scholarly journals Processing of subjectively and objectively invisible stimuli in human visual cortex

2020 ◽  
Author(s):  
Timo Stein ◽  
Daniel Kaiser ◽  
Johannes J. Fahrenfort ◽  
Simon van Gaal

AbstractThe study of unconscious processing requires a measure of conscious awareness. Awareness measures can be either subjective (based on participant’s report) or objective (based on perceptual performance). The preferred awareness measure depends on the theoretical position about consciousness, and may influence conclusions about the extent of unconscious processing and about the neural correlates of consciousness. We obtained fMRI measurements from 43 subjects while they viewed masked faces and houses that were either subjectively or objectively invisible. We show that neural representations of objectively invisible faces and houses are limited to visual (shape-related) object properties, while subjectively invisible stimuli are processed up to more abstract, categorical levels of representation. These results demonstrate that the hypothesized extent of unconscious information processing is determined by the measurement approach. Furthermore, our data show that subjective and objective approaches are associated with different neural correlates of consciousness and thus have implications for neural theories of consciousness.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Taishi Hosaka ◽  
Marino Kimura ◽  
Yuko Yotsumoto

AbstractWe have a keen sensitivity when it comes to the perception of our own voices. We can detect not only the differences between ourselves and others, but also slight modifications of our own voices. Here, we examined the neural correlates underlying such sensitive perception of one’s own voice. In the experiments, we modified the subjects’ own voices by using five types of filters. The subjects rated the similarity of the presented voices to their own. We compared BOLD (Blood Oxygen Level Dependent) signals between the voices that subjects rated as least similar to their own voice and those they rated as most similar. The contrast revealed that the bilateral superior temporal gyrus exhibited greater activities while listening to the voice least similar to their own voice and lesser activation while listening to the voice most similar to their own. Our results suggest that the superior temporal gyrus is involved in neural sharpening for the own-voice. The lesser degree of activations observed by the voices that were similar to the own-voice indicates that these areas not only respond to the differences between self and others, but also respond to the finer details of own-voices.


2014 ◽  
Vol 369 (1641) ◽  
pp. 20130211 ◽  
Author(s):  
Randolph Blake ◽  
Jan Brascamp ◽  
David J. Heeger

This essay critically examines the extent to which binocular rivalry can provide important clues about the neural correlates of conscious visual perception. Our ideas are presented within the framework of four questions about the use of rivalry for this purpose: (i) what constitutes an adequate comparison condition for gauging rivalry's impact on awareness, (ii) how can one distinguish abolished awareness from inattention, (iii) when one obtains unequivocal evidence for a causal link between a fluctuating measure of neural activity and fluctuating perceptual states during rivalry, will it generalize to other stimulus conditions and perceptual phenomena and (iv) does such evidence necessarily indicate that this neural activity constitutes a neural correlate of consciousness? While arriving at sceptical answers to these four questions, the essay nonetheless offers some ideas about how a more nuanced utilization of binocular rivalry may still provide fundamental insights about neural dynamics, and glimpses of at least some of the ingredients comprising neural correlates of consciousness, including those involved in perceptual decision-making.


Author(s):  
Qian Zheng ◽  
Weikai Wu ◽  
Hanting Pan ◽  
Niloy Mitra ◽  
Daniel Cohen-Or ◽  
...  

AbstractHumans regularly interact with their surrounding objects. Such interactions often result in strongly correlated motions between humans and the interacting objects. We thus ask: “Is it possible to infer object properties from skeletal motion alone, even without seeing the interacting object itself?” In this paper, we present a fine-grained action recognition method that learns to infer such latent object properties from human interaction motion alone. This inference allows us to disentangle the motion from the object property and transfer object properties to a given motion. We collected a large number of videos and 3D skeletal motions of performing actors using an inertial motion capture device. We analyzed similar actions and learned subtle differences between them to reveal latent properties of the interacting objects. In particular, we learned to identify the interacting object, by estimating its weight, or its spillability. Our results clearly demonstrate that motions and interacting objects are highly correlated and that related object latent properties can be inferred from 3D skeleton sequences alone, leading to new synthesis possibilities for motions involving human interaction. Our dataset is available at http://vcc.szu.edu.cn/research/2020/IT.html.


Author(s):  
Ali Motavalli ◽  
◽  
Javad Mahmoudi ◽  
Alireza Majdi ◽  
Saeed Sadigh-Eteghad ◽  
...  

Although there are numerous views about the concept of consciousness, no consensus exists regarding the meaning. However, with the aid of the latest neuroscientific developments, the misleading obstacles related to consciousness have been removed. Over the last few decades, neuroscientific efforts in determining the function of the brain and merging these findings with philosophical theories, have brought a more comprehensive perception of the notion of consciousness. In addition to metaphysical/ontological views of consciousness e.g., higher-order theories, reflexive theories, and representationalist theories, there are some brain directed topics in this matter which include but not are limited to neural correlates of consciousness (NCC), brain loop connectivity, and lateralization. This narrative review sheds light on cultural and historical aspects of consciousness in old and middle ages and introduces some of the prominent philosophical discussions related to mind and body. Also, it illustrates the correlation of brain function with states of consciousness with a focus on the roles of function and connectivity.


Cortex ◽  
2019 ◽  
Vol 120 ◽  
pp. 539-555
Author(s):  
María Hernández-Lorca ◽  
Kristian Sandberg ◽  
Dominique Kessel ◽  
Uxía Fernández-Folgueiras ◽  
Morten Overgaard ◽  
...  

2016 ◽  
Vol 17 (10) ◽  
pp. 666-666 ◽  
Author(s):  
Kristian Sandberg ◽  
Stefan Frässle ◽  
Michael Pitts

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