The Idea of the Brain: The Past and Future of Neuroscience

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Answering “no” after the resective surgery ( Fig 3A and 3B) challenges the reader to explain why, although the synaptic disconnection at a molecular scale in Step 2 ( Fig 2) does not change the conscious perception, the physical disconnection with a surgical scalpel nevertheless changes the participant’s conscious perception. Answering “yes” after surgically cutting the visual cortex ( Fig 3A) but “no” after its removal ( Fig 3B) implies that the distance of the resected neurons from the rest of the brain is vital for conscious perception. The distinction between surgery with ( Fig 3A) and without the removal ( Fig 3B) of the visual cortex raises interesting questions regarding the effect of the distance between brain regions on consciousness. For example, does the brain’s size (between species and even within the same species) affect consciousness due to the distance between brain regions? Regarding the thought experiment presented here, however, placing an electrode at the cell body to generate the cellular output effectively bypasses the critical nexus point in the apical dendrite. We, therefore, predict that the replay of activity at the cell bodies of pyramidal cells would, in this case, completely entail the former influence of the apical dendrite. Furthermore, DIT is agnostic about the intrinsic necessity of apical causality, per se, versus the resultant firing activity at the cell body. In this respect, DIT does not inform us whether the brain is conscious under replay or whether scattered brains are conscious. Whitehouse AJ, Bishop DV. Hemispheric division of function is the result of independent probabilistic biases. Neuropsychologia. 2009;47(8-9):1938-43. doi: 10.1016/j.neuropsychologia.2009.03.005 Integrated information theory [ 84– 86] quantifies consciousness based on the repertoire of all possible cause-and-effect interactions between the neurons in the brain’s network. Disconnecting the neurons in Step 2 abolished the network structure that underlies the interaction between neurons. However, in Step 1, the replay imposed particular (recorded) trains of action potentials and effectively vetoed all the interaction between the neurons, even though the synaptic connections were fully functional. Therefore, according to the assumptions of IIT, our participant already loses consciousness in Step 1. Cobb’s greater lesson is straightforward, but difficult: we should spend more time trying to understand the brain as it is, and as it functions in a comparative context, rather than through the lens of whatever metaphor or analogy happens to be handy or fashionable. His last paragraph is instructive, for it offers a series of scenarios based on connectomes, semiotics, semantics, cybernetics, control theory and so on. Each sentence begins with the word “Or”, although the last one is just followed by a dash, creating a blank screen like the final episode of The Sopranos, on to which we can write anything we please, or hope, or fear, or understand. As of now, we understand so little of the entity that allows us to understand.

To underscore the usefulness of replay as a potential experimental strategy, let us compare the replay of brain activity to a detailed simulation of the brain. A frequent objection to the view that a detailed simulation of the human brain can become conscious is that it merely manipulates symbols whose meaning depends on external interpretation, whereas neural activity is intrinsically meaningful to the brain [ 88]. In contrast to a simulation, the artificial neuronal firing induced by the replay is intrinsically meaningful to the brain/participant because it is an identical copy of intrinsically meaningful activity (i.e., an experience of green light). John Searle famously explained that “you could not digest pizza by running the program that simulates such digestion” [ 89]. Unlike biologically detailed simulations running on a computer, the replay is recorded and activated on the same substrate. Therefore, in contrast to a simulation of the stomach, recording and then replaying smooth muscle contraction and enzyme secretion would result in digestion. What would it imply about the nature of consciousness if replay would work for stomach digestion or the heart pumping blood but not for the brain and consciousness? In the “Future” section Cobb describes where brain science might be going, and which new metaphors and technologies may help. This was the most exciting part of the book. But to say too much would spoil the journey for you, dear reader. And this review is long enough already.

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It is history, but it’s modern “we don’t know” science history. It’s about brain connections and how we actually still don’t know anything about them. According to Zeki and colleagues [ 74], consciousness comprises nodes of micro-consciousnesses in different brain regions. Interestingly, in contrast to other theories, Zeki argues that consciousness is not unified [ 75]. Therefore, color and motion, for example, are consciously perceived in different parts of the cortex and only then bind together with other nodes to form a macro-consciousness. A micro-consciousness is autonomous [ 76] and does not require further processing. Therefore, the resected visual cortex in Step 3 may become micro-conscious of the green light during the replay. We could not find a direct reason as to why, according to Zeki, scattered brains during replay cannot bind together into a macro-consciousness. There was also a section which made me laugh out loud detailing an fMRI experiment performed on a salmon. I will leave the joy of discovering it to anyone who reads the book. In the 19th century, the electrical paradigm became less spark-like, and more like that modern miracle, the telegraph. Brain studies shifted from mechanism to function. Phrenologists measured lumps in the skull, on the theory that specific functions and capabilities arose from specific parts of the brain, so that talents and deficiencies could be explained by having excess or deficient brain matter, which one could discover by measuring lumps and dips in the skull. Thus one could “prove” that someone was a natural criminal, laborer, or intellectual by measuring the skull. For example, the fact that men’s brains are bigger than women’s was taken to prove that men are more intelligent than women. Phrenology was eventually discredited when scientists began looking at the actual brain, rather than the skull. Parts of the brain were indeed sometimes associated with mental abilities, but these were not enlarged nor did they lie beneath lumps. Still, some capabilities such as “intelligence” did not have seem to be localized. A surprisingly acrimonious debate emerged over whether specific mental activities were localized in the brain or whether they arose from the brain as a whole. This is an active debate, even today.

If the reader answers “yes” in Step 3, then a second resection or any number of additional resections should not change the reader’s answer. Iteratively resecting and re-resecting eventually leaves us with a brain in the form of geographically scattered individual neurons. Therefore, accepting the hypothesis in Step 3 results in a conscious scattered brain. The alternative, namely, arguing that scattered brains cannot be conscious, leads to rejecting the hypothesis that the firing of the neurons causes our conscious experience. The chapter feels like a summary of a ton of docs and ideas I've read before. Yet it's kinda dry. I rather read a more fun intro to this stuff. And if you watch docs on brain studies you already know most of this. Sha, Z., et al. (2021). Handedness and its genetic influences are associated with structural asymmetries of the cerebral cortex in 31,864 individuals. How modern philosophers describe consciousness. The definitions are frankly pointless to read about as it’s just random people with opinions. The split brain studies are interesting, but I know that already. This book is kinda basic. Gerade das Kapitel mit Bewusstsein fand ich besonders gut weil er deutlich hervorbringt, dass NIEMAND Ahnung darüber hat, wie es funktioniert und wo es im Gehirn verankert ist. Und überhaupt ob es wichtig ist, dass wir das wissen müssen. Und ob es nicht besser ist diese Debatte wichtigerer Themen gegenüber zu opfern.To start with: I did not like it. I did not like the unchallenged focus on the western history of neuroscience. There were so many other stories worth telling! Part three, "Future", is a brief exploration of where Cobb thinks research might go, and the many questions which remain unsolved. It looks at the flaws of current methodology and postulates how scientists might work past them. He makes some valid points, and whilst there are no easy answers, all neuroscientists should consider what he has to say.

The chapter is a bit weaker than the last one. I feel even more confused. The author often talks about how people overall were thinking or what a certain person was thinking. Yet it’s hard to understand who thought what and who these writers were. I guess I should assume they were popular people and that most people had the same ideas? I’m not sure that’s the case. All of that is from the “Past” section of the book. In the “Present” section Cobb describes our current understanding of how memory works, how circuits have limited explanatory power, and how brains are similar to but different from digital computers. He describes the chemical basis for neural and mental phenomena. He describes the current view, that mental functions are both local and global; though some regions must be present for specific functions, those function may still require the whole brain. I was surprised to learn that fMRI ���brain scans” are misleading, and that results from fMRI data are often over-hyped. The ancients believed the heart was the anatomical seat of thought and consciousness and considered the brain to be of relative little import.Of course in a work such as this there is a section on consciousness. And once again, I am glad to see that no one has a coherent definition of this, studies of the brain's relation to consciousness are thus fraught with issues based purely on arbitrary definitions (mostly from non-scientists), and as a result, providing any satisfactory universal answer to this question is like trying to hit a bullet, with another bullet, fired from two passing trains so that each bullet deflects onto a nail and piece of jello, respectively, and nails them to a wall on a third passing train. I tend to the materialist side of things here and think that woo-woo idiots keep making the definition more mysterious in the face of mounting physical evidence, just my two cents, and Cobb does everything he can to make this Mississippi mud pie of an issue as intellectually healthy as possible. It’s not the glorious old super theories explaining everythin