Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Cir Esp ; 101(2): 90-96, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35169328

RESUMO

Introduction: Treatment of patients with Coronavirus Disease 2019 (COVID-19) has affected the management of patients with colorectal cancer (CRC). The aim of this study was to compare the diagnosis delay, symptoms, and stage of patients with CRC during the pandemic with a control cohort. Material and methods: Patients referred to the CRC multidisciplinary team between September 2019 and January 2020 (cohort 1, control group) were compared with those who presented between September 2020 and March 2021 (cohort 2, pandemic group). Results: 389 patients were included, 169 in cohort 1 and 220 in cohort 2. No differences were observed in the main characteristics of the patients. CRC screening and anaemia were the most common causes leading to the diagnosis of the tumour in cohort 1 and 2, respectively (p < 0.001). Diagnostic and therapeutic delay was longer in cohort 2 [6.4 (95% CI 5.8-6.9) vs. 4.8 (95% CI 4.3-5.3) months, p < 0.001]. More patients required non-elective treatment in the pandemic cohort (15.5% vs. 9.5%, p = 0.080). The tumour stage was more advanced in patients in cohort 2 [positive nodes in 52.3% vs. 36.7% (p = 0.002), and metastatic disease in 23.6% vs. 16.6% (p = 0.087)]. Conclusion: CRC patients in the pandemic cohort had a longer diagnostic and therapeutic delay and less patients were diagnosed because of CRC screening. In addition, patients with CRC during the pandemic needed non-elective treatment more frequently than patients in the control cohort, and their tumour stage tended to be more advanced.


Introducción: La pandemia de la enfermedad por coronavirus 2019 ha afectado al manejo de los pacientes con cáncer colorrectal (CCR). El objetivo de este estudio fue comparar el retraso diagnóstico, la sintomatología y el estadio de los pacientes con CCR durante la pandemia con una cohorte histórica. Material y métodos: Los pacientes valorados en el comité multidisciplinar de CCR entre septiembre de 2019 y enero de 2020 (cohorte 1) se compararon con los presentados entre septiembre de 2020 y marzo de 2021 (cohorte 2). Resultados: Trescientos ochenta y nueve pacientes fueron incluidos, 169 en la cohorte 1 y 220 en la cohorte 2. El cribado del CCR y la anemia fueron las causas que llevaron al diagnóstico en más pacientes en la cohorte 1 y 2, respectivamente (p < 0,001). El retraso diagnóstico y terapéutico fue mayor en la cohorte 2 (6,4 [IC 95%: 5,8-6,9] vs. 4,8 [IC 95%: 4,3-5,3] meses, p < 0,001). En la cohorte pandémica hubo más pacientes que requirieron tratamiento urgente (15,5% vs. 9,5%, p = 0,080). El estadio tumoral fue más avanzado en la cohorte 2 (ganglios positivos en el 52,3% vs. 36,7% [p = 0,002] y enfermedad metastásica en el 23,6% vs. 16,6% [p = 0,087]). Conclusión: Los pacientes con CCR en la cohorte pandémica tenían un retraso diagnóstico y terapéutico más largo, y menos pacientes fueron diagnosticados en el cribado de CCR. Además, los pacientes con CCR durante la pandemia necesitaron tratamiento urgente con más frecuencia y su estadio tumoral fue más avanzado.

2.
J Neurosci ; 41(9): 1952-1969, 2021 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-33452225

RESUMO

Faces of different people elicit distinct fMRI patterns in several face-selective regions of the human brain. Here we used representational similarity analysis to investigate what type of identity-distinguishing information is encoded in three face-selective regions: fusiform face area (FFA), occipital face area (OFA), and posterior superior temporal sulcus (pSTS). In a sample of 30 human participants (22 females, 8 males), we used fMRI to measure brain activity patterns elicited by naturalistic videos of famous face identities, and compared their representational distances in each region with models of the differences between identities. We built diverse candidate models, ranging from low-level image-computable properties (pixel-wise, GIST, and Gabor-Jet dissimilarities), through higher-level image-computable descriptions (OpenFace deep neural network, trained to cluster faces by identity), to complex human-rated properties (perceived similarity, social traits, and gender). We found marked differences in the information represented by the FFA and OFA. Dissimilarities between face identities in FFA were accounted for by differences in perceived similarity, Social Traits, Gender, and by the OpenFace network. In contrast, representational distances in OFA were mainly driven by differences in low-level image-based properties (pixel-wise and Gabor-Jet dissimilarities). Our results suggest that, although FFA and OFA can both discriminate between identities, the FFA representation is further removed from the image, encoding higher-level perceptual and social face information.SIGNIFICANCE STATEMENT Recent studies using fMRI have shown that several face-responsive brain regions can distinguish between different face identities. It is however unclear whether these different face-responsive regions distinguish between identities in similar or different ways. We used representational similarity analysis to investigate the computations within three brain regions in response to naturalistically varying videos of face identities. Our results revealed that two regions, the fusiform face area and the occipital face area, encode distinct identity information about faces. Although identity can be decoded from both regions, identity representations in fusiform face area primarily contained information about social traits, gender, and high-level visual features, whereas occipital face area primarily represented lower-level image features.


Assuntos
Encéfalo/fisiologia , Reconhecimento Facial/fisiologia , Modelos Neurológicos , Mapeamento Encefálico/métodos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino
3.
Colorectal Dis ; 24(10): 1243-1244, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35575432

RESUMO

AIM: Pudendal neuralgia is a highly disabling entity with complex diagnostic and controversial treatment results. Surgical neurolysis has been shown to be the most effective treatment. Sacral root neurostimulation or posterior tibial nerve stimulation are used to rescue patients who either have not responded to surgery or have worsened after an initial improvement. METHODS: Given the excellent visualization of the pudendal nerve during laparoscopic pudendal release, we propose to combine this procedure with neurostimulation, taking advantage of the possibility of in situ placement of the electrode. The abdominal cavity is accessed laparoscopically through four ports, and after identifying and releasing the pudendal nerve a neurostimulation electrode is placed next to the nerve and is connected to a generator located in a subcutaneous pocket. RESULTS: This procedure has been performed in one patient with a satisfactory result. CONCLUSIONS: Laparoscopic pudendal release with neurostimulator prosthesis is an experimental technique that can be promising for the treatment of pudendal neuralgia.


Assuntos
Laparoscopia , Nervo Pudendo , Neuralgia do Pudendo , Humanos , Neuralgia do Pudendo/etiologia , Neuralgia do Pudendo/cirurgia , Nervo Pudendo/cirurgia , Resultado do Tratamento , Eletrodos Implantados
4.
Int J Mol Sci ; 23(16)2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-36012612

RESUMO

Spanish fir (Abies pinsapo Boiss.) is an endemic, endangered tree that has been scarcely investigated at the molecular level. In this work, the transcriptome of Spanish fir was assembled, providing a large catalog of expressed genes (22,769), within which a high proportion were full-length transcripts (12,545). This resource is valuable for functional genomics studies and genome annotation in this relict conifer species. Two intraspecific variations of A. pinsapo can be found within its largest population at the Sierra de las Nieves National Park: one with standard green needles and another with bluish-green needles. To elucidate the causes of both phenotypes, we studied different physiological and molecular markers and transcriptome profiles in the needles. "Green" trees showed higher electron transport efficiency and enhanced levels of chlorophyll, protein, and total nitrogen in the needles. In contrast, needles from "bluish" trees exhibited higher contents of carotenoids and cellulose. These results agreed with the differential transcriptomic profiles, suggesting an imbalance in the nitrogen status of "bluish" trees. Additionally, gene expression analyses suggested that these differences could be associated with different epigenomic profiles. Taken together, the reported data provide new transcriptome resources and a better understanding of the natural variation in this tree species, which can help improve guidelines for its conservation and the implementation of adaptive management strategies under climatic change.


Assuntos
Abies , Abies/genética , Mudança Climática , Perfilação da Expressão Gênica , Nitrogênio/metabolismo , Transcriptoma/genética , Árvores/genética
5.
Neuroimage ; 201: 116004, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31299368

RESUMO

Face-selective and voice-selective brain regions have been shown to represent face-identity and voice-identity, respectively. Here we investigated whether there are modality-general person-identity representations in the brain that can be driven by either a face or a voice, and that invariantly represent naturalistically varying face videos and voice recordings of the same identity. Models of face and voice integration suggest that such representations could exist in multimodal brain regions, and in unimodal regions via direct coupling between face- and voice-selective regions. Therefore, in this study we used fMRI to measure brain activity patterns elicited by the faces and voices of familiar people in face-selective, voice-selective, and person-selective multimodal brain regions. We used representational similarity analysis to (1) compare representational geometries (i.e. representational dissimilarity matrices) of face- and voice-elicited identities, and to (2) investigate the degree to which pattern discriminants for pairs of identities generalise from one modality to the other. We did not find any evidence of similar representational geometries across modalities in any of our regions of interest. However, our results showed that pattern discriminants that were trained to discriminate pairs of identities from their faces could also discriminate the respective voices (and vice-versa) in the right posterior superior temporal sulcus (rpSTS). Our findings suggest that the rpSTS is a person-selective multimodal region that shows a modality-general person-identity representation and integrates face and voice identity information.


Assuntos
Percepção Auditiva/fisiologia , Reconhecimento Facial/fisiologia , Reconhecimento Psicológico/fisiologia , Lobo Temporal/fisiologia , Voz , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
6.
Acta Neuropathol ; 137(4): 619-635, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30663001

RESUMO

Microglia nodule formation is a common feature in inflammatory brain diseases mediated by T lymphocytes such as viral and paraneoplastic encephalitis, multiple sclerosis, and Rasmussen encephalitis (RE). However, its role has not been fully understood yet. We hypothesized that, in RE, microglial nodules provide an environment for the initiation of the later dominating T-cell cytotoxicity. In RE stage 0, small primary microglia nodules could be identified in the absence of T cells. These primary nodules showed inflammasome activation and endosomal Toll-like receptor upregulation. In stage 1, T cells migrate into the parenchyma and intermingle with microglial cells, thereby forming secondary nodules in which neurons are destroyed. Whole-genome transcriptome analysis at this point showed upregulation of several inflammatory pathways including interferon signaling and major histocompatibility complex-I signaling. Inflammatory profiles, like the ones observed in RE, could be induced upon TLR3 stimulation in neonatal microglial cell cultures. Taken together, our results point towards activation of endosomal TLRs, resulting in increased interferon signaling, inflammasome activation, and chemokine upregulation as early steps in RE pathogenesis. This activity sets the scene for subsequent infiltration of T cells and destruction of neurons. Similar to RE, this microglial microenvironment might be a crucial step in other T-cell-mediated inflammatory brain diseases.


Assuntos
Encefalite/metabolismo , Inflamação/metabolismo , Microglia/metabolismo , Linfócitos T/metabolismo , Criança , Encefalite/imunologia , Encefalite/patologia , Feminino , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Inflamação/imunologia , Inflamação/patologia , Masculino , Microglia/imunologia , Microglia/patologia , Linfócitos T/imunologia , Linfócitos T/patologia
7.
J Neurosci ; 36(13): 3821-8, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-27030766

RESUMO

Face processing is mediated by interactions between functional areas in the occipital and temporal lobe, and the fusiform face area (FFA) and anterior temporal lobe play key roles in the recognition of facial identity. Individuals with developmental prosopagnosia (DP), a lifelong face recognition impairment, have been shown to have structural and functional neuronal alterations in these areas. The present study investigated how face selectivity is generated in participants with normal face processing, and how functional abnormalities associated with DP, arise as a function of network connectivity. Using functional magnetic resonance imaging and dynamic causal modeling, we examined effective connectivity in normal participants by assessing network models that include early visual cortex (EVC) and face-selective areas and then investigated the integrity of this connectivity in participants with DP. Results showed that a feedforward architecture from EVC to the occipital face area, EVC to FFA, and EVC to posterior superior temporal sulcus (pSTS) best explained how face selectivity arises in both controls and participants with DP. In this architecture, the DP group showed reduced connection strengths on feedforward connections carrying face information from EVC to FFA and EVC to pSTS. These altered network dynamics in DP contribute to the diminished face selectivity in the posterior occipitotemporal areas affected in DP. These findings suggest a novel view on the relevance of feedforward projection from EVC to posterior occipitotemporal face areas in generating cortical face selectivity and differences in face recognition ability. SIGNIFICANCE STATEMENT: Areas of the human brain showing enhanced activation to faces compared to other objects or places have been extensively studied. However, the factors leading to this face selectively have remained mostly unknown. We show that effective connectivity from early visual cortex to posterior occipitotemporal face areas gives rise to face selectivity. Furthermore, people with developmental prosopagnosia, a lifelong face recognition impairment, have reduced face selectivity in the posterior occipitotemporal face areas and left anterior temporal lobe. We show that this reduced face selectivity can be predicted by effective connectivity from early visual cortex to posterior occipitotemporal face areas. This study presents the first network-based account of how face selectivity arises in the human brain.


Assuntos
Reconhecimento Visual de Modelos/fisiologia , Prosopagnosia/diagnóstico , Lobo Temporal/patologia , Córtex Visual/patologia , Face , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Modelos Lineares , Imageamento por Ressonância Magnética , Masculino , Modelos Neurológicos , Dinâmica não Linear , Oxigênio/sangue , Estimulação Luminosa
8.
Behav Res Methods ; 49(1): 97-110, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-26822668

RESUMO

One thousand one hundred and twenty subjects as well as a developmental phonagnosic subject (KH) along with age-matched controls performed the Glasgow Voice Memory Test, which assesses the ability to encode and immediately recognize, through an old/new judgment, both unfamiliar voices (delivered as vowels, making language requirements minimal) and bell sounds. The inclusion of non-vocal stimuli allows the detection of significant dissociations between the two categories (vocal vs. non-vocal stimuli). The distributions of accuracy and sensitivity scores (d') reflected a wide range of individual differences in voice recognition performance in the population. As expected, KH showed a dissociation between the recognition of voices and bell sounds, her performance being significantly poorer than matched controls for voices but not for bells. By providing normative data of a large sample and by testing a developmental phonagnosic subject, we demonstrated that the Glasgow Voice Memory Test, available online and accessible from all over the world, can be a valid screening tool (~5 min) for a preliminary detection of potential cases of phonagnosia and of "super recognizers" for voices.


Assuntos
Memória , Testes Psicológicos , Reconhecimento Psicológico , Voz , Adolescente , Adulto , Idoso , Agnosia/diagnóstico , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Som , Adulto Jovem
9.
J Food Sci Technol ; 51(10): 2640-7, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25328206

RESUMO

In this work, cassava starch was modified by treatment with sodium hypochlorite (NaClO) at different concentrations (0.8, 2.0 and 5.0 % of active chlorine) and selected physicochemical properties of the oxidized starches were investigated. The native and modified samples were evaluated considering moisture, carboxyl content, apparent viscosity, susceptibility to syneresis, mid-infrared spectroscopy and crystallinity index. The treatment with NaClO resulted in alterations in carboxyl content of the oxidized starches that increased with increasing concentration of the oxidant. Oxidized starches also showed higher susceptibility to syneresis, as assessed by the release of liquid during freezing and thawing. Apparent viscosity analysis showed decrease in peak viscosity of the oxidized starches. X-ray diffractograms showed that the oxidation influenced the extent of cassava starch relative crystallinity found to lie between 34.4 % (native) and 39.9 % (2.0 % active chlorine). The infrared spectra are sensitive to structural changes on starch macromolecules and presented characteristic peaks as C-O-C of the six carbon glucose ring absorbs at 1,150-1,085 cm(-1) and due to axial deformation these bands changed with the crystal structure of the starch samples.

11.
Cognition ; 230: 105260, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36058103

RESUMO

Body posture and configuration provide important visual cues about the emotion states of other people. We know that bodily form is processed holistically, however, emotion recognition may depend on different mechanisms; certain body parts, such as the hands, may be especially important for perceiving emotion. This study therefore compared participants' emotion recognition performance when shown images of full bodies, or of isolated hands, arms, heads and torsos. Across three experiments, emotion recognition accuracy was above chance for all body parts. While emotions were recognized most accurately from full bodies, recognition performance from the hands was more accurate than for other body parts. Representational similarity analysis further showed that the pattern of errors for the hands was related to that for full bodies. Performance was reduced when stimuli were inverted, showing a clear body inversion effect. The high performance for hands was not due only to the fact that there are two hands, as performance remained well above chance even when just one hand was shown. These results demonstrate that emotions can be decoded from body parts. Furthermore, certain features, such as the hands, are more important to emotion perception than others. STATEMENT OF RELEVANCE: Successful social interaction relies on accurately perceiving emotional information from others. Bodies provide an abundance of emotion cues; however, the way in which emotional bodies and body parts are perceived is unclear. We investigated this perceptual process by comparing emotion recognition for body parts with that for full bodies. Crucially, we found that while emotions were most accurately recognized from full bodies, emotions were also classified accurately when images of isolated hands, arms, heads and torsos were seen. Of the body parts shown, emotion recognition from the hands was most accurate. Furthermore, shared patterns of emotion classification for hands and full bodies suggested that emotion recognition mechanisms are shared for full bodies and body parts. That the hands are key to emotion perception is important evidence in its own right. It could also be applied to interventions for individuals who find it difficult to read emotions from faces and bodies.


Assuntos
Emoções , Corpo Humano , Humanos , Reconhecimento Psicológico , Sinais (Psicologia) , Mãos , Expressão Facial
12.
iScience ; 26(10): 107763, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37954143

RESUMO

Here we examine whether our impressive ability to perceive upright faces arises from evolved orientation-specific mechanisms, our extensive experience with upright faces, or both factors. To do so, we tested Claudio, a man with a congenital joint disorder causing his head to be rotated back so that it is positioned between his shoulder blades. As a result, Claudio has seen more faces reversed in orientation to his own face than matched to it. Controls exhibited large inversion effects on all tasks, but Claudio performed similarly with upright and inverted faces in both detection and identity-matching tasks, indicating these abilities are the product of evolved mechanisms and experience. In contrast, he showed clear upright superiority when detecting "Thatcherized" faces (faces with vertically flipped features), suggesting experience plays a greater role in this judgment. Together, these findings indicate that both evolved orientation-specific mechanisms and experience contribute to our proficiency with upright faces.

13.
Cir Esp (Engl Ed) ; 101(2): 90-96, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36774002

RESUMO

INTRODUCTION: Treatment of patients with Coronavirus Disease 2019 (COVID-19) has affected the management of patients with colorectal cancer (CRC). The aim of this study was to compare the diagnosis delay, symptoms, and stage of patients with CRC during the pandemic with a control cohort. MATERIAL AND METHODS: Patients referred to the CRC multidisciplinary team between September 2019 and January 2020 (cohort 1, control group) were compared with those who presented between September 2020 and March 2021 (cohort 2, pandemic group). RESULTS: 389 patients were included, 169 in cohort 1 and 220 in cohort 2. No differences were observed in the main characteristics of the patients. CRC screening and anaemia were the most common causes leading to the diagnosis of the tumour in cohort 1 and 2, respectively (p<0.001). Diagnostic and therapeutic delay was longer in cohort 2 [6.4 (95% CI 5.8-6.9) vs. 4.8 (95% CI 4.3-5.3) months, p<0.001]. More patients required non-elective treatment in the pandemic cohort (15.5% vs. 9.5%, p=0.080). The tumour stage was more advanced in patients in cohort 2 [positive nodes in 52.3% vs. 36.7% (p=0.002), and metastatic disease in 23.6% vs. 16.6% (p=0.087)]. CONCLUSION: CRC patients in the pandemic cohort had a longer diagnostic and therapeutic delay and less patients were diagnosed because of CRC screening. In addition, patients with CRC during the pandemic needed non-elective treatment more frequently than patients in the control cohort, and their tumour stage tended to be more advanced.


Assuntos
COVID-19 , Neoplasias Colorretais , Humanos , Estudos Retrospectivos , Pandemias , COVID-19/epidemiologia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/terapia , Fatores de Tempo
14.
Brain Struct Funct ; 228(2): 677-685, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36786881

RESUMO

The relationship among brain structure, brain function, and behavior is of major interest in neuroscience, evolutionary biology, and psychology. This relationship is especially intriguing when considering hominoid-specific brain structures because they cannot be studied in widely examined models in neuroscience such as mice, marmosets, and macaques. The fusiform gyrus (FG) is a hominoid-specific structure critical for face processing that is abnormal in individuals with developmental prosopagnosia (DPs)-individuals who have severe deficits recognizing the faces of familiar people in the absence of brain damage. While previous studies have found anatomical and functional differences in the FG between DPs and NTs, no study has examined the shallow tertiary sulcus (mid-fusiform sulcus, MFS) within the FG that is a microanatomical, macroanatomical, and functional landmark in humans, as well as was recently shown to be present in non-human hominoids. Here, we implemented pre-registered analyses of neuroanatomy and face perception in NTs and DPs. Results show that the MFS was shorter in DPs than NTs. Furthermore, individual differences in MFS length in the right, but not left, hemisphere predicted individual differences in face perception. These results support theories linking brain structure and function to perception, as well as indicate that individual differences in MFS length can predict individual differences in face processing. Finally, these findings add to growing evidence supporting a relationship between morphological variability of late developing, tertiary sulci and individual differences in cognition.


Assuntos
Reconhecimento Facial , Humanos , Animais , Camundongos , Lobo Temporal/anatomia & histologia , Neuroanatomia , Cognição , Reconhecimento Visual de Modelos , Imageamento por Ressonância Magnética
15.
J Neurosci ; 31(5): 1820-4, 2011 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-21289192

RESUMO

Simulation models of expression recognition contend that to understand another's facial expressions, individuals map the perceived expression onto the same sensorimotor representations that are active during the experience of the perceived emotion. To investigate this view, the present study examines facial expression and identity recognition abilities in a rare group of participants who show facilitated sensorimotor simulation (mirror-touch synesthetes). Mirror-touch synesthetes experience touch on their own body when observing touch to another person. These experiences have been linked to heightened sensorimotor simulation in the shared-touch network (brain regions active during the passive observation and experience of touch). Mirror-touch synesthetes outperformed nonsynesthetic participants on measures of facial expression recognition, but not on control measures of face memory or facial identity perception. These findings imply a role for sensorimotor simulation processes in the recognition of facial affect, but not facial identity.


Assuntos
Expressão Facial , Reconhecimento Visual de Modelos , Reconhecimento Psicológico , Autoimagem , Percepção do Tato , Adulto , Emoções , Face , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos
16.
J Neurosci ; 31(2): 618-23, 2011 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-21228170

RESUMO

Despite a homogenous macroscopic appearance on magnetic resonance images, subregions of the amygdala express distinct functional profiles as well as corresponding differences in connectivity. In particular, histological analysis shows stronger connections for superficial (i.e., centromedial and cortical), compared with deep (i.e., basolateral and other), amygdala nuclei to lateral orbitofrontal cortex and stronger connections of deep compared with superficial, nuclei to polymodal areas in the temporal pole. Here, we use diffusion weighted imaging with probabilistic tractography to investigate these connections in humans. We use a data-driven approach to segment the amygdala into two subregions using k-means clustering. The identified subregions are spatially contiguous and their location corresponds to deep and superficial nuclear groups. Quantification of the connection strength between these amygdala clusters and individual target regions corresponds to qualitative histological findings in non-human primates, indicating such findings can be extrapolated to humans. We propose that connectivity profiles provide a potentially powerful approach for in vivo amygdala parcellation and can serve as a guide in studies that exploit functional and anatomical neuroimaging.


Assuntos
Tonsila do Cerebelo/fisiologia , Adulto , Tonsila do Cerebelo/anatomia & histologia , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Probabilidade , Adulto Jovem
17.
J Cogn Neurosci ; 23(7): 1723-40, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20617881

RESUMO

Regions of the occipital and temporal lobes, including a region in the fusiform gyrus (FG), have been proposed to constitute a "core" visual representation system for faces, in part because they show face selectivity and face repetition suppression. But recent fMRI studies of developmental prosopagnosics (DPs) raise questions about whether these measures relate to face processing skills. Although DPs manifest deficient face processing, most studies to date have not shown unequivocal reductions of functional responses in the proposed core regions. We scanned 15 DPs and 15 non-DP control participants with fMRI while employing factor analysis to derive behavioral components related to face identification or other processes. Repetition suppression specific to facial identities in FG or to expression in FG and STS did not show compelling relationships with face identification ability. However, we identified robust relationships between face selectivity and face identification ability in FG across our sample for several convergent measures, including voxel-wise statistical parametric mapping, peak face selectivity in individually defined "fusiform face areas" (FFAs), and anatomical extents (cluster sizes) of those FFAs. None of these measures showed associations with behavioral expression or object recognition ability. As a group, DPs had reduced face-selective responses in bilateral FFA when compared with non-DPs. Individual DPs were also more likely than non-DPs to lack expected face-selective activity in core regions. These findings associate individual differences in face processing ability with selectivity in core face processing regions. This confirms that face selectivity can provide a valid marker for neural mechanisms that contribute to face identification ability.


Assuntos
Face , Reconhecimento Visual de Modelos/fisiologia , Prosopagnosia/fisiopatologia , Lobo Temporal/fisiologia , Córtex Visual/fisiologia , Tonsila do Cerebelo/fisiologia , Percepção de Forma/fisiologia , Humanos , Imageamento por Ressonância Magnética , Processos Mentais/fisiologia , Estimulação Luminosa/métodos
18.
Neuroimage ; 58(3): 935-45, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21763435

RESUMO

Human beings are social organisms with an intrinsic desire to seek and participate in social interactions. Social anhedonia is a personality trait characterized by a reduced desire for social affiliation and reduced pleasure derived from interpersonal interactions. Abnormally high levels of social anhedonia prospectively predict the development of schizophrenia and contribute to poorer outcomes for schizophrenia patients. Despite the strong association between social anhedonia and schizophrenia, the neural mechanisms that underlie individual differences in social anhedonia have not been studied and are thus poorly understood. Deficits in face emotion recognition are related to poorer social outcomes in schizophrenia, and it has been suggested that face emotion recognition deficits may be a behavioral marker for schizophrenia liability. In the current study, we used functional magnetic resonance imaging (fMRI) to see whether there are differences in the brain networks underlying basic face emotion processing in a community sample of individuals low vs. high in social anhedonia. We isolated the neural mechanisms related to face emotion processing by comparing face emotion discrimination with four other baseline conditions (identity discrimination of emotional faces, identity discrimination of neutral faces, object discrimination, and pattern discrimination). Results showed a group (high/low social anhedonia) × condition (emotion discrimination/control condition) interaction in the anterior portion of the rostral medial prefrontal cortex, right superior temporal gyrus, and left somatosensory cortex. As predicted, high (relative to low) social anhedonia participants showed less neural activity in face emotion processing regions during emotion discrimination as compared to each control condition. The findings suggest that social anhedonia is associated with abnormalities in networks responsible for basic processes associated with social cognition, and provide a starting point for understanding the neural basis of social motivation and our drive to seek social affiliation.


Assuntos
Anedonia/fisiologia , Mapeamento Encefálico , Encéfalo/fisiopatologia , Emoções/fisiologia , Percepção Visual/fisiologia , Adulto , Expressão Facial , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Esquizofrenia/fisiopatologia
19.
Cortex ; 144: 109-132, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34666297

RESUMO

Face shape and surface textures are two important cues that aid in the perception of facial expressions of emotion. Additionally, this perception is also influenced by high-level emotion concepts. Across two studies, we use representational similarity analysis to investigate the relative roles of shape, surface, and conceptual information in the perception, categorisation, and neural representation of facial expressions. In Study 1, 50 participants completed a perceptual task designed to measure the perceptual similarity of expression pairs, and a categorical task designed to measure the confusability between expression pairs when assigning emotion labels to a face. We used representational similarity analysis and constructed three models of the similarities between emotions using distinct information. Two models were based on stimulus-based cues (face shapes and surface textures) and one model was based on emotion concepts. Using multiple linear regression, we found that behaviour during both tasks was related with the similarity of emotion concepts. The model based on face shapes was more related with behaviour in the perceptual task than in the categorical, and the model based on surface textures was more related with behaviour in the categorical than the perceptual task. In Study 2, 30 participants viewed facial expressions while undergoing fMRI, allowing for the measurement of brain representational geometries of facial expressions of emotion in three core face-responsive regions (the Fusiform Face Area, Occipital Face Area, and Superior Temporal Sulcus), and a region involved in theory of mind (Medial Prefrontal Cortex). Across all four regions, the representational distances between facial expression pairs were related to the similarities of emotion concepts, but not to either of the stimulus-based cues. Together, these results highlight the important top-down influence of high-level emotion concepts both in behavioural tasks and in the neural representation of facial expressions.


Assuntos
Sinais (Psicologia) , Expressão Facial , Encéfalo , Mapeamento Encefálico , Emoções , Humanos , Imageamento por Ressonância Magnética
20.
Brain ; 132(Pt 12): 3443-55, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19887506

RESUMO

Individuals with developmental prosopagnosia exhibit severe and lasting difficulties in recognizing faces despite the absence of apparent brain abnormalities. We used voxel-based morphometry to investigate whether developmental prosopagnosics show subtle neuroanatomical differences from controls. An analysis based on segmentation of T1-weighted images from 17 developmental prosopagnosics and 18 matched controls revealed that they had reduced grey matter volume in the right anterior inferior temporal lobe and in the superior temporal sulcus/middle temporal gyrus bilaterally. In addition, a voxel-based morphometry analysis based on the segmentation of magnetization transfer parameter maps showed that developmental prosopagnosics also had reduced grey matter volume in the right middle fusiform gyrus and the inferior temporal gyrus. Multiple regression analyses relating three distinct behavioural component scores, derived from a principal component analysis, to grey matter volume revealed an association between a component related to facial identity and grey matter volume in the left superior temporal sulcus/middle temporal gyrus plus the right middle fusiform gyrus/inferior temporal gyrus. Grey matter volume in the lateral occipital cortex was associated with component scores related to object recognition tasks. Our results demonstrate that developmental prosopagnosics have reduced grey matter volume in several regions known to respond selectively to faces and provide new evidence that integrity of these areas relates to face recognition ability.


Assuntos
Atrofia/patologia , Atrofia/fisiopatologia , Prosopagnosia/patologia , Prosopagnosia/fisiopatologia , Lobo Temporal/patologia , Lobo Temporal/fisiopatologia , Adulto , Atrofia/congênito , Mapeamento Encefálico , Dominância Cerebral/fisiologia , Face , Feminino , Lateralidade Funcional/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Reconhecimento Visual de Modelos/fisiologia , Comportamento Social , Córtex Visual/patologia , Córtex Visual/fisiopatologia , Vias Visuais/patologia , Vias Visuais/fisiopatologia , Percepção Visual/fisiologia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA