Cognitive Neuroscience Lecture 2: History & Background PDF

PSYC 4041: Cognitive Neuroscience Lecture 2: History & Background 1/22/2024 What is Cognitive Neuroscience? Cognitive neuroscience explores how the brain gives rise to the mind Cognitive neuroscience aims to provide a neural explanation of cognitive processes (perception, attention, memory, etc.) Ro...

PSYC 4041: Cognitive Neuroscience Lecture 2: History & Background 1/22/2024 What is Cognitive Neuroscience? Cognitive neuroscience explores how the brain gives rise to the mind Cognitive neuroscience aims to provide a neural explanation of cognitive processes (perception, attention, memory, etc.) Road Map: History and Introduction Philosophical beginnings (mind/body) Historical foundations, milestones, and pioneers Criticisms and challenges: Neuroskepticism? The “Mind-Body” Problem Question: How is it that a physical substance can give rise to our wide array of mental experiences? ▪ AKA: What is the relationship between our body and thoughts? ▪ AKA: What is the relationship between our brain and thoughts? Pre-dates the realization that the “seat” of the mind is located in the brain. The “Mind-Body” Problem Three historical perspectives: ▪ Dualism: mind and body are separate ▪ Dual-aspect theory ▪ Reductionism Dualism Rene Descartes (1596-1650) Mind and body are separate substances ▪ Body: physical and mortal ▪ Mind: non-physical and immortal ▪ Interact in the pineal gland According to Descartes, stimulation of the sense organs would cause vibrations in the body that would be picked up in the pineal gland. Dualism Rene Descartes (1596-1650) Mind and body are separate substances ▪ Body: physical and mortal ▪ Mind: non-physical and immortal ▪ Interact in the pineal gland Now we know that the pineal gland is part of the endocrine system and is involved in the regulation of sleep cycles. It has no known metaphysical properties. Dualism “There is little hope for cognitive neuroscience if dualism is true because the methods of physical and biological sciences cannot tap into the non-physical domain (if such a thing were to exist).” The “Mind-Body” Problem Three historical perspectives: ▪ Dualism: mind and body are separate ▪ Dual-aspect theory: mind and body are two sides of the same coin ▪ Reductionism Dual-Aspect Theory Barusch Spinoza (1632-1667) Mind and brain are not different things – but rather are different levels of explanation for the same thing Mind+brain together are a single entity that comprises both physical and non-physical properties Analogy: the nature of light → “wave-particle duality” The “Mind-Body” Problem Three historical perspectives: ▪ Dualism: mind and body are separate ▪ Dual-aspect theory: mind and body are two sides of the same coin ▪ Reductionism: the mind can be reduced to the parts of the brain Reductionism Cognitive or mind-based concepts (memories, emotions, etc.) will eventually be replaced by purely biological concepts (brain networks, neurotransmitters, etc.) As we progress, Psychology as a discipline may reduce to Biology ▪ Historical precedent for abandoning/replacing scientific ideas Reductionism xkcd.com/435/ Emergent properties? Counterpoint argues that mind-based concepts will always be useful to describe the nature of brain-based processes. (aka: Dual-aspect theory) Road Map: History and Introduction Philosophical beginnings (mind/body) Dualism, Reductionism, Dual-Aspect Theory Historical foundations, milestones, and pioneers Criticisms and challenges: Neuroskepticism? Road Map: History and Introduction Philosophical beginnings (mind/body) Dualism, Reductionism, Dual-Aspect Theory Historical foundations, milestones, and pioneers Criticisms and challenges: Neuroskepticism? Study of the brain throughout history Classical antiquity: “Finding” the brain 19th century: Phrenology 19th century: Cognitive neuropsychology 20th century: Psychology and the cognitive revolution Late 20th century: Birth of modern cognitive neuroscience Classical antiquity: “Finding” the brain Aristotle (384-322 BCE) ▪ ▪ ▪ Believed “seat” of cognition was in the heart Noticed that more intelligent species had higher brain:body ratios...but decided that the brain served as a “cooling system” for the heart Galen of Pergamon (~129-199 CE) ▪ ▪ ▪ Gladiatorial surgeon during Roman Empire Took note of nerves projecting to/from brain...but believed that the ventricles were the seat of mental experiences Ventricles, cerebrospinal fluid, cerebral cortex? What are the ventricles? Hollow, fluid-filled chambers in brain Contain cells that produce cerebrospinal fluid (CSF), which cushions the brain and removes waste product Widely considered critical to mental processes for millennium+ Ventricles, cerebrospinal fluid, cerebral cortex? Incorrect emphasis on the ventricles — at the expense of the cerebral cortex and cortical surface! 15th century drawing Modern drawing Study of the brain throughout history Classical antiquity: “Finding” the brain 19th century: Phrenology 19th century: Cognitive neuropsychology 20th century: Psychology and the cognitive revolution Late 20th century: Birth of modern cognitive neuroscience Early 1800s: Phrenology Franz Joseph Gall (1759-1828) Johann Spurzheim (1776-1832) ▪ Provided some of the first realistic drawings of the human brain de Viessens (1685) Gall & Spurzheim (1810) Early 1800s: Phrenology Gall and Spurzheim also introduced phrenology, which had three key assumptions: 1. Different brain regions = different functions/behaviors/traits 2. Regional brain size produce distortions on the skull 3. Sizes and distortions correlated with differences in psychological abilities and personality. Variations of assumptions #1 and #3 live on in modern cognitive neuroscience (functional specialization) Early 1800s: Phrenology Functional specializations espoused by phrenologists were nonsense ▪ ▪ ▪ “Destructiveness” “Firmness” “Love of animals”, etc. No scientific basis Skull shape or skull “bumps” have nothing to do with brain function or cognitive processes Phrenology Chart, 1800s Early 1800s: Phrenology Vaught’s Practical Character Reader (1902) Study of the brain throughout history Classical antiquity: “Finding” the brain 19th century: Phrenology 19th century: Cognitive neuropsychology 20th century: Psychology and the cognitive revolution Late 20th century: Birth of modern cognitive neuroscience Functional localization without phrenology Phrenology was mostly discredited by end of 1800s, BUT... The idea of functional specialization (in the brain) has stood the test of time into modern cognitive neuroscience More nuanced and rigorous view: ▪ Based on empirical evidence and careful observations ▪ Does not assume a simple 1:1 relationship between a brain region and a cognitive function ▪ Instead, some degree of specialization for neural processing in a particular region 19th century: Patients with brain damage Paul Broca (1861) ▪ ▪ Described two patients with damage to the same region of frontal lobe Trouble producing speech, but not comprehending speech Carl Wernicke (1874) ▪ ▪ Patient with brain damage to a temporal lobe area Trouble comprehending speech, but not producing speech Broca’s Aphasia vs Wernicke’s Aphasia Suggests at least two language functions in the brain (production / comprehension) that can be independently affected by brain damage Functions were inferred from empirical observations of patients with acquired brain damage (contrast with phrenology) This approach became known as cognitive neuropsychology — studying patients with natural brain damage to inform theories about the brain and cognition Study of the brain throughout history Classical antiquity: “Finding” the brain 19th century: Phrenology 19th century: Cognitive neuropsychology 20th century: Psychology and the cognitive revolution Late 20th century: Birth of modern cognitive neuroscience 20th century: Psychology without the brain “Brain agnostic” approach to studying the mind ▪ The black box of behaviorism Cognitive revolution of later 20th century: ▪ Influenced by what technology was (not) available to them ▪ Information-processing models of cognition from 1950s ▪ The computer as an analogy for how the mind works ▪ The mind is thought to take in and process information through a series of processing stages 20th century: Psychology without the brain Box-and-arrow models: e.g., Atkinson & Shiffrin’s Modal Model of Memory (1968) Bottom-up processing: The passage of information from simpler to more complex stages Top-down processing: When more complex processing stages influence information processing in simpler stages 19th century: Psychology without the brain Parallel vs Serial Processing: Are multiple inputs processed one-at-time (serial) or are they processed simultaneously (parallel)? Study of the brain throughout history Classical antiquity: “Finding” the brain 19th century: Phrenology 19th century: Cognitive neuropsychology 20th century: Psychology, behaviorism, & information-processing Late 20th century: Birth of modern cognitive neuroscience Road Map: History and Introduction Philosophical beginnings (mind/body) Dualism, Reductionism, Dual-Aspect Theory Historical foundations, milestones, and pioneers Phrenology, neuropsychology, cognitive revolution Criticisms and challenges: Neuroskepticism? Challenge: Is cognitive neuroscience just phrenology? William Uttal (2003) took umbrage with functional neuroimaging as a “new phrenology”: “I argue in this book that the excitement of the marvelous three-dimensional imaging machines and the allure of noninvasive studies of the human brain have been so enticing that... research has been carried out without adequate consideration of the logic of this research field.” William Uttal (1931-2017) Common challenges posed to cognitive neuroscience It is possible to study the mind without studying the brain Brain scans tell us WHERE cognition occurs, not HOW Cognitive neuroscience is just a new form of phrenology William Uttal (1931-2017) Common challenges posed to cognitive neuroscience It is possible to study the mind without studying the brain True! (But we can do more than that, too!) Brain scans tell us WHERE cognition occurs, not HOW Cognitive neuroscience is just a new form of phrenology William Uttal (1931-2017) Common challenges posed to cognitive neuroscience It is possible to study the mind without studying the brain Brain scans tell us WHERE cognition occurs, not HOW The first part is true! (But we can do more than that, too!) Cognitive neuroscience is just a new form of phrenology Cognitive neuroscience can be much more! William Uttal (1931-2017) Challenge: Is cognitive neuroscience just phrenology? Uttal argues that: “The attempt to localize cognitive processes in the brain presumes that we are right about what cognitive processes even exist.” ▪ Progress in cognitive science will inform cognitive neuroscience ▪ Progress in cognitive neuroscience (from thoughtful and rigorous experimentation) can inform theories in cognitive science Neuroskepticism versus neuromania Caution is warranted → critical thinking is paramount! Thoughtful consumers of neuroscience in the media Road Map: History and Introduction Philosophical beginnings (mind/body) Dualism, Reductionism, Dual-Aspect Theory Historical foundations, milestones, and pioneers Phrenology, neuropsychology, cognitive revolution Criticisms and challenges: Neuroskepticism? With great power comes great responsibility Note Taker volunteers? Next class : Intro to the Brain & Neuroanatomy