PS101.Chapter 3 - Psychology Themes and Variations Second...

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Unformatted text preview: Psychology: Themes and Variations Second Canadian Edition Chapter 3 The Biological Bases of Behaviour 2 Communication in the Nervous System Hardware: Glia structural support, insulation, and communication Neurons communication Soma cell body Dendrites receive Axon transmit away. 3 3 Neuron and Neural Impulse Figure 3.1 Structure of the neuron. PC Users Mac Users 4 4 Neural Communication: Insulation and Information Transfer Myelin sheath speeds up transmission Terminal Button end of axon; secretes neurotransmitters Neurotransmitters chemical messengers Synapse point at which neurons interconnect. 5 5 The Neural Impulse: Electrochemical Beginnings Hodgkin & Huxley (1952) giant squid Fluids inside and outside neuron Electrically charged particles (ions) Neuron at rest negative charge on inside compared to outside 70 millivolts resting potential. 6 6 The Neural Impulse: The Action Potential Stimulation causes cell membrane to open briefly Positively charged sodium ions flow in Shift in electrical charge travels along neuron The Action Potential All or none law. 7 7 8 8 Neural Animation 9 The Synapse: Chemicals as Signal Couriers Synaptic cleft Presynaptic neuron Postsynaptic neuron Receptor sites. Synaptic vesicles Neurotransmitters 10 10 Figure 3.3 The synapse. When a neural impulse reaches an axon's terminal buttons, it triggers the release of chemical messengers called neurotransmitters. The neurotransmitter molecules diffuse across the synaptic cleft and bind to receptor sites on the postsynaptic neuron. A specific neurotransmitter can bind only to receptor sites that its molecular structure will fit into, much like a key must fit a lock. 11 Synaptic Transmission PC Users Mac Users 12 12 When a Neurotransmitter Binds: The Postsynaptic Potential Voltage change at receptor site postsynaptic potential (PSP) Not allornone Changes the probability of the postsynaptic neuron firing Positive voltage shift excitatory PSP Negative voltage shift inhibitory PSP. 13 13 14 14 Signals: From Postsynaptic Potentials to Neural Networks One neuron, signals from thousands of other neurons Requires integration of signals PSPs add up, balance out Balance between IPSPs and EPSPs. 15 15 Signals: From Postsynaptic Potentials to Neural Networks II Neural networks Patterns of neural activity Interconnected neurons that fire together or sequentially Synaptic connections Elimination and creation Synaptic pruning. 16 16 17 17 Neurotransmitters Specific neurotransmitters work at specific synapses Agonist mimics neurotransmitter action Antagonist opposes action of a neurotransmitter 15 20 neurotransmitters known at present Interactions between neurotransmitter circuits. 18 18 Lock and key mechanism 19 19 Mouse Party 20 First Midterm October 18 in this room 50 multiple choice questions Students A to K arrive at 6:20 and write for 60 minutes (6:307:30) Students L to Z wait outside the door and enter at 7:45 and write for 60 minutes (8:009:00). 21 Organization of the Nervous System Central nervous system (CNS) brain and spinal cord Peripheral nervous system nerves that lie outside the central nervous system Afferent = toward the CNS Efferent = away from the CNS Somatic nervous system voluntary muscles and sensory receptors. 22 22 Organization of the Nervous System Peripheral nervous system nerves that lie outside the central nervous system Sympathetic Go (fightorflight) Parasympathetic Stop. Autonomic nervous system (ANS) controls automatic, involuntary functions 23 23 24 24 25 25 Studying the Brain: Research Methods Electroencephalography (EEG) Damage studies/lesioning Electrical stimulation (ESB) Transcranial Magnetic Stimulation. 26 26 27 27 Transcranial Magnetic Stimulation 28 Studying the Brain: Research Methods Brain imaging: computerized tomography (CAT) positron emission tomography (PET) magnetic resonance imaging (MRI). 29 29 30 30 Brain Regions and Functions Hindbrain vital functions medulla, pons, and cerebellum Midbrain sensory functions dopaminergic projections, reticular activating system Forebrain emotion, complex thought thalamus, hypothalamus, limbic system, cerebrum, cerebral cortex. 31 31 32 32 The Cerebrum: Two Hemispheres, Four Lobes Cerebral Hemispheres two specialized halves connected by the corpus collosum Left hemisphere verbal processing: language, speech, reading, writing Right hemisphere nonverbal processing: spatial, musical, visual recognition. 33 33 34 34 Right Brain/Left Brain PC Users Mac Users 35 35 Split Brain Patients 36 The Cerebrum: Two Hemispheres, Four Lobes Four Lobes: Occipital vision Parietal somatosensory Temporal auditory Frontal movement, executive control systems. 37 37 38 38 39 39 40 40 The Endocrine System: Glands and Hormones Hormones chemical messengers in the bloodstream Endocrine glands Pulsatile release by endocrine glands Negative feedback system Pituitary "master gland," growth hormone Thyroid metabolic rate Adrenal salt and carbohydrate metabolism Pancreas sugar metabolism Gonads sex hormones. 41 41 42 42 Genes and Behaviour: The Interdisciplinary Field of Behavioural Genetics Behavioural genetics = the study of the influence of genetic factors on behavioural traits Basic terminology: Chromosomes strands of DNA carrying genetic information Human cells contain 46 chromosomes in pairs (sexcells 23 single) Each chromosome thousands of genes, also in pairs. 43 43 Genes and Behaviour: The Interdisciplinary Field of Behavioural Genetics II Dominant, recessive Homozygous, heterozygous Genotype/Phenotype and Polygenic Inheritance. 44 44 Figure 3.25 Genetic material. This series of enlargements shows the main components of genetic material. (Top) In the nucleus of every cell are chromosomes, which carry the information needed to construct new human beings. (Centre) Chromosomes are threadlike strands of DNA that carry thousands of genes, the functional units of hereditary transmission. (Bottom) DNA is a spiralled double chain of molecules that can copy itself to reproduce. 45 45 Research Methods in Behavioural Genetics Family studies does it run in the family? Twin studies compare resemblance of identical (monozygotic) and fraternal (dizygotic) twins on a trait Adoption studies examine resemblance between adopted children and their biological and adoptive parents. 46 46 Twins Separated at Birth 47 48 48 49 49 50 50 Modern Approaches to the Nature vs. Nurture Debate Molecular Genetics: the study of the biochemical bases of genetic inheritance Behavioural Genetics Genetic mapping: locating specific genes The Human Genome Project The interactionist model Richard Rose (1995) "We inherit dispositions, not destinies." 51 51 Evolutionary Psychology: Behaviour in Terms of Adaptive Significance Based on Darwin's ideas of natural selection Adaptations behavioural as well as physical Fightorflight response Taste preferences Parental investment and mating. Reproductive success key 52 52 ...
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This note was uploaded on 10/14/2011 for the course PSYCH 101 taught by Professor Eibach during the Fall '11 term at Wilfred Laurier University .

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