Consciousness and the brain
Book title by Stanislas Dehaene (New York: Viking 2014), a copy of which can be downloaded here. (Note it is in EPUB format. EPUB readers can be downloaded free on the internet.) From the Introduction, the section “Cracking consciousness”:
“The word consciousness, as we use it in everyday speech, is loaded with fuzzy meanings, covering a broad range of complex phenomena. Our first task, then, will be to bring order to this confused state of affairs. We will have to narrow our subject matter to a definite point that can be subjected to precise experiments. As we will see, the contemporary science of consciousness distinguishes a minimum of three concepts: vigilance—the state of wakefulness, which varies when we fall asleep or wake up; attention—the focusing of our mental resources onto a specific piece of information; and conscious access—the fact that some of the attended information eventually enters our awareness and becomes reportable to others.
“What counts as genuine consciousness, I will argue, is conscious access—the simple fact that usually, whenever we are awake, whatever we decide to focus on may become conscious. Neither vigilance nor attention alone is sufficient. When we are fully awake and attentive, sometimes we can see an object and describe our perception to others, but sometimes we cannot—perhaps the object was too faint, or it was flashed too briefly to be visible. In the first case, we are said to enjoy conscious access, and in the second we are not (and yet as we shall see, our brain may be processing the information unconsciously).
“In the new science of consciousness, conscious access is a well-defined phenomenon, distinct from vigilance and attention. Furthermore, it can be easily studied in the laboratory. We now know of dozens of ways in which a stimulus can cross the border between unperceived and perceived, between invisible and visible, allowing us to probe what this crossing changes in the brain.
“Conscious access is also the gateway to more complex forms of conscious experience. In everyday language, we often conflate our consciousness with our sense of self—how the brain creates a point of view, an “I” that looks at its surroundings from a specific vantage point. Consciousness can also be recursive: our “I” can look down at itself, comment on its own performance, and even know when it does not know something. The good news is that even these higher-order meanings of consciousness are no longer inaccessible to experimentation. In our laboratories, we have learned to quantify what the “I” feels and reports, both about the external environment and about itself. We can even manipulate the sense of self, so that people may have an out-of-body experience while they lie inside a magnetic resonance imager.
“Some philosophers still think that none of the above ideas will suffice to solve the problem. The heart of the problem, they believe, lies in another sense of consciousness, which they call “phenomenal awareness”: the intuitive feeling, present in all of us, that our internal experiences possess exclusive qualities, unique qualia such as the exquisite sharpness of tooth pain or the inimitable greenness of a fresh leaf. These inner qualities, they argue, can never be reduced to a scientific neuronal description; by nature, they are personal and subjective, and thus they defy any exhaustive verbal communication to others. But I disagree, and I will argue that the notion of a phenomenal consciousness that is distinct from conscious access is highly misleading and leads down a slippery slope to dualism. We should start simple and first study conscious access. Once we clarify how any piece of sensory information can gain access to our mind and become reportable, then the insurmountable problem of our ineffable experiences will disappear.”
From the Introduction, section “signatures of conscious thoughts”: “These three ingredients—focusing on conscious access, manipulating conscious perception, and carefully recording introspection—have transformed the study of consciousness into a normal experimental science. We can probe the extent to which a picture that people claim not to have seen is in fact processed by the brain. As we will discover, a staggering amount of unconscious processing occurs beneath the surface of our conscious mind. Research using subliminal images has provided a strong platform to study the brain mechanisms of conscious experience. Modern brain imaging methods have given us a means of investigating… Read more »
In Chapter 1 it noted that subjective reports of conscious access were necessary. But it also noted this in the section “primacy of the subjective”: “Even in normal people, introspection can be demonstrably wrong. By definition, we have no access to our many unconscious processes—but this does not prevent us from making up stories about them. […] People often invent all sorts of contorted, after-the-fact interpretations for their decisions—oblivious to their true unconscious motivations. […] In that sense, the behaviorists were right: as a method, introspection provides a shaky ground for a science of psychology, because no amount of introspection… Read more »
Granted there is a huge unconscious underbelly to much of our thinking and behavior, even within our central executive system, as experimental data amply shows in Chapter 2. Its operation is critical and foundational to our survival and flourishing, and was undoubtedly naturally selected as such. Without it we would be utterly helpless. Plus there’s no way we could bring even a fraction of its operation into conscious awareness, nor would that be functionally viable even if we could. “But we should not get carried away. Some cognitive psychologists go as far as to propose that consciousness is a pure… Read more »
Chapter 3 explains that consciousness is useful for transforming fast, unconsciously processed information into a code that allows for slower executive examination and decision. This summarized code allows for the information to be stored in limited working memory. This in turn allows for us to not only remember the past but project into the future, something unconsciousness is incapable of being tied to present contingencies. Dehaene suggests this process has been naturally selected given the advantages it provides. Conscious information is also cross pollinated between individuals culturally, which allows for evolution beyond individual capacities. This creates “multicore social algorithms” which… Read more »
On the distinction between ultimate and proximate explanation, this* article notes that “ultimate explanations address evolutionary function (the ‘why’ question), and proximate explanations address the way in which that functionality is achieved (the ‘how’ question).” In Chapter 3 Dehaene opens with this: “In this book, however, I explore […] what philosophers call the ‘functionalist’ view of consciousness. Its thesis is that consciousness is useful. Conscious perception transforms incoming information into an internal code that allows it to be processed in unique ways. Consciousness is an elaborate functional property and as such is likely to have been selected, across millions of… Read more »
From Michael Cohen and Daniel Dennett (2011). “Consciousness cannot be separated from function.” Trends in Cognitive Sciences 15(8), pp. 358 – 364. “There are several theorists who have already realized the need for functions in developing theories of consciousness. Dehaene and colleagues have put forth a global neuronal workspace model that claims consciousness is defined by the orientation of top-down attention, long-distance feedback loops that extend into parietofrontal networks, and conscious reportability. […] There is still much work to be done in regards to how these functions and mechanisms interact. […] The upshot of function-based theories is that they make… Read more »
Panel Discussion on the Mind
Stanislas Dehaene, author of Consciousness and the Brain: Deciphering How the Brain Codes Our Thoughts, and Daniel Dennett, author of Intuition Pumps and Other Tools for Thinking, talked about their books on the workings of the human brain.“State of Mind: Consciousness and Thinking” was a panel at the 2014 Boston Book Festival, held October 25 in the sanctuary of Old South Church.
In the discussion in the last post the event starts out with the host saying they agree, so it’s not a debate. They do NOT agree on consciousness. From reading Dennett’s latest book he still maintains consciousness is a user illusion. Dehaene refutes this emphatically. But it appears they want to avoid a debate here so it’s just each of them talking in turn about their work, then answering questions. E.g. Dehaene said in this video at 12:25: “Consciousness is not an illusion. […] It’s an evolved function, it’s a useful function […] of sharing information […] to make the… Read more »
“Towards a cognitive neuroscience of self-awareness,” by Lou et al., Neuroscience and Biobehavioral Reviews 83, December 2017, pp. 765 – 73. The abstract: “Self-awareness is a pivotal component of conscious experience. It is correlated with a paralimbic network of medial prefrontal/anterior cingulate and medial parietal/posterior cingulate cortical ‘hubs’ and associated regions. “Electromagnetic and transmitter manipulation have demonstrated that the network is not an epiphenomenon but instrumental in generation of self-awareness. Thus, transcranial magnetic stimulation (TMS) targeting the hubs impedes different aspects of self-awareness with a latency of 160 ms. The network is linked by ∼40 Hz oscillations and regulated by… Read more »
Btw, Dennett does indeed accept human consciousness as the most advanced comprehension on earth. I think he’s more talking about some of the illusions we create ‘about’ consciousness like privileged access. And of course all the woo woo metaphysical stuff. I’m all for aligning (what he calls) my manifest image with the scientific image.
Another point he makes in From Bacteria to Bach and Back it that there is no special area of the brain for consciousness, that it just uses all of the other, specialized modular areas in the same ways. The neuroscience research I’ve been providing indeed shows cross-brain networks (like the global neural network) that are used in conscious but not in non-conscious operations. Same for some specific aspects of consciousness that highlight certain other networks not used in that way elsewhere.
In Chapter 11 of FBBB Dennett said the following on the manifest image when critics claim it is only an illusion: “In fact, it’s a version of what I have said about the manifest image of each species: a user-illusion brilliantly designed by evolution to fit the needs of its users. My version differs only in being willing and eager to endorse these ontologies as ways of carving up reality, not mere fictions but different versions of what actually exists: real patterns.” So our manifest image interprets actually existing reality to accommodate our needs. Of course it does. That such… Read more »
Kinds of realism, from Lakoff and Johnson, Philosophy in the Flesh (NY: Basic Books, 1999) “Perhaps the oldest of philosophical problems is the problem of what is real and how we can know it, if we can know it…. Aristotle concluded that we could know because our minds could directly grasp the essences of things in the world. This was ultimate metaphysical realism. There was no split between ontology (what there is) and epistemology (what you could know), because the mind was in direct touch with the world. “With Descartes, philosophy opened a gap between the mind and the world….… Read more »
Dennett said in chapter 14 of FBBB:
“We won’t have a complete science of consciousness until we can align our manifest-image identifications of mental states by their contents with scientific-image identifications of the subpersonal information structures and events that are causally responsible for generating the details of the user-illusion we take ourselves to operate in.”
He’s right about that except that consciousness is a empirically verified, neuroscientific reality, as Dehaene’s research attests.