Concept of Mind • Do you have a mind? – If so, where is it located? • Concept of mind – – – – – Sense of self Free Will Consciousness A little person in your head Immaterial spirit or soul • Biological Psychology approach to understanding mind – “.. in this book we explore the many ways in which the structures and actions of the brain produce mind and behavior.” Breedlove & Watson 2013, Biological Psychology, page 1. Mind – Body Problem •What is the relationship between mind and body? •First explicitly raised by Descartes •Dualism (Descartes’ version) •Mind (soul) Body (brain) are distinct •The Mind (soul) outlives the body and operates by nonphysical means. •Monism - (either Materialism or Physicalism): •Everything that actually exists is material, or physical •There is nothing beyond the physical world •Mind must be some feature or aspect of the Body (brain) Descartes’ Dualism • Animals have body (brain) and act in mechanical ways • Humans – can use words to express thoughts – use reason to solve problems creatively – must have something special: Mind (soul) • The Body (Brain) is a complex "machine". • The Mind (Soul) – distinct from the body – eternal and therefore non-physical •René Descartes' illustration of mind/body dualism. • Descartes believed inputs are passed on by the sensory • organs to the epiphysis in the brain and from there •to the immaterial spirit. •See his Meditations on First Philosophy[1] •From Wikipedia Mind-Body Problem •http://en.wikipedia.org/wiki/Mind%E2%80%93body_problem Reductionism •Related to Mind Body problem because it is often referred to as Reductive Physicalism •A theory that all complex systems can be completely understood in terms of their components. •The general attempt to explain and interpret phenomena by means of analysis into simpler components and principles at a different level of analysis. •The idea that certain things might be shown to be nothing but certain other sorts of things. •water is nothing but hydrogen and oxygen molecules •statements about water are reducible to statements about collections of H & O molecules. Hierarchy of Complex Systems to illustrate Reductionism A Non-Reductive Physicalist Account of Human Nature By Nancey Murphy Levels of Analysis in Biological Psychology What is wrong with the arrows on this picture? Levels of Analysis in Biological Psychology • “In principle, it is possible to reduce each explanatory series down to the molecular or atomic level, though for practical reasons this extent of reductionism is rare.” • “The units of each level of analysis are simpler in structure and organization than those of the level above.” – Biological Psychology by Breedlove and Watson page 10 • There are problems with these assumptions about reductionism. – Appears that you can explain everything at the atomic level – Is the atomic and molecular levels really simpler? Limitations of Reductionism • Gendle, Point #2: At present reductive physicalism is fundamentally unable to answer how basic biological, chemical, or physical processes create specific individual experience (“qualia”) – Qualia is subjective personal experience such as seeing the color blue. – Referred to as the “hard problem” of human consciousness. – An “explanatory gap” between our knowledge of neuroscience to explain subjective experience • Conscious awareness includes a sense of self – Humans have a very strong subjective sense of self – Which brings us back around to the concept of mind – Do you have a mind? • If so, where is it? • If so, what is it? • So are we stuck without an explanation for subjective experience? Limitations of Reductionism • Gendle point #3: promissory materialism is a provisionary position, and the inclusion of it in an empirically focus discussion of philosophy of mind is inappropriate. – Neuroscience will one day figure it all out. – There must be a mechanism that explains how the mind works • Gendle is being too harsh with this comment. – Speculation is okay as long as it does not substitute for explanation. – So, what type of explanations exists that could help explain the mind, body problem? Limitations of Reductionism • Application to Current Medical Science • Diagnosis is based on the assumption that information about individual parts is sufficient to explain the whole • However some medical problems occur because of interaction between parts produces behaviors that cannot be predicted by individual parts. – To understand Schizophrenia, cannot just focus on Dopamine levels or a set of genes – Need to take into account living conditions such as stressful environments Limitations of Reductionism • Gendle point #1: There currently exists no one single theoretical framework that can completely account for how mental phenomena arise from physical processes occurring in the nervous system. – Neither monist reductive physicalism nor Cartesian dualism is acceptable. • But other approaches such as non-reductive physicalism – The mind is an emergent property of the brain. • Such as patterns of activity in brain circuits – Mind is more than the sum of brain parts • i.e. not an additive process • could be a nonlinear system explained by chaos theory – Similar to Ryle’s concept of “intelligent acts” – Or Jonah Lehrer’s example “the mind is like music” • The Limits of Reductionism Posted by Jonah Lehrer on January 21, 2008 • http://scienceblogs.com/cortex/2008/01/21/the-limits-of-reductionism/ Levels of Analysis in Biological Psychology We Are All Alike and We Are All Different –Bacterial DNA in Human Genomes Nature vs Nurture Confusion • Nature vs Nurture (genes vs environment) is a false dichotomy • All mature traits are a combination of genes and environment – for example: • • • • Language Binocular Vision Aggressive behavior Sexual orientation • "To ask what's more important, nature or nurture, is like asking what's more important to the area of a rectangle, its length or its width." attributed to Donald Hebb • length and width can be changed independently of each other but they always are dependent on each other Figure 1.9 Identical Twins but Nonidentical Brains and Behavior Nature and Nurture Interaction • (Genotype) * (Environment) Phenotype – – – – Genes you are born with Environment you are exposed to Both are always present This is not an additive process • Genes + environment is incorrect • Interaction of genes and environment • Phenotype is an emergent property of genes and environment • * No complete explanation for how this interaction works Nature and Nurture Interaction • Relationship between genes and behavior – – – – Genes are expressed to produce proteins Proteins provide the structure and chemistry of neurons Neurons are connected into brain circuits Brain Circuits process information for sensory, perception, cognition, behavior and so on – There are no genes with a specific behavioral function • A Gene for playing the piano • A Gene for playing basketball • A Gene for math ability – However, genes do influence all of these to some extent Nature Nurture Interaction • Environmental signals (Experience) – odor of food, sound of a predator or sight of a mate – Information processed through the nervous system – molecular biology of brain circuits is modified (neuroplasticity) • long lasting changes to the chemistry and anatomy of neurons. • Genes expression plays a crucial role in this process – Genes code for proteins – Genes are signaled by the environment to express proteins – This is the basis of memory formation which we will cover in chapter 17 Nature Nurture Interaction • Intelligence Example – Low genetic heritability for sense of humor, food preferences, political attitude, religious affiliation – However intelligence (g factor) is distinctly influenced by genetic heritability – But there are no specific genes for intelligence, maybe for brain size and certainly for number of neurons – Twin studies indicate 50% genetic influence – Environmental factors must be the other 50% • Although this changes across your life span with more environmental influence at a young age and less as you get older • So the nature - nurture interaction changes with development Role of endophenotypes in mental illness • Endophenotypes are subcomponents or parts of a phenotype – Sequence variations within specific genes related to specific neural system dysfunctions – Can be used as biological markers – They do not directly cause the disease – But represent the individual susceptibility to the disease – Such as sensory gating ratios in Schizophrenia • Environmental factors such as stressor interact with the endophenotypes Nature Nurture Interaction Autism example • Historical opinion on the etiology of autism – (1) that autism is caused by some specific genetic abnormality, spawning a search for the “autism gene”, – (2) that autism is the result of some specific environmental factor or condition, including a “lack of maternal warmth” • Genetic: 60% concordance in monozygotic twins – identified genetic factors explain only a small • Environment: deficits in social perception – Children with reduced social cognitive development – Parents may also have a reduced social perception Determinism Determinism is the philosophical proposition that every event is causally determined by an unbroken chain of prior occurrences. If all processes in the world were due to the mechanical interplay of atoms so that the physical matter of the universe operates according to a set of fixed, knowable laws. Genetic determinism: genes determine a physical or behavioral phenotype. Environmental determinism: experience determines a physical or behavioral phenotype