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1.
J Exp Child Psychol ; 225: 105535, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36041236

RESUMO

During complex tasks, we use working memory to actively maintain goal sets and direct attention toward goal-relevant information in the environment. However, working memory is severely limited, and storing information in working memory is cognitively effortful. Previous work by Kibbe and Kowler [2011, Journal of Vision, 11(3), Article 14] showed that adults strategically modulate reliance on working memory during complex, goal-oriented tasks, varying the amount of information they store in working memory depending both on the cognitive demands of the task and on the ease with which task-relevant information can be accessed from the environment. We asked whether children, whose working memory and executive functions are undergoing significant developmental change, also use working memory strategically during complex tasks. Forty-six 8-10-year-old children searched through arrays of hidden objects to find three that belonged to a given category defined over the objects' features. We manipulated the cognitive demands of the task by increasing the complexity of the category. We manipulated the exploration costs of the task by varying the rate at which task-relevant information could be accessed. We measured children's search patterns to gain insights into how the children used working memory during the task. We found that as the cognitive demands of the task increased, children stored less information in working memory, relying more on exploration. When exploration was costlier, children explored less, storing more in working memory. These results suggest that developing children, like adults, make strategic decisions about when to explore versus when to store during a complex, goal-oriented task.


Assuntos
Função Executiva , Memória de Curto Prazo , Adulto , Atenção , Criança , Humanos
2.
J Exp Child Psychol ; 226: 105562, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36257254

RESUMO

Low-level visual features (e.g., motion, contrast) predict eye gaze during video viewing. The current study investigated the effect of narrative coherence on the extent to which low-level visual salience predicts eye gaze. Eye movements were recorded as 4-year-olds (n = 20) and adults (n = 20) watched a cohesive versus random sequence of video shots from a 4.5-min full vignette from Sesame Street. Overall, visual salience was a stronger predictor of gaze in adults than in children, especially when viewing a random shot sequence. The impact of narrative coherence on children's gaze was limited to the short period of time surrounding cuts to new video shots. The discussion considers potential direct effects of visual salience as well as incidental effects due to overlap between salient features and semantic content. The findings are also discussed in the context of developing video comprehension.


Assuntos
Atenção , Fixação Ocular , Adulto , Criança , Humanos , Pré-Escolar , Movimentos Oculares , Semântica , Compreensão
3.
J Exp Child Psychol ; 226: 105569, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36332436

RESUMO

Joint Attention (JA) in parent-infant interaction has been demonstrated to contribute to infants' language outcomes. A limited number of studies have investigated the characteristics of JA episodes during parent-toddler interaction in relation to toddlers' language development. The majority of these studies were conducted with mothers, whereas JA with fathers remains understudied. The current study investigated JA episodes during interactions with mothers and fathers separately as well as longitudinal associations with child language outcomes. A total of 31 toddlers (18 girls) and their mothers and fathers participated in the study at ages 2 years (M = 24.07 months, SD = 1.45) and 3 years (M = 37.44 months, SD = 1.72). JA episodes were observed during free play interactions at age 2 and were coded microanalytically; receptive and expressive language skills were assessed by Bayley Scales of Infant and Toddler Development-Third Edition at ages 2 and 3. No significant differences in JA episodes were found between mother-toddler and father-toddler dyads. Whereas JA characteristics with mothers were not found to be significantly associated with toddlers' language outcomes, multiple linear regression analyses showed that paternal education and parent-followed JA episodes during father-toddler interaction at age 2 explained a significant amount of variance in toddlers' expressive language skills at age 3. Findings suggest that JA episodes during interactions with fathers might benefit toddlers' expressive language development.


Assuntos
Desenvolvimento da Linguagem , Idioma , Feminino , Lactente , Criança , Humanos , Pré-Escolar , Linguagem Infantil , Cognição , Atenção
4.
J Environ Manage ; 325(Pt B): 116671, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36335701

RESUMO

Increasing attention has been given to the impact of PM2.5 concentration on human health. Exploring the influential factors of PM2.5 is conducive to improving air quality. Most existing studies explore the factors that influence the PM2.5 concentration from the perspective of cities or urban agglomerations, while few studies are conducted from the perspective of climate zones. We used the standard deviation ellipse and spatial autocorrelation analysis to explore the spatial-temporal evolution of the PM2.5 concentration in different climate zones in China during 2000-2018. We used differentiated EKC to construct panel regression models to explore the differences in the influential factors of the PM2.5 concentration in three climate zones. The number of cities with PM2.5 concentration less than 35 µg/m3 increased in the different climate zones. The center of gravity of the PM2.5 concentration has remained at the junction of the temperate and subtropical monsoon climate zones. The PM2.5 concentration had a high positive spatial autocorrelation in the different climate zones. The high-high clustering areas were located in the south of the temperate monsoon climate zone and the north of the subtropical monsoon climate zone. There was an inverted "U-shaped" curve between the PM2.5 concentration and economic development in China that varied in different climate zones. Identifying the differences in the influential factors of PM2.5 concentration in different climate zones will help to accelerate the implementation of the EKC inflection point.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Humanos , Material Particulado/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental , Poluição do Ar/análise , Cidades , China , Atenção
5.
Artigo em Inglês | MEDLINE | ID: mdl-36181957

RESUMO

Humans gain knowledge about threats not only from their own experiences but also from observing others' behavior. A neutral stimulus is associated with a threat stimulus for several times and the neutral stimulus will evoke fear responses, which is known as fear conditioning. When encountering a new event that is similar to one previously associated with a threat, one may feel afraid and produce fear responses. This is called fear generalization. Previous studies have mostly focused on fear conditioning and generalization based on direct learning, but few have explored how observational fear learning affects fear conditioning and generalization. To the best of our knowledge, no previous study has focused on the neural correlations of fear conditioning and generalization based on observational learning. In the present study, 58 participants performed a differential conditioning paradigm in which they learned the associations between neutral cues (i.e., geometric figures) and threat stimuli (i.e., electric shock). The learning occurred on their own (i.e., direct learning) and by observing other participant's responses (i.e., observational learning); the study used a within-subjects design. After each learning condition, a fear generalization paradigm was conducted by each participant independently while their behavioral responses (i.e., expectation of a shock) and electroencephalography (EEG) recordings or responses were recorded. The shock expectancy ratings showed that observational learning, compared to direct learning, reduced the differentiation between the conditioned threatening stimuli and safety stimuli and the increased shock expectancy to the generalization stimuli. The EEG indicated that in fear learning, threatening conditioned stimuli in observational and direct learning increased early discrimination (P1) and late motivated attention (late positive potential [LPP]), compared with safety conditioned stimuli. In fear generalization, early discrimination, late motivated attention, and orienting attention (alpha-event-related desynchronization [alpha-ERD]) to generalization stimuli were reduced in the observational learning condition. These findings suggest that compared to direct learning, observational learning reduces differential fear learning and increases the generalization of fear, and this might be associated with reduced discrimination and attentional function related to generalization stimuli.


Assuntos
Medo , Generalização Psicológica , Humanos , Medo/fisiologia , Generalização Psicológica/fisiologia , Condicionamento Clássico/fisiologia , Aprendizagem/fisiologia , Atenção
6.
J Exp Child Psychol ; 226: 105554, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36208491

RESUMO

From 10 months of age, human infants start to understand the function of the eyes in the looking behavior of others to the point where they preferentially orient toward an object if the social partner has open eyes rather than closed eyes. Thus far, gaze following has been investigated in controlled laboratory paradigms. The current study investigated this early ability using a remote live testing procedure, testing infants in their everyday environment while manipulating whether the experimenter could or could not see some target objects. A total of 32 11- and 12-month-old infants' looking behavior was assessed, varying the experimenter's eye status condition (open eyes vs closed eyes) in a between-participant design. Results showed that infants followed the gaze of a virtual social partner and that they preferentially followed open eyes rather than closed eyes. These data generalize past laboratory findings to a noisier home environment and demonstrate gaze processing capacities of infants to a virtual partner interacting with the participants in a live setup.


Assuntos
Atenção , Comportamento do Lactente , Lactente , Humanos , Fixação Ocular
7.
Behav Brain Res ; 437: 114145, 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36206819

RESUMO

Behavioral flexibility (or set-shifting), which is regulated by the prefrontal cortex (PFC), is often impaired in patients with attention-deficit/hyperactivity disorder (ADHD), which is characterized by poor inhibitory control and reinforcement learning. Transcranial direct current stimulation (tDCS) has been proposed as a means of noninvasive brain stimulation and a potential therapeutic tool for modulating behavioral flexibility. Animal studies can pave the way to know if tDCS application can potentially benefit rule- and goal-based activities in ADHD. Spontaneously hypertensive rats (SHRs) and inbred Wistar-Kyoto (WKY) rats were used as an animal model of ADHD and controls, respectively, and their strategy set-shifting abilities, including initial discrimination, set-shifting, and reversal learning tasks under 0-s or 15-s reinforcer delivery delay conditions, were evaluated. The tDCS treatment had a limited effect on the performance of the SHRs and WKY rats in initial discrimination task under 0-s delay condition. Under the 15-s delay condition, the SHRs had longer lever-press reaction times and/or more trial omissions than the WKY rats did when completing set-shifting and reversal-learning tasks. Among the SHRs, tDCS treatment improved the rats' reaction times and/or reduced their trial omissions in the set-shifting and reversal-learning tasks. Although tDCS may improve delayed reinforcement learning set-shifting performance in SHRs, further studies are required to clarify the responsible mechanism.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Estimulação Transcraniana por Corrente Contínua , Animais , Ratos , Ratos Endogâmicos WKY , Atenção/fisiologia , Ratos Endogâmicos SHR , Modelos Animais de Doenças
8.
Appl Ergon ; 106: 103892, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36191405

RESUMO

This study aims to investigate whether behavioral variability and participants' self-ratings can be used to detect mind-wandering while driving and to examine their effects on braking performance during a driving task. We created a novel driving task and added a sustained attention response task (SART). We examined the effects of mind-wandering on braking performance and whether mind-wandering could be detected from SART response variability. The within-subjects results showed that self-reports of inattentiveness during driving correlated significantly with SART response variability. Multiple regression analysis with brake reaction time as the dependent variable revealed a significant relationship between self-reports of inattentiveness and mind-wandering. However, there were no other consistent linear associations between mind-wandering and SART response variability. Our results not only suggest that inattentiveness to driving caused by mind-wandering impairs braking performance but also emphasize the importance and difficulty of detecting this state from behavioral data alone.


Assuntos
Atenção , Condução de Veículo , Humanos , Atenção/fisiologia , Tempo de Reação , Autorrelato
9.
Behav Neurosci ; 136(2): 195-205, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34941318

RESUMO

Although the interrupting effect of chronic pain on voluntary-directed attention is well-documented, research on the impact of chronic pain on involuntary-directed attention remains incomplete. This study aimed to investigate the influence of chronic pain on involuntary as well as voluntary allocation of attention as, respectively, indexed by the P3a and P3b components in the event-related potential derived from the electroencephalogram. Both involuntary and voluntary captures of attention were compared between 33 patients with chronic pain and 33 healthy controls using an auditory three-stimulus oddball task (with standard, target, and unexpected distractor tones). The results revealed a reduced P3a amplitude as well as a reduced P3b amplitude in patients with chronic pain compared to healthy controls, indicating a detrimental effect of chronic pain on involuntary and voluntary attention, respectively. This study extends the picture of the impairing effects of chronic pain on attentional allocation to a current task and attentional allocation to information outside the focus of attention. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Dor Crônica , Atenção , Eletroencefalografia , Potenciais Evocados , Humanos
10.
Artif Intell Med ; 133: 102407, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36328667

RESUMO

Recently, Artificial Intelligence namely Deep Learning methods have revolutionized a wide range of domains and applications. Besides, Digital Pathology has so far played a major role in the diagnosis and the prognosis of tumors. However, the characteristics of the Whole Slide Images namely the gigapixel size, high resolution and the shortage of richly labeled samples have hindered the efficiency of classical Machine Learning methods. That goes without saying that traditional methods are poor in generalization to different tasks and data contents. Regarding the success of Deep learning when dealing with Large Scale applications, we have resorted to the use of such models for histopathological image segmentation tasks. First, we review and compare the classical UNet and Att-UNet models for colon cancer WSI segmentation in a sparsely annotated data scenario. Then, we introduce novel enhanced models of the Att-UNet where different schemes are proposed for the skip connections and spatial attention gates positions in the network. In fact, spatial attention gates assist the training process and enable the model to avoid irrelevant feature learning. Alternating the presence of such modules namely in our Alter-AttUNet model adds robustness and ensures better image segmentation results. In order to cope with the lack of richly annotated data in our AiCOLO colon cancer dataset, we suggest the use of a multi-step training strategy that also deals with the WSI sparse annotations and unbalanced class issues. All proposed methods outperform state-of-the-art approaches but Alter-AttUNet generates the best compromise between accurate results and light network. The model achieves 95.88% accuracy with our sparse AiCOLO colon cancer datasets. Finally, to evaluate and validate our proposed architectures we resort to publicly available WSI data: the NCT-CRC-HE-100K, the CRC-5000 and the Warwick colon cancer histopathological dataset. Respective accuracies of 99.65%, 99.73% and 79.03% were reached. A comparison with state-of-art approaches is established to view and compare the key solutions for histopathological image segmentation.


Assuntos
Neoplasias do Colo , Processamento de Imagem Assistida por Computador , Humanos , Processamento de Imagem Assistida por Computador/métodos , Inteligência Artificial , Aprendizado de Máquina Supervisionado , Neoplasias do Colo/diagnóstico por imagem , Atenção
11.
BMC Bioinformatics ; 23(1): 458, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36329384

RESUMO

BACKGROUND: Biomedical named entity recognition (BioNER) is a basic and important task for biomedical text mining with the purpose of automatically recognizing and classifying biomedical entities. The performance of BioNER systems directly impacts downstream applications. Recently, deep neural networks, especially pre-trained language models, have made great progress for BioNER. However, because of the lack of high-quality and large-scale annotated data and relevant external knowledge, the capability of the BioNER system remains limited. RESULTS: In this paper, we propose a novel fully-shared multi-task learning model based on the pre-trained language model in biomedical domain, namely BioBERT, with a new attention module to integrate the auto-processed syntactic information for the BioNER task. We have conducted numerous experiments on seven benchmark BioNER datasets. The proposed best multi-task model obtains F1 score improvements of 1.03% on BC2GM, 0.91% on NCBI-disease, 0.81% on Linnaeus, 1.26% on JNLPBA, 0.82% on BC5CDR-Chemical, 0.87% on BC5CDR-Disease, and 1.10% on Species-800 compared to the single-task BioBERT model. CONCLUSION: The results demonstrate our model outperforms previous studies on all datasets. Further analysis and case studies are also provided to prove the importance of the proposed attention module and fully-shared multi-task learning method used in our model.


Assuntos
Mineração de Dados , Redes Neurais de Computação , Mineração de Dados/métodos , Benchmarking , Idioma , Atenção
12.
Sleep Med Clin ; 17(4): 647-656, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36333083

RESUMO

Obstructive sleep apnea (OSA) is highly prevalent sleep disorder that causes sleep fragmentation, frequent awakenings, and intermittent hypoxia. Both OSA and cognitive decline increase in prevalence with factors such as increasing age and body mass. Multiple areas of cognition can be affected, including attention, executive function, memory, as well as emotional functioning through direct effects on brain health. Although positive airway pressure therapy has shown to improve some aspects of cognitive functioning, it does not fully alleviate all cognitive complaints. Inclusion of complementary approaches to comorbidities associated with OSA could potentially enhance treatment outcomes.


Assuntos
Disfunção Cognitiva , Apneia Obstrutiva do Sono , Humanos , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/epidemiologia , Apneia Obstrutiva do Sono/terapia , Função Executiva , Cognição , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/terapia , Disfunção Cognitiva/etiologia , Atenção
13.
Sci Rep ; 12(1): 18717, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36333393

RESUMO

Learning, rendered in an implicit (unconscious) or explicit (conscious) way, is a crucial part of our daily life. Different factors, like attention or motivation, influence the transformation from implicit to explicit memory. Via virtual reality a lively and engaging surrounding can be created, whereby motivational processes are assumed to be a vital part of the transition from implicit to explicit memory. In the present study, we tested the impact of an enriched virtual reality compared to two conventional, non-enriched 2D-computer-screen based tasks on implicit to explicit memory transformation, using an audio-visual sequential association task. We hypothesized, that the immersive nature of the VR surrounding enhances the transfer from implicit to explicit memory. Notably, the overall amount of learned sequence pairs were not significantly different between experimental groups, but the degree of awareness was affected by the different settings. However, we observed an increased level of explicitly remembered pairs within the VR group compared to two screen-based groups. This finding clearly demonstrates that a near-natural experimental setting affects the transformation process from implicit to explicit memory.


Assuntos
Aprendizagem , Memória , Rememoração Mental , Estado de Consciência , Atenção
14.
BMC Psychol ; 10(1): 251, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36333780

RESUMO

BACKGROUND: Emotional stimuli used as targets of working memory (WM) tasks can moderate age-related differences in WM performance, showing that aging is associated with reductions in negativity bias. This phenomenon is referred to as the positivity effect. However, there is little research on whether emotional distractors have a similar moderating effect. Moreover, the underlying neural mechanism of this effect has not been studied. In this study, we examined the behavioral and neurophysiological basis for age differences in resistance to emotional distractors within WM. METHODS: Older adults (n = 30, ages 60-74) and young adults (n = 35, ages 19-26) performed a 2-back task in which a digit was superimposed on a face with a happy, angry, or neutral expression as a distractor. Event-related potential (ERP) was simultaneously recorded to assess P2, N2, and later positive potential (LPP) amplitudes. RESULTS: Older adults were less accurate and slower than young adults on the WM task. Moreover, the results demonstrated a significant interaction between age and emotional valence on response accuracy, young adults' performance was worse when the distractor was neutral or positive than when it was negative, but there was no effect of the emotional valence of distractors on older adults' WM performance. ERP analyses revealed greater P2 amplitude in older adults than young adults, regardless of the emotional valence of distractors. However, older adults and young adults did not differ on N2 or LPP amplitude, and negative distractors elicited greater N2 than positive distractors in both age groups. CONCLUSIONS: The behavioral findings provided evidence of age-related reductions in negativity bias. Thus, the behavioral measures indicated a positivity effect in WM. However, the ERP results did not show this same interaction. These discrepant results raise questions about whether and to what extent older and young adults differ in controlling the effect of emotional distractors in WM.


Assuntos
Atenção , Memória de Curto Prazo , Adulto Jovem , Humanos , Idoso , Pessoa de Meia-Idade , Adulto , Memória de Curto Prazo/fisiologia , Atenção/fisiologia , Emoções/fisiologia , Potenciais Evocados/fisiologia , Envelhecimento/psicologia
15.
16.
Sci Rep ; 12(1): 18789, 2022 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-36335137

RESUMO

Selective listening to cocktail-party speech involves a network of auditory and inferior frontal cortical regions. However, cognitive and motor cortical regions are differentially activated depending on whether the task emphasizes semantic or phonological aspects of speech. Here we tested whether processing of cocktail-party speech differs when participants perform a shadowing (immediate speech repetition) task compared to an attentive listening task in the presence of irrelevant speech. Participants viewed audiovisual dialogues with concurrent distracting speech during functional imaging. Participants either attentively listened to the dialogue, overtly repeated (i.e., shadowed) attended speech, or performed visual or speech motor control tasks where they did not attend to speech and responses were not related to the speech input. Dialogues were presented with good or poor auditory and visual quality. As a novel result, we show that attentive processing of speech activated the same network of sensory and frontal regions during listening and shadowing. However, in the superior temporal gyrus (STG), peak activations during shadowing were posterior to those during listening, suggesting that an anterior-posterior distinction is present for motor vs. perceptual processing of speech already at the level of the auditory cortex. We also found that activations along the dorsal auditory processing stream were specifically associated with the shadowing task. These activations are likely to be due to complex interactions between perceptual, attention dependent speech processing and motor speech generation that matches the heard speech. Our results suggest that interactions between perceptual and motor processing of speech relies on a distributed network of temporal and motor regions rather than any specific anatomical landmark as suggested by some previous studies.


Assuntos
Córtex Auditivo , Percepção da Fala , Humanos , Fala/fisiologia , Estimulação Acústica/métodos , Percepção da Fala/fisiologia , Imageamento por Ressonância Magnética , Atenção/fisiologia , Córtex Auditivo/fisiologia , Mapeamento Encefálico/métodos
17.
Sensors (Basel) ; 22(21)2022 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-36365814

RESUMO

Due to the complexity of sea surface environments, such as speckles and side lobes of ships, ship wake, etc., the detection of ship targets in synthetic aperture radar (SAR) images is still confronted with enormous challenges, especially for small ship targets. Aiming at the key problem of ship target detection in the complex environments, the article proposes a constant false alarm rate (CFAR) algorithm for SAR ship target detection based on the attention contrast mechanism of intensity and texture feature fusion. First of all, the local feature attention contrast enhancement is performed based on the intensity dissimilarity and the texture feature difference described by local binary pattern (LBP) between ship targets and sea clutter, so as to realize the target enhancement and background suppression. Furthermore, the adaptive CFAR ship target detection method based on generalized Gamma distribution (GΓD) which can fit the clutter well by the goodness-of-fit analyses is carried out. Finally, the public datasets HRSID and LS-SSDD-v1.0 are used to verify the effectiveness of the proposed detection method. A large number of experimental results show that the proposed method can suppress clutter background and speckle noise and improve the target-to-clutter rate (TCR) significantly, and has the relative high detection rate and low false alarm rate in the complex background and multi-target marine environments.


Assuntos
Radar , Navios , Algoritmos , Atenção
18.
Sensors (Basel) ; 22(21)2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36366030

RESUMO

Recent years have witnessed an increasing interest in deploying state-of-the-art augmented reality (AR) head-mounted displays (HMDs) for agri-food applications. The benefits of AR HMDs to agri-food industry stakeholders (e.g., food suppliers, retail/food service) have received growing attention and recognition. AR HMDs enable users to make healthier dietary choices, experience novel changes in their perception of taste, enhance the cooking and food shopping experience, improve productivity at work and enhance the implementation of precision farming. Therefore, although development costs are still high, the case for integration of AR in food chains appears to be compelling. This review will present the most recent developments of AR HMDs for agri-food relevant applications. The summarized applications can be clustered into different themes: (1) dietary and food nutrition assessment; (2) food sensory science; (3) changing the eating environment; (4) retail food chain applications; (5) enhancing the cooking experience; (6) food-related training and learning; and (7) food production and precision farming. Limitations of current practices will be highlighted, along with some proposed applications.


Assuntos
Realidade Aumentada , Óculos Inteligentes , Atenção , Aprendizagem
19.
Sensors (Basel) ; 22(21)2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36366169

RESUMO

Forward-looking sonar is a technique widely used for underwater detection. However, most sonar images have underwater noise and low resolution due to their acoustic properties. In recent years, the semantic segmentation model U-Net has shown excellent segmentation performance, and it has great potential in forward-looking sonar image segmentation. However, forward-looking sonar images are affected by noise, which prevents the existing U-Net model from segmenting small objects effectively. Therefore, this study presents a forward-looking sonar semantic segmentation model called Feature Pyramid U-Net with Attention (FPUA). This model uses residual blocks to improve the training depth of the network. To improve the segmentation accuracy of the network for small objects, a feature pyramid module combined with an attention structure is introduced. This improves the model's ability to learn deep semantic and shallow detail information. First, the proposed model is compared against other deep learning models and on two datasets, of which one was collected in a tank environment and the other was collected in a real marine environment. To further test the validity of the model, a real forward-looking sonar system was devised and employed in the lake trials. The results show that the proposed model performs better than the other models for small-object and few-sample classes and that it is competitive in semantic segmentation of forward-looking sonar images.


Assuntos
Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Processamento de Imagem Assistida por Computador/métodos , Semântica , Som , Atenção
20.
J Neuroeng Rehabil ; 19(1): 123, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36369027

RESUMO

BACKGROUND: In older adults, the extent to which performing a cognitive task when standing diminishes postural control is predictive of future falls and cognitive decline. The neurophysiology of such "dual-tasking" and its effect on postural control (i.e., dual-task cost) in older adults are poorly understood. The purpose of this study was to use electroencephalography (EEG) to examine the effects of dual-tasking when standing on brain activity in older adults. We hypothesized that compared to single-task "quiet" standing, dual-task standing would decrease alpha power, which has been linked to decreased motor inhibition, as well as increase the ratio of theta to beta power, which has been linked to increased attentional control. METHODS: Thirty older adults without overt disease completed four separate visits. Postural sway together with EEG (32-channels) were recorded during trials of standing with and without a concurrent verbalized serial subtraction dual-task. Postural control was measured by average sway area, velocity, and path length. EEG metrics included absolute alpha-, theta-, and beta-band powers as well as theta/beta power ratio, within six demarcated regions-of-interest: the left and right anterior, central, and posterior regions of the brain. RESULTS: Most EEG metrics demonstrated moderate-to-high between-day test-retest reliability (intra-class correlation coefficients > 0.70). Compared with quiet standing, dual-tasking decreased alpha-band power particularly in the central regions bilaterally (p = 0.002) and increased theta/beta power ratio in the anterior regions bilaterally (p < 0.001). A greater increase in theta/beta ratio from quiet standing to dual-tasking in numerous demarcated brain regions correlated with greater dual-task cost (i.e., absolute increase, indicative of worse performance) to postural sway metrics (r = 0.45-0.56, p < 0.01). Lastly, participants who exhibited greater alpha power during dual-tasking in the anterior-right (r = 0.52, p < 0.01) and central-right (r = 0.48, p < 0.01) regions had greater postural sway velocity during dual-tasking. CONCLUSION: In healthy older adults, alpha power and theta/beta power ratio change with dual-task standing. The change in theta/beta power ratio in particular may be related to the ability to regulate standing postural control when simultaneously performing unrelated, attention-demanding cognitive tasks. Modulation of brain oscillatory activity might therefore be a novel target to minimize dual-task cost in older adults.


Assuntos
Atenção , Equilíbrio Postural , Humanos , Idoso , Reprodutibilidade dos Testes , Equilíbrio Postural/fisiologia , Atenção/fisiologia , Posição Ortostática , Encéfalo , Cognição/fisiologia
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