68 research outputs found
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How Beliefs about Self-creation Inflate Value in the Human Brain
Humans have a tendency to overvalue their own ideas and creations. Understanding how these errors in judgement emerge is important for explaining suboptimal decisions, as when individuals and groups choose self-created alternatives over superior or equal ones. We show that such overvaluation is a reconstructive process that emerges when participants believe they have created an item, regardless of whether this belief is true or false. This overvaluation is observed both when false beliefs of self-creation are elicited (Experiment 1) or implanted (Experiment 2). Using brain imaging data we highlight the brain processes mediating an interaction between value and belief of self-creation. Specifically, following the creation manipulation there is an increased functional connectivity during valuation between the right caudate nucleus, where we show BOLD activity correlated with subjective value, and the left amygdala, where we show BOLD activity is linked to subjective belief. Our study highlights psychological and neurobiological processes through which false beliefs alter human valuation and in doing so throw light on a common source of error in judgements of value
Perception Test: A Diagnostic Benchmark for Multimodal Video Models
We propose a novel multimodal video benchmark - the Perception Test - to
evaluate the perception and reasoning skills of pre-trained multimodal models
(e.g. Flamingo, BEiT-3, or GPT-4). Compared to existing benchmarks that focus
on computational tasks (e.g. classification, detection or tracking), the
Perception Test focuses on skills (Memory, Abstraction, Physics, Semantics) and
types of reasoning (descriptive, explanatory, predictive, counterfactual)
across video, audio, and text modalities, to provide a comprehensive and
efficient evaluation tool. The benchmark probes pre-trained models for their
transfer capabilities, in a zero-shot / few-shot or limited finetuning regime.
For these purposes, the Perception Test introduces 11.6k real-world videos, 23s
average length, designed to show perceptually interesting situations, filmed by
around 100 participants worldwide. The videos are densely annotated with six
types of labels (multiple-choice and grounded video question-answers, object
and point tracks, temporal action and sound segments), enabling both language
and non-language evaluations. The fine-tuning and validation splits of the
benchmark are publicly available (CC-BY license), in addition to a challenge
server with a held-out test split. Human baseline results compared to
state-of-the-art video QA models show a significant gap in performance (91.4%
vs 43.6%), suggesting that there is significant room for improvement in
multimodal video understanding.
Dataset, baselines code, and challenge server are available at
https://github.com/deepmind/perception_testComment: 25 pages, 11 figure
Inequity aversion improves cooperation in intertemporal social dilemmas
Groups of humans are often able to find ways to cooperate with one another in
complex, temporally extended social dilemmas. Models based on behavioral
economics are only able to explain this phenomenon for unrealistic stateless
matrix games. Recently, multi-agent reinforcement learning has been applied to
generalize social dilemma problems to temporally and spatially extended Markov
games. However, this has not yet generated an agent that learns to cooperate in
social dilemmas as humans do. A key insight is that many, but not all, human
individuals have inequity averse social preferences. This promotes a particular
resolution of the matrix game social dilemma wherein inequity-averse
individuals are personally pro-social and punish defectors. Here we extend this
idea to Markov games and show that it promotes cooperation in several types of
sequential social dilemma, via a profitable interaction with policy
learnability. In particular, we find that inequity aversion improves temporal
credit assignment for the important class of intertemporal social dilemmas.
These results help explain how large-scale cooperation may emerge and persist.Comment: 15 pages, 8 figure
Daratumumab after allogeneic hematopoietic cell transplantation for multiple myeloma is safe and synergies with pre-existing chronic graft versus host disease. A retrospective study from the CMWP EBMT
The Neural Representation of Prospective Choice during Spatial Planning and Decisions
We are remarkably adept at inferring the consequences of our actions, yet the neuronal mechanisms that allow us to plan a sequence of novel choices remain unclear. We used functional magnetic resonance imaging (fMRI) to investigate how the human brain plans the shortest path to a goal in novel mazes with one (shallow maze) or two (deep maze) choice points. We observed two distinct anterior prefrontal responses to demanding choices at the second choice point: one in rostrodorsal medial prefrontal cortex (rd-mPFC)/superior frontal gyrus (SFG) that was also sensitive to (deactivated by) demanding initial choices and another in lateral frontopolar cortex (lFPC), which was only engaged by demanding choices at the second choice point. Furthermore, we identified hippocampal responses during planning that correlated with subsequent choice accuracy and response time, particularly in mazes affording sequential choices. Psychophysiological interaction (PPI) analyses showed that coupling between the hippocampus and rd-mPFC increases during sequential (deep versus shallow) planning and is higher before correct versus incorrect choices. In short, using a naturalistic spatial planning paradigm, we reveal how the human brain represents sequential choices during planning without extensive training. Our data highlight a network centred on the cortical midline and hippocampus that allows us to make prospective choices while maintaining initial choices during planning in novel environments
Pan-cancer analysis of whole genomes
Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe
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Comprehensive analysis of chromothripsis in 2,658 human cancers using whole-genome sequencing
Chromothripsis is a mutational phenomenon characterized by massive, clustered genomic rearrangements that occurs in cancer and other diseases. Recent studies in selected cancer types have suggested that chromothripsis may be more common than initially inferred from low-resolution copy-number data. Here, as part of the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA), we analyze patterns of chromothripsis across 2,658 tumors from 38 cancer types using whole-genome sequencing data. We find that chromothripsis events are pervasive across cancers, with a frequency of more than 50% in several cancer types. Whereas canonical chromothripsis profiles display oscillations between two copy-number states, a considerable fraction of events involve multiple chromosomes and additional structural alterations. In addition to non-homologous end joining, we detect signatures of replication-associated processes and templated insertions. Chromothripsis contributes to oncogene amplification and to inactivation of genes such as mismatch-repair-related genes. These findings show that chromothripsis is a major process that drives genome evolution in human cancer
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
Mona Chollet, Chez soi. Une odyssée de l’espace domestique
La définition du domicile traitée tout au long de l’ouvrage de Mona Chollet, est celle d’un espace à l’écart de la vie sociale : « aimer rester chez soi, c’est se singulariser, faire défection. C’est s’affranchir du regard et du contrôle social » (p. 28). Il permet à son habitant de se réfugier, de se ressourcer et finalement de se réassurer une disponibilité et donc une maîtrise par rapport à ses activités et ses relations sociales. Par le choix assumé de parler du « chez soi » sans recul, ..
Beyond the Matrix: Using Multi-Agent-Reinforcement Learning and Behavioral Experiments to Study Social-Ecological Systems
Social-ecological systems, in which agents interact with each other and their environment are important both for sustainability applications and for understanding how human intelligence functions in context. In such systems, the environment shapes the agents’ experience and actions, and in turn collective action of agents changes social and physical aspects of the environment. Current investigation approach relies on a lean design, with discrete actions and outcomes and little scope for varying environmental parameters. Modern artificial intelligence (AI) techniques provide new avenues to model complex social worlds, preserving more of their characteristics, and allowing them to capture a variety of social phenomena. These techniques can be fed back to the laboratory where they make it easier to design experiments in complex social situations without compromising their tractability for computational modeling. This novel approach can help researchers bring together insights from human cognition, sustainability, and AI, to tackle real world problems of social ecological systems
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