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

4. Brain Structure

5. DRUGS

6. 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

7. Evolution

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

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

10. “Synthetic Psychology” Ex. Phototaxis Braightenberg: Vehicles

11. 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

12. 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

14. 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

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

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

19. Action Potential

20. 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

22. Movement of a Signal

24. 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)

26. 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

27. 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

29. Synapses

30. Release of Neurotransmitter

32. Synapses

33. 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

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

36. Reflexes: A model

37. 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

38. 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

43. 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

44. Brain Structure (midline)

45. Structure: Central Core

46. Structure: X-Ray View

47. 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

48. 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

49. –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)

50. 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)

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

52. Disorders of Planning and Social Cognition Caused by damage to prefrontal area –Disrupts executive control– processes that allow us to direct and regulate our own cognitive activities e.g., setting priorities, planning, strategizing, ignoring distracters

53. Apraxias Difficulty in carrying out purposeful movements without the loss of muscle strength or coordination –Disconnection between primary and non- primary motor areas –Able to carry out each part of a complex movement, but disruption lies in coordination of the movements

54. Agnosias Visual agnosia: disturbance in recognizing visual stimuli despite the ability to see and describe them –Patient videoPatient video Prosopagnosia: inability to recognize faces (fusiform face area) –Patient videoPatient video –Patient videoPatient video Neglect Syndrome: complete inattentiveness to stimuli on one side of the body –Patient videoPatient video Akinetopsia: inability to perceive movement –“I see the world in snapshots – like frames of a move but most of the frames are missing”

55. Aphasias Broca’s Aphasia: disturbance in speech production, caused by damage to Broca’s area –Patient videoPatient video Agrammaticism Anomia Difficulty with articulation Wernicke’s Aphasia: disturbance in speech comprehension, caused by damage to Wernicke’s area –Patient videoPatient video Disruption in recognition of spoken words Disruption in comprehension of the meaning of words Inability to convert thought into words

56. Localization of Function

57. Localization/Topographic Projection

58. Localization/Topographic Proj.

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

60. 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)

61. What and where pathways of vision

62. (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

63. 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)

64. Split Brain

66. Split brain patient

67. 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)

68. 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.

72. 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

73. 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