164 research outputs found

    Inferring the direction of implied motion depends on visual awareness

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    Visual awareness of an event, object, or scene is, by essence, an integrated experience, whereby different visual features composing an object (e.g., orientation, color, shape) appear as an unified percept and are processed as a whole. Here, we tested in human observers whether perceptual integration of static motion cues depends on awareness by measuring the capacity to infer the direction of motion implied by a static visible or invisible image under continuous flash suppression. Using measures of directional adaptation, we found that visible but not invisible implied motion adaptors biased the perception of real motion probes. In a control experiment, we found that invisible adaptors implying motion primed the perception of subsequent probes when they were identical (i.e., repetition priming), but not when they only shared the same direction (i.e., direction priming). Furthermore, using a model of visual processing, we argue that repetition priming effects are likely to arise as early as in the primary visual cortex. We conclude that although invisible images implying motion undergo some form of nonconscious processing, visual awareness is necessary to make inferences about motion direction

    Invisible, but how? The depth of unconscious processing as inferred from different suppression techniques

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    To what level are invisible stimuli processed by the brain in the absence of conscious awareness? Taking stock of the evidence to this day, it is widely accepted that simple visual properties of invisible stimuli are processed; however, the existence of higher-level unconscious processing (e.g., involving semantic or executive functions) remains a matter of debate. After several years of research in the field of unconscious processing, we became aware of a number of methodological aspects which need to be controlled carefully to help resolve discrepant findings in the literature. These aspects relate to: (1) when and how visibility is assessed; (2) when and how unconscious processing is assessed; (3) whether spatiotemporal attention is directed or, at least, measured; (4) whether adequate control conditions are used to rule out alternate explanations; (5) whether the studies are sufficiently powered and account for individual differences. Yet even when these aspects are carefully controlled, there may be, and probably are, some inherent differences in the amount of information let through by the different invisibility-inducing techniques (the “psychophysical magic” arsenal, Kim and Blake, 2005). We launched this Research Topic to foster investigations into these inherent differences (note previous attempts, Breitmeyer et al., 2004; Almeida et al., 2008; Kanai et al., 2010; Faivre et al., 2012)

    Sustained invisibility through crowding and continuous flash suppression: a comparative review

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    The study of non-conscious vision benefits from several alternative methods that allow the suppression of an image from awareness. Here, we present and compare two of them that are particularly well-suited for creating sustained periods of invisibility, namely visual crowding and continuous flash suppression (CFS). In visual crowding, a peripheral image surrounded by similar flankers becomes impossible to discriminate. In CFS, an image presented to one eye becomes impossible to detect when rapidly changing patterns are presented to the other eye. After discussing the experimental specificities of each method, we give a comparative overview of the main empirical results derived from them, from the mere analysis of low-level features to the extraction of semantic contents. We conclude by proposing practical guidelines and future directions to obtain more quantitative and systematic measures of non-conscious processes under prolonged stimulation

    Multisensory Integration in Complete Unawareness: Evidence From Audiovisual Congruency Priming

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    Multisensory integration is thought to require conscious perception. Although previous studies have shown that an invisible stimulus could be integrated with an audible one, none have demonstrated integration of two subliminal stimuli of different modalities. Here, pairs of identical or different audiovisual target letters (the sound /b/ with the written letter “b” or “m,” respectively) were preceded by pairs of masked identical or different audiovisual prime digits (the sound /6/ with the written digit “6” or “8,” respectively). In three experiments, awareness of the audiovisual digit primes was manipulated, such that participants were either unaware of the visual digit, the auditory digit, or both. Priming of the semantic relations between the auditory and visual digits was found in all experiments. Moreover, a further experiment showed that unconscious multisensory integration was not obtained when participants did not undergo prior conscious training of the task. This suggests that following conscious learning, unconscious processing suffices for multisensory integration

    Entrainment of Voluntary Movement to Undetected Auditory Regularities

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    In physics “entrainment” refers to the synchronization of two coupled oscillators with similar fundamental frequencies. In behavioral science, entrainment refers to the tendency of humans to synchronize their movements with rhythmic stimuli. Here, we asked whether human subjects performing a tapping task would entrain their tapping to an undetected auditory rhythm surreptitiously introduced in the guise of ambient background noise in the room. Subjects performed two different tasks, one in which they tapped their finger at a steady rate of their own choosing and one in which they performed a single abrupt finger tap on each trial after a delay of their own choosing. In both cases we found that subjects tended to tap in phase with the inducing modulation, with some variability in the preferred phase across subjects, consistent with prior research. In the repetitive tapping task, if the frequency of the inducing stimulus was far from the subject’s own self-paced frequency, then entrainment was abolished, consistent with the properties of entrainment in physics. Thus, undetected ambient noise can influence self-generated movements. This suggests that uncued decisions to act are never completely endogenous, but are subject to subtle unnoticed influences from the sensory environment

    Visual consciousness and bodily self-consciousness

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    Purpose of review: In recent years, consciousness has become a central topic in cognitive neuroscience. This review focuses on the relation between bodily self-consciousness - the feeling of being a subject in a body - and visual consciousness - the subjective experience associated with the perception of visual signals. Recent findings: Findings from clinical and experimental work have shown that bodily self-consciousness depends on specific brain networks and is related to the integration of signals from multiple sensory modalities including vision. In addition, recent experiments have shown that visual consciousness is shaped by the body, including vestibular, tactile, proprioceptive, and motor signals. Summary: Several lines of evidence suggest reciprocal relationships between vision and bodily signals, indicating that a comprehensive understanding of visual and bodily self-consciousness requires studying them in unison

    Nanopore Sequencing Enables Comprehensive Transposable Element Epigenomic Profiling

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    Transposable elements (TEs) drive genome evolution and are a notable source of pathogenesis, including cancer. While CpG methylation regulates TE activity, the locus-specific methylation landscape of mobile human TEs has to date proven largely inaccessible. Here, we apply new computational tools and long-read nanopore sequencing to directly infer CpG methylation of novel and extant TE insertions in hippocampus, heart, and liver, as well as paired tumor and non-tumor liver. As opposed to an indiscriminate stochastic process, we find pronounced demethylation of young long interspersed element 1 (LINE-1) retrotransposons in cancer, often distinct to the adjacent genome and other TEs. SINE-VNTR-Alu\ua0(SVA) retrotransposons, including their internal tandem repeat-associated CpG island, are near-universally methylated. We encounter allele-specific TE methylation and demethylation of aberrantly expressed young LINE-1s in normal tissues. Finally, we recover the complete sequences of tumor-specific LINE-1 insertions and their retrotransposition hallmarks, demonstrating how long-read sequencing can simultaneously survey the epigenome and detect somatic TE mobilization

    Vuorovaikutteisen suunnittelun haasteet ja mahdollisuudet metsÀtalouden vesiensuojelussa

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    Rapport de l'expertise scientifique collectiveLes animaux peuvent-ils Ă©prouver des Ă©motions, peuvent-ils penser, ont-ils une histoire de vie ? Depuis l’AntiquitĂ©, les philosophes ont proposĂ© des rĂ©ponses contrastĂ©es Ă  ces questions. Du XIXĂšme siĂšcle Ă  nos jours, la rĂ©flexion sur ce que sont les animaux s’est enrichie d’apports scientifiques : thĂ©orie de l’évolution, Ă©thologie, neurophysiologie, sciences cognitives. Mais la conscience animale reste toujours l’objet de dĂ©bats importants dans la communautĂ© scientifique. Ainsi en 2012 un groupe de scientifiques de premier plan a Ă©prouvĂ© la nĂ©cessitĂ© de publier un manifeste intitulĂ© « DĂ©claration de Cambridge sur la Conscience », qui Ă©nonce qu’« une convergence de preuves indique que les animaux non humains disposent des substrats neuro-anatomiques, neurochimiques et neurophysiologiques des Ă©tats conscients ainsi que la capacitĂ© d’exprimer des comportements intentionnels...».Les connaissances actuelles, dont cette expertise collective propose une synthĂšse, montrent que les animaux possĂšdent un large Ă©ventail de capacitĂ©s cognitives associĂ©es Ă  des comportements plus ou moins complexes. Les formes de conscience Ă©tudiĂ©es chez les humains supposent des capacitĂ©s cognitives distinctes que l’on retrouve chez certains animaux. Peut-on en postuler que ceux-ci ont des formes de consciences Ă©quivalentes Ă  celles de l’homme, sans ĂȘtre forcĂ©ment identiques ?L’étude des niveaux et des contenus de la conscience chez les animaux est en passe de devenir un enjeu scientifique important en raison de la complexitĂ© du sujet et des controverses qu’il ne manquera pas de susciter. Enfin, les acquis scientifiques dans ce domaine invitent Ă  reprendre les rĂ©flexions morales concernant les relations que les hommes entretiennent avec les animaux (et particuliĂšrement avec les animaux domestiques

    Inhibition of Chondrosarcoma Growth by mTOR Inhibitor in an In Vivo Syngeneic Rat Model

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    BACKGROUND: Chondrosarcomas are the second most frequent primary malignant type of bone tumor. No effective systemic treatment has been identified in advanced or adjuvant phases for chondrosarcoma. The aim of the present study was to determine the antitumor effects of doxorubicin and everolimus, an mTOR inhibitor on chondrosarcoma progression. METHODS AND FINDINGS: Doxorubin and/or everolimus were tested in vivo as single agent or in combination in the rat orthotopic Schwarm chondrosarcoma model, in macroscopic phase, as well as with microscopic residual disease. Response to everolimus and/or doxorubicin was evaluated using chondrosarcoma volume evolution (MRI). Histological response was evaluated with % of tumor necrosis, tumor proliferation index, metabolism quantification analysis between the treated and control groups. Statistical analyses were performed using chi square, Fishers exact test. Doxorubicin single agent has no effect of tumor growth as compared to no treatment; conversely, everolimus single agent significantly inhibited tumor progression in macroscopic tumors with no synergistic additive effect with doxorubicin. Everolimus inhibited chondrosarcoma proliferation as evaluated by Ki67 expression did not induce the apoptosis of tumor cells; everolimus reduced Glut1 and 4EBP1 expression. Importantly when given in rats with microscopic residual diseases, in a pseudo neoadjuvant setting, following R1 resection of the implanted tumor, everolimus significantly delayed or prevented tumor recurrence. CONCLUSIONS: MTOR inhibitor everolimus blocks cell proliferation, Glut1 expression and HIF1a expression, and prevents in vivo chondrosarcoma tumor progression in both macroscopic and in adjuvant phase post R1 resection. Taken together, our preclinical data indicate that mTOR inhibitor may be effective as a single agent in treating chondrosarcoma patients. A clinical trial evaluating mTOr inhibitor as neo-adjuvant and adjuvant therapy in chondrosarcoma patients is being constructed
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