Whitehead's Philosophy: The Higher Phases of Experience

Philosophy ◽  
1946 ◽  
Vol 21 (78) ◽  
pp. 57-78
Author(s):  
Sydney E. Hooper
Keyword(s):  
Conscious Experience ◽  
Late Phase ◽  
Conscious Perception ◽  
High Grade ◽  
Important Type ◽  
Subjective Form

In my last article I described fully the important type of entity in Whitehead's philosophy called “propositions,” and explained the part they played in conscious experience. We learnt that “consciousness” was a certain kind of emergent quality associated with the late phase of concrescence of some high-grade actual entities. It was pointed out that whenever consciousness was present in experience, this proved to be the subjective form of an integral synthetic feeling composed of (1) a physical feeling and (2) a pro-positional feeling. This integral feeling was said to be a feeling of contrast between “actuality” and “ideality,” between a fact and a possibility. That is to say consciousness is the subjective form of the feeling of a contrast between what actuality is, and might not be, or what actuality is not, and yet might be. We can now proceed to deal with a number of higher phases of experience such as “belief,” “conscious perception,” “judgment,” together with experiences termed by Whitehead “physical purposes.”

scholarly journals Representational ‘touch’ and modulatory ‘retouch’—two necessary neurobiological processes in thalamocortical interaction for conscious experience

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Talis Bachmann
Keyword(s):  
Pyramidal Neurons ◽  
Conscious Experience ◽  
General Purpose ◽  
Cortical Layer ◽  
Integration Theory ◽  
Conscious Perception ◽  
Dendritic Integration ◽  
States Of Consciousness ◽  
Historical Origins

Abstract Theories of consciousness using neurobiological data or being influenced by these data have been focused either on states of consciousness or contents of consciousness. These theories have occasionally used evidence from psychophysical phenomena where conscious experience is a dependent experimental variable. However, systematic catalog of many such relevant phenomena has not been offered in terms of these theories. In the perceptual retouch theory of thalamocortical interaction, recently developed to become a blend with the dendritic integration theory, consciousness states and contents of consciousness are explained by the same mechanism. This general-purpose mechanism has modulation of the cortical layer-5 pyramidal neurons that represent contents of consciousness as its core. As a surplus, many experimental psychophysical phenomena of conscious perception can be explained by the workings of this mechanism. Historical origins and current views inherent in this theory are presented and reviewed.

scholarly journals Molecular Imaging of Carotid Plaque Vulnerability

2014 ◽  
Vol 39 (1) ◽  
pp. 5-12 ◽  
Author(s):  
Angelika Alonso ◽  
Dimitrios Artemis ◽  
Michael G. Hennerici
Keyword(s):  
Molecular Imaging ◽  
Carotid Endarterectomy ◽  
Contrast Enhancement ◽  
Phase Contrast ◽  
Late Phase ◽  
High Grade ◽  
Contrast Enhanced Ultrasound ◽  
Plaque Vulnerability ◽  
Carotid Plaques ◽  
Contrast Enhanced

Background: Carotid endarterectomy (CEA) has been shown to be beneficial in patients with high-grade symptomatic carotid artery stenosis. Patients with high-grade asymptomatic stenosis may only exceptionally benefit from CEA during periods of increased plaque vulnerability. Imaging modalities to characterize unstable, vulnerable plaques are strongly needed for better risk stratification in these patients. Summary: Contrast-enhanced ultrasound (CEUS) is a novel and noninvasive technique capable to identify several surrogate markers of vulnerable carotid plaques. The use of specific ultrasound microbubbles allows a reliable detection of microulcerations due to an optimized visualization of the plaque-lumen border. As microbubbles are strictly intravascular tracers, the detection of individual microbubbles within the plaque corresponds to intraplaque neovessels. The accuracy of CEUS in the visualization of newly formed microvessels has been confirmed in histological studies on carotid endarterectomy specimens. Together with the formation of adventitial vasa vasorum, intraplaque neovascularization is a strong predictor for symptomatic disease. The phenomenon of late phase contrast enhancement is based on the adherence of microbubble-containing monocytes on inflamed endothelium. Recent studies suggest that late phase contrast enhancement may reflect endothelial inflammation or activation within carotid plaques. The development of conjugated microbubbles that bind to specific ligands such as thrombotic material or neovessels has led to the term ‘molecular imaging'. CEUS with microbubbles targeted to P-selectin and VCAM-1, key molecules in leukocyte trafficking, was used to detect an inflammatory plaque phenotype, whereas microbubbles coupled to the VEGF-receptor may allow for a detection of neovascularization. Even though imaging with targeted microbubbles is yet in an experimental stage, this technique can visualize active plaque reorganization with increased vulnerability leading to generation of arterio-arterial embolism. Key Messages: The use of contrast-enhanced ultrasound can be recommended to assess atherosclerotic carotid lesions at risk for rupture. Prospective clinical studies are needed to validate the use of CEUS in patients with high risks of recurrent large artery strokes. In particular, this applies to the detection of intraplaque neovascularization, a well-established marker in preclinical and observational studies, while the clinical significance of late phase contrast enhancement still needs to be determined.

scholarly journals Apical amplification—a cellular mechanism of conscious perception?

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Tomáš Marvan ◽  
Michal Polák ◽  
Talis Bachmann ◽  
William A Phillips
Keyword(s):  
Conscious Experience ◽  
Mental States ◽  
Cellular Mechanism ◽  
Conscious Perception ◽  
Context Sensitive ◽  
Processing Theory ◽  
Transmission Of Information ◽  
The Individual ◽  
Apical Dendrites ◽  
Integrated Information Theory

Abstract 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.

scholarly journals Apical Amplification – A Cellular Mechanism of Conscious Perception?

2021 ◽  
Author(s):  
Tomas Marvan ◽  
Michal Polák ◽  
Talis Bachmann ◽  
William A. Phillips
Keyword(s):  
Perceptual Experience ◽  
Sensory Input ◽  
Conscious Experience ◽  
Cellular Mechanism ◽  
Conscious Perception ◽  
Context Sensitive ◽  
Processing Theory ◽  
Recurrent Processing ◽  
Theoretical View ◽  
Integrated Information Theory

We present a theoretical view of the cellular foundations fornetwork-level processes involved in producing our conscious experience.Inputs to apical synapses in layer 1 of a large subset of neocortical cellsare summed at an integration zone near the top of their apical trunk. Theseinputs come from diverse sources, and provide a context within which thetransmission of information abstracted from sensory input to their basal andperisomatic synapses can be amplified when relevant. We argue that apicalamplification (AA) enables conscious perceptual experience and makes it moreflexible, and thus more adaptive, by being sensitive to context. AA providesa possible mechanism for recurrent processing theory that avoids strongloops. It makes the broadcasting hypothesized by global neuronal workspacetheories feasible while preserving the distinct contributions of theindividual cells receiving the broadcast. It also provides mechanisms thatcontribute to the holistic aspects of integrated information theory. As AAis highly dependent on cholinergic, aminergic, and other neuromodulators, itrelates the specific contents of conscious experience to global mental statesand to fluctuations in arousal when awake. We conclude that apical dendritesprovide a cellular mechanism for the context-sensitive selectiveamplification that is a cardinal prerequisite of conscious perception.

scholarly journals Sensorimotor predictions shape reported conscious visual experience in a breaking Continuous Flash Suppression task

2020 ◽  
Author(s):  
Lina Skora ◽  
Anil Seth ◽  
Ryan Bradley Scott
Keyword(s):  
Bayesian Analysis ◽  
Null Hypothesis ◽  
Visual Experience ◽  
Bayes Factor ◽  
Instrumental Conditioning ◽  
Conscious Experience ◽  
Predictive Processing ◽  
Conscious Perception ◽  
Continuous Flash Suppression ◽  
The World

Accounts of predictive processing propose that conscious experience is influenced not only by passive predictions about the world, but also by predictions encompassing how the world changes in relation to our actions – that is, on predictions about sensorimotor contingencies. We tested whether valid sensorimotor predictions, in particular learned associations between stimuli and actions, shape reports about conscious visual experience. Two experiments used instrumental conditioning to build sensorimotor predictions linking different stimuli with distinct actions. Conditioning was followed by a breaking continuous flash suppression (b-CFS) task, measuring the speed of reported breakthrough for different pairings between the stimuli and prepared actions, comparing those congruent and incongruent with the trained sensorimotor predictions. In Experiment 1, counterbalancing of the response actions within the b-CFS task was achieved by repeating the same action within each block but having them differ across the two blocks. Experiment 2 sought to increase the predictive salience of the actions by avoiding the repetition within blocks. In Experiment 1, breakthrough times were numerically shorter for congruent than incongruent pairings, but Bayesian analysis supported the null hypothesis of no influence from the sensorimotor predictions. In Experiment 2, reported conscious perception was significantly faster for congruent than for incongruent pairings. A meta-analytic Bayes factor combining the two experiments confirmed this effect. Altogether, we provide evidence for a key implication of the action-oriented predictive processing approach to conscious perception, namely that sensorimotor predictions shape our conscious experience of the world.

scholarly journals INTERNAL AND EXTERNAL NEURAL SYNCHRONIZATION DURING CONSCIOUS PERCEPTION

2004 ◽  
Vol 14 (02) ◽  
pp. 825-842 ◽  
Author(s):  
RAMESH SRINIVASAN
Keyword(s):  
Steady State ◽  
Phase Distribution ◽  
Modulation Frequency ◽  
Conscious Experience ◽  
Partial Coherence ◽  
Conscious Perception ◽  
Steady State Response ◽  
State Response ◽  
Neocortical Dynamics ◽  
Stimulus Modulation

Binocular rivalry is a useful experimental paradigm to investigate aspects of neocortical dynamics related to conscious perception. Frequency-tagged EEG responses to a sine-flickered visual stimulus were contrasted between episodes of perceptual dominance, i.e. conscious perception of that stimulus and perceptual nondominance, i.e. conscious perception of a rival stimulus presented at a different frequency to the other eye. The amplitude and phase distribution of the stimulus-evoked steady-state responses depended on the stimulus modulation frequency, consistent with the presence of global resonance phenomena. At the apparent global resonance frequency, conscious perception of the stimulus modulated the steady-state response over the entire array of electrodes. These effects were significant at electrodes far from the primary visual cortex, including temporal, central, and frontal electrodes. The phase structure of the steady-state response was also investigated using coherence measures. Coherence between electrodes mostly increased during conscious perception of the stimulus. Analysis of partial coherence, removing stimulus-locked responses, indicated that synchronization of each signal to the stimulus flicker at each electrode and synchronization between signals that vary with respect to the stimulus flicker at each electrode both contribute to observed increases in coherence during conscious perception. These distinct modes of synchronization may reflect two different physiological mechanisms by which sensory signals are integrated across the cerebral cortex during conscious experience.

scholarly journals Dissociation between Awareness and Spatial Coding: Evidence from Unilateral Neglect

2012 ◽  
Vol 24 (4) ◽  
pp. 854-867 ◽  
Author(s):  
Barbara Treccani ◽  
Roberto Cubelli ◽  
Roberta Sellaro ◽  
Carlo Umiltà ◽  
Sergio Della Sala
Keyword(s):  
Brain Damage ◽  
Causal Relation ◽  
Conscious Experience ◽  
Conscious Perception ◽  
Spatial Coding ◽  
Unilateral Neglect ◽  
Individual Object ◽  
Object Features

Prevalent theories about consciousness propose a causal relation between lack of spatial coding and absence of conscious experience: The failure to code the position of an object is assumed to prevent this object from entering consciousness. This is consistent with influential theories of unilateral neglect following brain damage, according to which spatial coding of neglected stimuli is defective, and this would keep their processing at the nonconscious level. Contrary to this view, we report evidence showing that spatial coding and consciousness can dissociate. A patient with left neglect, who was not aware of contralesional stimuli, was able to process their color and position. However, in contrast to (ipsilesional) consciously perceived stimuli, color and position of neglected stimuli were processed separately. We propose that individual object features, including position, can be processed without attention and consciousness and that conscious perception of an object depends on the binding of its features into an integrated percept.

scholarly journals Growing Evidence for Separate Neural Mechanisms for Attention and Consciousness

2020 ◽  
Author(s):  
Alexander Maier ◽  
Naotsugu Tsuchiya
Keyword(s):  
Conscious Experience ◽  
Empirical Studies ◽  
Attentional Focus ◽  
Neural Mechanisms ◽  
Conscious Perception ◽  
Special Issue ◽  
Tight Coupling ◽  
Detailed Understanding ◽  
The Past ◽  
The World

Our conscious experience of the world seems to go in lockstep with our attentional focus: we tend to see, hear, taste and feel what we attend to, and vice versa. This tight coupling between attention and consciousness has given rise to the idea that these two phenomena are indivisible. In the late 1950s, the honoree of this special issue, Charles Eriksen, was among a small group of early pioneers that sought to investigate whether a transient increase in overall level of attention (alertness) in response to a noxious stimulus can be decoupled from conscious perception using experimental techniques. Recent years saw a similar debate regarding whether attention and consciousness are two dissociable processes. Initial evidence that attention and consciousness are two separate processes primarily rested on behavioral data. However, the past couple of years witnessed an explosion of studies aimed at testing this conjecture using neuroscientific techniques. Here we provide an overview of these and related empirical studies on the distinction between the neuronal correlates of attention and consciousness, and detail how advancements in theory and technology can bring about a more detailed understanding of the two. We argue that the most promising approach will combine ever evolving neurophysiological and interventionist tools with quantitative, empirically testable theories of consciousness that are grounded in a mathematically formalized understanding of phenomenology.

scholarly journals Early Visual Responses Predict Conscious Face Perception within and between Subjects during Binocular Rivalry

2013 ◽  
Vol 25 (6) ◽  
pp. 969-985 ◽  
Author(s):  
Kristian Sandberg ◽  
Bahador Bahrami ◽  
Ryota Kanai ◽  
Gareth Robert Barnes ◽  
Morten Overgaard ◽  
...  
Keyword(s):  
Face Perception ◽  
Binocular Rivalry ◽  
Neural Activity ◽  
Time Window ◽  
Conscious Experience ◽  
Time Range ◽  
Conscious Perception ◽  
Visual Responses ◽  
Physical Stimulation ◽  
Better Than

Previous studies indicate that conscious face perception may be related to neural activity in a large time window around 170–800 msec after stimulus presentation, yet in the majority of these studies changes in conscious experience are confounded with changes in physical stimulation. Using multivariate classification on MEG data recorded when participants reported changes in conscious perception evoked by binocular rivalry between a face and a grating, we showed that only MEG signals in the 120–320 msec time range, peaking at the M170 around 180 msec and the P2m at around 260 msec, reliably predicted conscious experience. Conscious perception could not only be decoded significantly better than chance from the sensors that showed the largest average difference, as previous studies suggest, but also from patterns of activity across groups of occipital sensors that individually were unable to predict perception better than chance. In addition, source space analyses showed that sources in the early and late visual system predicted conscious perception more accurately than frontal and parietal sites, although conscious perception could also be decoded there. Finally, the patterns of neural activity associated with conscious face perception generalized from one participant to another around the times of maximum prediction accuracy. Our work thus demonstrates that the neural correlates of particular conscious contents (here, faces) are highly consistent in time and space within individuals and that these correlates are shared to some extent between individuals.

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