1. The Brain and Behavior 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: What does the signal do? Reflexes: A model Brain Organizing Principles and Functions

2. Functions Communication Coordination Control Cognition Complexity

3. Brain Structure

4. 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. 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

13. 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

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

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

18. Action Potential

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

21. Movement of a Signal

23. 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)

25. 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

26. 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

28. Synapses

29. Release of Neurotransmitter

31. Synapses

32. 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

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

35. Reflexes: A model

36. 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

41. The Brain and Behavior 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: What does the signal do? Reflexes: A model Brain Organizing Principles and Functions

42. 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

43. 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

44. CT scanMRI scan

45. –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)

46. Connectivity measures Structural connectivity – measures the movement of water molecules to chart the white matter tracts (visualizing anatomy) Diffusion Tensor Imaging (DTI) Diffusion Spectrum Imaging (DSI) Functional connectivity – uses resting-state fMRI data to chart cortical regions with temporal synchrony (correlation of activation patterns)

47. Localization of Function Different parts of the brain serve specialized functions Sensory Information Motor Control Perception Language Planning and Social Cognition

48. Localization of Function

49. Localization/Topographic Projection

50. Localization of motor and sensory function Topographical organization Cortical representation related to function not mass What does the homunculus tell us?

51. Connectivity Autism – Neurodevelopmental disorder marked by social and communicative deficits and presence of repetitive behaviors Underconnectivity theory – autism phenotype comes from reduction in global connectivity (long distance connections between frontal and parietal/occipital regions) and increase in local connectivity (particularly in visual areas)

52. (Van Essen & Dierker, 2007) Association cortex – regions not receiving direct sensory input. Involved in perception, language, social and executive functioning. Comparison of human and macaque monkey brain show that major areas of cortical expansion occur in association cortex

53. Cerebral Cortex Most projection areas have contralateral organization: –Left hemisphere receives information from right side of body (sensory), or controls right side of body (motor) –Right hemisphere receives information from left side of body (sensory), or controls left side of body (motor)

54. Split Brain

56. Split brain patient

57. Phantom Limb Pain Amputees often feel pain in a limb after it has been removed Sensation in limb can be felt when touching other areas of body (most common: lost hand feels touch of face)

58. Plasticity The brain is plastic—subject to alteration in the way it functions, such as: Changes in the brain’s overall architecture in response to stimulation and environmental experience The central nervous system can grow new neurons: But limited ability to do so with cortical injury This promotes stability in the brain’s connections but is an obstacle to recovery from brain damage.

59. Plasticity Neurons are subject to alteration in the way they function, such as: Changes in how much neurotransmitter a presynaptic neuron releases Changes in neuron sensitivity to neurotransmitters Creating new connections by growing new dendritic spines

60. 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