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1.
J Neurosci ; 43(23): 4352-4364, 2023 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-37160365

RESUMO

Cognitive demand is thought to modulate two often used, but rarely combined, measures: pupil size and neural α (8-12 Hz) oscillatory power. However, it is unclear whether these two measures capture cognitive demand in a similar way under complex audiovisual-task conditions. Here we recorded pupil size and neural α power (using electroencephalography), while human participants of both sexes concurrently performed a visual multiple object-tracking task and an auditory gap detection task. Difficulties of the two tasks were manipulated independent of each other. Participants' performance decreased in accuracy and speed with increasing cognitive demand. Pupil size increased with increasing difficulty for both the auditory and the visual task. In contrast, α power showed diverging neural dynamics: parietal α power decreased with increasing difficulty in the visual task, but not with increasing difficulty in the auditory task. Furthermore, independent of task difficulty, within-participant trial-by-trial fluctuations in pupil size were negatively correlated with α power. Difficulty-induced changes in pupil size and α power, however, did not correlate, which is consistent with their different cognitive-demand sensitivities. Overall, the current study demonstrates that the dynamics of the neurophysiological indices of cognitive demand and associated effort are multifaceted and potentially modality-dependent under complex audiovisual-task conditions.SIGNIFICANCE STATEMENT Pupil size and oscillatory α power are associated with cognitive demand and effort, but their relative sensitivity under complex audiovisual-task conditions is unclear, as is the extent to which they share underlying mechanisms. Using an audiovisual dual-task paradigm, we show that pupil size increases with increasing cognitive demands for both audition and vision. In contrast, changes in oscillatory α power depend on the respective task demands: parietal α power decreases with visual demand but not with auditory task demand. Hence, pupil size and α power show different sensitivity to cognitive demands, perhaps suggesting partly different underlying neural mechanisms.


Assuntos
Percepção Auditiva , Pupila , Masculino , Feminino , Humanos , Pupila/fisiologia , Percepção Auditiva/fisiologia , Eletroencefalografia , Desempenho Psicomotor/fisiologia , Cognição
2.
Ophthalmic Physiol Opt ; 44(1): 23-31, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37641939

RESUMO

INTRODUCTION: Despite the critical importance of binocular vision integrity in daily activities, there exists limited understanding of how alterations in binocular vision integrity impact gaze behaviour during dynamic, complex psychomotor skills. This study aimed to measure how alterations in binocular vision integrity, created by Bangerter filters (BF), affect gaze behaviour during multiple object tracking (MOT). METHODS: During the experiment, 22 volunteers completed the MOT task under three different visual conditions. The first condition involved natural binocular viewing, while the second and third conditions used 0.4 and 0.2 neutral density BF, respectively, resulting in monocular blur in the sensorially dominant eye. During the MOT task, participants were instructed to track three of eight balls for 10 s, and the speed was adjusted using a staircase procedure. Throughout the task, the following gaze parameters were recorded: fixation duration, saccade duration, amplitude and frequency as well as blink rate. RESULTS: During MOT execution, participants employed three gaze strategies regardless of viewing conditions: saccadic movements were predominant, followed by maintaining fixation on a central location throughout the trial and to a lesser extent, smooth pursuit eye movements. There was a significant effect of manipulating viewing conditions on the MOT scores (p = 0.046, η2 = 0.09). As the viewing conditions became more difficult, we observed a decrease in fixation duration (p = 0.004, η2 = 0.16) and blink rate (p < 0.001, η2 = 0.20) and an increase in saccadic amplitude (p < 0.001, η2 = 0.29). CONCLUSIONS: The results support the notion that perceptual-cognitive skills depend on the integrity of binocular vision, underscoring the sensitivity of gaze behaviours to any impairment of binocular function.


Assuntos
Transtornos da Visão , Visão Binocular , Humanos , Visão Monocular
3.
J Sports Sci Med ; 23(2): 276-288, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38841643

RESUMO

Agility, defined as the ability to rapidly respond to unforeseen events, constitutes a central performance component in football. Existing agility training approaches often focus on change of direction that does not reflect the complex motor-cognitive demands on the pitch. The objective of this study is to examine the effects of a novel motor-cognitive dual-task agility training (Multiple-object tracking integrated into agility training) on agility and football-specific test performance parameters, compared to agility and a change of direction (COD) training. Adult male amateur football players (n = 42; age: 27±6; height: 181±7cm; weight: 80±12kg) were randomly allocated to one of the three intervention groups (COD, agility, agility + multiple object tracking). The Loughborough Soccer Passing Test (LSPT), a dribbling test with/without cognitive task as well as the Random Star Run (with/without ball) and the modified T-Test were assessed before and after a 6-week training period. Time effects within the T-Test (F = 83.9; p < 0.001; η2 = 0.68) and dribbling test without cognitive task (F = 23.9; p < 0.001; η2 = 0.38) with improvements of all intervention groups (p < 0.05) were found. Dribbling with cognitive task revealed a time effect (F = 7.8; p = 0.008; η2 = 0.17), with improvements exclusively in the agility and dual-task agility groups (p < 0.05). Random Star Run with and without ball exhibited a time (F = 38.8; p < 0.001; η2 = 0.5; F = 82.7; p < 0.001; η2 = 0.68) and interaction effect (F = 14.14; p < 0.001; η2 = 0.42; F = 27.8; p < 0.001; η2 = 0.59), with improvements for the agility and dual-task agility groups. LSPT showed no time, group or interaction effect. The effects of change of direction training are limited to change of direction and dribbling test performance within preplanned scenarios. In contrast, motor-cognitive agility interventions result in notable enhancements in football-specific and agility tests, incorporating decision-making and multitasking components. No differences were observed between agility and agility + multiple object tracking. To achieve a transfer to game-relevant performance, coaches should focus on integrating cognitive challenges into motor training.


Assuntos
Desempenho Atlético , Cognição , Destreza Motora , Futebol , Humanos , Masculino , Desempenho Atlético/fisiologia , Desempenho Atlético/psicologia , Futebol/fisiologia , Adulto , Cognição/fisiologia , Destreza Motora/fisiologia , Adulto Jovem , Condicionamento Físico Humano/métodos , Condicionamento Físico Humano/fisiologia , Teste de Esforço/métodos , Corrida/fisiologia
4.
J Neurosci ; 42(46): 8709-8715, 2022 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-36202616

RESUMO

Keeping track of the location of multiple moving objects is one of the well documented functions of visual attention. However, the mechanism of attentional selection that supports such continuous tracking is unclear. In particular, it has been proposed that target selection in early visual cortex occurs in parallel, with tracking errors arising because of attentional limitations at later processing stages. Here, we examine whether, instead, total attentional capacity for enhancement of early visual processing of tracked targets is shared between all attended stimuli. If the magnitude of attentional facilitation of multiple tracked targets was a key limiting factor of tracking ability, then one should expect it to drop systematically with increasing set-size of tracked targets. Human observers (male and female) were instructed to track two, four, or six moving objects among a pool of identical distractors. Steady-state visual evoked potentials (SSVEPs) recorded during the tracking period revealed that the processing of tracked targets was consistently amplified compared with the processing of the distractors. The magnitude of this amplification decreased with increasing set size, and at lateral occipital electrodes it closely followed inverse proportionality to the number of tracked items, suggesting that limited attentional resources must be shared among the tracked stimuli. Accordingly, the magnitude of attentional facilitation predicted the behavioral outcome at the end of the trial. Together, these findings demonstrate that the limitations of multiple object tracking (MOT) across set-sizes stem from the limitations of top-down selective attention already at the early stages of visual processing.SIGNIFICANCE STATEMENT The ability to selectively attend to relevant features or objects is the key to flexibility of perception and action in the continuously changing environment. This ability is demonstrated in the multiple object tracking (MOT) task where observers monitor multiple independently moving objects at different locations in the visual field. The role of early attentional enhancement in tracking was previously acknowledged in the literature, however, the limitations on tracking were thought to arise during later stages of processing. Here, we demonstrate that the strength of attentional facilitation depends on the number of tracked objects and predicts successful tracking performance. Thus, it is the limitations of attentional enhancement at the early stages of visual processing that determine behavioral performance limits.


Assuntos
Percepção de Movimento , Córtex Visual , Masculino , Feminino , Humanos , Potenciais Evocados Visuais , Percepção de Movimento/fisiologia , Percepção Visual/fisiologia , Campos Visuais , Córtex Visual/fisiologia , Estimulação Luminosa
5.
Conscious Cogn ; 108: 103456, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36657222

RESUMO

Inattentional blindness is the failure to notice an unexpected object in plain sight when attention is otherwise engaged. We investigated what determines observers' attentional set in a dynamic-counting inattentional blindness paradigm, when task instructions and visual distinctiveness of task-relevant objects were either congruent or in opposition. In seven experiments, observers counted bounces by task-relevant objects, with the instruction either to count-by-shape (squares, diamonds, crosses) or count-by-colour (blue, purple). To manipulate visual distinctiveness, we varied the extent to which task-relevant and task-irrelevant objects looked different on two dimensions: shape and colour. When colour better distinguished task-relevant from task-irrelevant objects, observers-even if instructed count-by-shape-reported an unexpected object that matched the colour of task-relevant objects. Crucially, when instructed count-by-colour, but shape better distinguished task-relevant from task-irrelevant objects, observers reported an unexpected object that matched the shape of task-relevant objects. We conclude that observers set their attention to promote efficient task performance.


Assuntos
Transtornos Mentais , Percepção Visual , Humanos , Cognição , Cegueira , Análise e Desempenho de Tarefas
6.
Perception ; 52(3): 195-212, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36596275

RESUMO

Categorical perception (CP) describes our tendency to perceive the visual world in a categorical manner, suggesting that high-level cognition may affect perception. While most studies are conducted in static visual scenes, Sun and colleagues found CP effects of color in multiple object tracking (MOT). This study used functional magnetic resonance imaging to investigate the neural mechanism behind the categorical effects of color in MOT. Categorical effects were associated with activities in a broad range of brain regions, including both the ventral (V4, middle temporal gyrus) and dorsal pathways (MT + /V5, inferior parietal lobule) of feature processing, as well as frontal regions (middle frontal gyrus, medial superior frontal gyrus). We proposed that these regions are hierarchically organized and responsible for distinct functions. The color-selective V4 encodes color categories, making cross-category colors more discriminable than within-category colors. Meanwhile, the language and/or semantic regions encode the verbal information of the colors. Both visual and nonvisual codes of color categories then modulate the activities of motion-sensitive MT + areas and frontal areas responsible for attentional processes.


Assuntos
Lobo Parietal , Lobo Temporal , Humanos , Cor , Estimulação Luminosa , Cognição , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética
7.
Proc Natl Acad Sci U S A ; 117(39): 24581-24589, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32938799

RESUMO

In the real world, complex dynamic scenes often arise from the composition of simpler parts. The visual system exploits this structure by hierarchically decomposing dynamic scenes: When we see a person walking on a train or an animal running in a herd, we recognize the individual's movement as nested within a reference frame that is, itself, moving. Despite its ubiquity, surprisingly little is understood about the computations underlying hierarchical motion perception. To address this gap, we developed a class of stimuli that grant tight control over statistical relations among object velocities in dynamic scenes. We first demonstrate that structured motion stimuli benefit human multiple object tracking performance. Computational analysis revealed that the performance gain is best explained by human participants making use of motion relations during tracking. A second experiment, using a motion prediction task, reinforced this conclusion and provided fine-grained information about how the visual system flexibly exploits motion structure.


Assuntos
Percepção de Movimento , Percepção Visual , Adulto , Sequência de Bases , Feminino , Humanos , Masculino , Movimento , Adulto Jovem
8.
Sensors (Basel) ; 23(8)2023 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-37112365

RESUMO

Self-driving vehicles must be controlled by navigation algorithms that ensure safe driving for passengers, pedestrians and other vehicle drivers. One of the key factors to achieve this goal is the availability of effective multi-object detection and tracking algorithms, which allow to estimate position, orientation and speed of pedestrians and other vehicles on the road. The experimental analyses conducted so far have not thoroughly evaluated the effectiveness of these methods in road driving scenarios. To this aim, we propose in this paper a benchmark of modern multi-object detection and tracking methods applied to image sequences acquired by a camera installed on board the vehicle, namely, on the videos available in the BDD100K dataset. The proposed experimental framework allows to evaluate 22 different combinations of multi-object detection and tracking methods using metrics that highlight the positive contribution and limitations of each module of the considered algorithms. The analysis of the experimental results points out that the best method currently available is the combination of ConvNext and QDTrack, but also that the multi-object tracking methods applied on road images must be substantially improved. Thanks to our analysis, we conclude that the evaluation metrics should be extended by considering specific aspects of the autonomous driving scenarios, such as multi-class problem formulation and distance from the targets, and that the effectiveness of the methods must be evaluated by simulating the impact of the errors on driving safety.

9.
Sensors (Basel) ; 24(1)2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38203093

RESUMO

Multiple object tracking (MOT) plays an important role in intelligent video-processing tasks, which aims to detect and track all moving objects in a scene. Joint-detection-and-tracking (JDT) methods are thriving in MOT tasks, because they accomplish the detection and data association in a single stage. However, the slow training convergence and insufficient data association limit the performance of JDT methods. In this paper, the anchor-based query (ABQ) is proposed to improve the design of the JDT methods for faster training convergence. By augmenting the coordinates of the anchor boxes into the learnable queries of the decoder, the ABQ introduces explicit prior spatial knowledge into the queries to focus the query-to-feature learning of the JDT methods on the local region, which leads to faster training speed and better performance. Moreover, a new template matching (TM) module is designed for the JDT methods, which enables the JDT methods to associate the detection results and trajectories with historical features. Finally, a new transformer-based MOT method, ABQ-Track, is proposed. Extensive experiments verify the effectiveness of the two modules, and the ABQ-Track surpasses the performance of the baseline JDT methods, TransTrack. Specifically, the ABQ-Track only needs to train for 50 epochs to achieve convergence, while that for TransTrack is 150 epochs.

10.
Scand J Psychol ; 64(4): 437-452, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36892531

RESUMO

Multiple object tracking (MOT) is generally regarded as a pure attention-consuming task that draws heavily on attention resources. In the present study, we adopted a cross-channel visual-audio dual-task paradigm, i.e., the MOT task combined with the concurrent auditory N-back working memory task, to test whether working memory indeed plays a necessary role in the process of multiple tracking, as well as to further identify the specific types of working memory components involved in this process. Experiments 1a and 1b examined the relationship between the MOT task and nonspatial object working memory (OWM) processing by manipulating the tracking load and working memory load, respectively. Results in both experiments indicated that the concurrent nonspatial OWM task did not have a significant effect on the tracking capacity of the MOT task. In contrast, Experiments 2a and 2b examined the relationship between the MOT task and spatial working memory (SWM) processing by a similar approach. Results in both experiments indicated that the concurrent SWM task significantly impaired the tracking capacity of the MOT task, showing a gradual decrease with increasing SWM load. Overall, our study provides empirical evidence that multiple object tracking does involve working memory, primarily related to spatial working memory rather than nonspatial object working memory, which sheds more light on the mechanisms of multiple object tracking.


Assuntos
Atenção , Memória de Curto Prazo , Humanos
11.
Eur J Neurosci ; 55(5): 1200-1214, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35075713

RESUMO

Converging evidence shows that our visual system can track multiple visual, independently moving items over time. This is accomplished location-based by maintaining the individual spatial information of each target item or object-based by constructing an abstract object-based representation out of the tracked items. Previous work showed specific behavioural, electrophysiological and haemodynamic markers for location-based or object-based representations of the relevant targets by probing the encoded information subsequently after tracking. However, domain-specific differences of representational correlates during visual tracking itself have not been reported yet. The current study aims to identify spectral properties of the electrophysiological signal during tracking that might indicate location-based versus object-based maintenance of visual information. Subjects had to covertly track four out of eight visually identical items for several seconds while electrophysiological signals were recorded. Subsequently, a probe consisting of four items appeared and the subjects had to indicate with a button press whether the probe matched all targets or not. Subjects employing an object-based strategy showed an enhanced gamma response during the presentation of the target items at the beginning of the trial. On the other hand, subjects using a location-based strategy showed enhanced gamma synchronization throughout the tracking itself. Both the object- and location-based gamma responses yielded identical spatial topographical field distributions. These results indicate that object-based tracking is supported by enhanced encoding during the initial presentation of the targets to be tracked. Location-based tracking is characterized by the sustained maintenance of the individual targets during the entire tracking period in that same processing network.


Assuntos
Percepção de Movimento , Atenção/fisiologia , Humanos , Percepção de Movimento/fisiologia , Desempenho Psicomotor
12.
Perception ; 51(8): 539-548, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35668637

RESUMO

We assessed the association between measures of dynamic visual acuity and a multiple object tracking task in physically active young adults. Ninety-four young adults performed the dynamic visual acuity and multiple object tracking tasks. Dynamic visual acuity was measured for horizontal and random walk motion paths at four target speeds (5, 10, 20, and 30°/s). For the multiple object tracking task, participants had to track three out of eight balls for 10 s, and the object speed was adjusted by a staircase procedure. We found that multiple object tracking performance was associated with better identification of horizontally and randomly moving targets in the dynamic visual acuity test (p < .001, r = -.35 [-.52, -.16]; and p < .001, r = -.52 [-.65, -.35]; respectively). This effect was consistent across all target speeds (all p-values<0.05). However, static visual acuity did not correlate with any measure of dynamic visual acuity or multiple object tracking (p > 0.170 in all cases). This study provides novel insights into the association between the ability to identify horizontally and randomly moving targets and track multiple objects. Future studies are needed to determine the potential utility of dynamic visual acuity for talent identification and predicting sports performance in real-game situations.


Assuntos
Percepção de Movimento , Humanos , Movimento (Física) , Acuidade Visual , Adulto Jovem
13.
J Integr Neurosci ; 21(4): 122, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35864773

RESUMO

BACKGROUND: Although an extensive body of literature is trying to verify the acute effects of exercise, findings are highly contradictory due to many different study protocols. The number of studies using an intermittent exercise (IE) protocol is limited, especially with regard to comparison across the life span. We examined whether the effects of a HIIE protocol on performance in a perceptual-cognitive task (NeuroTracker® (NT)) differed between children, young adults, and older adults to address this gap. METHODS: A total of 36 participants participated in the present study: 12 children (CH, 6 females, 9.83 ± 1.19 years), 12 young adults (YA, 6 females, 23.5 ± 3.55 years), and 12 older adults (OA, 4 females, 66.92 ± 4.08 years). The IE treadmill protocol used in the present study consisted of eleven 30-second intervals at 90% VO2max, interspersed with 2-minute active recovery periods at 50% VO2max. Before and during this exercise protocol, three series of the NeuroTracker® task were performed after 5, 15, and 25 minutes. RESULTS: We observed a significant main effect time and a significant main effect group regarding absolute NT scores and progression during IE. YA had significantly higher absolute NT scores than CH and OA. The normalized perceptual-cognitive task progression was observed in OA and YA but not in CH. YA, in particular, showed progression in the NT performance during IE. CONCLUSIONS: The present study confirmed previous findings on age-related differences in NT performance. Based on these findings, the effects of different exercise protocols (e.g., continuous vs. intermittent) seem to be a worthwhile subject for future investigations. Normalized speed thresholds should best capture improvement differences between groups to compare results across studies better, as pre-test values are taken as the baseline.


Assuntos
Exercício Físico , Idoso , Criança , Exercício Físico/psicologia , Feminino , Humanos , Projetos Piloto , Adulto Jovem
14.
Sensors (Basel) ; 22(15)2022 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-35957422

RESUMO

Joint detection and embedding (JDE) methods usually fuse the target motion information and appearance information as the data association matrix, which could fail when the target is briefly lost or blocked in multi-object tracking (MOT). In this paper, we aim to solve this problem by proposing a novel association matrix, the Embedding and GioU (EG) matrix, which combines the embedding cosine distance and GioU distance of objects. To improve the performance of data association, we develop a simple, effective, bottom-up fusion tracker for re-identity features, named SimpleTrack, and propose a new tracking strategy which can mitigate the loss of detection targets. To show the effectiveness of the proposed method, experiments are carried out using five different state-of-the-art JDE-based methods. The results show that by simply replacing the original association matrix with our EG matrix, we can achieve significant improvements in IDF1, HOTA and IDsw metrics, and increase the tracking speed of these methods by around 20%. In addition, our SimpleTrack has the best data association capability among the JDE-based methods, e.g., 61.6 HOTA and 76.3 IDF1, on the test set of MOT17 with 23 FPS running speed on a single GTX2080Ti GPU.

15.
Sensors (Basel) ; 22(1)2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35009928

RESUMO

The paper considers the problem of tracking an unknown and time-varying number of unlabeled moving objects using multiple unordered measurements with unknown association to the objects. The proposed tracking approach integrates Bayesian nonparametric modeling with Markov chain Monte Carlo methods to estimate the parameters of each object when present in the tracking scene. In particular, we adopt the dependent Dirichlet process (DDP) to learn the multiple object state prior by exploiting inherent dynamic dependencies in the state transition using the dynamic clustering property of the DDP. Using the DDP to draw the mixing measures, Dirichlet process mixtures are used to learn and assign each measurement to its associated object identity. The Bayesian posterior to estimate the target trajectories is efficiently implemented using a Gibbs sampler inference scheme. A second tracking approach is proposed that replaces the DDP with the dependent Pitman-Yor process in order to allow for a higher flexibility in clustering. The improved tracking performance of the new approaches is demonstrated by comparison to the generalized labeled multi-Bernoulli filter.

16.
Behav Res Methods ; 54(3): 1508-1529, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34786653

RESUMO

Performance in everyday tasks, such as driving and sport, requires allocation of attention to task-relevant information and the ability to inhibit task-irrelevant information. Yet there are individual differences in this attentional function ability. This research investigates a novel task for measuring attention for action, called the Multiple Object Avoidance task (MOA), in its relation to the everyday tasks of driving and sport. The aim in Study 1 was to explore the efficacy of the MOA task to predict simulated driving behaviour and hazard perception. Whilst also investigating its test-retest reliability and how it correlates to self-report driving measures. We found that superior performance in the MOA task predicted simulated driving performance in complex environments and was superior at predicting performance compared to the Useful Field of View task. We found a moderate test-retest reliability and a correlation between the attentional lapses subscale of the Driving Behaviour Questionnaire. Study 2 investigated the discriminative power of the MOA in sport by exploring performance differences in those that do and do not play sports. We also investigated if the MOA shared attentional elements with other measures of visual attention commonly attributed to sporting expertise: Multiple Object Tracking (MOT) and cognitive processing speed. We found that those that played sports exhibited superior MOA performance and found a positive relationship between MOA performance and Multiple Object Tracking performance and cognitive processing speed. Collectively, this research highlights the utility of the MOA when investigating visual attention in everyday contexts.


Assuntos
Cognição , Humanos , Reprodutibilidade dos Testes
17.
Eur J Neurosci ; 54(9): 7289-7300, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34591329

RESUMO

Attentive motion tracking deficits measured using multiple object tracking (MOT) tasks have been identified in a number of neurodevelopmental disorders such as amblyopia and autism. These deficits are often attributed to the abnormal development of high-level attentional networks. However, neuroimaging evidence from amblyopia suggests that reduced MOT performance can be explained by impaired function in motion-sensitive area MT+ alone. To test the hypothesis that a subtle disruption of MT+ function could cause MOT impairment, we assessed whether continuous theta burst stimulation (cTBS) of MT+ influenced MOT task accuracy in individuals with normal vision. The MOT stimulus consisted of four target and four distractor dots and was presented at ±10° eccentricity (right/left hemifield). fMRI-guided cTBS was applied to left MT+. Participants (n = 13, age: 27 ± 3) attended separate active and sham cTBS sessions where the MOT task was completed before, 5-min post- and 30-min post-cTBS. Active cTBS significantly impaired MOT task accuracy relative to baseline for the right (stimulated) hemifield 5-min (10 ± 2% reduction) and 30-min (14 ± 3% reduction) post-stimulation. No impairment occurred within the left (control) hemifield after active cTBS or for either hemifield after sham cTBS. These results highlight the importance of lower level motion processing for MOT, suggesting that a minor disruption of MT+ function alone is sufficient to cause a deficit in MOT performance.


Assuntos
Atenção , Estimulação Magnética Transcraniana , Adulto , Humanos , Imageamento por Ressonância Magnética , Ritmo Teta , Adulto Jovem
18.
BMC Geriatr ; 21(1): 405, 2021 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193074

RESUMO

BACKGROUND: Body movement-controlled video games involving physical motion and visual attention may have the potential to train both abilities simultaneously. Our purpose was to determine the associations between performance in these games and visual attention, balance and mobility in a group of older adults. The long-term goal is to identify the optimal type of interactive games with regards to training potential. METHODS: Fifty healthy adults aged 65+ years participated in this cross-sectional study. Visual attention was measured with static and dynamic versions of a useful field of view (UFV) and a multiple object tracking (MOT) test. Balance was measured with a force plate in bi-pedal quiet stance test (QST) and one-legged stance (OLST). Gait variability and walking speed were assessed with the Five Meter Walk Test (5MWT). Four Microsoft™ Xbox® 360 Kinect™ interactive video games were chosen based on the apparent levels of visual attention demand. RESULTS: Visual attention (UFV and MOT) was significantly associated with performance in Xbox® Kinect™ games that appeared to have a high visual attention demand (p < 0.05), while there was minimal or no significant association with games with apparent low visual attention demand. Balance and mobility show correlations with visual attention, and with Xbox games. CONCLUSION: The results suggest that there are relationships between visual attention, balance, mobility and Xbox® Kinect™ game performance. Since different Xbox® games were associated with different balance, mobility and visual attention scores, a variety of such games, rather than a single game, may be most effective for training for falls prevention.


Assuntos
Jogos de Vídeo , Acidentes por Quedas , Idoso , Estudos Transversais , Humanos , Movimento , Equilíbrio Postural
19.
Sensors (Basel) ; 21(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34640672

RESUMO

The idea of SLAM (Simultaneous Localization and Mapping) being a solved problem revolves around the static world assumption, even though autonomous systems are gaining environmental perception capabilities by exploiting the advances in computer vision and data-driven approaches. The computational demands and time complexities remain the main impediment in the effective fusion of the paradigms. In this paper, a framework to solve the dynamic SLAM problem is proposed. The dynamic regions of the scene are handled by making use of Visual-LiDAR based MODT (Multiple Object Detection and Tracking). Furthermore, minimal computational demands and real-time performance are ensured. The framework is tested on the KITTI Datasets and evaluated against the publicly available evaluation tools for a fair comparison with state-of-the-art SLAM algorithms. The results suggest that the proposed dynamic SLAM framework can perform in real-time with budgeted computational resources. In addition, the fused MODT provides rich semantic information that can be readily integrated into SLAM.


Assuntos
Algoritmos , Semântica
20.
Sensors (Basel) ; 21(22)2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34833680

RESUMO

The human brain can effortlessly perform vision processes using the visual system, which helps solve multi-object tracking (MOT) problems. However, few algorithms simulate human strategies for solving MOT. Therefore, devising a method that simulates human activity in vision has become a good choice for improving MOT results, especially occlusion. Eight brain strategies have been studied from a cognitive perspective and imitated to build a novel algorithm. Two of these strategies gave our algorithm novel and outstanding results, rescuing saccades and stimulus attributes. First, rescue saccades were imitated by detecting the occlusion state in each frame, representing the critical situation that the human brain saccades toward. Then, stimulus attributes were mimicked by using semantic attributes to reidentify the person in these occlusion states. Our algorithm favourably performs on the MOT17 dataset compared to state-of-the-art trackers. In addition, we created a new dataset of 40,000 images, 190,000 annotations and 4 classes to train the detection model to detect occlusion and semantic attributes. The experimental results demonstrate that our new dataset achieves an outstanding performance on the scaled YOLOv4 detection model by achieving a 0.89 mAP 0.5.


Assuntos
Algoritmos , Semântica , Encéfalo , Humanos , Movimentos Sacádicos
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