77 research outputs found
Face-to-Face Contrastive Learning for Social Intelligence Question-Answering
Creating artificial social intelligence - algorithms that can understand the
nuances of multi-person interactions - is an exciting and emerging challenge in
processing facial expressions and gestures from multimodal videos. Recent
multimodal methods have set the state of the art on many tasks, but have
difficulty modeling the complex face-to-face conversational dynamics across
speaking turns in social interaction, particularly in a self-supervised setup.
In this paper, we propose Face-to-Face Contrastive Learning (F2F-CL), a graph
neural network designed to model social interactions using factorization nodes
to contextualize the multimodal face-to-face interaction along the boundaries
of the speaking turn. With the F2F-CL model, we propose to perform contrastive
learning between the factorization nodes of different speaking turns within the
same video. We experimentally evaluated the challenging Social-IQ dataset and
show state-of-the-art results
Factorized Contrastive Learning: Going Beyond Multi-view Redundancy
In a wide range of multimodal tasks, contrastive learning has become a
particularly appealing approach since it can successfully learn representations
from abundant unlabeled data with only pairing information (e.g., image-caption
or video-audio pairs). Underpinning these approaches is the assumption of
multi-view redundancy - that shared information between modalities is necessary
and sufficient for downstream tasks. However, in many real-world settings,
task-relevant information is also contained in modality-unique regions:
information that is only present in one modality but still relevant to the
task. How can we learn self-supervised multimodal representations to capture
both shared and unique information relevant to downstream tasks? This paper
proposes FactorCL, a new multimodal representation learning method to go beyond
multi-view redundancy. FactorCL is built from three new contributions: (1)
factorizing task-relevant information into shared and unique representations,
(2) capturing task-relevant information via maximizing MI lower bounds and
removing task-irrelevant information via minimizing MI upper bounds, and (3)
multimodal data augmentations to approximate task relevance without labels. On
large-scale real-world datasets, FactorCL captures both shared and unique
information and achieves state-of-the-art results on six benchmarks.Comment: Code available at: https://github.com/pliang279/FactorC
Dynamic behavior analysis via structured rank minimization
Human behavior and affect is inherently a dynamic phenomenon involving temporal evolution of patterns manifested through a multiplicity of non-verbal behavioral cues including facial expressions, body postures and gestures, and vocal outbursts. A natural assumption for human behavior modeling is that a continuous-time characterization of behavior is the output of a linear time-invariant system when behavioral cues act as the input (e.g., continuous rather than discrete annotations of dimensional affect). Here we study the learning of such dynamical system under real-world conditions, namely in the presence of noisy behavioral cues descriptors and possibly unreliable annotations by employing structured rank minimization. To this end, a novel structured rank minimization method and its scalable variant are proposed. The generalizability of the proposed framework is demonstrated by conducting experiments on 3 distinct dynamic behavior analysis tasks, namely (i) conflict intensity prediction, (ii) prediction of valence and arousal, and (iii) tracklet matching. The attained results outperform those achieved by other state-of-the-art methods for these tasks and, hence, evidence the robustness and effectiveness of the proposed approach
Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study
Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised
Neuronal mechanisms and circuits underlying repetitive behaviors in mouse models of autism spectrum disorder
Autism spectrum disorder (ASD) refers to a broad spectrum of neurodevelopmental disorders characterized by three central behavioral symptoms: impaired social interaction, impaired social communication, and restricted and repetitive behaviors. However, the symptoms are heterogeneous among patients and a number of ASD mouse models have been generated containing mutations that mimic the mutations found in human patients with ASD. Each mouse model was found to display a unique set of repetitive behaviors. In this review, we summarize the repetitive behaviors of the ASD mouse models and variations found in their neural mechanisms including molecular and electrophysiological features. We also propose potential neuronal mechanisms underlying these repetitive behaviors, focusing on the role of the cortico-basal ganglia-thalamic circuits and brain regions associated with both social and repetitive behaviors. Further understanding of molecular and circuitry mechanisms of the repetitive behaviors associated with ASD is necessary to aid the development of effective treatments for these disorders
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