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The Brain and Behavior Outline

This outline explores the functions and evolution of the brain, focusing on the basic unit of the neuron and how signals are generated, moved, and processed through synapses. It also covers reflexes and the organizing principles of the brain.

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The Brain and Behavior Outline

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  1. The Brain and BehaviorOutline • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal get started? • Action Potential: How does a signal move? • Synapses: What does the signal do? • Reflexes: A model • Brain Organizing Principles and Functions

  2. Functions • Communication • Coordination • Control • Cognition • Complexity

  3. Brain Structure

  4. Brain Structure DRUGS

  5. Outline: Start With A Mechanistic View • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal get started? • Action Potential: How does a signal move? • Synapses: What does the signal do? • Reflexes: A model • Brain Organizing Principles and Functions

  6. Evolution

  7. Evolution • None • Nerve net • Segmented • Cephalization: an organizing principle • brain-mind correlation not always obvious! • Computer analogy (hardware/software) • Kineses • Taxes • Reflexes

  8. Simple Behaviors • Kinesis (potato bug, jumping beans) • Taxes (moth / maggot / fly / tick) • Reflex: (knee jerk) • Descartes 1637 St. Germaine on the Seine • Pineal • Mechanist

  9. “Synthetic Psychology” Ex. Phototaxis • Braightenberg: Vehicles

  10. Outline • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal get started? • Action Potential: How does a signal move? • Synapses • Reflexes: A model • Brain Organizing Principles and Functions

  11. The Neuron • 100 billion with thousands of connections • Varied in size, shape, function • Function of neuron sending signals in real time (ex.) • What is the signal? - electrical / chemical

  12. Outline • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal originate? • Action Potential: How does a signal move? • Synapses • Reflexes: A model • Brain Organizing Principles and Functions

  13. Origin of nerve signal • Function of neuron sending signals in real time (ex.) • What is the signal? - electrical / chemical

  14. Generation • Two forces: • Electrical (ionic) • Chemical (concentration) • Give rise to steady-state voltage “resting potential” • Universal in cells

  15. Action Potential

  16. Outline • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal get started? • Action Potential: How does a signal move? • Synapses • Reflexes: A model • Brain Organizing Principles and Functions

  17. Movement of a Signal

  18. Action Potential • Cell actions • Speed: Muller (light), Helmholtz (43 m/sec)--myelinization • Refractoriness • All or none law-above threshold all equal • Coding of intensity: frequency codes intensity + recruitment (organizing principle)

  19. Outline • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal get started? • Action Potential: How does a signal move? • Synapses • Reflexes: A model • Brain Organizing Principles and Functions

  20. Synapses: What happens when signal reaches end of neuron? • Two types of actions - excitatory / inhibitory • Chemical model with multiple & functionally different neurotransmitters • Temporal & spatial summation

  21. Synapses

  22. Release of Neurotransmitter

  23. Synapses

  24. Outline • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal get started? • Action Potential: How does a signal move? • Synapses • Reflexes: A model • Brain Organizing Principles and Functions

  25. A Model for building behavior out of simple building blocks • Reflexes: • Building a model • Simple to complex • Voting behavior: • Competing inputs • Building complexity

  26. Reflexes: A model

  27. Outline • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal get started? • Action Potential: How does a signal move? • Synapses • Reflexes: A model • Brain Organizing Principles and Functions

  28. Principles and Functions • Cephalization • All-or-None Law • Frequency Coding of Intensity • Doctrine of Specific Nerve Energies • Localization of Function (+ Integration) • Topographic Projection (& Distortion) • Split Brain (Crossed Connections) • Connectivity & Functional Connectivity • Neuro-plasticity & Reorganization

  29. The Brain and BehaviorOutline • Functions • Evolution: structure and behavior • Basic Unit: The Neuron • Generation: How does a signal get started? • Action Potential: How does a signal move? • Synapses: What does the signal do? • Reflexes: A model • Brain Organizing Principles and Functions

  30. Brain Structure (midline)

  31. Brain Structure

  32. Structure: Central Core

  33. Structure: X-Ray View

  34. Methods for studying the brain • Single-cell and population recordings • Animal studies • Surgical patient studies • Stimulation • Animal studies • Surgical patient studies • Damage • Animal lesions • Human injury • Human surgical lesions • Neuroimaging

  35. Electroencephalogram (EEG) recording • Electrodes are placed on the surface of the scalp and record/amplify the electrical signal given off by the brain • Event Related Potentials (ERPs) are used to study how the brain responds to different stimuli or events

  36. Measures changes in blood-oxygen-level-dependent (BOLD) activation Areas of the brain that are engaged more in a task, require oxygen rich blood Result show a very small but highly significant percent change in BOLD activation (the entire brain is active all the time) Functional Magnetic Resonance Imagingin (fMRI)

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