Using masking techniques combined with electrophysiological recordings is a promising way to study neural correlates of visual awareness, as shown in recent studies. Here I comment on the following puzzling aspects typical for this endeavour that have made obstacles for a potentially even more impressive progress. First, the continuing practice of confounds between objective stimulus variables and subjective dependent measures. Second, complexity of timing the emergence of subjective conscious percept which is partly due to complex interactivity between target and mask. (...) Third, the ambiguity of the concept of neural correlates of awareness. (shrink)

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The idea that the thalamo-cortical system is the crucial constituent of the neurobiological mechanisms of consciousness has a long history. For the last few decades, however, consciousness research has to a large extent overlooked the interplay between the cortex and thalamus. Here we revive an integrated view of the neurobiology of consciousness by presenting and discussing several recent major findings about the role of the thalamocortical interactions in consciousness. Based on these findings we propose a specific cellular mechanism how thalamic (...) nuclei modulate the integration of different processing streams within single cortical pyramidal neurons. This theory is inspired by recent work done in rodents, but it integrates decades of work conducted on various species. We illustrate how this new view readily explains various properties and experimental phenomena associated with conscious experience. We discuss the implications of this idea and some of the experiments that need to be done in order to test it. Our view bridges two long-standing perspectives on the neural mechanisms of consciousness and proposes that cortical and thalamo-cortical processing interact at the level of single pyramidal cells. (shrink)

We present a theoretical view of the cellular foundations for network-level processes involved in producing our conscious experience. Inputs to apical synapses in layer 1 of a large subset of neocortical cells are summed at an integration zone near the top of their apical trunk. These inputs come from diverse sources and provide a context within which the transmission of information abstracted from sensory input to their basal and perisomatic synapses can be amplified when relevant. We argue that apical amplification (...) enables conscious perceptual experience and makes it more flexible, and thus more adaptive, by being sensitive to context. Apical amplification provides a possible mechanism for recurrent processing theory that avoids strong loops. It makes the broadcasting hypothesized by global neuronal workspace theories feasible while preserving the distinct contributions of the individual cells receiving the broadcast. It also provides mechanisms that contribute to the holistic aspects of integrated information theory. As apical amplification is highly dependent on cholinergic, aminergic, and other neuromodulators, it relates the specific contents of conscious experience to global mental states and to fluctuations in arousal when awake. We conclude that apical dendrites provide a cellular mechanism for the context-sensitive selective amplification that is a cardinal prerequisite of conscious perception. (shrink)

If successive, brief visual images are exposed for recognition or for psychophysical ratings, various effects and phenomena of fast dynamics of conscious perception such as mutual masking, metacontrast, proactive enhancement of contrast, proactive speed-up of the latency of subjective visual experience, the Fröhlich Effect, the Tandem Effect, attentional facilitation by visuospatial precuing, and some others have been found. The theory proposed to deal with these phenomena proceeds from the assumption that two types of brain processes are necessary in order to (...) consciously recognize visual stimuli: fast, specific processes of encoding that allocate and reactivate the stimulus representation which is based on the activity of selected cortical neurons and relatively slower processes of facilitation of the activity of this specific representation that are mediated by the excitatory modulation of the EPSPs of those selected cortical neurons by the ascending input from nonspecific thalamus. Theperceptual retouchconstruct is proposed in order to characterize and analyze the interaction of and . The neurophysiological characteristics of this bifunctional system of afference help to put forward several predictions that are found to be consistent with the empirical regularities of the above-described perceptual-attentional phenomena. These data form a body of converging evidence that is consistent with the predictions of the perceptual retouch approach. (shrink)

We introduce a new version of the perceptual retouch model. This model was used for explaining properties of temporal interaction of successive objects in reaching conscious representation. The new model incorporates two interactive binding operations – binding features for objects and binding the bound feature-objects with a large scale oscillatory system that corresponds to perceptual consciousness. Here, the typical result of masking experiments – second object advantage in conscious perception – is achieved by applying the effects of a common synchronizing (...) oscillator with a delay. This delayed modulation of each of the feature-binding first-order oscillators that represent emerging and decaying neural activities of each of the objects guarantees that the oscillating synchrony of the feature-neurons of the following object is higher than the synchrony of the feature-neurons of the first presented object. Thus we model the fact that the following object dominates the preceding object in conscious perception. We also show the capacity of the model to simulate illusory misbinding of features from different objects. The third qualitative effect, the relative release of the first object from backward masking is achieved by priming the non-specific oscillatory modulation ahead in time. (shrink)

While the majority of perceptual phenomena based research on consciousness is implicitly nomothetic, some idiographic perspective can be sometimes highly valuable for it. It may turn out that after having had a closer look at individual differences in the expression of psychometric functions a need to revise some nomothetic laws considered as the general ones arises as well. A study of individual differences in metacontrast masking published in this issue superbly illustrates this. A myriad of urgent research objectives emerges out (...) of this study, most of them important both for clearing up the still messy theoretical picture on visual masking and for the beginning of asking whether perceptual awareness mechanisms are so universal at all. In this commentary the problems pertinent to this issue are discussed. (shrink)

Additional experiments show that P-consciousness and A consciousness can be empirically dissociated for the theoretically so phisticated observer. Phenomenal consciousness can have several degrees that are indirectly measurable.

Experimental Phenomena of Consciousness is the definitive collection of consciousness phenomena in which awareness emerges as an experimental variable.

“Finding out” about the visual world as approached from the organismic level may well include the “filling-in” type of perceptual completion if considered in terms of underlying neurophysiological mechanisms. But “filling in” can be interpreted not only as a result of within-level propagating of neural activity, but as a byproduct of the process that is necessary for modulating preconscious information about physically present objects or events so as to generate conscious quality in attending to them.

Originally presented as the author's thesis, Bonn, 1976.

Das Buch ist eine fur den gebildeten Laien verstandliche Einfuhrung in die historische Entwicklung der Grundlagenforschung der Mathematik von der Axiomatik Euklids uber die Prazisierung der Analysis in der Neuzeit und die durch die Entwicklung der Mengenlehre verursachte Grundlagenkrise der Moderne (ausfuhrliche Behandlung der sogenannten Antinomien) bis zu den Godelschen Satzen uber formale Systeme. Da im Gegensatz zu den modernen Umwalzungen in den Grundlagen anderer Wissenschaften (z.B. der Physik) die dazu parallele Erscheinung in der Mathematik immer noch nicht allgemein bekannt (...) ist, wird dabei ein Beitrag geliefert zum Verstandnis des Wesens und der philosophischen Bedeutung der modernen Mathematik.". (shrink)

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain (...) in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain (...) in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

The economic shutdown and national lockdown following the outbreak of COVID-19 have increased demand for unpaid work at home, particularly among families with children, and reduced demand for paid work. Concurrently, the share of the workforce that has relocated its workplace to home has also increased. In this article, we examine the consequences of these processes for the allocation of time among paid work, housework, and care work for men and women in Israel. Using data on 2,027 Israeli adults whom (...) we followed since the first week of March, we focus on the effect of the second lockdown in Israel on the gender division of both paid and unpaid work. We find that as demand for housework caused by the lockdown increases, women—especially with children—increase their housework much more than men do, particularly when they work from home. The consequences of work from home and other flexible work arrangements for gender inequality within the family are discussed. (shrink)