterior regions that processes the physical properties of a stimulus, and frontal regions that process more abstract properties such as category information. The superior temporal sulcus (STS) is known to be involved in face and emotion perception, but the nature of its processing remains unknown. Here, we used targeted fMRI measurements of the STS to investigate whether its representations of facial expressions are categorical or noncategorical. Multivoxel pattern analysis showed that even though subjects were performing a categorization task, the left STS contained graded, noncategorical representations. In the right STS, representations showed evidence for both stimulus-related gradations and a categorical boundary

Function-based Intersubject Alignment of Human Cortical Anatomy

Making conclusions about the functional neuroanatomical organization of the human brain requires methods for relating the functional anatomy of an individual's brain to population variability. We have developed a method for aligning the functional neuroanatomy of individual brains based on the patterns of neural activity that are elicited by viewing a movie. Instead of basing alignment on functionally defined areas, whose location is defined as the center of mass or the local maximum response, the alignment is based on patterns of response as they are distributed spatially both within and across cortical areas. The method is implemented in the two-dimensional manifold of an inflated, spherical cortical surface. The method, although developed using movie data, generalizes successfully to data obtained with another cognitive activation paradigm—viewing static images of objects and faces—and improves group statistics in that experiment as measured by a standard general linear model (GLM) analysis

Translation, cross-cultural adaptation and psychometric properties of the Nepali versions of numerical pain rating scale and global rating of change

Background: Pain intensity and patients' impression of global improvement are widely used patient-reported outcome measures (PROMs) in clinical practice and research. They are commonly assessed using the Numerical Pain Rating Scale (NPRS) and Global Rating of Change (GROC) questionnaires. The GROC is essential as an anchor for evaluating the psychometric properties of PROMs. Both of these PROMs are translated to many languages and have shown excellent psychometric properties. Their availability in Nepali would facilitate pain research and cross-cultural comparison of research findings. Therefore, the objectives of this study were to translate and cross-culturally adapt the NPRS and GROC into Nepali and to assess the psychometric properties of the Nepali version of the NPRS (NPRS-NP). Methods: After translating and cross-culturally adapting the NPRS and GROC into Nepali using recommended guidelines, NPRS-NP was administered to 104 individuals with musculoskeletal pain twice. The Nepali version of the GROC (GROC-NP) was administered at the follow-up for anchor-based assessment. (1) Test-retest reliability and minimum detectable change (MDC) among the stable group, (2) construct validity (by single sample t-test within the improved group and independent sample t-test between groups), and (3) concurrent validity were assessed. Receiver operating characteristic (ROC) curves were plotted to determine the responsiveness of the NPRS-NP using the area under the curve (AUC), and minimum important changes (MIC) for small, medium and large improvements. Results: Significant cultural adaptations were required to obtain relevant Nepali versions of both the NPRS and GROC. The NPRS-NP showed excellent test-retest reliability and a MDC of 1.13 points. NPRS-NP demonstrated a good construct validity by significant within-group difference in mean of NPRS score- t(63)= 7.57, P < 0.001 and statistically significant difference of mean score- t(98)= -4.24, P < .001 between the stable and improved groups. It demonstrated moderate concurrent correlation with the GROC-NP; r = 0.43, P < 0.01. Responsiveness of the NPRS-NP was shown at three levels with AUC = 0.68-0.82, and MIC = 1.17-1.33. Conclusions: The NPRS and GROC were successfully translated and culturally adapted into Nepali. The NPRS-NP demonstrated good reliability, validity and responsiveness in assessing musculoskeletal pain intensity in a Nepali population

Differential activation of frontoparietal attention networks by social and symbolic spatial cues

Perception of both gaze-direction and symbolic directional cues (e.g. arrows) orient an observer’s attention toward the indicated location. It is unclear, however, whether these similar behavioral effects are examples of the same attentional phenomenon and, therefore, subserved by the same neural substrate. It has been proposed that gaze, given its evolutionary significance, constitutes a ‘special’ category of spatial cue. As such, it is predicted that the neural systems supporting spatial reorienting will be different for gaze than for non-biological symbols. We tested this prediction using functional magnetic resonance imaging to measure the brain’s response during target localization in which laterally presented targets were preceded by uninformative gaze or arrow cues. Reaction times were faster during valid than invalid trials for both arrow and gaze cues. However, differential patterns of activity were evoked in the brain. Trials including invalid rather than valid arrow cues resulted in a stronger hemodynamic response in the ventral attention network. No such difference was seen during trials including valid and invalid gaze cues. This differential engagement of the ventral reorienting network is consistent with the notion that the facilitation of target detection by gaze cues and arrow cues is subserved by different neural substrates

Differential Activation of Frontoparietal Attention Networks by Social and Symbolic Spatial Cues

Perception of both gaze-direction and symbolic directional cues (e.g. arrows) orient an observer’s attention toward the indicated location. It is unclear, however, whether these similar behavioral effects are examples of the same attentional phenomenon and, therefore, subserved by the same neural substrate. It has been proposed that gaze, given its evolutionary significance, constitutes a ‘special’ category of spatial cue. As such, it is predicted that the neural systems supporting spatial reorienting will be different for gaze than for non-biological symbols. We tested this prediction using functional magnetic resonance imaging to measure the brain’s response during target localization in which laterally presented targets were preceded by uninformative gaze or arrow cues. Reaction times were faster during valid than invalid trials for both arrow and gaze cues. However, differential patterns of activity were evoked in the brain. Trials including invalid rather than valid arrow cues resulted in a stronger hemodynamic response in the ventral attention network. No such difference was seen during trials including valid and invalid gaze cues. This differential engagement of the ventral reorienting network is consistent with the notion that the facilitation of target detection by gaze cues and arrow cues is subserved by different neural substrates

Distributed representations of dynamic facial expressions in the superior temporal sulcus.

Previous research on the superior temporal sulcus (STS) has shown that it responds more to facial expressions than to neutral faces. Here, we extend our understanding of the STS in two ways. First, using targeted high-resolution fMRI measurements of the lateral cortex and multivoxel pattern analysis, we show that the response to seven categories of dynamic facial expressions can be decoded in both the posterior STS (pSTS) and anterior STS (aSTS). We were also able to decode patterns corresponding to these expressions in the frontal operculum (FO), a structure that has also been shown to respond to facial expressions. Second, we measured the similarity structure of these representations and found that the similarity structure in the pSTS significantly correlated with the perceptual similarity structure of the expressions. This was the case regardless of whether we used pattern classification or more traditional correlation techniques to extract the neural similarity structure. These results suggest that distributed representations in the pSTS could underlie the perception of facial expressions

Distributed representations of dynamic facial expressions in the superior temporal sulcus.

Previous research on the superior temporal sulcus (STS) has shown that it responds more to facial expressions than to neutral faces. Here, we extend our understanding of the STS in two ways. First, using targeted high-resolution fMRI measurements of the lateral cortex and multivoxel pattern analysis, we show that the response to seven categories of dynamic facial expressions can be decoded in both the posterior STS (pSTS) and anterior STS (aSTS). We were also able to decode patterns corresponding to these expressions in the frontal operculum (FO), a structure that has also been shown to respond to facial expressions. Second, we measured the similarity structure of these representations and found that the similarity structure in the pSTS significantly correlated with the perceptual similarity structure of the expressions. This was the case regardless of whether we used pattern classification or more traditional correlation techniques to extract the neural similarity structure. These results suggest that distributed representations in the pSTS could underlie the perception of facial expressions

Multisensory causal inference in the brain

At any given moment, our brain processes multiple inputs from its different sensory modalities (vision, hearing, touch, etc.). In deciphering this array of sensory information, the brain has to solve two problems: (1) which of the inputs originate from the same object and should be integrated and (2) for the sensations originating from the same object, how best to integrate them. Recent behavioural studies suggest that the human brain solves these problems using optimal probabilistic inference, known as Bayesian causal inference. However, how and where the underlying computations are carried out in the brain have remained unknown. By combining neuroimaging-based decoding techniques and computational modelling of behavioural data, a new study now sheds light on how multisensory causal inference maps onto specific brain areas. The results suggest that the complexity of neural computations increases along the visual hierarchy and link specific components of the causal inference process with specific visual and parietal regions