Left parietal lobe activation to auditory mismatch?

The original article to which this Commentary refers was published in the November, 2002 issue of Human Brain Mapping (Park H-J, Kwon JS, Youn T, Pae JS, Kim J-J, Kim M-S, Ha K-S. Statistical Parametric Mapping of LORETA Using High-Density EEG and Individual MRI: Application to Mismatch Negativities in Schizophrenia. Hum Brain Mapp 2002;17:168-178).     

“Aha!” effects in a guessing riddle task: An ERP study

In the August 2004 issue of Human Brain Mapping, it should have been noted that Drs. Yue‐Jia Luo and Jing Luo contributed equally to their ERP study of “Aha!” effects in a guessing riddle task [Hum Brain Mapp 22(4):261–270]. Correspondence should be addressed to Dr. Yue‐Jia Luo at luoyj@psych.ac.cn . Hum Brain Mapp 23:128, 2004. © 2004 Wiley‐Liss, Inc.     

Resting state functional connectivity of the ventral auditory pathway in musicians with absolute pitch

Absolute pitch (AP) is the ability to recognize pitch chroma of tonal sound without external references, providing a unique model of the human auditory system (Zatorre: Nat Neurosci 6 ( 2003 ) 692–695). In a previous study (Kim and Knösche: Hum Brain Mapp ( 2016 ) 3486–3501), we identified enhanced intracortical myelination in the right planum polare (PP) in musicians with AP, which could be a potential site for perceptional processing of pitch chroma information. We speculated that this area, which initiates the ventral auditory pathway, might be crucially involved in the perceptual stage of the AP process in the context of the “dual pathway hypothesis” that suggests the role of the ventral pathway in processing nonspatial information related to the identity of an auditory object (Rauschecker: Eur J Neurosci 41 ( 2015 ) 579–585). To test our conjecture on the ventral pathway, we investigated resting state functional connectivity (RSFC) using functional magnetic resonance imaging (fMRI) from musicians with varying degrees of AP. Should our hypothesis be correct, RSFC via the ventral pathway is expected to be stronger in musicians with AP, whereas such group effect is not predicted in the RSFC via the dorsal pathway. In the current data, we found greater RSFC between the right PP and bilateral anteroventral auditory cortices in musicians with AP. In contrast, we did not find any group difference in the RSFC of the planum temporale (PT) between musicians with and without AP. We believe that these findings support our conjecture on the critical role of the ventral pathway in AP recognition. Hum Brain Mapp 38:3899–3916, 2017. © 2017 Wiley Periodicals, Inc.     

Thickness profile generation for the corpus callosum using Laplace's equation

The corpus callosum facilitates communication between the cerebral hemispheres. Morphological abnormalities of the corpus callosum have been identified in numerous psychiatric and neurological disorders. To quantitatively analyze the thickness profile of the corpus callosum, we adapted an automatic thickness measurement method, which was originally used on magnetic resonance (MR) images of the cerebral cortex (Hutton et al. [ 2008 ]: NeuroImage 40:1701–10; Jones et al. [ 2002 ]: Hum Brain Mapp 11:12–32; Schmitt and Böhme [ 2002 ]: NeuroImage 16:1103–9; Yezzi and Prince [ 2003 ]: IEEE Trans Med Imaging 22:1332–9), to MR images of the corpus callosum. The thickness model was derived by computing a solution to Laplace's equation evaluated on callosal voxels. The streamlines from this solution form non‐overlapping, cross‐sectional contours the lengths of which are modeled as the callosal thickness. Apart from the semi‐automated segmentation and endpoint selection procedures, the method is fully automated, robust, and reproducible. We compared the Laplace method with the orthogonal projection technique previously published (Walterfang et al. [ 2009a ]: Psych Res Neuroimaging 173:77–82; Walterfang et al. [ 2008a ]: Br J Psychiatry 192:429–34; Walterfang et al. [ 2008b ]: Schizophr Res 103:1–10) on a cohort of 296 subjects, composed of 86 patients with chronic schizophrenia (CSZ), 110 individuals with first‐episode psychosis, 100 individuals at ultra‐high risk for psychosis (UHR; 27 of whom later developed psychosis, UHR‐P, and 73 who did not, UHR‐NP), and 55 control subjects (CTL). We report similar patterns of statistically significant differences in regional callosal thickness with respect to the comparisons CSZ vs. CTL, UHR vs. CTL, UHR‐P vs. UHR‐NP, and UHR vs. CTL. Hum Brain Mapp, 2011. © 2011 Wiley Periodicals, Inc.     

A meta-analytic study of changes in brain activation in depression

The article to which this erratum refers is published in this issue, Hum Brain Mapp (2008) 29:683–695. © 2008 Wiley-Liss, Inc.     

Common neural correlates of emotion perception in humans

Whether neuroimaging findings support discriminable neural correlates of emotion categories is a longstanding controversy. Two recent meta‐analyses arrived at opposite conclusions, with one supporting (Vytal and Hamann [ 2010 ]: J Cogn Neurosci 22:2864–2885) and the other opposing this proposition (Lindquist et al. [ 2012 ]: Behav Brain Sci 35:121–143). To obtain direct evidence regarding this issue, we compared activations for four emotions within a single fMRI design. Angry, happy, fearful, sad and neutral stimuli were presented as dynamic body expressions. In addition, observers categorized motion morphs between neutral and emotional stimuli in a behavioral experiment to determine their relative sensitivities. Brain–behavior correlations revealed a large brain network that was identical for all four tested emotions. This network consisted predominantly of regions located within the default mode network and the salience network. Despite showing brain–behavior correlations for all emotions, muli‐voxel pattern analyses indicated that several nodes of this emotion general network contained information capable of discriminating between individual emotions. However, significant discrimination was not limited to the emotional network, but was also observed in several regions within the action observation network. Taken together, our results favor the position that one common emotional brain network supports the visual processing and discrimination of emotional stimuli. Hum Brain Mapp 36:4184–4201, 2015. © 2015 Wiley Periodicals, Inc.     

Comparing functional MRI protocols for small,iron‐rich basal ganglia nuclei such as the subthalamic nucleus at 7 T and 3 T

The basal ganglia (BG) form a network of subcortical nuclei. Functional magnetic resonance imaging (fMRI) in the BG could provide insight in its functioning and the underlying mechanisms of Deep Brain Stimulation (DBS). However, fMRI of the BG with high specificity is challenging, because the nuclei are small and variable in their anatomical location. High resolution fMRI at field strengths of 7 Tesla (T) could help resolve these challenges to some extent. A set of MR protocols was developed for functional imaging of the BG nuclei at 3 T and 7 T. The protocols were validated using a stop‐signal reaction task (Logan et al. [ 1984 ]: J Exp Psychol: Human Percept Perform 10:276–291). Compared with sub‐millimeter 7 T fMRI protocols aimed at cortex, a reduction of echo time and spatial resolution was strictly necessary to obtain robust Blood Oxygen Level Dependent (BOLD) sensitivity in the BG. An fMRI protocol at 3 T with identical resolution to the 7 T showed no robust BOLD sensitivity in any of the BG nuclei. The results suggest that the subthalamic nucleus, as well as the substantia nigra, red nucleus, and the internal and external parts of the globus pallidus show increased activation in failed stop trials compared with successful stop and go trials. Hum Brain Mapp 38:3226–3248, 2017. © 2017 Wiley Periodicals, Inc.     

Gray matter volumes of early sensory regions are associated with individual differences in sensory processing

Sensory processing (i.e., the manner in which the nervous system receives, modulates, integrates, and organizes sensory stimuli) is critical when humans are deciding how to react to environmental demands. Although behavioral studies have shown that there are stable individual differences in sensory processing, the neural substrates that implement such differences remain unknown. To investigate this issue, structural magnetic resonance imaging scans were acquired from 51 healthy adults and individual differences in sensory processing were assessed using the Sensory Profile questionnaire (Brown et al.: Am J Occup Ther 55 (2001) 75–82). There were positive relationships between the Sensory Profile modality‐specific subscales and gray matter volumes in the primary or secondary sensory areas for the visual, auditory, touch, and taste/smell modalities. Thus, the present results suggest that individual differences in sensory processing are implemented by the early sensory regions. Hum Brain Mapp 38:6206–6217, 2017. © 2017 Wiley Periodicals, Inc.     

Genetic effect of MTHFR C677T polymorphism on the structural covariance network and white‐matter integrity in Alzheimer's disease

The 677 C to T transition in the MTHFR gene is a genetic determinant for hyperhomocysteinemia. We investigated whether this polymorphism modulates gray matter (GM) structural covariance networks independently of white‐matter integrity in patients with Alzheimer's disease (AD). GM structural covariance networks were constructed by 3D T1‐magnetic resonance imaging and seed‐based analysis. The patients were divided into two genotype groups: C homozygotes (n = 73) and T carriers (n = 62). Using diffusion tensor imaging and white‐matter parcellation, 11 fiber bundle integrities were compared between the two genotype groups. Cognitive test scores were the major outcome factors. The T carriers had higher homocysteine levels, lower posterior cingulate cortex GM volume, and more clusters in the dorsal medial lobe subsystem showing stronger covariance strength. Both posterior cingulate cortex seed and interconnected peak cluster volumes predicted cognitive test scores, especially in the T carriers. There were no between‐group differences in fiber tract diffusion parameters. The MTHFR 677T polymorphism modulates posterior cingulate cortex‐anchored structural covariance strength independently of white matter integrities. Hum Brain Mapp 38:3039–3051, 2017. © 2017 The Authors Human Brain Mapping Published Wiley by Periodicals, Inc.     

Neurobiological origin of spurious brain morphological changes: A quantitative MRI study

The high gray‐white matter contrast and spatial resolution provided by T1‐weighted magnetic resonance imaging (MRI) has made it a widely used imaging protocol for computational anatomy studies of the brain. While the image intensity in T1‐weighted images is predominantly driven by T1, other MRI parameters affect the image contrast, and hence brain morphological measures derived from the data. Because MRI parameters are correlates of different histological properties of brain tissue, this mixed contribution hampers the neurobiological interpretation of morphometry findings, an issue which remains largely ignored in the community. We acquired quantitative maps of the MRI parameters that determine signal intensities in T1‐weighted images (R₁ (=1/T1), R₂*, and PD) in a large cohort of healthy subjects (n = 120, aged 18–87 years). Synthetic T1‐weighted images were calculated from these quantitative maps and used to extract morphometry features—gray matter volume and cortical thickness. We observed significant variations in morphometry measures obtained from synthetic images derived from different subsets of MRI parameters. We also detected a modulation of these variations by age. Our findings highlight the impact of microstructural properties of brain tissue—myelination, iron, and water content—on automated measures of brain morphology and show that microstructural tissue changes might lead to the detection of spurious morphological changes in computational anatomy studies. They motivate a review of previous morphological results obtained from standard anatomical MRI images and highlight the value of quantitative MRI data for the inference of microscopic tissue changes in the healthy and diseased brain. Hum Brain Mapp 37:1801–1815, 2016. © 2016 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.     

Event‐related fMRI at 7T reveals overlapping cortical representations for adjacent fingertips in S1 of individual subjects

Recent fMRI studies of the human primary somatosensory cortex have been able to differentiate the cortical representations of different fingertips at a single‐subject level. These studies did not, however, investigate the expected overlap in cortical activation due to the stimulation of different fingers. Here, we used an event‐related design in six subjects at 7 Tesla to explore the overlap in cortical responses elicited in S1 by vibrotactile stimulation of the five fingertips. We found that all parts of S1 show some degree of spatial overlap between the cortical representations of adjacent or even nonadjacent fingertips. In S1, the posterior bank of the central sulcus showed less overlap than regions in the post‐central gyrus, which responded to up to five fingertips. The functional properties of these two areas are consistent with the known layout of cytoarchitectonically defined subareas, and we speculate that they correspond to subarea 3b (S1 proper) and subarea 1, respectively. In contrast with previous fMRI studies, however, we did not observe discrete activation clusters that could unequivocally be attributed to different subareas of S1. Venous maps based on T2*‐weighted structural images suggest that the observed overlap is not driven by extra‐vascular contributions from large veins. Hum Brain Mapp 35:2027–2043, 2014. © 2013 The Authors Human Brain Mapping published by Wiley Periodicals, Inc.     

Meta‐analysis of psychophysiological interactions: Revisiting cluster‐level thresholding and sample sizes

Within the neuroimaging community, coordinate based meta‐analyses (CBMAs) are essential for aggregating findings across studies and testing whether those studies report similar anatomical locations. This approach has been predominantly applied to studies that focus on whether activation of a brain region is associated with a given psychological process. In a recent paper, we used CBMA to examine a distinct set of studies—that is, those focusing on whether connectivity between brain regions is modulated by a given psychological process (Smith et al. [2016]: Hum Brain Mapp 37:2904–2917). Specifically, we reviewed 284 studies examining brain connectivity with psychophysiological interactions (PPI). Our meta‐analytic results indicated that PPI yields connectivity patterns that are consistent across studies and that can be specific for a given psychological process and seed region. After publication of our findings, we learned that the analysis software we used to conduct our CBMAs (GingerALE v2.3.3) contained an implementation error that led to results that were more liberal than intended. Here, we comment on the impact of this implementation error on the results of our paper, new recommendations for sample sizes in CBMAs, and the importance of communication between software users and developers. We show that our key claims are supported in a reanalysis and that our results are robust to new guidelines on sample sizes. Hum Brain Mapp 38:588–591, 2017. © 2016 Wiley Periodicals, Inc.     

Mapping complementary features of cross‐species structural connectivity to construct realistic “Virtual Brains”

Modern systems neuroscience increasingly leans on large‐scale multi‐lab neuroinformatics initiatives to provide necessary capacity for biologically realistic modeling of primate whole‐brain activity. Here, we present a framework to assemble primate brain's biologically plausible anatomical backbone for such modeling initiatives. In this framework, structural connectivity is determined by adding complementary information from invasive macaque axonal tract tracing and non‐invasive human diffusion tensor imaging. Both modalities are combined by means of available interspecies registration tools and a newly developed Bayesian probabilistic modeling approach to extract common connectivity evidence. We demonstrate how this novel framework is embedded in the whole‐brain simulation platform called The Virtual Brain (TVB). Hum Brain Mapp 38:2080–2093, 2017. © 2017 Wiley Periodicals, Inc.     

Emotional context facilitates cortical prediction error responses

In the predictive coding framework, mismatch negativity (MMN) is regarded a correlate of the prediction error that occurs when top–down predictions conflict with bottom–up sensory inputs. Expression‐related MMN is a relatively novel construct thought to reflect a prediction error specific to emotional processing, which, however, has not yet been tested directly. Our paradigm includes both neutral and emotional deviants, thereby allowing for investigating whether expression‐related MMN is emotion‐specific or unspecifically arises from violations of a given sequence. Twenty healthy participants completed a visual sequence oddball task where they were presented with (1) sequence deviants, (2) emotional sequence deviants, and (3) emotional deviants. Mismatch components were assessed at ventral occipitotemporal scalp sites and analyzed regarding their amplitudes, spatiotemporal profiles, and neuronal sources. Expression‐related MMN could be clearly separated from its neutral counterpart in all investigated aspects. Specifically, expression‐related MMN showed enhanced amplitude, shorter latency, and different neuronal sources. Our results, therefore, provide converging evidence for a quantitative specificity of expression‐related MMN and seems to provide an opportunity to study prediction error during preattentive emotional processing. Our neurophysiological evidence ultimately suggests that a basic cognitive operator, the prediction error, is enhanced at the cortical level by processing of emotionally salient stimuli. Hum Brain Mapp 36:3641–3652, 2015. © 2015 Wiley Periodicals, Inc.     

Analysis of family‐wise error rates in statistical parametric mapping using random field theory

This technical report revisits the analysis of family‐wise error rates in statistical parametric mapping—using random field theory—reported in (Eklund et al. [ 2015 ]: arXiv 1511.01863). Contrary to the understandable spin that these sorts of analyses attract, a review of their results suggests that they endorse the use of parametric assumptions—and random field theory—in the analysis of functional neuroimaging data. We briefly rehearse the advantages parametric analyses offer over nonparametric alternatives and then unpack the implications of (Eklund et al. [ 2015 ]: arXiv 1511.01863) for parametric procedures. Hum Brain Mapp, 40:2052–2054, 2019. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.     

Motor imagery of hand actions: Decoding the content of motor imagery from brain activity in frontal and parietal motor areas

How motor maps are organized while imagining actions is an intensely debated issue. It is particularly unclear whether motor imagery relies on action‐specific representations in premotor and posterior parietal cortices. This study tackled this issue by attempting to decode the content of motor imagery from spatial patterns of Blood Oxygen Level Dependent (BOLD) signals recorded in the frontoparietal motor imagery network. During fMRI‐scanning, 20 right‐handed volunteers worked on three experimental conditions and one baseline condition. In the experimental conditions, they had to imagine three different types of right‐hand actions: an aiming movement, an extension–flexion movement, and a squeezing movement. The identity of imagined actions was decoded from the spatial patterns of BOLD signals they evoked in premotor and posterior parietal cortices using multivoxel pattern analysis. Results showed that the content of motor imagery (i.e., the action type) could be decoded significantly above chance level from the spatial patterns of BOLD signals in both frontal (PMC, M1) and parietal areas (SPL, IPL, IPS). An exploratory searchlight analysis revealed significant clusters motor‐ and motor‐associated cortices, as well as in visual cortices. Hence, the data provide evidence that patterns of activity within premotor and posterior parietal cortex vary systematically with the specific type of hand action being imagined. Hum Brain Mapp 37:81–93, 2016. © 2015 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.     

Surprise beyond prediction error

Surprise drives learning. Various neural “prediction error” signals are believed to underpin surprise‐based reinforcement learning. Here, we report a surprise signal that reflects reinforcement learning but is neither un/signed reward prediction error (RPE) nor un/signed state prediction error (SPE). To exclude these alternatives, we measured surprise responses in the absence of RPE and accounted for a host of potential SPE confounds. This new surprise signal was evident in ventral striatum, primary sensory cortex, frontal poles, and amygdala. We interpret these findings via a normative model of surprise. Hum Brain Mapp 35:4805–4814, 2014. © 2014 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc.     

Reading in the brain of children and adults: A meta‐analysis of 40 functional magnetic resonance imaging studies

We used quantitative, coordinate‐based meta‐analysis to objectively synthesize age‐related commonalities and differences in brain activation patterns reported in 40 functional magnetic resonance imaging (fMRI) studies of reading in children and adults. Twenty fMRI studies with adults (age means: 23–34 years) were matched to 20 studies with children (age means: 7–12 years). The separate meta‐analyses of these two sets showed a pattern of reading‐related brain activation common to children and adults in left ventral occipito‐temporal (OT), inferior frontal, and posterior parietal regions. The direct statistical comparison between the two meta‐analytic maps of children and adults revealed higher convergence in studies with children in left superior temporal and bilateral supplementary motor regions. In contrast, higher convergence in studies with adults was identified in bilateral posterior OT/cerebellar and left dorsal precentral regions. The results are discussed in relation to current neuroanatomical models of reading and tentative functional interpretations of reading‐related activation clusters in children and adults are provided. Hum Brain Mapp 36:1963–1981, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. .     

A somatosensory‐to‐motor cascade of cortical areas engaged in perceptual decision making during tactile pattern discrimination

The processes underlying perceptual decision making are diverse and typically engage a distributed network of brain areas. It is a particular challenge to establish a sensory‐to‐motor functional hierarchy in such networks. This is because single‐cell recordings mainly study the nodes of decision networks in isolation but seldom simultaneously. Moreover, imaging methods, which allow simultaneously accessing information from overall networks, typically suffer from either the temporal or the spatial resolution necessary to establish a detailed functional hierarchy in terms of a sequential recruitment of areas during a decision process. Here we report a novel analytical approach to work around these latter limitations: using temporal differences in human fMRI activation profiles during a tactile discrimination task with immediate versus experimentally delayed behavioral responses, we could derive a linear functional gradient across task‐related brain areas in terms of their relative dependence on sensory input versus motor output. The gradient was established by comparing peak latencies of activation between the two response conditions. The resulting time differences described a continuum that ranged from zero time difference, indicative for areas that process information related to the sensory input and, thus, are invariant to the response delay instruction, to time differences corresponding to the delayed response onset, thus indicating motor‐related processing. Taken together with our previous findings (Li Hegner et al. [ 2015 ]: Hum Brain Mapp 36:3339–3350), our results suggest that the anterior insula reflects the ultimate perceptual stage within the uncovered sensory‐to‐motor gradient, likely translating sensory information into a categorical abstract (non‐motor) decision. Hum Brain Mapp 38:1172–1181, 2017. © 2016 Wiley Periodicals, Inc.     

Investigation of morphometric variability of subthalamic nucleus,red nucleus,and substantia nigra in advanced Parkinson's disease patients using automatic segmentation and PCA‐based analysis

Subthalamic nucleus (STN) deep brain stimulation (DBS) is an effective surgical therapy to treat Parkinson's disease (PD). Conventional methods employ standard atlas coordinates to target the STN, which, along with the adjacent red nucleus (RN) and substantia nigra (SN), are not well visualized on conventional T1w MRIs. However, the positions and sizes of the nuclei may be more variable than the standard atlas, thus making the pre‐surgical plans inaccurate. We investigated the morphometric variability of the STN, RN and SN by using label‐fusion segmentation results from 3T high resolution T2w MRIs of 33 advanced PD patients. In addition to comparing the size and position measurements of the cohort to the Talairach atlas, principal component analysis (PCA) was performed to acquire more intuitive and detailed perspectives of the measured variability. Lastly, the potential correlation between the variability shown by PCA results and the clinical scores was explored. Hum Brain Mapp 35:4330–4344, 2014. © 2014 Wiley Periodicals, Inc .