Study Of The Mind, Behavior - Intro To Neuroscience

Unit 1 Psychology  Study of the mind, behavior  Empiricism: application based on observational study Biopsychology  Older term that replaces physiological psychology  Area aimed at the study of biological determinant of behavior  Biopsychology has been replaced by neuroscience  Both areas aim to discover biological bases for behavior Is it biological or psychological?  It’s both  Everything that is psychological is fundamentally biological if you take the perspective that we are a living organism and therefore everything we are is biological.  Another question is how much of our behavior is genetically determined, strictly determined? o We have genetic predispositions that make us more likely to act a certain way than those who do not. o Neuro Law  As we will discover, some of our behavior is mostly under the control of genetics and other behaviors are mostly learned. All have components of both. o Cultural influence Neuroscience  Interdisciplinary and scientific approaches to the study of the mind and brain o Neurochemistry o Neurophysiology o o o o Neuroanatomy Neuropharmacology Neuropsychology: the study of brain damage Psychophysiology  Ex, Sound or sight that might provoke anxiety o Cognitive Neuroscience o Comparative Psychology/Neuroethology  What makes Neuroscience distinct? o Scientific approach o Interdisciplinary approach o The relationship between brain and behavior  The mind  How does it go bad? How do you optimize brain development?  Why Behavioral Neuroscience? o Borrows best of many disciplines (biology, psychology, chemistry, philosophy, etc.) o Always grounded in behavior o We study all species and some are interested primarily in non-human animals o Many of us use animals to better understand human brain-behavior relationships Four Conceptual Approaches to Behavioral Neuroscience  Evolutionary/Comparative/Ethological/Genetic  Anatomical/Physiological  Learning/Behavioral  Perceptual/Cognitive o Use animals mostly for all **Categories are different than book’s** The Mind-Body Problem  What is the relationship between the mind and body? o Inanimate objects like trucks and soda machines often act as if they have a mind o Where is your mind?  Greeks thought it was in your heart  Romans discovered the truth (gladiators)  Mind is in your brain  Why is it important?  Mind is not soul o We cannot define soul  The classical position o Dualism (Aristotle): the mind and the body are separate entities  Problem: So, why does brain damage then change behavior? o Interactionism (or Cartesian Dualism): the mind and the body are separate, but they interact in some way?  Problem: How does nonmaterial affect material?  This violates fundamental laws of physics  DeCartes  Peneal gland: unsymmetrical, where God interacts with us  The modern position o Epiphenomenalism (Aristotle): the mind and consciousness are incidental bi-products of a functioning human brain o Monism: the mind and the body are one and the same—and the brain is really all there is, the mind is an illusion.  Majority has taken this position  Drugs alter feelings, opinions  Central state identity theory o Functionalism: the “mind” is what matters, no matter what produces it, Coke machine or brain. The “machine” should be a “black box” What Philosophical Assumptions do Neuroscientists make?  Materialism o Physicists tell us that all there is in the world is matter and energy— that is it! o Certainly, all we can study scientifically is matter and energy, physics tells us that (Remember: E=mc 2) o Anything other than matter and energy is outside the realm of physics and therefore outside the realm of science generally (and therefore neuroscience).  Determinism o Every event has a cause (though some might be remote) o These causes can be determined, discovered, catalogued, and used to predict future events. o If events were not determined, then science would be a poor career choice because there would be no certainty! o This is FUNDAMENTAL to science o We need to distinguish between:  Distal causation: distant, remote, complex to understand  Proximal causation: immediate causes: stimuli and environment o Very often our explanation will have both:  Alcoholism is combination of a genetic predisposition for alcoholism (distal/ultimate cause) and high levels of stress in environment plus availability of ETOH (proximal causation) o Ultimate causation: Teleology  WHY does this happen?  Science, neuroscience can only answer some of these questions  Why do we have 2 eyes? We can answer that, tentatively.  Why are we here?  WHY—we cannot answer that question.  Science is not adept at answering teleological question. [[Include as many predictable variables as possible to help calculate/determine cause o Predictions are never perfect—there is always an error  Biggest scientific project (NASA) has 2% error  Why scientists can never declare that God doesn’t exist  Claiming to have knowledge you don’t have  No definitive claims o So they say there are no miracles—there is an error—an unrealized knowledge that should explain it o Use prediction to build models with as little error as possible]]  Mechanism o Causes have a PHYSICAL base (materialism) o Only physical determinants of behavior can be quantified, observed, and measured o The universe behaves in a regular and orderly manner—stuff does not just “happen” (lawfulness)  Everything is determined o No miracles! (why is that?)  Science cannot investigate miracles, and naturalistic explanations do not allow them as a possible alternate explanation.  Reductionism o Complex phenomena can often be “reduced” to simpler physical processes o Each finer level of analysis relies on more basic, fundamental, more molecular processes o Explanations tend to move from the molar (behavioral) to the molecular (anatomy, physiology, neurochemistry) Why do Neuroscientists still rely on both Molar and Molecular explanations?  Different levels of analysis are more useful for some questions that other (e.g., “how can I improve my performance in this class?”)  In most cases, we are ultimately interested in molar questions (that is, questions about behavior) [as—although some of us just like molecular approaches because we are curious!]  When it comes to pathology, the more you know the better—which may be a universal truth! Empricisim  A method of obtaining information by observation and experimentation (“data”)  These data are used to generate explanations, hypotheses, and theories  The hypotheses and theories developed are then tested  Predictive theories are retained, faulty ones are modified or discarded  Scientists replicate the work of others and either verify it or criticize it— theories are then corrected. o Science self-corrects.  The defining characteristic of scientific explanations is that they are empirically testable.  Competing theories are tested, and faulty assumptions or non-predictive theories are revised or discarded.  Scientists are doubters who redo, or replicate, the work of others. They discover mistakes. They trust only data! Evolution How did we get here?  Science say the Big Bang Theory, but have no evidence of what was before that o It could have been God (cannot disprove it!) o Thus began evolution  13 billion years ago Natural History, Cosmology, Evolution, and Genetics  Natural History: Understanding the earth, and the history of life on earth, from a scientific perspective  Cosmology: Theories of the origin of the earth, of live, of the universe  Evolution: The theory of evolution is a comprehensive, integrative, scientific account of the origin of species o Must be skeptical—we’ve been wrong about a lot of things (Pluto, Mars), but we correct them  Genetics: The biological mechanisms that code for an organism’s structure and function, including reproduction. Genetics  Darwin’s Theory of Evolution by Means of Natural Selection o Charles Darwin  On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (1859)  The Voyage of the Beagle  Biologist on a ship  Darwin observed systematic differences among organisms, which varies as a function of their environmental demands  We tend to form subspecies based on looks (religion etc)  Evolution by Means of Natural Selection o Other theories of evolution had been proposed earlier (e.g.: Lamark’s theory of “Acquired Characteristics”) o Darwin’s was novel because of the mechanism: Natural Selection Neo-Darwinian Theory  Theory: well-substantiated, predictive, highly reliable equation (not a guess!)  Corrected version of Darwin’s theory  Basic ideas of Darwinian Evolution intact  Incorporates modifications based on recent evidence (e.g., S. Gould’s notion of “punctuated equilibrium”)  Incorporates modern genetic theory (Mendel’s work was done more than 30 years after “Origin of Species,” well after Darwin’s death)  Modern research is biochemical genetics  Neo-Darwinian Evolution: ENVIRONMENT o Life exists in an uncaring environment o Environment provides ecological niche  No assurance niche will remain constant  We are clever enough to be able to live in almost any ecological environment  Neo-Darwinian Evolution: LIFE o Some groups of chemicals have the ability to self-replicate o On Earth, these chemicals are DNA o With unlimited resources, life replicated unchecked  Neo-Darwinian Evolution: HEREDITY o Characteristics are passed from parent to off-spring o DNA codes for these characteristics, and is passed from parents to offspring at conception  Neo-Darwinian Evolution: CONTINUITY o Organisms related not only to parents, but to every other living organism o Notion of “Common Ancestor” o Some organisms have recent common ancestors (humans and chimpanzees), other more remote (humans and armadillos)  98% of our DNA in common with chimps o Does not mean one organism “evolved from” another (humans did not “evolve from monkeys”)  Neo-Darwinian Evolution: SEX o Genes perpetuate themselves through [sexual] reproduction o Not all members of a species reproduce with the same success (or with the same frequency) o Most organisms reproduce in ever-increasing numbers o Sexual selection (we are choosey)  Neo-Darwinian Evolution: VARIABILITY o Both parents contribute equally to genetic makeup of off-spring o However, the genetic “mixture” is different each time (that is, the 50% from father is randomly determined from each organism) o Some errors get introduced during reproduction (e.g.: genetic mutations) o Ex. Corn  Have particular genomes  Neo-Darwinian Evolution: NATURAL SELECTION o Usually, resources are limited: selective pressure o Organisms must compete for limited resources o Some members of a species are better able to compete: survival of the fittest  = Who has the most kids?  Neo-Darwinian Evolution: NATURAL SELECTION & “FITNESS” o Fitness is defined as an organism’s ability to survive and reproduce o “Success” is the organism’s ability to pass on its genes to future generations o Some members of a species are better able to compete: survival of the fittest o Richard Dawkins’ The Selfish Gene: the idea of inclusive fitness o “Fitness” is only meaningful in the context of specific selective pressures (or environments) o As environment changes, so does fitness o “Fitness does not mean better, only “better adapted to the environment”  Evolution doesn’t mean progress, it just means we’re still here o Evolution does not mean “progress” or “improvement,” only that a species has changed in response to changes in the environment o Meaningless to talk of organisms being “more highly evolved”  Why is Darwinian Evolution so Controversial? o Places humans squarely within the realm of all organisms, not “above” the collection o Removes humans from being a “special” creature (though humans can still be unique) o Often misunderstood as an attack on religious explanations, or as being incompatible with theology or religion—not true o Fails to address the ultimate “why” question—What is our purpose for being here? (as do all scientific theories fail at this)  Darwinian intended for evolution to supplant religion  However, He does not discount the role of God  His book is an attempt to explain scientifically how we got here  Genetics **More slides online** Behavioral Genetics  Behavior o Due to following genetic factors:  (Error) assumed  Heritability (h2)  Environmental Factors (e2)  Unique Environmental Influences (ENS)  Shared Environmental Influences (E S) o (graph in notes) o H2 + ES + ENS = 1.00 o Scientists are concerned about impact of environment  And GENES READ OVER IQ TEST EXPERIMENT N BOOK Brain Behavior Relationships General Layout of the Nervous System  Central Nervous System (CNS) o Brain (in the skull) o Spinal cord (in the spine)  Makes decisions  Peripheral Nervous System (PNS) o Located outside of the skull and spine o Serves to bring info into the CNS and carry signals out of the CNS  Somatic (movement)  Afferent nerves (sensory)  Efferent nerves (motor)  Autonomic Nervous System (breathing, heart rate, etc)  Sympathetic and parasympathetic nerves  Generally have opposite effects  Two-stage neural paths, neuron exiting the CNS synapses on a second-stage neuron before the target organ  Sympathetic o Thoracic and lumbar o “fight or flight” o second stage neurons are far from the target organ  Parasympathetic o Cranial and sacral o “rest and restore” o Second stage neurons are near the target organ  Both are efferent  Meninges, Ventricles and Cerebrospinal Fluid (CSF) o CNS encased in bone and covered by three meninges  Dura mater—tough outer membrane  Arachnoid membrane—web-like  Pia mater—adheres to CNS surface o Cerebrospinal Fluid (CSF)  Fluid serves as cushion o Human ventricles  Directions o Dorsal = superior o Posterior = inferior = caudal (human) o Caudal = toward tail (posterior) Exam questions review Hominins developed 6 million years again Analogous In the study of heritability, estimates, increasing the genetic diversity of the subjects without introducing other changes would likely increase the heritability estimate Among the poor, heritability estimate of IQ was close to 0. Among the affluent, the heritability estimate of IQ was close to one. Morgan’s Canon