PSYCHOLOGY 11002 General Psychology

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PSYCHOLOGY 110-02General Psychology

• University of Southern Mississippi
• Department of Psychology
• Dr. David J. Echevarria, PhD
• Spring 2008
• david.echevarria_at_usm.edu
• www.usm.edu/neurolab

Chapter 3 The Biological Basis of Behavior
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Chapter 3 The Biological Bases of Behavior
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Communication in the Nervous System

• Hardware
• Glia structural support and insulation
• Neurons communication
• Soma cell body
• Dendrites receive
• Axon transmit away

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Neuron and Neural Impulse
Mac OS X
Windows
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Figure 3.1 Structure of the neuron
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Neural CommunicationInsulation and Information
Transfer

• Myelin sheath speeds up transmission
• Terminal Button end of axon secretes
  neurotransmitters
• Neurotransmitters chemical messengers
• Synapse point at which neurons interconnect

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The Neural ImpulseElectrochemical 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

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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

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Figure 3.2 The neural impulse
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The Synapse Chemicals as Signal Couriers

• Synaptic cleft
• Presynaptic neuron
• Synaptic vesicles
• Neurotransmitters
• Postsynaptic neuron
• Receptor sites

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Synaptic Transmission
Mac OS X
Windows
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Figure 3.3 The synapse
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When a Neurotransmitter BindsThe Postsynaptic
Potential

• Voltage change at receptor site postsynaptic
  potential (PSP)
• Not all-or-none
• Changes the probability of the postsynaptic
  neuron firing
• Positive voltage shift excitatory PSP
• Negative voltage shift inhibitory PSP

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Figure 3.4 Overview of synaptic transmission
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Signals From Postsynaptic Potentialsto Neural
Networks

• One neuron, signals from thousands of other
  neurons
• Requires integration of signals
• PSPs add up, balance out
• Balance between IPSPs and EPSPs
• Neural networks
• Patterns of neural activity
• Interconnected neurons that fire together or
  sequentially

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Signals From Postsynaptic Potentialsto Neural
Networks

• Synaptic connections
• Elimination and creation
• Synaptic pruning

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Figure 3.5 Synaptic pruning
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Neurotransmitters

• Specific neurotransmitters work at specific
  synapses
• Lock and key mechanism
• Agonist mimics neurotransmitter action
• Antagonist opposes action of a neurotransmitter
• 15 20 neurotransmitters known at present
• Interactions between neurotransmitter circuits

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Table 3.1 Common Neurotransmitters and Some of
their Functions
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Organization of the Nervous System

• Central nervous system (CNS)
• Afferent toward the CNS
• Efferent away from the CNS
• Peripheral nervous system
• Somatic nervous system
• Autonomic nervous system (ANS)
• Sympathetic
• Parasympathetic

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Figure 3.6 Organization of the human nervous
system
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Figure 3.7 The central and peripheral nervous
systems
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Imagine You Are Relaxing At Home
Figure 3.8 The autonomic nervous system (ANS)
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Figure 3.8 The autonomic nervous system (ANS)
Suddenly there is a knock at the doorwho is it???
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Sympathetic Nervous system activation
Figure 3.8 The autonomic nervous system (ANS)
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Studying the Brain Research Methods

• Electroencephalography (EEG)
• Damage studies/lesioning
• Electrical stimulation (ESB)
• Transcranial magnetic stimulation (TMS)
• Brain imaging
• computerized tomography
• positron emission tomography
• magnetic resonance imaging

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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

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The CerebrumTwo 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

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The CerebrumTwo Hemispheres, Four Lobes

• Four Lobes
• Occipital vision
• Parietal - somatosensory
• Temporal - auditory
• Frontal movement, executive control systems

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Right Brain/Left Brain
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!!!
Figure 3.16 Structures and areas in the human
brain
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Figure 3.18 The cerebral hemispheres and the
corpus callosum
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Figure 3.19 The cerebral cortex in humans
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Figure 3.20 The primary motor cortex
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Figure 3.21 Language processing in the brain