Scientific Understanding of Consciousness
Experts Shaped My Understanding
My understanding of consciousness has been shaped by the ideas of science experts who have thought about the topic. Although much research has been done on the brain during recent decades, the current efforts have barely scratched the surface.
The central feature of my understanding of consciousness is Gerald Edelman’s Dynamic Core hypothesis. The dynamic core is a continuing theme throughout this website. Much of the individual discussion should be viewed in the context of the dynamic core.
Antonio Damasio – I have adopted Damasio’s concepts of proto-self, core self, autobiographical self, core consciousness, extended consciousness (human-type consciousness) into my understanding of consciousness. I have also adopted Damasio’s concept of Convergence-Divergence Zones.
Paraphrase Highlights from Damasio reference paraphrases
Joseph LeDoux -- Professor of Neuroscience and Psychology at New York University; also director of the Center for the Neuroscience of Fear and Anxiety, a multi-university collaboration. – My intention has been to adopt LeDoux’s expert knowledge of the emotional brain, along with his concepts of the tight relationship of the emotional and cognitive functions of the brain. I believe his concepts of the functions of synapses as a basis consciousness is closely related to Edelman’s dynamic core concept.
Paraphrase Highlights from LeDoux reference paraphrases
Brain operates as a Reality Emulator (Llinás; I of the Vortex, 13)
The brain is a closed system modulated by the senses. The brain is a self-activating system. It is capable of emulating reality, even in the absence of input from reality, as occurs in dream states and daydreaming. (Llinás; I of the Vortex, 56-57)
Prediction is the ultimate and most pervasive of all brain functions. (Llinás; I of the Vortex, 127)
Paraphrase Highlights from Llinás reference paraphrases
Joaquín Fuster — the world’s preeminent expert on the frontal lobes, with his concept of the “Perception-Action Cycle” and his concept of “active memory,” which may be an earlier name for “working memory.”
Christof Koch - Ideas and thought on the neural correlates of consciousness have been influenced by Christof Koch, who worked with Francis Crick. Recently moved from Caltech to become chief scientific officer of Allen Institute for Brain Research in Seattle. (Science, 8 April 2011, 155)
Francis Crick (1916-2004) -- Ideas and thoughts on consciousness.
György Buzsáki - exploration of neural mechanisms of oscillation and synchronization in the neocortex and hippocampus.
Susan Greenfield's concept of gestalts mediated by neuronal assemblies provides a mechanism for conceptualizing Edelman's hypothesis of the dynamic core within the thalamocortical system.
Eric Kandel -- memory
Allan Hobson, -- Professor of Psychiatry, Harvard Medical School. Created the AIM model of consciousness, comprised of three components: (1) Activity, (2) Information source, (3) Modulation.
Hobson also hypothesizes that sleep and dreaming, in addition to memory consolidation, facilitate neural assembly fragmentation, self-organization, creativity.
Edmund Rolls discussions of cortical functionality.
Alan Baddeley – Working memory model comprised of (1) central executive, (2) visuospatial sketchpad, (3) episodic buffer, (4) phonological loop.
Michael Gazzaniga — Professor of Psycholodgy and Director of SAGE Center for the Study of Mind, University of California Santa Barbara; extensive study of split-brain patients with lateralization of functions.
David LaBerge — Output fibers of the thalamus activate specific clusters of neurons in every area of cortex, and simulations of thalamocortical circuitry show that thalamic output can amplify neural activity in the target regions.
Donald O. Hebb — His theory of cell assembly and plasticity has been a traditional influence since the mid-twentieth century.
Vernon Mountcastle – Columnar architecture extends across all six layers of neocortex. Macrocolumns about 0.8 mm diameter.
Christoph von der Malsburg – Dynamic Link Architecture: two central hypotheses: (1) binding by signal correlations, and (2) short-term synaptic modification.
Wolf Singer – Temporal correlations in neural processing; interconnected cortical areas are permanently active; self-organize assemblies in parallel within a few reentrant cycles (40 Hz), representations consist of large, widely-distributed assemblies of coherently active neurons.
Shimon Ullman – Counterstreams: bidirectional search between an incoming pattern and stored object representations.
Bradley Postle – Rather than specialized working memory systems in the forebrain, a growing body of data suggests that working memory is mediated by sustained attention to information represented in systems that have evolved to perform perception-, representation-, or action-related functions
Gordon Shepherd – Synaptic organization of the brain, particularly the olfactory bulb and its comparison and contrast with the neocortex.
Larry Squire – memory
Victor Johnston -- professor of psychobiology at New Mexico State University, author of Why We Feel -- Conscious experiences are evolved emergent properties of biological brains. (Johnston; Why We Feel, 58)
Consciousness is a dynamic organization existing within many different areas of the brain. Brain architecture is characterized by abundant reciprocal connections between cortical regions, recurrent pathways that permit feedback and reactivation of active areas, and lateral inhibition that focuses neural activity within active centers by inhibiting less active adjacent regions. (Johnston; Why We Feel, 122-123)
Two types of feelings; affects and emotions. Affects directly evoked by sensory inputs (pain, hunger, thirst), Emotions internally produced (anger, love). (Johnston; Why We Feel, 61)
John Ratey, M.D. — clinical professor of psychiatry at Harvard Medical School.
Adam Zeman, consultant neurologist at Western General Hospital, Edinburgh; senior lecturer in the department of clinical neurosciences, Edinburgh University.
John Searle — Professor of Philosophy, University of California, Berkeley; Mystery of Consciousness – one of the few philosophers I agree with (on most things).
John Eccles -- Nobel Prize winner, very informative material on brain anatomy and physiology, although I don’t agree with his religious convictions.
Giulio Tononi has used computer simulation to gain insight into the brain's thalamocortical system functionality. He has stated that: "By using computer simulation, it is possible to show that high integrated information requires networks that conjoin functional specialization with functional integration. In approximate terms, this kind of functionality is characteristic of the mammalian thalamocortical system: different parts of the cerebral cortex are specialized for different functions, yet a vast network of connections allows these parts to interact profusely. And indeed, as much neurological evidence indicates, the thalamocortical system is precisely the part of the brain that cannot be severely impaired without loss of consciousness.", (Giulio Tononi, Biol. Bull. 215: 216-242, December 2008) Computer simulations such as this strongly support my understanding of the brain's dynamic core of consciousness in the thalamocortical system. Consciousness arises as an emergent property of neuronal network activity in the dynamic core of the biological neural network, which evolved over millions of years, and indeed is based upon molecular and cellular evolution extending back billions of years.
Nonetheless, I take issue with Giulio Tononi in his statements regarding his Integrated Information Theory (IIT) in which he claims that consciousness can be attributed to non-biological systems. He has stated that: “Integrated information theory (IIT) posits that to the extent that a mechanism is capable of generating integrated information, no matter whether it is organic or not, whether it is built of neurons or of silicon chips, and independent of its ability to report, it will have consciousness.” (Giulio Tononi, Biol. Bull. 215: 216-242, December 2008) My understanding of consciousness is not consistent with this statement. My working hypothesis of consciousness posits an emergent property of a biological network of neurons resulting from billions of years of evolution.
Antti Revonsuo has endorsed temporal coding and synchronization, with Gestalt criteria for perceptual grouping.
(I think his "Master Loop" hypothesis would be augmented and better served via recursion and Bayesian inference with Fuster's perception-action cycle. His Master Loop would then just be a part of the Dynamic Core.
His "world simulation" concept fits in well with Llinás' s concept of the brain as a "reality emulator" and the notion of consciousness as "dream functionality modulated by the senses.")
A representative sample of experts is contained in the Table of Contents of Essential Sources in the Scientific Study of Consciousness.
It is important not to be distracted by pseudoscientific, ethereal, razzle-dazzle discussions sprinkled with the words ‘quantum’, ‘qbits’, etc. Chief among these are the musings of Roger Penrose, Stuart Hameroff, and their followers.
Some people believe that qualia represent very profound events in neuronal function dealing with quantum mechanical structures of neurons that include the detailed organization of microtubules and microfilaments. Llinás doubts that this topic is worth pursuing at any serious level. (Llinás; I of the Vortex, 209)
Also to be avoided are aimless philosophical wanderings into the vestiges of Dualism, Materialism, etc. Computers can never achieve consciousness, although computer simulation can provide much insight about the functionality of biological neural networks. Always keep in mind that consciousness is an emergent property of biological systems that are the product of billions of years of evolution.
Can computers be programmed to have the consciousness? The answer is NO! Consciousness depends on affective experience (i.e. the experience of one's own emotional patterns). True affects and their near infinite variations can only arise from living biological systems and their developmental processes. (Greenspan; First Idea, 292)
I must point out, however, that some experts, along with their distractions on certain topics, can have much to offer. Stuart Hameroff, for example, is an anesthesiologist whose discussion of the effects of anesthesia is informative and interesting.
Textbooks and Other References
I’ll list a few here; a more complete list is in Book References List.
Kandel, et.al, Principles of Neural Science — the authoritative reference in neuroscience.
Dale Purves, et.al, Neuroscience, an excellent textbook, easy to read and very informative.
Hirsch, Neuroanatomy, a unique computer-modeled display of brain anatomical features; very informative for spatial relationships of brain stem features, limbic system.
Gilbert, Developmental Biology – an excellent textbook
Sanes, et.al, Development of the Nervous System – authoritative, excellent
Topics that bear on Consciousness
Kauffman, At Home in the Universe
Return to — Home Page
Link to — Consciousness Subject Outline
Further discussion — Covington Theory of Consciousness