Principles of Neural Science - Eric Kandel  ## Metadata - Author: **Eric Kandel** - Full Title: Principles of Neural Science - Category: #articles - Tags: #brain #neuroscience - URL: https://readwise.io/reader/document_raw_content/28026766 ## Highlights - The current challenge in the unification within biology, which we outline in this book, is the unification of the study of behavior—the science of the mind—and neural science—the science of the brain. ([View Highlight](https://read.readwise.io/read/01grdjjw6v00sshpwzrfphnct7)) - Physiological investigation of the nervous system began in the late 1700s when the Italian physician and physicist Luigi Galvani discovered that muscle and nerve cells produce electricity. ([View Highlight](https://read.readwise.io/read/01grdkd5b8dt52824rbwwpvh3r)) - The brain comprises seven major structures: the medulla oblongata, pons, cerebellum, midbrain, diencephalon, and cerebrum ([View Highlight](https://read.readwise.io/read/01grdmbwtxsexpbtqnsepmzt09)) - The fron- tal lobe is largely concerned with short-term memory and planning future actions and with control of move- ment; the parietal lobe with somatic sensation, with forming a body image and relating it to extrapersonal space; the occipital lobe with vision; and the temporal lobe with hearing and—through its deep structures, the hippocampus and amygdaloid nuclei—with learn- ing, memory, and emotion. ([View Highlight](https://read.readwise.io/read/01grg4c74db9e805g1gstx62fj)) - result of a stroke could not speak, although he could understand language perfectly well. This patient had no motor deficits of the tongue, mouth, or vocal cords that would affect his ability to speak. In fact, he could utter isolated words, whistle, and sing a melody with- out difficulty. But he could not speak grammatically or create complete sentences, nor could he express ideas in writing. Postmortem examination of this patient’s brain showed a lesion in the posterior region of the frontal lobe, now called Broca’s area ([View Highlight](https://read.readwise.io/read/01grg5b09x87jp8nn5w41xqeq8)) - This discovery led Broca to announce in 1864: “Nous parlons avec l’hémisphère gauche!” (We speak with the left hemisphere!) ([View Highlight](https://read.readwise.io/read/01grg4qb1z0sm104yt87epbjs7)) - Here the receptive and expressive zones for speech are intact, but the neuro- nal fibers that connect them are destroyed. This conduc- tion aphasia, as it is now called, is characterized by an incorrect use of words (paraphasia). Patients with con- duction aphasia understand words that they hear and read and have no motor difficulties when they speak. ([View Highlight](https://read.readwise.io/read/01grg58j5q1b1kte8ffe4bbm5w)) - he angular gyrus, specialized for processing both auditory and visual information. ([View Highlight](https://read.readwise.io/read/01grg55p2t54yt2a83dmytyxm2)) - Most influential was Lashley, who was deeply skeptical of the cytoarchitectonic approach to func- tional mapping of the cortex. “The ‘ideal’ architectonic map is nearly worthless,” Lashley wrote. “The area subdivisions are in large part anatomically meaning- less, and misleading as to the presumptive functional divisions of the cortex.” His skepticism was reinforced by his studies of the effects of various brain lesions on the ability of rats to learn to run a maze. From these studies Lashley concluded that the severity of a learn- ing defect depended on the size of the lesion, not on its precise location. Disillusioned, Lashley—and after him many other psychologists—concluded that learn- ing and other higher mental functions have no special locus in the brain and consequently cannot be attrib- uted to specific collections of neurons. ([View Highlight](https://read.readwise.io/read/01grg5ehdfv4vjf17ysgj6j2a1)) - functional specialization is a key organizing principle in the cerebral cortex, extending even to individual columns of cells within a functional area. Indeed, the brain is divided into many more functional regions than Brodmann envisaged. ([View Highlight](https://read.readwise.io/read/01grg5grt7sfxfwxzy7j55xg5q)) - Functional MRI, a noninvasive imaging technique for visualizing activ- ity in the brain, has not only confirmed that reading and speaking activate different brain areas but has also revealed that the act of thinking about a word’s mean- ing in the absence of sensory inputs activates a still dif- ferent area in the left frontal cortex ([View Highlight](https://read.readwise.io/read/01grg5nctkfaceqy1qwzgzk79j)) - Charles Darwin suggested that the acquisition of language is an inborn instinct comparable to that for upright posture. Children acquire the grammar of their native language simply by listening to their par- ents speak. They do not have to be taught the specific rules of grammar. In 1960 the linguist Noam Chomsky elaborated on Darwin’s notion. He proposed that chil- dren acquire a language so easily and naturally because humans, unlike other primates, have the innate capabil- ity of generalizing to a complete and coherent language from a limited sample of sentences. Based on an analy- sis of the structure of sentences in various languages, Chomsky argued that all natural languages share a common design, which he called universal grammar. The existence of universal grammar, he argued, implies that there is an innate system in the human brain that evolved to mediate this grammatical design of language. ([View Highlight](https://read.readwise.io/read/01grg5yswz8jcpsfxw5j3tetmk)) - —we now think that all cognitive abilities result from the inter- action of many processing mechanisms distributed in several regions of the brain ([View Highlight](https://read.readwise.io/read/01gsnhrvk9eg1rkh3h0k6f88ay)) - . Perception, movement, language, thought, and memory are all made possible by the interlinkage of serial and parallel processing in discrete brain regions, each with specific func- tions ([View Highlight](https://read.readwise.io/read/01gsnht8y7kmd6vhcfegyq0zae)) - Mental Processes Are the End Product of the Interactions Between Elementary Processing Units in the Brain ([View Highlight](https://read.readwise.io/read/01gsnj0qx6tenhq7z2j45zjp3b)) - Tags: #resolution #emergence - Simple introspection suggests that we store each piece of our knowledge as a single representation that can be recalled by memory-jogging stimuli or even by the imagination alone ([View Highlight](https://read.readwise.io/read/01gsnhy3jt2bf4e8xvmt24154w)) - Knowledge about grandmother is not stored as a single representation but rather is subdivided into distinct categories and stored separately. ([View Highlight](https://read.readwise.io/read/01gsnjaxwhpyf7x1879nh62bpe)) - Individual nerve cells or neurons are the basic units of the brain. The human brain contains a huge number of these cells, on the order of 1011 neurons ([View Highlight](https://read.readwise.io/read/01gsnjr290p0abrg14shr0rf59)) - the complexity of human behavior depends less on the variety of neurons than on their organization into anatomical circuits with precise functions ([View Highlight](https://read.readwise.io/read/01gsnjreff12vnmxxqsypc9mss)) - Multipolar neurons predominate in the nervous system of vertebrates. They typically have a single axon and many dendritic structures emerging from various points around the cell body ([View Highlight](https://read.readwise.io/read/01gsnmgtszd938z81eh6pmhz6e)) - Neurons are thus classified into three large groups: unipolar, bipolar, and multipolar. ([View Highlight](https://read.readwise.io/read/01gsnmfes55p90p1mkb2162atz)) - Unipolar neurons are the simplest because they have a single primary process, which usually gives rise to many branches. One branch serves as the axon; other branches function as receiving structures ([View Highlight](https://read.readwise.io/read/01gsnmftr50ebt2e8g5ysx9ry8)) - Bipolar neurons have an oval soma that gives rise to two distinct processes: a dendritic structure that receives signals from the periphery of the body and an axon that carries information toward the central nerv- ous system ([View Highlight](https://read.readwise.io/read/01gsnmg3m2zc9r2rf6jvdedkjt)) - Conversely, a single motor cell in the knee jerk circuit receives 200 to 450 input con- tacts from approximately 130 sensory cells. This pat- tern of connection is called convergence (Figure 2–7B). It is common at the output stages of the nervous sys- tem; a target motor cell that receives information from many sensory neurons is able to integrate information from many sources. Convergence also ensures that a motor neuron is activated only if a sufficient number of sensory neurons become activated together. ([View Highlight](https://read.readwise.io/read/01gsnnhd2f85pf7c19v1wr7whx))