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1.
Dev Sci ; 27(4): e13482, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38332650

RESUMO

In adults, spatial location plays a special role in visual object processing. People are more likely to judge two sequentially presented objects as being identical when they appear in the same location compared to in different locations (a phenomenon referred to as Spatial Congruency Bias [SCB]). However, no comparable Identity Congruency Bias (ICB) is found, suggesting an asymmetric location-identity relationship in object binding. What gives rise to this asymmetric congruency bias? This paper considered two possible hypotheses. Hypothesis 1 suggests that the asymmetric congruency bias results from an inherently special role of location in the visual system. In contrast, Hypothesis 2 suggests that the asymmetric congruency bias is a product of development, reflecting people's experience with the world. To distinguish the two hypotheses, we tested both adults' and 5-year-old children's SCB and ICB by Identity Judgment Experiments and Spatial Judgment Experiments, respectively. The study found that adults only exhibited a SCB, but no ICB. However, young children exhibited both SCB and ICB, suggesting a symmetric congruency bias and reciprocal influences between location and identity in early development. The results indicate that the asymmetric location-identity relationship develops as object identity's influence on location gets pruned away, while location's influence on identity is preserved, possibly due to people's gained experiences with regularities of the world. RESEARCH HIGHLIGHTS: Adults exhibit Spatial Congruency Bias-an asymmetric location-identity relationship with location biasing their judgment of object identities, but not vice versa. Asymmetric congruency bias may result from an inherently special role of location in visual system (Hypothesis 1) or accumulated experiences with the world (Hypothesis 2). To distinguish the two hypotheses, the study investigated the Spatial Congruency Bias and Identity Congruency Bias in both adults and 5-year-old children. Unlike adults who exhibited only Spatial Congruency Bias, 5-year-old children exhibited both Spatial Congruency Bias and Identity Congruency Bias.


Assuntos
Cognição , Percepção Espacial , Percepção Visual , Humanos , Pré-Escolar , Feminino , Percepção Espacial/fisiologia , Cognição/fisiologia , Masculino , Percepção Visual/fisiologia , Adulto , Desenvolvimento Infantil/fisiologia , Julgamento/fisiologia , Adulto Jovem , Estimulação Luminosa , Viés
2.
Mem Cognit ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39080186

RESUMO

Recent studies showed that real-world items are better remembered in visual working memory (VWM) than visually similar stimuli that are stripped of their semantic meaning. However, the exact nature of this advantage remains unclear. We used meaningful and meaningless stimuli in a location-reproduction VWM task. Employing a mixture-modeling analysis, we examined whether semantic meaning enables more item locations to be remembered, whether it improves the precision of the locations stored in memory, or whether it improves binding between the specific items and their locations. Participants were presented with streams of four (Experiments 1 & 2) or six (Experiment 3) real-world items, or their scrambled, meaningless counterparts. Each item was presented at a unique location, and the task was to reproduce one item's location. Overall, location memory was consistently better for real-world items compared with their scrambled counterparts. Furthermore, the results revealed that participants were less likely to make swap errors for the meaningful items, but there was no effect of conceptual meaning on the guess rate or the precision of the report. In line with previous findings, these results indicate that conceptual meaning enhances VWM for arbitrary stimulus properties such as item location, and this improvement is primarily due to a more efficient identity-location binding rather than an increase in the quantity or quality (precision) of the locations held in memory.

3.
Sensors (Basel) ; 23(20)2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37896586

RESUMO

Nearshore water depth plays a crucial role in scientific research, navigation management, coastal zone protection, and coastal disaster mitigation. This study aims to address the challenge of insufficient feature extraction from remote sensing data in nearshore water depth inversion. To achieve this, a convolutional neural network with spatial location integration (CNN-SLI) is proposed. The CNN-SLI is designed to extract deep features from remote sensing data by considering the spatial dimension. In this approach, the spatial location information of pixels is utilized as two additional channels, which are concatenated with the input feature image. The resulting concatenated image data are then used as the input for the convolutional neural network. Using GF-6 remote sensing images and measured water depth data from electronic nautical charts, a nearshore water depth inversion experiment was conducted in the waters near Nanshan Port. The results of the proposed method were compared with those of the Lyzenga, MLP, and CNN models. The CNN-SLI model demonstrated outstanding performance in water depth inversion, with impressive metrics: an RMSE of 1.34 m, MAE of 0.94 m, and R2 of 0.97. It outperformed all other models in terms of overall inversion accuracy and regression fit. Regardless of the water depth intervals, CNN-SLI consistently achieved the lowest RMSE and MAE values, indicating excellent performance in both shallow and deep waters. Comparative analysis with Kriging confirmed that the CNN-SLI model best matched the interpolated water depth, further establishing its superiority over the Lyzenga, MLP, and CNN models. Notably, in this study area, the CNN-SLI model exhibited significant performance advantages when trained with at least 250 samples, resulting in optimal inversion results. Accuracy evaluation on an independent dataset shows that the CNN-SLI model has better generalization ability than the Lyzenga, MLP, and CNN models under different conditions. These results demonstrate the superiority of CNN-SLI for nearshore water depth inversion and highlight the importance of integrating spatial location information into convolutional neural networks for improved performance.

4.
Int J Audiol ; 61(5): 371-379, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34126838

RESUMO

OBJECTIVE: To investigate the role of the spatial position of conversing talkers, that is, spatially separated or co-located, in the listener's short-term memory of running speech and listening effort. DESIGN: In two experiments (between-subject), participants underwent a dual-task paradigm, including a listening (primary) task wherein male and female talkers spoke coherent texts. Talkers were either spatially separated or co-located (within-subject). As a secondary task, visually presented tasks were used. Experiment I involved a number-judgement task, and Experiment II entailed switching between number and letter-judgement task. STUDY SAMPLE: Twenty-four young adults who reported normal hearing and normal or corrected to normal vision participated in each experiment. They were all students from the RWTH Aachen University. RESULTS: In both experiments, similar short-term memory performance of running speech was found independently of talkers being spatially separated or co-located. Performance in the secondary tasks, however, differed between these two talkers' auditory stimuli conditions, indicating that spatially separated talkers imposed reduced listening effort compared to their co-location. CONCLUSION: The findings indicated that auditory-perceptive information, such as the spatial position of talkers, plays a role in higher-level auditory cognition, that is, short-term memory of running speech, even when listening in quiet.


Assuntos
Corrida , Percepção da Fala , Feminino , Testes Auditivos , Humanos , Esforço de Escuta , Masculino , Fala , Adulto Jovem
5.
Hautarzt ; 73(1): 5-14, 2022 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-34846552

RESUMO

The association between geographic and medical aspects is a well-known phenomenon, which also occurs in dermatological research. This article reviews the field of health geography, the history of the association between spatial location and health, and focuses on current areas of research. Research focusing on explaining regional variations in health refer to individual aspects and needs, population factors, environmental factors, and health care delivery structures in specific regions, as well as the interaction between them. Regional healthcare research is primarily concerned with access to health services and on the utilisation of those services. Methodologically, the analysis of geodata and the application of geographic information systems (GIS) and spatial modelling play a major role in this field. Dermatological research and dermatological practice can benefit from the findings of the regional analysis of access, utilisation, and variations in order to obtain a more detailed picture of care and thus to optimise care.


Assuntos
Dermatologia , Sistemas de Informação Geográfica , Geografia , Acessibilidade aos Serviços de Saúde , Humanos
6.
Exp Brain Res ; 239(8): 2509-2518, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34142190

RESUMO

Recent studies have hypothesized that the stereotypical representation of the body may reflect some functional aspects of routine actions that are performed in specific peripersonal domains. For example, the lower and upper limbs tend to 'act' in different peripersonal spaces and perform different functions. The present study aims to directly investigate the relationship between body representation and the spatial context where actions are performed. By means of a modified version of the body image task, we investigated body representation before and after a sorting task training in two groups of participants who were asked to carry out the same task/actions in two different spaces: on a table or on the floor, while sitting on a chair. Findings showed that a significant recalibration of the perceived upper arms' length occurred when participants were asked to perform a motor task on the floor. These results seem to suggest that the modulation of the body representation reflects an increase action capabilities driven by the contribution of motor training, and importantly, the location in which the action occurs. Furthermore, the modulation was not limited to the body part actively involved in the action (the arms), it extended to other upper body parts (the torso) to maintain, we propose, a functionally coherent representation of the upper body.


Assuntos
Imagem Corporal , Percepção Espacial , Braço , Corpo Humano , Humanos , Espaço Pessoal
7.
Soc Sci Res ; 98: 102581, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34247726

RESUMO

In this paper, a national Danish survey is used to explore the rural happiness paradox in developed countries. This paradox revolves around the observation that rural residents tend to report higher subjective well-being than urban residents in developed countries. Based on three different rural-urban classifications, the paper provides a solid confirmation of the rural happiness paradox in Denmark. The paper tests three hypotheses regarding the factors behind the rural happiness paradox and finds strong support for two of the hypotheses. Thus, higher bonding social capital in rural areas and higher access to nature amenities in rural areas were found to contribute to the rural happiness paradox in Denmark. As for the third hypothesis, the paper finds no significant evidence that rural-urban differences in spatial location satisfaction (measured by the correspondence between actual and preferred residential location on the rural-urban continuum) contribute to the rural happiness paradox in Denmark.


Assuntos
Felicidade , Capital Social , Países Desenvolvidos , Humanos , Satisfação Pessoal , População Rural
8.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 38(6): 1081-1086, 2021 Dec 25.
Artigo em Zh | MEDLINE | ID: mdl-34970890

RESUMO

In this paper, a new surface electromyography (sEMG) signal decomposition method based on spatial location is proposed for the high-density sEMG signals in dynamic muscle contraction. Firstly, according to the waveform correlation of each muscle motor units (MU) in each channel, the firing times are extracted, and then the firing times are classified by the spatial location of MU. The MU firing trains are finally obtained. The simulation results show that the accuracy rate of a single MU firing train after classification is more than 91.67%. For real sEMG signals, the accuracy rate to find a same MU by the "two source" method is over (88.3 ± 2.1)%. This paper provides a new idea for dynamic sEMG signal decomposition.


Assuntos
Contração Muscular , Músculo Esquelético , Potenciais de Ação , Simulação por Computador , Eletromiografia
9.
Ecol Lett ; 23(10): 1451-1459, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32656918

RESUMO

Ecological processes in food webs depend on species interactions. By identifying broad-scaled interaction patterns, important information on species' ecological roles may be revealed. Here, we use the group model to examine how spatial resolution and proximity influence group structure. We examine a data set from the Barents Sea, with food webs described for both the whole region and 25 subregions. We test how the group structure in the networks differ comparing (1) the regional metaweb to subregions and (2) subregion to subregion. We find that more than half the species in the metaweb change groups when compared to subregions. Between subregions, networks with similar group structure are spatially related. Interestingly, although species overlap is important for similarity in group structure, there are notable exceptions. Our results highlight that species ecological roles vary depending on fine-scaled differences in the patterns of interactions, and that local network characteristics are important to consider.


Assuntos
Cadeia Alimentar , Estrutura de Grupo
10.
Hum Brain Mapp ; 41(7): 1711-1724, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31860166

RESUMO

Scarce previous data on how the location where an emotional stimulus appears in the visual scene modulates its perception suggest that, for functional reasons, a perceptual advantage may exist, vertically, for stimuli presented at the lower visual field (LoVF) and, horizontally, for stimuli presented at the left visual field (LeVF). However, this issue has been explored through a limited number of spatial locations, usually in a single spatial dimension (e.g., horizontal) and invariant eccentricities. Event-related potentials (ERPs) were recorded from 39 participants perceiving brief neutral (wheels) and emotional stimuli (spiders) presented at 17 different locations, one foveal and 16 at different peripheral coordinates. As a secondary scope, we explored the role of the magnocellular (M) and the parvocellular (P) visual pathways by presenting an isoluminant/heterochromatic (P-biased) and a heteroluminant/isochromatic version (M-biased) of each stimulus. Emo > Neu effects were observed in PN1 (120 ms) for stimuli located at fovea, and in PN2 (215 ms) for stimuli located both at fovea and diverse peripheral regions. A factorial approach to these effects further revealed that: (a) emotional stimuli presented in the periphery are efficiently perceived, without evident decrease from para- to perifovea; (b) peripheral Emo > Neu effects are reflected 95 ms later than foveal Emo > Neu effects in ERPs; (c) LoVF is more involved than UVF in these effects; (d) our data fail to support the LeVF advantage previously reported, and (e) Emo > Neu effects were significant for both M and P stimuli.


Assuntos
Emoções/fisiologia , Potenciais Evocados/fisiologia , Retina/fisiologia , Percepção Visual/fisiologia , Adolescente , Adulto , Mapeamento Encefálico , Eletroencefalografia , Feminino , Fóvea Central/diagnóstico por imagem , Fóvea Central/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Campos Visuais , Vias Visuais/diagnóstico por imagem , Vias Visuais/fisiologia , Adulto Jovem
11.
Trop Anim Health Prod ; 52(3): 1103-1114, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31729631

RESUMO

In Xayaboury province, located in the northern region of Lao PDR, the foot and mouth disease (FMD) vaccination campaign just began in 2009. Up until now, a small number of farms have been vaccinated. When FMD outbreaks occur, it is interesting to determine the risk factors of FMD, especially in the area where vaccination rates are low. The questionnaire survey, using a case-control design at the household level, was carried out. From 59 villages with a total number of 434 households, 181 households who experienced FMD were assigned as case households, 146 households without FMD occurrence inside the outbreak villages as inside control households, and 107 households without FMD occurrence outside the outbreak villages as outside control households. Household owners were interviewed. The logistic regression model was used to identify the relationship between FMD occurrence (dependent variable) and the collected data (independent variables), including the social status of livestock owners, FMD prevention strategies, and farm locations. A non-parametric test was performed to determine the association of FMD and network parameters of animal movements among villages. In general, results show that a limited number of holders did vaccinate animals before the outbreaks (13.8-17.8%). The results indicated that livestock owners who had known information about FMD before the outbreaks had been less severely affected by the FMD outbreak than the owners who had not known information about FMD (P < 0.01, OR 0.16, 95% CI 0.09-0.29). Before the outbreaks, higher FMD risk was observed in owners who sold the livestock through animal traders (P < 0.01, OR 4.76, 95% CI 1.68-13.50). Spatial data show that households in the community closer to the main roads had higher FMD risk (P < 0.01, OR 4.76, 95% CI 1.68-13.50). In addition, the network parameters including in-degree, out-degree, and betweenness indicated that the villages with high movements of livestock were at high risk of FMD (P < 0.05). The present study emphasized the importance of the government units to distribute the information about FMD to all livestock farmers in Xayaboury. Disease awareness and prevention strategy should be prioritized in areas close to high density communities and in the trading of livestock.


Assuntos
Doenças dos Bovinos/epidemiologia , Fazendeiros/estatística & dados numéricos , Febre Aftosa/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Vacinação/veterinária , Adulto , Animais , Estudos de Casos e Controles , Bovinos , Doenças dos Bovinos/virologia , Fazendeiros/psicologia , Feminino , Febre Aftosa/virologia , Vírus da Febre Aftosa/fisiologia , Humanos , Laos/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco
12.
Epilepsy Behav ; 94: 189-194, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30970297

RESUMO

In children with epilepsy, the impact of surgery including or sparing the mesial temporal lobes (TLs) on visuospatial memory has not been thoroughly investigated, and a clear pattern of hemispheric lateralization has not been observed. The primary aim of this study was to examine visuospatial learning and memory outcomes in children with epilepsy prior to and one year after surgical excision, to determine whether outcomes differed as a function of the localization and lateralization of surgical excisions. Forty-six children who underwent unilateral TL surgery with sparing of the mesial structures (TL group, N = 21, 16 left) or including mesial structures (TL + M group, N = 25 children, 12 left) were retrospectively recruited. Outcomes on the Children's Memory Scale (CMS) Dot Locations subtest (learning, immediate, and delayed recall scores) were examined prior to and following epilepsy surgery. Results revealed significantly reduced visuospatial memory (delayed recall) in the TL + M compared with the TL group after surgery. Despite this significant postoperative difference, there was no significant change in learning, immediate, or delayed recall scores in either group. However, inspection of individual change scores showed that fewer children in the TL + M group improved in delayed recall after surgery (7.2%) compared with children in the TL group (30%) whereas a similar proportion of children in the TL + M (30.4%) and TL (23.3%) groups showed a decline. There were no significant differences in learning or memory scores as a function of seizure laterality before or after surgery and no differences in change over time. Seizure outcome, age at surgery, age at seizure onset, and percentage life with epilepsy were not related to visuospatial learning or memory outcomes; however, greater number of antiepileptic drugs (AEDs) following surgery was related to poorer visuospatial memory (delayed recall) in the TL + M group. In summary, the results show that visuospatial learning and memory performance do not seem to show a significant decline following TL resections in childhood, regardless of whether or not surgery includes the mesial TL and involves the left or right hemisphere. However, although mesial TL excisions might not result in a deficit in visuospatial memory, they may hinder progressions made after surgery. Further research is needed to examine how resection of the mesial TL (alone or in combination with lateral TL structures) affects visuospatial memory outcomes in children, as well as to investigate the degree to which other treatment factors, such as medication, may affect visual memory outcomes.


Assuntos
Epilepsia do Lobo Temporal/cirurgia , Síndrome de Kluver-Bucy/psicologia , Transtornos da Memória/etiologia , Transtornos da Memória/psicologia , Aprendizagem Espacial , Adolescente , Idade de Início , Criança , Pré-Escolar , Feminino , Lateralidade Funcional , Humanos , Lactente , Masculino , Rememoração Mental , Testes Neuropsicológicos , Complicações Pós-Operatórias/psicologia , Estudos Retrospectivos , Resultado do Tratamento
13.
J Biomed Inform ; 91: 103112, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30738189

RESUMO

BACKGROUND AND OBJECTIVE: Retrieval of medical images from an anatomically diverse dataset is a challenging task. Objective of our present study is to analyse the automated medical image retrieval system incorporating topic and location probabilities to enhance the performance. MATERIALS AND METHODS: In this paper, we present an automated medical image retrieval system using Topic and Location Model. The topic information is generated using Guided Latent Dirichlet Allocation (GuidedLDA) method. A novel Location Model is proposed to incorporate the spatial information of visual words. We also introduce a new metric called position weighted Precision (wPrecision) to measure the rank order of the retrieved images. RESULTS: Experiments on two large medical image datasets - IRMA 2009 and Multimodal dataset - revealed that the proposed method outperforms existing medical image retrieval systems in terms of Precision and Mean Average Precision. The proposed method achieved better Mean Average Precision (86.74%) compared to the recent medical image retrieval systems using the Multimodal dataset with 7200 images. The proposed system achieved better Precision (97.5%) for top ten images compared to the recent medical image retrieval systems using IRMA 2009 dataset with 14,410 images. CONCLUSION: Supplementing spatial details of visual words to the Topic Model enhances the retrieval efficiency of medical images from large repositories. Such automated medical image retrieval systems can be used to assist physician to retrieve medical images with better precision compared to the state-of-the-art retrieval systems.


Assuntos
Simulação por Computador , Diagnóstico por Imagem , Interpretação de Imagem Assistida por Computador/métodos , Armazenamento e Recuperação da Informação/métodos , Humanos , Probabilidade
14.
Sensors (Basel) ; 19(5)2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30813618

RESUMO

To solve the problems of the large differences in gray value and inaccurate positioning of feature information during infrared-visible image registration, we propose an automatic and robust algorithm for registering planar infrared-visible image sequences through spatio-temporal association. In particular, we first create motion vector distribution descriptors which represent the temporal motion information of foreground contours in adjacent frames to complete coarse registration without feature extraction. Then, for precise registration, we extracted FAST corners of the foreground, which are described by the spatial location distribution of contour points based on connected blob detection, and match these corners using bidirectional optimal maximum strategy. Finally, a reservoir updated by Better-In, Worse-Out (BIWO) strategy is established to save matched point pairs and obtain the optimal global transformation matrix. Extensive evaluations on the LITIV dataset well demonstrate the effectiveness of the proposed algorithm. Particularly, our algorithm achieves lower registration overlapping errors than the other two state-of-the-arts.

15.
Brief Bioinform ; 17(5): 863-76, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-26515531

RESUMO

Recent computational methodologies, such as individual-based modelling, pave the way to the search for explanatory insight into the collective behaviour of molecules. Many reviews offer an up-to-date perspective about such methodologies, but little is discussed about the practical information requirements involved. The biological information used as input should be easily and routinely determined in the laboratory, publicly available and, preferably, organized in programmatically accessible databases. This review is the first to provide a systematic and comprehensive overview of available resources for the modelling of metabolic events at the molecular scale. The glycolysis pathway of Escherichia coli, which is one of the most studied pathways in Microbiology, serves as case study. This curation addressed structural information about E. coli (i.e. defining the simulation environment), the reactions forming the glycolysis pathway including the enzymes and the metabolites (i.e. the molecules to be represented), the kinetics of each reaction (i.e. behavioural logic of the molecules) and diffusion parameters for all enzymes and metabolites (i.e. molecule movement in the environment). Furthermore, the interpretation of relevant biological features, such as molecular diffusion and enzyme kinetics, and the connection of experimental determination and simulation validation are detailed. Notably, the information from classical theories, such as enzymatic rates and diffusion coefficients, is translated to simulation parameters, such as collision efficiency and particle velocity.


Assuntos
Modelos Biológicos , Bases de Dados Factuais , Escherichia coli , Cinética , Software
16.
Scand J Med Sci Sports ; 28(12): 2558-2566, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30030921

RESUMO

Voluntary surface electromyography (sEMG) amplitude is known to be influenced by both electrode position and subcutaneous adipose tissue thickness, and these factors likely compromise both between- and within-individual comparisons. Normalization of voluntary sEMG amplitude to evoked maximum M-wave parameters (MMAX peak-to-peak [P-P] and Area) may remove the influence of electrode position and subcutaneous tissue thickness. The purpose of this study was to: (a) assess the influence of electrode position on voluntary, evoked (MMAX P-P and Area), and normalized sEMG measurements across the surface of the vastus lateralis (VL; experiment 1: n = 10); and (b) investigate if MMAX normalization removes the confounding influence of subcutaneous tissue thickness [muscle-electrode distance (MED) from ultrasound imaging] on sEMG amplitude (experiment 2; n = 41). Healthy young men performed maximum voluntary contractions (MVCs) and evoked twitch contractions during both experiments. Experiment 1: voluntary sEMG during MVCs was influenced by electrode location (P ≤ 0.046, ES≥1.49 "large"), but when normalized to MMAX P-P showed no differences between VL sites (P = 0.929) which was not the case when normalized to MMAX Area (P < 0.004). Experiment 2: voluntary sEMG amplitude was related to MED, which explained 31%-38% of the variance. Normalization of voluntary sEMG amplitude to MMAX P-P or MMAX Area reduced but did not consistently remove the influence of MED which still explained up to 16% (MMAX P-P) and 23% (MMAX Area) of the variance. In conclusion, MMAX P-P was the better normalization parameter for removing the influence of electrode location and substantially reduced but did not consistently remove the influence of subcutaneous adiposity.


Assuntos
Adiposidade , Eletrodos , Eletromiografia , Músculo Quadríceps/fisiologia , Estimulação Elétrica , Humanos , Masculino , Contração Muscular , Torque , Adulto Jovem
17.
Hippocampus ; 24(3): 354-62, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24339224

RESUMO

In the Ts65Dn/DnJ mouse model of Down syndrome (DS), hippocampal deficits of learning and memory are the most robust features supporting this mouse as a valid cognitive model of DS. Although dentate gyrus (DG) dysfunction is suggested by excessive GABAergic inhibition, its role in perturbing DG functions in DS is unknown. We hypothesize that in the Ts65Dn/DnJ mouse, the specific role of the DG is disturbed in its support of contextual and spatial information. Support for this hypothesis comes from rats with DG lesions that show similar deficits. In order to test this hypothesis, we have developed a novel series of spontaneous exploratory tasks that emphasize the importance of recognizing spatial and contextual cues and that involve DG function. The results with this exploratory battery show that Ts65Dn/DnJ mice are impaired in DG-dependent short-term recognition tests involving object recognition with contextual cues, in place recognition and in metric distance recognition relative to wild type littermate controls. Further, whereas Ts65Dn/DnJ mice can recognize object novelty in the absence of contextual cues after a 5-min delay, they cannot do so after a delay of 24 h, suggesting a problem with CA1-mediated consolidation. The results also show that Ts65Dn/DnJ mice are not impaired in tasks (object recognition and configural object recognition) that are mediated by the perirhinal cortex (PRh). These results implicate the DG as a specific therapeutic target and the PRh as a potential therapeutic strength for future research to ameliorate learning and memory in DS.


Assuntos
Cognição/fisiologia , Giro Denteado/fisiopatologia , Modelos Animais de Doenças , Síndrome de Down/fisiopatologia , Transtornos da Memória/fisiopatologia , Reconhecimento Psicológico , Comportamento Espacial/fisiologia , Animais , Animais Congênicos , Síndrome de Down/psicologia , Hipocampo/fisiopatologia , Masculino , Transtornos da Memória/etiologia , Transtornos da Memória/psicologia , Camundongos , Camundongos Endogâmicos C3H , Camundongos Transgênicos , Lobo Temporal/fisiopatologia , Translocação Genética , Trissomia
18.
Sci Rep ; 14(1): 16781, 2024 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-39039267

RESUMO

Biofilms are known to be critical for Legionella settlement in engineered water systems and are often associated with Legionnaire's Disease events. One of the key features of biofilms is their heterogeneous three-dimensional structure which supports the establishment of microbial interactions and confers protection to microorganisms. This work addresses the impact of Legionella pneumophila colonization of a Pseudomonas fluorescens biofilm, as information about the interactions between Legionella and biofilm structures is scarce. It combines a set of meso- and microscale biofilm analyses (Optical Coherence Tomography, Episcopic Differential Interference Contrast coupled with Epifluorescence Microscopy and Confocal Laser Scanning Microscopy) with PNA-FISH labelled L. pneumophila to tackle the following questions: (a) does the biofilm structure change upon L. pneumophila biofilm colonization?; (b) what happens to L. pneumophila within the biofilm over time and (c) where is L. pneumophila preferentially located within the biofilm? Results showed that P. fluorescens structure did not significantly change upon L. pneumophila colonization, indicating the competitive advantage of the first colonizer. Imaging of PNA-labelled L. pneumophila showed that compared to standard culture recovery it colonized to a greater extent the 3-day-old P. fluorescens biofilms, presumably entering in VBNC state by the end of the experiment. L. pneumophila was mostly located in the bottom regions of the biofilm, which is consistent with the physiological requirements of both bacteria and confers enhanced Legionella protection against external aggressions. The present study provides an expedited methodological approach to address specific systematic laboratory studies concerning the interactions between L. pneumophila and biofilm structure that can provide, in the future, insights for public health Legionella management of water systems.


Assuntos
Biofilmes , Legionella pneumophila , Pseudomonas fluorescens , Biofilmes/crescimento & desenvolvimento , Legionella pneumophila/fisiologia , Pseudomonas fluorescens/fisiologia , Legionella/fisiologia , Microscopia Confocal , Tomografia de Coerência Óptica
19.
Neurobiol Learn Mem ; 106: 163-76, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23999220

RESUMO

Repeated exposure to an auditory stimulus leads to habituation of the electrophysiological and immediate-early-gene (IEG) expression response in the auditory system. A novel auditory stimulus reinstates this response in a form of dishabituation. This has been interpreted as the start of new memory formation for this novel stimulus. Changes in the location of an otherwise identical auditory stimulus can also dishabituate the IEG expression response. This has been interpreted as an integration of stimulus identity and stimulus location into a single auditory object, encoded in the firing patterns of the auditory system. In this study, we further tested this hypothesis. Using chronic multi-electrode arrays to record multi-unit activity from the auditory system of awake and behaving zebra finches, we found that habituation occurs to repeated exposure to the same song and dishabituation with a novel song, similar to that described in head-fixed, restrained animals. A large proportion of recording sites also showed dishabituation when the same auditory stimulus was moved to a novel location. However, when the song was randomly moved among 8 interleaved locations, habituation occurred independently of the continuous changes in location. In contrast, when 8 different auditory stimuli were interleaved all from the same location, a separate habituation occurred to each stimulus. This result suggests that neuronal memories of the acoustic identity and spatial location are different, and that allocentric location of a stimulus is not encoded as part of the memory for an auditory object, while its acoustic properties are. We speculate that, instead, the dishabituation that occurs with a change from a stable location of a sound is due to the unexpectedness of the location change, and might be due to different underlying mechanisms than the dishabituation and separate habituations to different acoustic stimuli.


Assuntos
Estimulação Acústica , Percepção Auditiva/fisiologia , Habituação Psicofisiológica/fisiologia , Memória/fisiologia , Localização de Som/fisiologia , Animais , Feminino , Tentilhões , Vocalização Animal/fisiologia
20.
Atten Percept Psychophys ; 85(2): 463-473, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36539573

RESUMO

Sound-induced flash illusion (SiFI) is an auditory-dominated effect in which observers will misperceive the number of flashes due to simultaneously presented beeps, which includes fission and fusion illusions. Although several individual differences have been found in SiFI, little is known about the effect of personality traits. In the present study, we presented flashes in near space and beeps in far space (Vnear_Afar) and flashes in far space and beeps in near space (Vfar_Anear) to better approximate the real world. We collected 103 participants' Big Five questionnaire results and their SiFI task performance to investigate the difference in trait level on the SiFI in the performance of accuracy, d' and c. The results show that all five personality traits had certain effects on the SiFI to different degrees, and different personality traits played different roles in the fission illusion and fusion illusion. The high agreeableness group was more prone to the fission illusion, and the report criteria were less strict. The report criteria of the low neuroticism group were stricter for the fusion illusion. The extraversion, conscientiousness and low openness groups were more prone to the fusion illusion in the Vnear_Afar condition than in the Vfar_Anear condition. The study indicated that personality traits were important but easily overlooked factors in multisensory illusion, which might make a difference between the fission illusion and the fusion illusion.


Assuntos
Ilusões , Humanos , Estimulação Acústica/métodos , Percepção Auditiva , Estimulação Luminosa/métodos , Personalidade , Percepção Visual
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