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41
Behavioral interpretations of intrinsic connectivity networks
- J. Cogn. Neurosci
, 2011
"... ■ An increasingly large number of neuroimaging studies have investigated functionally connected networks during rest, provid-ing insight into human brain architecture. Assessment of the func-tional qualities of resting state networks has been limited by the task-independent state, which results in a ..."
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Cited by 38 (3 self)
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■ An increasingly large number of neuroimaging studies have investigated functionally connected networks during rest, provid-ing insight into human brain architecture. Assessment of the func-tional qualities of resting state networks has been limited by the task-independent state, which results in an inability to relate these networks to specific mental functions. However, it was recently demonstrated that similar brain networks can be extracted from resting state data and data extracted from thousands of task-based neuroimaging experiments archived in the BrainMap database. Here, we present a full functional explication of these intrinsic connectivity networks at a standard loworder decomposition using a neuroinformatics approach based on the BrainMap behavioral taxonomy as well as a stratified, data-driven ordering of cognitive processes. Our results serve as a resource for functional interpreta-tions of brain networks in resting state studies and future inves-tigations into mental operations and the tasks that drive them. ■
Source monitoring 15 years later: What have we learned from fMRI about the neural mechanisms of source memory
- Psychological Bulletin
, 2009
"... Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic ..."
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Cited by 36 (3 self)
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Focusing primarily on functional magnetic resonance imaging (fMRI), this article reviews evidence regarding the roles of subregions of the medial temporal lobes, prefrontal cortex, posterior representational areas, and parietal cortex in source memory. In addition to evidence from standard episodic memory tasks assessing accuracy for neutral information, the article considers studies assessing the qualitative characteristics of memories, the encoding and remembering of emotional information, and false memories, as well as evidence from populations that show disrupted source memory (older adults, individuals with depression, posttraumatic stress disorder, or schizophrenia). Although there is still substantial work to be done, fMRI is advancing understanding of source memory and highlighting unresolved issues. A continued 2-way interaction between cognitive theory, as illustrated by the source monitoring framework (M. K. Johnson, S. Hashtroudi, & D. S. Lindsay, 1993), and evidence from cognitive neuroimaging studies should clarify conceptualization of cognitive processes (e.g., feature binding, retrieval, monitoring), prior knowledge (e.g., semantics, schemas), and specific features (e.g., perceptual and emotional information) and of how they combine to create true and false memories.
Spatial cognition and the hippocampus: The anterior–posterior axis
- Journal of cognitive neuroscience
, 2013
"... All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately. ..."
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Cited by 6 (0 self)
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All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.
EXPLORING FUNCTIONAL CONNECTIVITY IN FMRI VIA CLUSTERING
, 2009
"... In this paper we investigate the use of data driven clustering methods for functional connectivity analysis in fMRI. In particular, we consider the K-Means and Spectral Clustering algorithms as alternatives to the commonly used Seed-Based Analysis. To enable clustering of the entire brain volume, we ..."
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Cited by 4 (1 self)
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In this paper we investigate the use of data driven clustering methods for functional connectivity analysis in fMRI. In particular, we consider the K-Means and Spectral Clustering algorithms as alternatives to the commonly used Seed-Based Analysis. To enable clustering of the entire brain volume, we use the Nyström Method to approximate the necessary spectral decompositions. We apply K-Means, Spectral Clustering and Seed-Based Analysis to resting-state fMRI data collected from 45 healthy young adults. Without placing any a priori constraints, both clustering methods yield partitions that are associated with brain systems previously identified via Seed-Based Analysis. Our empirical results suggest that clustering provides a valuable tool for functional connectivity analysis.
Ventral fronto-temporal pathway supporting cognitive control of episodic memory retrieval
- Cereb. Cortex , http://dx.doi.org/ E.M. Aminoff et al. / Neuropsychologia
, 2013
"... Achieving our goals often requires guiding access to relevant information from memory. Such goal-directed retrieval requires inter-actions between systems supporting cognitive control, including ven-trolateral prefrontal cortex (VLPFC), and those supporting declarative memory, such as the medial tem ..."
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Achieving our goals often requires guiding access to relevant information from memory. Such goal-directed retrieval requires inter-actions between systems supporting cognitive control, including ven-trolateral prefrontal cortex (VLPFC), and those supporting declarative memory, such as the medial temporal lobes (MTL). However, the pathways by which VLPFC interacts with MTL during retrieval are underspecified. Prior neuroanatomical evidence suggests that a polysynaptic ventral fronto-temporal pathway may support VLPFC– MTL interactions. To test this hypothesis, human participants were scanned using fMRI during performance of a source-monitoring task. The strength of source information was varied via repetition during encoding. Single encoding events should produce a weaker memory trace, thus recovering source information about these items should demand greater cognitive control. Results demonstrated that cortical targets along the ventral path—anterior VLPFC, temporal pole, anterior parahippocampus, and hippocampus—exhibited in-creases in univariate BOLD response correlated with increases in controlled retrieval demand, independent of factors related to response selection. Further, a functional connectivity analysis indi-cated that these regions functionally couple and are distinguishable from a dorsal pathway related to response selection demands. These data support a ventral retrieval pathway linking PFC and MTL.
Spatial Patterns and Functional Profiles for Discovering Structure in fMRI Data
, 2008
"... We explore unsupervised, hypothesis-free methods for fMRI analysis in two different types of experiments. First, we employ clustering to identify large-scale functionally homogeneous systems. We formulate a generative mixture model, derive the EM algorithm and apply it to delineate functional syste ..."
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Cited by 2 (0 self)
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We explore unsupervised, hypothesis-free methods for fMRI analysis in two different types of experiments. First, we employ clustering to identify large-scale functionally homogeneous systems. We formulate a generative mixture model, derive the EM algorithm and apply it to delineate functional systems. We also investigate spectral clustering in application to this problem and demonstrate that both methods give rise to similar partitions of the brain based on resting state fMRI data. Second, we demonstrate how to extend this approach to include information about the experimental protocol. Specifically, we formulate a mixture model in the space of possible profiles of brain response to stimuli. In both applications, our methods confirm previously known results in brain mapping and point to new research directions for exploratory analysis of fMRI data.
A Differentiation Account of Recognition Memory: Evidence from fMRI
"... ■ Differentiation models of recognition memory predict a strength-based mirror effect in the distributions of subjective memory strength. Subjective memory strength should increase for targets and simultaneously decrease for foils following a strongly encoded list compared with a weakly encoded list ..."
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■ Differentiation models of recognition memory predict a strength-based mirror effect in the distributions of subjective memory strength. Subjective memory strength should increase for targets and simultaneously decrease for foils following a strongly encoded list compared with a weakly encoded list. An alternative explanation for the strength-based mirror effect is that participants adopt a stricter criterion following a strong list than a weak list. Behavioral experiments support the differentiation
REVIEW
"... In vivo and in vitro studies establishing haptoglobin as a major susceptibility gene for diabetic vascular disease ..."
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In vivo and in vitro studies establishing haptoglobin as a major susceptibility gene for diabetic vascular disease
Hemispheric asymmetry of visual scene processing in the human brain: evidence from repetition priming and intrinsic activity
- Cereb. Cortex
, 2012
"... Asymmetrical specialization of cognitive processes across the cerebral hemispheres is a hallmark of healthy brain development and an important evolutionary trait underlying higher cognition in humans. While previous research, including studies of priming, divided visual field presentation, and split ..."
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Asymmetrical specialization of cognitive processes across the cerebral hemispheres is a hallmark of healthy brain development and an important evolutionary trait underlying higher cognition in humans. While previous research, including studies of priming, divided visual field presentation, and split-brain patients, demon-strates a general pattern of right/left asymmetry of form-specific versus form-abstract visual processing, little is known about brain organization underlying this dissociation. Here, using repetition priming of complex visual scenes and high-resolution functional magnetic resonance imaging (MRI), we demonstrate asymmetrical form specificity of visual processing between the right and left hemispheres within a region known to be critical for processing of visual spatial scenes (parahippocampal place area [PPA]). Next, we use resting-state functional connectivity MRI analyses to demonstrate that this functional asymmetry is associated with
Reduced Anterior Temporal and Hippocampal Functional Connectivity During Face Processing Discriminates Individuals with Social Anxiety Disorder from Healthy Controls and Panic Disorder, and Increases Following Treatment
"... Group functional magnetic resonance imaging (fMRI) studies suggest that anxiety disorders are associated with anomalous brain activation and functional connectivity (FC). However, brain-based features sensitive enough to discriminate individual subjects with a specific anxiety disorder and that trac ..."
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Group functional magnetic resonance imaging (fMRI) studies suggest that anxiety disorders are associated with anomalous brain activation and functional connectivity (FC). However, brain-based features sensitive enough to discriminate individual subjects with a specific anxiety disorder and that track symptom severity longitudinally, desirable qualities for putative disorder-specific biomarkers, remain to be identified. Blood oxygen level-dependent (BOLD) fMRI during emotional face perceptual tasks and a new, large-scale and condition-dependent FC and machine learning approach were used to identify features (pair-wise correlations) that discriminated patients with social anxiety disorder (SAD, N 16) from controls (N 19). We assessed whether these features discriminated SAD from panic disorder (PD, N 16), and SAD from controls in an independent replication sample that performed a similar task at baseline (N: SAD 15, controls 17) and following 8-weeks paroxetine treatment (N: SAD 12, untreated controls 7). High SAD vs HCs discrimination (area under the ROC curve, AUC, arithmetic mean of sensitivity and specificity) was achieved with two FC features during unattended neutral face perception (AUC 0.88, Po0.05 corrected). These features also discriminated SAD vs PD (AUC 0.82, P 0.0001) and SAD vs HCs in the independent replication sample (FC during unattended angry face perception, AUC 0.71, P 0.01). The most informative FC was left hippocampus-left temporal pole, which was reduced in both SAD samples (replication
