background activity
EEGAgent: A Unified Framework for Automated EEG Analysis Using Large Language Models
Zhao, Sha, Peng, Mingyi, Jiang, Haiteng, Li, Tao, Li, Shijian, Pan, Gang
Scalable and generalizable analysis of brain activity is essential for advancing both clinical diagnostics and cognitive research. Electroencephalography (EEG), a non-invasive modality with high temporal resolution, has been widely used for brain states analysis. However, most existing EEG models are usually tailored for individual specific tasks, limiting their utility in realistic scenarios where EEG analysis often involves multi-task and continuous reasoning. In this work, we introduce EEGAgent, a general-purpose framework that leverages large language models (LLMs) to schedule and plan multiple tools to automatically complete EEG-related tasks. EEGAgent is capable of performing the key functions: EEG basic information perception, spatiotemporal EEG exploration, EEG event detection, interaction with users, and EEG report generation. To realize these capabilities, we design a toolbox composed of different tools for EEG prepro-cessing, feature extraction, event detection, etc. These capabilities were evaluated on public datasets, and our EEGAgent can support flexible and interpretable EEG analysis, highlighting its potential for real-world clinical applications.
Short-term Temporal Dependency Detection under Heterogeneous Event Dynamic with Hawkes Processes
Chen, Yu, Li, Fengpei, Schneider, Anderson, Nevmyvaka, Yuriy, Amarasingham, Asohan, Lam, Henry
Many event sequence data exhibit mutually exciting or inhibiting patterns. Reliable detection of such temporal dependency is crucial for scientific investigation. The de facto model is the Multivariate Hawkes Process (MHP), whose impact function naturally encodes a causal structure in Granger causality. However, the vast majority of existing methods use direct or nonlinear transform of standard MHP intensity with constant baseline, inconsistent with real-world data. Under irregular and unknown heterogeneous intensity, capturing temporal dependency is hard as one struggles to distinguish the effect of mutual interaction from that of intensity fluctuation. In this paper, we address the short-term temporal dependency detection issue. We show the maximum likelihood estimation (MLE) for cross-impact from MHP has an error that can not be eliminated but may be reduced by order of magnitude, using heterogeneous intensity not of the target HP but of the interacting HP. Then we proposed a robust and computationally-efficient method modified from MLE that does not rely on the prior estimation of the heterogeneous intensity and is thus applicable in a data-limited regime (e.g., few-shot, no repeated observations). Extensive experiments on various datasets show that our method outperforms existing ones by notable margins, with highlighted novel applications in neuroscience.
Stimulus Evoked Independent Factor Analysis of MEG Data with Large Background Activity
This paper presents a novel technique for analyzing electromagnetic imaging data obtained using the stimulus evoked experimental paradigm. The technique is based on a probabilistic graphical model, which describes the data in terms of underlying evoked and interference sources, and explicitly models the stimulus evoked paradigm. The new algorithm outperforms existing techniques on two real datasets, as well as on simulated data.
You're muted... or are you? Videoconferencing apps may listen even when mic is off
Kassem Fawaz's brother was on a videoconference with the microphone muted when he noticed that the microphone light was still on--indicating, inexplicably, that his microphone was being accessed. Alarmed, he asked Fawaz, an expert in online privacy and an assistant professor of electrical and computer engineering at the University of WisconsinโMadison, to look into the issue. Fawaz and graduate student Yucheng Yang investigated whether this "mic-off-light-on" phenomenon was more widespread. They tried out many different videoconferencing applications on major operating systems, including iOS, Android, Windows and Mac, checking to see if the apps still accessed the microphone when it was muted. "It turns out, in the vast majority of cases, when you mute yourself, these apps do not give up access to the microphone," says Fawaz. "And that's a problem. When you're muted, people don't expect these apps to collect data."
A Hybrid Attention Mechanism for Weakly-Supervised Temporal Action Localization
Islam, Ashraful, Long, Chengjiang, Radke, Richard J.
Weakly supervised temporal action localization is a challenging vision task due to the absence of ground-truth temporal locations of actions in the training videos. With only video-level supervision during training, most existing methods rely on a Multiple Instance Learning (MIL) framework to predict the start and end frame of each action category in a video. However, the existing MIL-based approach has a major limitation of only capturing the most discriminative frames of an action, ignoring the full extent of an activity. Moreover, these methods cannot model background activity effectively, which plays an important role in localizing foreground activities. In this paper, we present a novel framework named HAM-Net with a hybrid attention mechanism which includes temporal soft, semi-soft and hard attentions to address these issues. Our temporal soft attention module, guided by an auxiliary background class in the classification module, models the background activity by introducing an "action-ness" score for each video snippet. Moreover, our temporal semi-soft and hard attention modules, calculating two attention scores for each video snippet, help to focus on the less discriminative frames of an action to capture the full action boundary. Our proposed approach outperforms recent state-of-the-art methods by at least 2.2% mAP at IoU threshold 0.5 on the THUMOS14 dataset, and by at least 1.3% mAP at IoU threshold 0.75 on the ActivityNet1.2 dataset. Code can be found at: https://github.com/asrafulashiq/hamnet.
Reliable counting of weakly labeled concepts by a single spiking neuron model
Rapp, Hannes, Nawrot, Martin Paul, Stern, Merav
Making an informed, correct and quick decision can be life-saving. It's crucial for animals during an escape behaviour or for autonomous cars during driving. The decision can be complex and may involve an assessment of the amount of threats present and the nature of each threat. Thus, we should expect early sensory processing to supply classification information fast and accurately, even before relying the information to higher brain areas or more complex system components downstream. Today, advanced convolutional artificial neural networks can successfully solve visual detection and classification tasks and are commonly used to build complex decision making systems. However, in order to perform well on these tasks they require increasingly complex, "very deep" model structure, which is costly in inference run-time, energy consumption and number of training samples, only trainable on cloud-computing clusters. A single spiking neuron has been shown to be able to solve recognition tasks for homogeneous Poisson input statistics, a commonly used model for spiking activity in the neocortex. When modeled as leaky integrate and fire with gradient decent learning algorithm it was shown to posses a variety of complex computational capabilities. Here we improve its implementation. We also account for more natural stimulus generated inputs that deviate from this homogeneous Poisson spiking. The improved gradient-based local learning rule allows for significantly better and stable generalization. We also show that with its improved capabilities it can count weakly labeled concepts by applying our model to a problem of multiple instance learning (MIL) with counting where labels are only available for collections of concepts. In this counting MNIST task the neuron exploits the improved implementation and outperforms conventional ConvNet architecture under similar condtions.
Bullguard Premium Protection review: A solid security suite that likes to bark
Bullguard Premium Protection is feature-packed with what the company calls "next gen anti-malware," a new game optimization tool, and a "firewall on steroids." As a premium security suite it certainly has all the necessary features and then some. Bullguard's protection is also highly rated by independent AV testing organizations, but this combination of heavy security does come with its problems, especially for older machines. Bullguard tries to be a very simple desktop application to navigate and understand. For the most part it succeeds, though you do have to get used to its logic.
6 smart settings to make your Android phone anticipate your needs
There's no denying that our smartphones have made our lives so much easier, putting our contacts and schedules, our driving directions, the whole internet, right at our fingertips. But if you're using an Android phone you might be leaving even more convenience on the table. There are a bunch of super-smart settings in Nougat and Google Now that'll make your Android device feel like it's 10 steps ahead of you. Your Android phone can be proactively telling you how long it'll take to get to work in the morning, and nudging you when your favorite team is about to take the field. Your device can keep itself unlocked whenever it's on you, and those snapshots you just took can automatically be arranged into beautiful collages.
Convergent Bayesian formulations of blind source separation and electromagnetic source estimation
Knuth, Kevin H., Vaughan, Herbert G. Jr
We consider two areas of research that have been developing in parallel over the last decade: blind source separation (BSS) and electromagnetic source estimation (ESE). BSS deals with the recovery of source signals when only mixtures of signals can be obtained from an array of detectors and the only prior knowledge consists of some information about the nature of the source signals. On the other hand, ESE utilizes knowledge of the electromagnetic forward problem to assign source signals to their respective generators, while information about the signals themselves is typically ignored. We demonstrate that these two techniques can be derived from the same starting point using the Bayesian formalism. This suggests a means by which new algorithms can be developed that utilize as much relevant information as possible. We also briefly mention some preliminary work that supports the value of integrating information used by these two techniques and review the kinds of information that may be useful in addressing the ESE problem.