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1.
Cortex ; 148: 121-138, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35168154

RESUMO

While the brain regions involved in action observation are relatively well documented in humans and primates, how these regions communicate to help understand and predict actions remains poorly understood. Traditional views emphasized a feed-forward architecture in which visual features are organized into increasingly complex representations that feed onto motor programs in parietal and then premotor cortices where the matching of observed actions upon the observer's own motor programs contributes to action understanding. Predictive coding models place less emphasis on feed-forward connections and propose that feed-back connections from premotor regions back to parietal and visual neurons represent predictions about upcoming actions that can supersede visual inputs when actions become predictable, with visual input then merely representing prediction errors. Here we leverage the notion that feed-back connections target specific cortical layers to help adjudicate across these views. Specifically, we test whether observing sequences of hand actions in their natural order, which permits participants to predict upcoming actions, triggers more feed-back input to parietal regions than seeing the same actions in a scrambled sequence that hinders making predictions. Using submillimeter fMRI acquisition at 7T, we find that watching predictable sequences triggers more action-related activity (as measured using intersubject functional correlation) in the parietal cortical area PFt at depths receiving feed-back connections (layers III and V/VI) than watching the exact same actions in scrambled and hence unpredictable sequence. In addition, functional connectivity analysis performed using intersubject functional connectivity confirms that these increased action-related signals in PFt could originate from ventral premotor region BA44. This data showcases the utility of intersubject functional correlation in combination with 7T MRI to explore the architecture of social cognition under more naturalistic conditions, and provides evidence for models that emphasize the importance of feed-back connections in action prediction.


Assuntos
Mapeamento Encefálico , Percepção Visual , Animais , Correlação de Dados , Mãos/fisiologia , Humanos , Imageamento por Ressonância Magnética , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/fisiologia , Desempenho Psicomotor/fisiologia , Percepção Visual/fisiologia
2.
Neuroimage ; 213: 116731, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32173409

RESUMO

Multiband (MB) or Simultaneous multi-slice (SMS) acquisition schemes allow the acquisition of MRI signals from more than one spatial coordinate at a time. Commercial availability has brought this technique within the reach of many neuroscientists and psychologists. Most early evaluation of the performance of MB acquisition employed resting state fMRI or the most basic tasks. In this study, we tested whether the advantages of using MB acquisition schemes generalize to group analyses using a cognitive task more representative of typical cognitive neuroscience applications. Twenty-three subjects were scanned on a Philips 3 â€‹T scanner using five sequences, up to eight-fold acceleration with MB-factors 1 to 4, SENSE factors up to 2 and corresponding TRs of 2.45s down to 0.63s, while they viewed (i) movie blocks showing complex actions with hand object interactions and (ii) control movie blocks without hand object interaction. Data were processed using a widely used analysis pipeline implemented in SPM12 including the unified segmentation and canonical HRF modelling. Using random effects group-level, voxel-wise analysis we found that all sequences were able to detect the basic action observation network known to be recruited by our task. The highest t-values were found for sequences with MB4 acceleration. For the MB1 sequence, a 50% bigger voxel volume was needed to reach comparable t-statistics. The group-level t-values for resting state networks (RSNs) were also highest for MB4 sequences. Here the MB1 sequence with larger voxel size did not perform comparable to the MB4 sequence. Altogether, we can thus recommend the use of MB4 (and SENSE 1.5 or 2) on a Philips scanner when aiming to perform group-level analyses using cognitive block design fMRI tasks and voxel sizes in the range of cortical thickness (e.g. 2.7 â€‹mm isotropic). While results will not be dramatically changed by the use of multiband, our results suggest that MB will bring a moderate but significant benefit.


Assuntos
Encéfalo/fisiologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Mapeamento Encefálico/métodos , Neurociência Cognitiva/métodos , Humanos
3.
Brain ; 142(12): 3791-3805, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31747689

RESUMO

Our cerebellum has been proposed to generate prediction signals that may help us plan and execute our motor programmes. However, to what extent our cerebellum is also actively involved in perceiving the action of others remains to be elucidated. Using functional MRI, we show here that observing goal-directed hand actions of others bilaterally recruits lobules VI, VIIb and VIIIa in the cerebellar hemispheres. Moreover, whereas healthy subjects (n = 31) were found to be able to discriminate subtle differences in the kinematics of observed limb movements of others, patients suffering from spinocerebellar ataxia type 6 (SCA6; n = 21) were severely impaired in performing such tasks. Our data suggest that the human cerebellum is actively involved in perceiving the kinematics of the hand actions of others and that SCA6 patients' deficits include a difficulty in perceiving the actions of other individuals. This finding alerts us to the fact that cerebellar disorders can alter social cognition.


Assuntos
Cerebelo/fisiopatologia , Percepção de Movimento/fisiologia , Ataxias Espinocerebelares/fisiopatologia , Mapeamento Encefálico , Cerebelo/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Desempenho Psicomotor/fisiologia , Ataxias Espinocerebelares/diagnóstico por imagem
4.
Soc Neurosci ; 9(5): 536-47, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24968101

RESUMO

Oxytocin has been implicated in parent-infant attachment and social recognition. With respect to emotion recognition memory, both memory-enhancing and impairing effects have been observed, suggesting an influence of individual factors. We assessed the effects of oxytocin on memory for infant cues, and whether these effects are moderated by self-reported childhood emotional maltreatment. Nulliparous females (N = 102) participated in a randomized, double-blind, between-subjects study with intranasal oxytocin or placebo administration. Participants' memory was tested using the Baby Social Reward Task, where participants were asked to select the happier infant from a pair of two infants based on the information that they received about the infants' mood in the previous phase. Participants reporting more childhood emotional maltreatment were less accurate in this task after inhaling oxytocin. Our findings add to a growing body of literature showing that the effects of intranasal oxytocin on memory and social behavior are moderated by adverse early life experiences.


Assuntos
Fármacos do Sistema Nervoso Central/administração & dosagem , Maus-Tratos Infantis/psicologia , Lactente , Memória/fisiologia , Ocitocina/administração & dosagem , Percepção Social , Administração Intranasal , Sinais (Psicologia) , Método Duplo-Cego , Emoções , Expressão Facial , Feminino , Humanos , Aprendizagem/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Testes Psicológicos , Tempo de Reação , Inquéritos e Questionários , Adulto Jovem
5.
Physiol Behav ; 131: 123-8, 2014 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-24768649

RESUMO

Childhood emotional maltreatment has been associated with a higher risk for maltreating one's own offspring. In the current study, we explored a possible role of oxytocin in mediating the association between childhood emotional maltreatment and participants' interpretation of infant facial expressions. Oxytocin levels were measured in 102 female participants using saliva samples. They rated the mood of thirteen infants with happy, sad and neutral facial expressions. Emotional maltreatment indirectly influenced responses to happy infant faces by modulating oxytocin levels: higher self-reported emotional maltreatment was related to higher levels of salivary oxytocin which were in turn related to a more positive evaluation of happy infant expressions, but not to the evaluation of sad infant expressions. Oxytocin receptor polymorphism rs53576 did not moderate the relation between maltreatment experiences and salivary oxytocin levels. Early emotional maltreatment might indirectly affect emotional information processing by altering the oxytonergic system.


Assuntos
Maus-Tratos Infantis/psicologia , Emoções , Expressão Facial , Ocitocina/metabolismo , Reconhecimento Visual de Modelos/fisiologia , Saliva/metabolismo , Face , Feminino , Técnicas de Genotipagem , Humanos , Lactente , Julgamento/fisiologia , Modelos Neurológicos , Estimulação Luminosa , Polimorfismo Genético , Receptores de Ocitocina/genética , Inquéritos e Questionários , Adulto Jovem
6.
Dev Sci ; 17(2): 257-69, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24330495

RESUMO

Attractive individuals are perceived as having various positive personality qualities. Positive personality qualities can in turn increase perceived attractiveness. However, the developmental origins of the link between attractiveness and personality are not understood. This is important because infant attractiveness ('cuteness') elicits caregiving from adults, and infant personality ('temperament') shapes caregiving behaviour. While research suggests that adults have more positive attitudes towards cuter infants, it is not known whether positive infant temperament can increase the perception of infant cuteness. We investigated the impact of experimentally established infant temperament on adults' perception of cuteness and desire to view individual faces. Ataseline, adults rated the cuteness of, and keypressed to view, images of unfamiliar infants with neutral facial expressions. Training required adults to learn about an infant's 'temperament', through repeated pairing of the neutral infant face with positive or negative facial expressions and vocalizations. Adults then re-rated the original neutral infant faces. Post-training, there were significant changes from baseline: infants who were mostly happy were perceived as cuter and adults expended greater effort to view them. Infants who were mostly sad were not perceived as cuter and adults expended less effort to view them. Our results suggest that temperament has clear consequences for how adults perceive 'bonnie' babies. Perception of infant cuteness is not based on physical facial features alone, and is modifiable through experience.


Assuntos
Emoções , Temperamento , Adolescente , Adulto , Cuidadores , Comunicação , Face , Expressão Facial , Feminino , Humanos , Lactente , Masculino , Motivação , Percepção , Recompensa , Comportamento Social , Adulto Jovem
7.
Attach Hum Dev ; 15(5-6): 603-17, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24299137

RESUMO

Children vary hugely in how demanding of their caregivers they are. This creates differences in demands on parents during observation, making the comparison of sensitivity between parents difficult. It would therefore be of interest to create standard situations in which all caregivers are faced with the same level of demand. This study developed an ecologically valid but standardized setting using an infant simulator with interactive features, the Leiden Infant Simulator Sensitivity Assessment (LISSA). The infant simulator resembles a real infant in appearance and it produces crying sounds that are life-like. The simulator begins with fussing and progresses to more intense crying in case of no care or inappropriate care. It responds by being calm again if appropriate care is given. One hundred and eighty-one female participants took care of the infant simulator for two evenings and in a 30 min lab session with increasing competing demands. Sensitive parenting behavior during the lab session was coded with the Ainsworth Sensitivity Scale. Sensitivity ratings covered the whole range of the scale (1-9), and were stable across settings (free play, competing demands). Sensitivity was related to an increase of positive affect during caretaking, and insensitivity was related to intended harsh caregiving response during a computerized cry paradigm. Sensitivity was unrelated to social desirability and self-reported quality of care given to the infant simulator. We discuss the potentials of the infant simulator for research on sensitive parenting, for preventive interventions, and for clinical practices.


Assuntos
Empatia , Manequins , Relações Mãe-Filho/psicologia , Pesquisadores/educação , Ensino/normas , Adolescente , Adulto , Choro , Feminino , Humanos , Lactente , Países Baixos , Observação , Inquéritos e Questionários , Adulto Jovem
8.
Front Neurosci ; 6: 174, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23233832

RESUMO

We addressed the question how long salivary oxytocin levels remain elevated after intranasal administration, and whether it makes a difference when 16 or 24 IU of oxytocin administration is used. Oxytocin levels were measured in saliva samples collected from 46 female participants right before intranasal administration (at 9:30 a.m.) of 16 IU (n = 18) or 24 IU (n = 10) of oxytocin, or a placebo (n = 18), and each hour after administration, for 7 h in total. Oxytocin levels did not differ among conditions before use of the nasal spray. Salivary oxytocin levels in the placebo group showed high stability across the day. After oxytocin administration oxytocin levels markedly increased, they peaked around 1 h after administration, and were still significantly elevated 7 h after administration. The amount of oxytocin (16 or 24 IU) did not make a difference for oxytocin levels. The increase of oxytocin levels for at least 7 h shows how effective intranasal administration of oxytocin is. Our findings may raise ethical questions about potentially persisting behavioral effects after participants have left the lab setting. More research into the long-term neurological and behavioral effects of sniffs of oxytocin is urgently needed.

9.
Case Rep Anesthesiol ; 2012: 370412, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23082254

RESUMO

Fetal hydantoin syndrome is a rare disorder that is believed to be caused by exposure of a fetus to the anticonvulsant drug phenytoin. The classic features of fetal hydantoin syndrome include craniofacial anomalies, prenatal and postnatal growth deficiencies, underdeveloped nails of the fingers and toes, and mental retardation. Less frequently observed anomalies include cleft lip and palate, microcephaly, ocular defects, cardiovascular anomalies, hypospadias, umbilical and inguinal hernias, and significant developmental delays. Anaesthesia for incidental surgery in such a patient poses unique challenges for the anesthesiologist. We report the successful management of a 4-year-old male child with fetal hydantoin syndrome, cleft palate, spina bifida, atrial septal defect, and dextrocardia for tibialis anterior lengthening under subarachnoid block.

10.
Indian J Nucl Med ; 27(1): 59-62, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23599605

RESUMO

Skeletal manifestations are common in hematologic disorders. Benign entities such as Sickle cell disease develop microvascular embolization causing skeletal crisis. Leukemia, acute myeloblastic or lymphoblastic may develop bone marrow infarcts. Compromised immunity makes them susceptible to secondary infection leading to osteomyelitis or septic arthritis. Exposure to steroids may lead to osteonecrosis in these cases. Presented here is an atlas of various scintigraphic skeletal manifestations encountered over the past 10 years, in hematologic disorders.

11.
Indian J Nucl Med ; 27(2): 119-21, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23723586

RESUMO

Von Hippel-Lindau (VHL) syndrome is a hereditary autosomal dominant disorder caused by defective tumor suppression gene at 3p25-p26. The gene for VHL disease is found on chromosome 3, and is inherited in a dominant fashion. The VHL gene is a tumor suppressor gene. This means that its role in a normal cell is to stop the uncontrolled growth and proliferation. It is characterized by abnormal growth of blood vessels. It strikes the eyes, central nervous system, kidneys, endocrine glands, etc. It predisposes the patient to retinal angiomas, central nervous system hemangioblastoma, renal cell carcinoma (RCC), pheochromocytomas, islet cell tumor of the pancreas, endolymphatic sac tumors, renal, pancreatic, epididymal cysts. We present a case of familial VHL syndrome whose Fluorine 18-fluorodeoxyglucose positron emission tomography-computed tomography scan was truly positive for adrenal pheochromocytoma but was falsely negative for RCC. Review of literature related to this entity is made.

12.
Indian J Nucl Med ; 25(4): 160-3, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21713225

RESUMO

Intraocular choroidal metastasis is a very rare cause of blindness. Choroidal hemangioma and melanoma are other causes that may mimic the condition. Carcinoma of breast is the most common primary malignancy that accounts for choroidal metastasis in females and carcinoma of lung is the most common cause in males. Other primary neoplasms which can uncommonly metastasize to the choroid are testis, gastrointestinal tract, kidney, thyroid, pancreas, and prostate. Metastatic neoplasm to the eye outnumbers the primary tumors such as retinoblastomas and malignant melanoma. Sonography is usually the initial investigation after fundus examination to look for the architecture of the lesion. However, it lacks in specificity. We present a case of carcinoma of breast that had visual disturbances and wholebody F18-fluorodeoxyglucose, positron emission tomography-computerized tomography (FDG PET CT) revealed a choroidal lesion in addition to cerebral, pulmonary, and skeletal metastases. Choroidal metastasis from carcinoma of lung has been reported previously on FDG PET. To the best of our knowledge, this is the first case report of carcinoma of breast demonstrating choroid metastasis on F18-FDG PET CT scan.

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