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1.
Nature ; 632(8023): 131-138, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39020167

RESUMO

A single dose of psilocybin, a psychedelic that acutely causes distortions of space-time perception and ego dissolution, produces rapid and persistent therapeutic effects in human clinical trials1-4. In animal models, psilocybin induces neuroplasticity in cortex and hippocampus5-8. It remains unclear how human brain network changes relate to subjective and lasting effects of psychedelics. Here we tracked individual-specific brain changes with longitudinal precision functional mapping (roughly 18 magnetic resonance imaging visits per participant). Healthy adults were tracked before, during and for 3 weeks after high-dose psilocybin (25 mg) and methylphenidate (40 mg), and brought back for an additional psilocybin dose 6-12 months later. Psilocybin massively disrupted functional connectivity (FC) in cortex and subcortex, acutely causing more than threefold greater change than methylphenidate. These FC changes were driven by brain desynchronization across spatial scales (areal, global), which dissolved network distinctions by reducing correlations within and anticorrelations between networks. Psilocybin-driven FC changes were strongest in the default mode network, which is connected to the anterior hippocampus and is thought to create our sense of space, time and self. Individual differences in FC changes were strongly linked to the subjective psychedelic experience. Performing a perceptual task reduced psilocybin-driven FC changes. Psilocybin caused persistent decrease in FC between the anterior hippocampus and default mode network, lasting for weeks. Persistent reduction of hippocampal-default mode network connectivity may represent a neuroanatomical and mechanistic correlate of the proplasticity and therapeutic effects of psychedelics.


Assuntos
Encéfalo , Alucinógenos , Rede Nervosa , Psilocibina , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Encéfalo/citologia , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Mapeamento Encefálico , Rede de Modo Padrão/citologia , Rede de Modo Padrão/diagnóstico por imagem , Rede de Modo Padrão/efeitos dos fármacos , Rede de Modo Padrão/fisiologia , Alucinógenos/farmacologia , Alucinógenos/administração & dosagem , Voluntários Saudáveis , Hipocampo/citologia , Hipocampo/diagnóstico por imagem , Hipocampo/efeitos dos fármacos , Hipocampo/fisiologia , Imageamento por Ressonância Magnética , Metilfenidato/farmacologia , Metilfenidato/administração & dosagem , Rede Nervosa/citologia , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/fisiologia , Psilocibina/farmacologia , Psilocibina/administração & dosagem , Percepção Espacial/efeitos dos fármacos , Percepção do Tempo/efeitos dos fármacos , Ego
2.
Nature ; 617(7960): 351-359, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37076628

RESUMO

Motor cortex (M1) has been thought to form a continuous somatotopic homunculus extending down the precentral gyrus from foot to face representations1,2, despite evidence for concentric functional zones3 and maps of complex actions4. Here, using precision functional magnetic resonance imaging (fMRI) methods, we find that the classic homunculus is interrupted by regions with distinct connectivity, structure and function, alternating with effector-specific (foot, hand and mouth) areas. These inter-effector regions exhibit decreased cortical thickness and strong functional connectivity to each other, as well as to the cingulo-opercular network (CON), critical for action5 and physiological control6, arousal7, errors8 and pain9. This interdigitation of action control-linked and motor effector regions was verified in the three largest fMRI datasets. Macaque and pediatric (newborn, infant and child) precision fMRI suggested cross-species homologues and developmental precursors of the inter-effector system. A battery of motor and action fMRI tasks documented concentric effector somatotopies, separated by the CON-linked inter-effector regions. The inter-effectors lacked movement specificity and co-activated during action planning (coordination of hands and feet) and axial body movement (such as of the abdomen or eyebrows). These results, together with previous studies demonstrating stimulation-evoked complex actions4 and connectivity to internal organs10 such as the adrenal medulla, suggest that M1 is punctuated by a system for whole-body action planning, the somato-cognitive action network (SCAN). In M1, two parallel systems intertwine, forming an integrate-isolate pattern: effector-specific regions (foot, hand and mouth) for isolating fine motor control and the SCAN for integrating goals, physiology and body movement.


Assuntos
Mapeamento Encefálico , Cognição , Córtex Motor , Mapeamento Encefálico/métodos , Mãos/fisiologia , Imageamento por Ressonância Magnética , Córtex Motor/anatomia & histologia , Córtex Motor/fisiologia , Humanos , Recém-Nascido , Lactente , Criança , Animais , Macaca/anatomia & histologia , Macaca/fisiologia , Pé/fisiologia , Boca/fisiologia , Conjuntos de Dados como Assunto
3.
Nature ; 603(7902): 654-660, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35296861

RESUMO

Magnetic resonance imaging (MRI) has transformed our understanding of the human brain through well-replicated mapping of abilities to specific structures (for example, lesion studies) and functions1-3 (for example, task functional MRI (fMRI)). Mental health research and care have yet to realize similar advances from MRI. A primary challenge has been replicating associations between inter-individual differences in brain structure or function and complex cognitive or mental health phenotypes (brain-wide association studies (BWAS)). Such BWAS have typically relied on sample sizes appropriate for classical brain mapping4 (the median neuroimaging study sample size is about 25), but potentially too small for capturing reproducible brain-behavioural phenotype associations5,6. Here we used three of the largest neuroimaging datasets currently available-with a total sample size of around 50,000 individuals-to quantify BWAS effect sizes and reproducibility as a function of sample size. BWAS associations were smaller than previously thought, resulting in statistically underpowered studies, inflated effect sizes and replication failures at typical sample sizes. As sample sizes grew into the thousands, replication rates began to improve and effect size inflation decreased. More robust BWAS effects were detected for functional MRI (versus structural), cognitive tests (versus mental health questionnaires) and multivariate methods (versus univariate). Smaller than expected brain-phenotype associations and variability across population subsamples can explain widespread BWAS replication failures. In contrast to non-BWAS approaches with larger effects (for example, lesions, interventions and within-person), BWAS reproducibility requires samples with thousands of individuals.


Assuntos
Mapeamento Encefálico , Encéfalo , Imageamento por Ressonância Magnética , Mapeamento Encefálico/métodos , Cognição , Conjuntos de Dados como Assunto , Humanos , Imageamento por Ressonância Magnética/métodos , Neuroimagem , Fenótipo , Reprodutibilidade dos Testes
4.
Cereb Cortex ; 34(9)2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39277800

RESUMO

Structural connectivity (SC) between distant regions of the brain support synchronized function known as functional connectivity (FC) and give rise to the large-scale brain networks that enable cognition and behavior. Understanding how SC enables FC is important to understand how injuries to SC may alter brain function and cognition. Previous work evaluating whole-brain SC-FC relationships showed that SC explained FC well in unimodal visual and motor areas, but only weakly in association areas, suggesting a unimodal-heteromodal gradient organization of SC-FC coupling. However, this work was conducted in group-averaged SC/FC data. Thus, it could not account for inter-individual variability in the locations of cortical areas and white matter tracts. We evaluated the correspondence of SC and FC within three highly sampled healthy participants. For each participant, we collected 78 min of diffusion-weighted MRI for SC and 360 min of resting state fMRI for FC. We found that FC was best explained by SC in visual and motor systems, as well as in anterior and posterior cingulate regions. A unimodal-to-heteromodal gradient could not fully explain SC-FC coupling. We conclude that the SC-FC coupling of the anterior-posterior cingulate circuit is more similar to unimodal areas than to heteromodal areas.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Vias Neurais , Humanos , Masculino , Encéfalo/fisiologia , Encéfalo/diagnóstico por imagem , Adulto , Feminino , Imageamento por Ressonância Magnética/métodos , Vias Neurais/fisiologia , Vias Neurais/diagnóstico por imagem , Mapeamento Encefálico/métodos , Adulto Jovem , Imagem de Difusão por Ressonância Magnética , Descanso/fisiologia , Substância Branca/fisiologia , Substância Branca/diagnóstico por imagem
5.
Cereb Cortex ; 34(2)2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38372292

RESUMO

The cerebral cortex is organized into distinct but interconnected cortical areas, which can be defined by abrupt differences in patterns of resting state functional connectivity (FC) across the cortical surface. Such parcellations of the cortex have been derived in adults and older infants, but there is no widely used surface parcellation available for the neonatal brain. Here, we first demonstrate that existing parcellations, including surface-based parcels derived from older samples as well as volume-based neonatal parcels, are a poor fit for neonatal surface data. We next derive a set of 283 cortical surface parcels from a sample of n = 261 neonates. These parcels have highly homogenous FC patterns and are validated using three external neonatal datasets. The Infomap algorithm is used to assign functional network identities to each parcel, and derived networks are consistent with prior work in neonates. The proposed parcellation may represent neonatal cortical areas and provides a powerful tool for neonatal neuroimaging studies.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Adulto , Recém-Nascido , Humanos , Imageamento por Ressonância Magnética/métodos , Neuroimagem , Córtex Cerebral/diagnóstico por imagem , Algoritmos , Processamento de Imagem Assistida por Computador/métodos
7.
Cereb Cortex ; 33(15): 9250-9262, 2023 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-37293735

RESUMO

The thalamus is a critical relay center for neural pathways involving sensory, motor, and cognitive functions, including cortico-striato-thalamo-cortical and cortico-ponto-cerebello-thalamo-cortical loops. Despite the importance of these circuits, their development has been understudied. One way to investigate these pathways in human development in vivo is with functional connectivity MRI, yet few studies have examined thalamo-cortical and cerebello-cortical functional connectivity in development. Here, we used resting-state functional connectivity to measure functional connectivity in the thalamus and cerebellum with previously defined cortical functional networks in 2 separate data sets of children (7-12 years old) and adults (19-40 years old). In both data sets, we found stronger functional connectivity between the ventral thalamus and the somatomotor face cortical functional network in children compared with adults, extending previous cortico-striatal functional connectivity findings. In addition, there was more cortical network integration (i.e. strongest functional connectivity with multiple networks) in the thalamus in children than in adults. We found no developmental differences in cerebello-cortical functional connectivity. Together, these results suggest different maturation patterns in cortico-striato-thalamo-cortical and cortico-ponto-cerebellar-thalamo-cortical pathways.


Assuntos
Cerebelo , Imageamento por Ressonância Magnética , Adulto , Criança , Humanos , Adulto Jovem , Cerebelo/diagnóstico por imagem , Vias Neurais/diagnóstico por imagem , Tálamo/diagnóstico por imagem , Corpo Estriado
8.
Proc Natl Acad Sci U S A ; 118(13)2021 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-33753484

RESUMO

Whole-brain resting-state functional MRI (rs-fMRI) during 2 wk of upper-limb casting revealed that disused motor regions became more strongly connected to the cingulo-opercular network (CON), an executive control network that includes regions of the dorsal anterior cingulate cortex (dACC) and insula. Disuse-driven increases in functional connectivity (FC) were specific to the CON and somatomotor networks and did not involve any other networks, such as the salience, frontoparietal, or default mode networks. Censoring and modeling analyses showed that FC increases during casting were mediated by large, spontaneous activity pulses that appeared in the disused motor regions and CON control regions. During limb constraint, disused motor circuits appear to enter a standby mode characterized by spontaneous activity pulses and strengthened connectivity to CON executive control regions.


Assuntos
Giro do Cíngulo/fisiologia , Plasticidade Neuronal/fisiologia , Descanso/fisiologia , Adulto , Mapeamento Encefálico , Função Executiva/fisiologia , Feminino , Giro do Cíngulo/citologia , Giro do Cíngulo/diagnóstico por imagem , Voluntários Saudáveis , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/fisiologia
9.
Proc Natl Acad Sci U S A ; 118(34)2021 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34404728

RESUMO

The hippocampus is critically important for a diverse range of cognitive processes, such as episodic memory, prospective memory, affective processing, and spatial navigation. Using individual-specific precision functional mapping of resting-state functional MRI data, we found the anterior hippocampus (head and body) to be preferentially functionally connected to the default mode network (DMN), as expected. The hippocampal tail, however, was strongly preferentially functionally connected to the parietal memory network (PMN), which supports goal-oriented cognition and stimulus recognition. This anterior-posterior dichotomy of resting-state functional connectivity was well-matched by differences in task deactivations and anatomical segmentations of the hippocampus. Task deactivations were localized to the hippocampal head and body (DMN), relatively sparing the tail (PMN). The functional dichotomization of the hippocampus into anterior DMN-connected and posterior PMN-connected parcels suggests parallel but distinct circuits between the hippocampus and medial parietal cortex for self- versus goal-oriented processing.


Assuntos
Mapeamento Encefálico , Hipocampo/fisiologia , Rede Nervosa/fisiologia , Lobo Parietal/fisiologia , Adulto , Bases de Dados Factuais , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Memória Episódica , Vias Neurais , Análise e Desempenho de Tarefas , Adulto Jovem
11.
Cereb Cortex ; 32(13): 2868-2884, 2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-34718460

RESUMO

The striatum and cerebral cortex are interconnected via multiple recurrent loops that play a major role in many neuropsychiatric conditions. Primate corticostriatal connections can be precisely mapped using invasive tract-tracing. However, noninvasive human research has not mapped these connections with anatomical precision, limited in part by the practice of averaging neuroimaging data across individuals. Here we utilized highly sampled resting-state functional connectivity MRI for individual-specific precision functional mapping (PFM) of corticostriatal connections. We identified ten individual-specific subnetworks linking cortex-predominately frontal cortex-to striatum, most of which converged with nonhuman primate tract-tracing work. These included separable connections between nucleus accumbens core/shell and orbitofrontal/medial frontal gyrus; between anterior striatum and dorsomedial prefrontal cortex; between dorsal caudate and lateral prefrontal cortex; and between middle/posterior putamen and supplementary motor/primary motor cortex. Two subnetworks that did not converge with nonhuman primates were connected to cortical regions associated with human language function. Thus, precision subnetworks identify detailed, individual-specific, neurobiologically plausible corticostriatal connectivity that includes human-specific language networks.


Assuntos
Corpo Estriado , Córtex Motor , Animais , Mapeamento Encefálico/métodos , Corpo Estriado/diagnóstico por imagem , Lobo Frontal/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Vias Neurais/diagnóstico por imagem , Núcleo Accumbens , Córtex Pré-Frontal/diagnóstico por imagem , Putamen
12.
Proc Natl Acad Sci U S A ; 117(29): 17308-17319, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32632019

RESUMO

The human brain is organized into large-scale networks identifiable using resting-state functional connectivity (RSFC). These functional networks correspond with broad cognitive domains; for example, the Default-mode network (DMN) is engaged during internally oriented cognition. However, functional networks may contain hierarchical substructures corresponding with more specific cognitive functions. Here, we used individual-specific precision RSFC to test whether network substructures could be identified in 10 healthy human brains. Across all subjects and networks, individualized network subdivisions were more valid-more internally homogeneous and better matching spatial patterns of task activation-than canonical networks. These measures of validity were maximized at a hierarchical scale that contained ∼83 subnetworks across the brain. At this scale, nine DMN subnetworks exhibited topographical similarity across subjects, suggesting that this approach identifies homologous neurobiological circuits across individuals. Some DMN subnetworks matched known features of brain organization corresponding with cognitive functions. Other subnetworks represented separate streams by which DMN couples with other canonical large-scale networks, including language and control networks. Together, this work provides a detailed organizational framework for studying the DMN in individual humans.


Assuntos
Encéfalo/fisiologia , Idioma , Rede Nervosa/fisiologia , Adulto , Mapeamento Encefálico , Cognição , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
13.
Proc Natl Acad Sci U S A ; 117(7): 3808-3818, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32015137

RESUMO

The amygdala is central to the pathophysiology of many psychiatric illnesses. An imprecise understanding of how the amygdala fits into the larger network organization of the human brain, however, limits our ability to create models of dysfunction in individual patients to guide personalized treatment. Therefore, we investigated the position of the amygdala and its functional subdivisions within the network organization of the brain in 10 highly sampled individuals (5 h of fMRI data per person). We characterized three functional subdivisions within the amygdala of each individual. We discovered that one subdivision is preferentially correlated with the default mode network; a second is preferentially correlated with the dorsal attention and fronto-parietal networks; and third subdivision does not have any networks to which it is preferentially correlated relative to the other two subdivisions. All three subdivisions are positively correlated with ventral attention and somatomotor networks and negatively correlated with salience and cingulo-opercular networks. These observations were replicated in an independent group dataset of 120 individuals. We also found substantial across-subject variation in the distribution and magnitude of amygdala functional connectivity with the cerebral cortex that related to individual differences in the stereotactic locations both of amygdala subdivisions and of cortical functional brain networks. Finally, using lag analyses, we found consistent temporal ordering of fMRI signals in the cortex relative to amygdala subdivisions. Altogether, this work provides a detailed framework of amygdala-cortical interactions that can be used as a foundation for models relating aberrations in amygdala connectivity to psychiatric symptoms in individual patients.


Assuntos
Tonsila do Cerebelo/fisiologia , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Atenção , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Mapeamento Encefálico , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Feminino , Humanos , Individualidade , Imageamento por Ressonância Magnética , Masculino , Psiquiatria , Adulto Jovem
14.
Neuroimage ; 254: 119138, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35339687

RESUMO

Diffusion imaging aims to non-invasively characterize the anatomy and integrity of the brain's white matter fibers. We evaluated the accuracy and reliability of commonly used diffusion imaging methods as a function of data quantity and analysis method, using both simulations and highly sampled individual-specific data (927-1442 diffusion weighted images [DWIs] per individual). Diffusion imaging methods that allow for crossing fibers (FSL's BedpostX [BPX], DSI Studio's Constant Solid Angle Q-Ball Imaging [CSA-QBI], MRtrix3's Constrained Spherical Deconvolution [CSD]) estimated excess fibers when insufficient data were present and/or when the data did not match the model priors. To reduce such overfitting, we developed a novel Bayesian Multi-tensor Model-selection (BaMM) method and applied it to the popular ball-and-stick model used in BedpostX within the FSL software package. BaMM was robust to overfitting and showed high reliability and the relatively best crossing-fiber accuracy with increasing amounts of diffusion data. Thus, sufficient data and an overfitting resistant analysis method enhance precision diffusion imaging. For potential clinical applications of diffusion imaging, such as neurosurgical planning and deep brain stimulation (DBS), the quantities of data required to achieve diffusion imaging reliability are lower than those needed for functional MRI.


Assuntos
Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Algoritmos , Teorema de Bayes , Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Difusão , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Humanos , Reprodutibilidade dos Testes
15.
Proc Natl Acad Sci U S A ; 116(45): 22851-22861, 2019 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-31611415

RESUMO

Resting-state functional magnetic resonance imaging (fMRI) has provided converging descriptions of group-level functional brain organization. Recent work has revealed that functional networks identified in individuals contain local features that differ from the group-level description. We define these features as network variants. Building on these studies, we ask whether distributions of network variants reflect stable, trait-like differences in brain organization. Across several datasets of highly-sampled individuals we show that 1) variants are highly stable within individuals, 2) variants are found in characteristic locations and associate with characteristic functional networks across large groups, 3) task-evoked signals in variants demonstrate a link to functional variation, and 4) individuals cluster into subgroups on the basis of variant characteristics that are related to differences in behavior. These results suggest that distributions of network variants may reflect stable, trait-like, functionally relevant individual differences in functional brain organization.


Assuntos
Encéfalo/fisiologia , Mapeamento Encefálico/métodos , Humanos , Imageamento por Ressonância Magnética , Vias Neurais/fisiologia
16.
Cereb Cortex ; 30(3): 1716-1734, 2020 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-31504262

RESUMO

Spontaneous infra-slow (<0.1 Hz) fluctuations in functional magnetic resonance imaging (fMRI) signals are temporally correlated within large-scale functional brain networks, motivating their use for mapping systems-level brain organization. However, recent electrophysiological and hemodynamic evidence suggest state-dependent propagation of infra-slow fluctuations, implying a functional role for ongoing infra-slow activity. Crucially, the study of infra-slow temporal lag structure has thus far been limited to large groups, as analyzing propagation delays requires extensive data averaging to overcome sampling variability. Here, we use resting-state fMRI data from 11 extensively-sampled individuals to characterize lag structure at the individual level. In addition to stable individual-specific features, we find spatiotemporal topographies in each subject similar to the group average. Notably, we find a set of early regions that are common to all individuals, are preferentially positioned proximal to multiple functional networks, and overlap with brain regions known to respond to diverse behavioral tasks-altogether consistent with a hypothesized ability to broadly influence cortical excitability. Our findings suggest that, like correlation structure, temporal lag structure is a fundamental organizational property of resting-state infra-slow activity.


Assuntos
Encéfalo/fisiologia , Hemodinâmica/fisiologia , Rede Nervosa/fisiologia , Descanso/fisiologia , Mapeamento Encefálico/métodos , Eletroencefalografia/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Fenômenos Fisiológicos do Sistema Nervoso
17.
Neuroimage ; 217: 116866, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32325210

RESUMO

Denoising fMRI data requires assessment of frame-to-frame head motion and removal of the biases motion introduces. This is usually done through analysis of the parameters calculated during retrospective head motion correction (i.e., 'motion' parameters). However, it is increasingly recognized that respiration introduces factitious head motion via perturbations of the main (B0) field. This effect appears as higher-frequency fluctuations in the motion parameters (>0.1 â€‹Hz, here referred to as 'HF-motion'), primarily in the phase-encoding direction. This periodicity can sometimes be obscured in standard single-band fMRI (TR 2.0-2.5 â€‹s) due to aliasing. Here we examined (1) how prevalent HF-motion effects are in seven single-band datasets with TR from 2.0 to 2.5 â€‹s and (2) how HF-motion affects functional connectivity. We demonstrate that HF-motion is more common in older adults, those with higher body mass index, and those with lower cardiorespiratory fitness. We propose a low-pass filtering approach to remove the contamination of high frequency effects from motion summary measures, such as framewise displacement (FD). We demonstrate that in most datasets this filtering approach saves a substantial amount of data from FD-based frame censoring, while at the same time reducing motion biases in functional connectivity measures. These findings suggest that filtering motion parameters is an effective way to improve the fidelity of head motion estimates, even in single band datasets. Particularly large data savings may accrue in datasets acquired in older and less fit participants.


Assuntos
Artefatos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Movimento (Física) , Vias Neurais/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Índice de Massa Corporal , Mapeamento Encefálico , Criança , Bases de Dados Factuais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiologia , Oxigênio/sangue , Aptidão Física , Estudos Retrospectivos , Adulto Jovem
18.
Neuroimage ; 208: 116400, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31778819

RESUMO

Head motion represents one of the greatest technical obstacles in magnetic resonance imaging (MRI) of the human brain. Accurate detection of artifacts induced by head motion requires precise estimation of movement. However, head motion estimates may be corrupted by artifacts due to magnetic main field fluctuations generated by body motion. In the current report, we examine head motion estimation in multiband resting state functional connectivity MRI (rs-fcMRI) data from the Adolescent Brain and Cognitive Development (ABCD) Study and comparison 'single-shot' datasets. We show that respirations contaminate movement estimates in functional MRI and that respiration generates apparent head motion not associated with functional MRI quality reductions. We have developed a novel approach using a band-stop filter that accurately removes these respiratory effects from motion estimates. Subsequently, we demonstrate that utilizing a band-stop filter improves post-processing fMRI data quality. Lastly, we demonstrate the real-time implementation of motion estimate filtering in our FIRMM (Framewise Integrated Real-Time MRI Monitoring) software package.


Assuntos
Artefatos , Neuroimagem Funcional/normas , Movimentos da Cabeça , Imageamento por Ressonância Magnética/normas , Respiração , Adolescente , Criança , Feminino , Humanos , Masculino
19.
Neuroimage ; 199: 427-439, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31175969

RESUMO

fMRI studies of human memory have identified a "parietal memory network" (PMN) that displays distinct responses to novel and familiar stimuli, typically deactivating during initial encoding but robustly activating during retrieval. The small size of PMN regions, combined with their proximity to the neighboring default mode network, makes a targeted assessment of their responses in highly sampled subjects important for understanding information processing within the network. Here, we describe an experiment in which participants made semantic decisions about repeatedly-presented stimuli, assessing PMN BOLD responses as items transitioned from experimentally novel to repeated. Data are from the highly-sampled subjects in the Midnight Scan Club dataset, enabling a characterization of BOLD responses at both the group and single-subject level. Across all analyses, PMN regions deactivated in response to novel stimuli and displayed changes in BOLD activity across presentations, but did not significantly activate to repeated items. Results support only a portion of initially hypothesized effects, in particular suggesting that novelty-related deactivations may be less susceptible to attentional/task manipulations than are repetition-related activations within the network. This in turn suggests that novelty and familiarity may be processed as separable entities within the PMN.


Assuntos
Mapeamento Encefálico/métodos , Rememoração Mental/fisiologia , Rede Nervosa/fisiologia , Lobo Parietal/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto , Reconhecimento Facial/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Lobo Parietal/diagnóstico por imagem , Adulto Jovem
20.
Hum Brain Mapp ; 40(2): 361-376, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30251766

RESUMO

Neuroimaging studies have implicated a set of striatal and orbitofrontal cortex (OFC) regions that are commonly activated during reward processing tasks. Resting-state functional connectivity (RSFC) studies have demonstrated that the human brain is organized into several functional systems that show strong temporal coherence in the absence of goal-directed tasks. Here we use seed-based and graph-theory RSFC approaches to characterize the systems-level organization of putative reward regions of at rest. Peaks of connectivity from seed-based RSFC patterns for the nucleus accumbens (NAcc) and orbitofrontal cortex (OFC) were used to identify candidate reward regions which were merged with a previously used set of regions (Power et al., 2011). Graph-theory was then used to determine system-level membership for all regions. Several regions previously implicated in reward-processing (NAcc, lateral and medial OFC, and ventromedial prefrontal cortex) comprised a distinct, preferentially coupled system. This RSFC system is stable across a range of connectivity thresholds and shares strong overlap with meta-analyses of task-based reward studies. This reward system shares between-system connectivity with systems implicated in cognitive control and self-regulation, including the fronto-parietal, cingulo-opercular, and default systems. Differences may exist in the pathways through which control systems interact with reward system components. Whereas NAcc is functionally connected to cingulo-opercular and default systems, OFC regions show stronger connectivity with the fronto-parietal system. We propose that future work may be able to interrogate group or individual differences in connectivity profiles using the regions delineated in this work to explore potential relationships to appetitive behaviors, self-regulation failure, and addiction.


Assuntos
Conectoma , Rede Nervosa/fisiologia , Núcleo Accumbens/fisiologia , Córtex Pré-Frontal/fisiologia , Recompensa , Autocontrole , Adolescente , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Núcleo Accumbens/diagnóstico por imagem , Córtex Pré-Frontal/diagnóstico por imagem , Adulto Jovem
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