Article
Ecology
Anne Kempel, Eric Allan, Martin M. Gossner, Malte Jochum, James B. Grace, David A. Wardle
Summary: In the absence of disturbance, ecosystems often undergo decline or retrogression, resulting in reductions in primary productivity, plant biomass, nutrient cycling and foliar quality. However, the effects of ecosystem retrogression on higher trophic levels, such as herbivores and predators, are not well understood. This study shows that the availability of nutrients strongly influences invertebrate herbivore biomass when predator abundance is low, but shifts to top-down control when predators are abundant. These findings highlight the importance of considering nutrient-independent variation in predator abundance when studying trophic cascades and herbivore effects on plant communities.
Article
Multidisciplinary Sciences
Jinwei Xing, Elizabeth R. Chrastil, Douglas A. Nitz, Jeffrey L. Krichmar
Summary: Humans and animals have the ability to translate their position from one spatial frame of reference to another, and seamlessly switch between top-down and first-person views. The medial temporal lobe and other cortical regions are found to contribute to this function. By using variational autoencoders to reconstruct views, researchers gain insights into how the neural system carries out these computations.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
Yonatan Vanunu, Jared M. Hotaling, Mike E. Le Pelley, Ben R. Newell
Summary: The study shows that initial attention in risky choice is driven by perceptual properties of the stimulus, while subsequent choices are more influenced by goal-driven factors. Options with the highest values and largest font sizes have the greatest impact on choice, while distractors may attract attention but do not affect actual decision-making.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Neurosciences
Jose M. G. Penalver, David Lopez-Garcia, Carlos Gonzalez-Garcia, Blanca Aguado-Lopez, Juan M. Gorriz, Maria Ruz
Summary: Proactive cognition brain models are widely used and acknowledged nowadays. This study aimed to investigate the similarities and differences in the preparatory activity of selective attention and perceptual expectation. EEG data showed that both manipulations led to a significant prediction of the relevant or expected target category. However, the neural patterns were unique to each condition, indicating distinct mechanisms in attention and expectation. These findings contribute to our understanding of top-down anticipatory processing in the brain.
Article
Multidisciplinary Sciences
Jafar Doostmohammadi, Marc Alwin Gieselmann, Jochem van Kempen, Reza Lashgari, Ali Yoonessi, Alexander Thiele
Summary: Sharp-wave ripples (SWRs) are observed in the hippocampus during offline states, but their association with awake conscious and goal-directed behavior is unknown. This study found that ripple activity also occurs in macaque visual areas V1 and V4 during focused spatial attention. The occurrence of ripples is influenced by stimulus characteristics and attentional focus. During attention cued to the receptive field, ripples reduced the monkey's reaction time in detecting behaviorally relevant events. These findings suggest that ripple activity is not limited to offline states but occurs in neocortex during active attentive states.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Neurosciences
Min Shao, Lingxiao Li, Xiong Li, Zilong Wei, Junyao Wang, Mingyu Hong, Xiaocui Liu, Jing Meng
Summary: Prolonged exposure to others' suffering can lead to empathy fatigue, but shifting attention from emotional to cognitive components can mitigate this fatigue. This research investigates how top-down attention influences empathy fatigue in auditory and visual modalities.
Article
Neurosciences
Faqiang Liu, Rong Zhao
Summary: This study successfully enhances the performance of spiking neural networks (SNNs) by introducing a top-down attention mechanism, resulting in improved robustness and computing efficiency. The study utilizes a hybrid network model and a weakly-supervised objective, avoiding labor-intensive annotations, and demonstrates the superior performance of the model through comprehensive evaluations.
FRONTIERS IN NEUROSCIENCE
(2022)
Article
Computer Science, Artificial Intelligence
Yanxia Xie, Junhua Sun
Summary: In this paper, a graph-based top-down visual attention model is constructed to extract lockwires from complex backgrounds using the multiscale top-hat transformation. The proposed method includes constructing multiscale anisotropic Gaussian structuring elements to obtain the top-hat feature map, constructing an undirected graph based on a novel connectivity function, and extracting lockwire candidates by minimizing the redefined cost function using an improved shortest path algorithm. Saliency metrics are designed to enhance the saliency of lockwires while weakening backgrounds. Experimental results demonstrate the superior performance of the proposed method compared to state-of-the-art methods.
EXPERT SYSTEMS WITH APPLICATIONS
(2023)
Article
Multidisciplinary Sciences
Jian Ding, Zheng Ye, Fei Xu, Xiangmei Hu, Hao Yu, Shen Zhang, Yanni Tu, Qiuyu Zhang, Qingyan Sun, Tianmiao Hua, Zhong-Lin Lu
Summary: This study explores the relative contributions of higher-order and primary visual cortex to visual perception by modulating transcranial direct current stimulation. The findings suggest that suppressing top-down influence of the higher-order visual cortex reduces behavioral and neuronal contrast sensitivity and increases contrast thresholds. Additionally, the study indicates that the top-down influence increases contrast sensitivity by reducing internal additive noise and the impact of external noise.
Article
Neurosciences
James K. Moran, Julian Keil, Alexander Masurovsky, Stefan Gutwinski, Christiane Montag, Daniel Senkowski
Summary: This study found that patients with schizophrenia showed reduced intersensory attention effects for unisensory stimuli compared to healthy controls, but not for bisensory stimuli. At the neural level, schizophrenia patients exhibited decreased intersensory attention effects for bisensory stimuli. However, there were no significant differences between schizophrenia patients and healthy controls in terms of multisensory integration.
Article
Computer Science, Information Systems
Chaowei Fang, Haibin Tian, Dingwen Zhang, Qiang Zhang, Jungong Han, Junwei Han
Summary: This paper proposes a novel framework based on densely nested top-down flows for salient object detection. The framework enhances the propagation of high-level features, alleviates the gradient vanishing issues, and improves memory efficiency. The integration of this framework with EfficientNet leads to a highly light-weighted SOD model.
SCIENCE CHINA-INFORMATION SCIENCES
(2022)
Article
Computer Science, Information Systems
Yingwei Pan, Yehao Li, Ting Yao, Tao Mei
Summary: This article discusses a technique for image captioning that utilizes a bottom-up and top-down attention mechanism to select and describe salient objects based on human subjective experience. The proposed approach uses the object sequence of interest as top-down signals to guide caption generation and incorporates an attention mechanism to integrate bottom-up and top-down signals. It also introduces a contrastive learning-based objective to ensure reliable and explainable cross-modal reasoning.
ACM TRANSACTIONS ON MULTIMEDIA COMPUTING COMMUNICATIONS AND APPLICATIONS
(2023)
Article
Computer Science, Information Systems
Ashkan Taghipour, Hassan Ghassemian
Summary: The paper introduces a visual attention approach to leverage hyperspectral anomaly detection, integrating spatial and spectral anomaly features, and outperforms six state-of-the-art anomaly detection methods in the experiment.
JOURNAL OF VISUAL COMMUNICATION AND IMAGE REPRESENTATION
(2021)
Article
Multidisciplinary Sciences
Lena Warnke, Jan P. de Ruiter
Summary: Listeners can recognize speaker changes by relying on both acoustic features and linguistic representations. However, the coherence of the conversation plays a crucial role in this process. When utterances make sense for different speakers to say, even if they are spoken by the same person, listeners perceive them as being spoken by different speakers. On the other hand, when the pragmatic coherence is disrupted by scrambling word order, listeners are unable to detect speaker changes.
SCIENTIFIC REPORTS
(2023)
Article
Psychology, Experimental
Hannah L. Delchau, Bruce K. Christensen, Ottmar Lipp, Stephanie C. Goodhew
Summary: This study examined the relationship between social anxiety and biased attention toward threatening facial expressions, finding that individuals with higher levels of social anxiety exhibit selective deficits in attentional shifting towards happy faces when paired with angry faces, but not with neutral faces.
Review
Computer Science, Information Systems
Thumeera R. Wanasinghe, Raymond G. Gosine, Lesley Anne James, George K. I. Mann, Oscar de Silva, Peter J. Warrian
IEEE INTERNET OF THINGS JOURNAL
(2020)
Article
Engineering, Aerospace
Mahmoud A. K. Gomaa, Oscar de Silva, George K. Mann, Raymond G. Gosine
Summary: This article introduces an IMM filter with multiple models for improving the visual-inertial navigation performance of microaerial vehicles. By combining conventional VIN and drag force VIN within an error-state IMM filtering framework, the system's adaptability and consistency in different scenarios are enhanced. The design of measurement models using epipolar geometry constraints improves computational efficiency of state updates.
IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS
(2021)
Article
Engineering, Electrical & Electronic
Eranga Fernando, Oscar De Silva, George K. Mann, Raymond Gosine
Summary: This study performs a nonlinear observability analysis on RF range assisted INS for localizing quadrotor MAVs in indoor environments. The proposed INS formulation incorporates aerodynamic drag forces and eliminates the need for a velocity sensor. The analysis identifies unobservable conditions and validates them through numerical simulation, enabling range assisted localization with fewer RF range nodes.
IEEE SENSORS JOURNAL
(2022)
Review
Automation & Control Systems
Didula Dissanayaka, Thumeera R. Wanasinghe, Oscar De Silva, Awantha Jayasiri, George K. Mann
Summary: This paper provides a comprehensive review of advanced navigation methods for unmanned aerial vehicles (UAVs) used in parcel delivery, with a focus on state-of-the-art sensor configurations and multi-sensor data fusion architectures. It also discusses the safety regulations imposed by regulatory bodies in the US and Canada for UAV navigation. The paper explores the integration of visual lidar odometry and mapping (VLOAM) with GPS to overcome the limitations of existing navigation solutions, presenting a comparative study and numerical simulations to validate the regulatory compliance of the integrated system under common GPS failure cases.
IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING
(2023)
Article
Automation & Control Systems
Mahmoud A. K. Gomaa, Oscar De Silva, George K. Mann, Raymond G. Gosine
Summary: This article presents the design of a stability-guaranteed nonlinear model predictive controller for quadrotor-type microaerial vehicles. The controller is computationally less demanding and provides more stable closed-loop performance. The proposed controller uses the shortest stabilizing prediction horizon and enables fast optimization for implementing fast trajectories. MATLAB simulations and real-time lab experiments validate the improved performance of the controller.
IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY
(2023)
Article
Automation & Control Systems
Mahmoud A. K. Gomaa, Oscar De Silva, George K. Mann, Raymond G. Gosine
Summary: This article proposes a novel NMPC method for multi-rotor aerial vehicles. The method is designed without considering stabilizing terminal costs or constraints, and ensures closed-loop stability by designing a tailored running cost. The performance of the proposed method is evaluated through numerical simulations, and the results show superior performance in terms of tracking accuracy, convergence rate, and computation time.
IEEE CONTROL SYSTEMS LETTERS
(2022)
Proceedings Paper
Automation & Control Systems
Nushen M. Senevirathna, Oscar De Silva, George K. Mann, Raymond G. Gosine
2020 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS)
(2020)
Proceedings Paper
Automation & Control Systems
Mahmoud A. K. Gomaa, Oscar De Silva, George K. Mann, Raymond G. Gosine
2020 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS)
(2020)
Proceedings Paper
Automation & Control Systems
Mahmoud A. K. Gomaa, Oscar De Silva, George K. I. Mann, Raymond G. Gosine, Robert Hengeveld
2020 AMERICAN CONTROL CONFERENCE (ACC)
(2020)
Article
Robotics
Trung Nguyen, George K. I. Mann, Andrew Vardy, Raymond G. Gosine
JOURNAL OF ROBOTICS
(2020)
Proceedings Paper
Automation & Control Systems
R. K. P. S. Ranaweera, R. A. M. Abayasiri, R. A. R. C. Gopura, T. S. S. Jayawardena, G. K. Mann
CONFERENCE PROCEEDINGS OF 2019 5TH INTERNATIONAL CONFERENCE ON CONTROL, AUTOMATION AND ROBOTICS (ICCAR)
(2019)
Proceedings Paper
Computer Science, Artificial Intelligence
Eranga Fernando, Oscar De Silva, George K. Mann, Raymond G. Gosine
2019 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS)
(2019)
Proceedings Paper
Automation & Control Systems
Thumeera R. Wanasinghe, Benjamin Robert Dowden, Oscar De Silva, George K. I. Mann, Cyril Lundrigan
2019 INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA)
(2019)
Article
Computer Science, Information Systems
Thumeera R. Wanasinghe, Leah Wroblewski, Bui K. Petersen, Raymond G. Gosine, Lesley Anne James, Oscar De Silva, George K. Mann, Peter J. Warrian
Article
Computer Science, Information Systems
Thumeera R. Wanasinghe, Raymond G. Gosine, Oscar De Silva, George K. I. Mann, Lesley Anne James, Peter Warrian