1 / 49

Biological Psychology Neural and Hormonal Systems – Module 3 How the Brain Governs Behavior – Module 4

Biological Psychology Neural and Hormonal Systems – Module 3 How the Brain Governs Behavior – Module 4 . Intro Psych Jan 30-Feb 4, 2009 Classes #7-9. “So why do we have to study biology in a psych class?”. Let me use Phineas Gage to help answer this question…. “He was no longer Gage…”.

michi
Download Presentation

Biological Psychology Neural and Hormonal Systems – Module 3 How the Brain Governs Behavior – Module 4

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Biological Psychology Neural and Hormonal Systems – Module 3How the Brain Governs Behavior – Module 4 Intro Psych Jan 30-Feb 4, 2009 Classes #7-9

  2. “So why do we have to study biology in a psych class?” • Let me use Phineas Gage to help answer this question…

  3. “He was no longer Gage…” • Several different angles of where the rod passed through his skull

  4. There is a Phineas Gage display in the Warren Medical Museum at Harvard University • This is what went through his brain (see below)… • 3½ feet in length; 1¼ inch in diameter

  5. Some history buffs travel to the tiny town of Cavendish, VT

  6. Biological Roots of Behavior • Franz Gall (1758-1828) • Austrian physicist who invented phrenology • He felt that bumps on the skull could reveal our mental abilities and character traits. • Introduced as being scientific but its use was exploited by “quacks on gullible individuals” • Became similar to that of astrology, palm-reading and tarot • Although, ill-fated theory was laughed at by scientific community of that day – it may have had some validity • Localization of brain functions somehow hit the mark

  7. The Nervous System • Electrochemical communication system that enables us to think, feel, and behave • Complex beyond comprehension • Although, human brains are more complex our nervous systems and those of animals operate in a similar fashion – advantage of this is experimentation

  8. Major Components • Neurons • Rapidly respond to signals and quickly send signals of their own • Glial cells • Help neurons to communicate, keep chemical environment stable, secrete chemicals to help restore damage, and respond to signals from neurons – enable neurons to function

  9. Axons • Function • Carries signals away from the cell body • Pass information along to other nuerons, or to muscles or glands • Type of Signal Carried • The action potential, an all-or-nothing electrochemical signal that shoots down the axon to vesicles at the tip of the axon, releasing neurotransmitters

  10. Synapse • Very small gap between neurons • For communication to occur between cells, the signal must be transferred across this gap • Function • Provides an area for the transfer of signals between neurons, usually between axon and dendrite

  11. Dendrite • Function • Detects and carries signals to the cell body • Type of Signal Carried • The postsynaptic potential, which is an electrochemical signal moving toward the cell body

  12. Receptors • Function • Proteins on the cell membrane that receive chemical signals • Type of Signal Carried • Recognizes certain neurotransmitters, thus allowing it to begin a postsynaptic potential in the dendrite

  13. Okay, so how do neurons actually transmit information? • A neuron: • Receives signals form other neurons through its branching dendrites and cell body • Then combines these signals in the cell body • And then transmits an electrical impulse downits axon

  14. Transmitting information… • The impulse is called the action potential which is a brief electrical charge that travels down the axon like a line of dominoes falling, each one tripping up the next • This is real electricity as a handful of neurons produce enough power to light up a flashlight • When electrical signals reach the end of the axon, they stimulate the release of chemical messengers – neurotransmitters

  15. Neurotransmitters • Function • A chemical released by one cell that binds to the receptors on another cell • Type of Signal Carried • A chemical message telling the next cell to fire or not to fire its own action potential

  16. The Nervous System • Allows researchers to study simple animals such as squids and sea slugs to help us better understand the organization of our own brains

  17. Divisions of the Nervous System • Consists of two systems • Central Nervous System • Brain and spinal cord • Peripheral Nervous System • Which connects the CNS to the rest of the body

  18. Organization of the Nervous System

  19. Peripheral Nervous System • Two components: • Somatic Nervous System • Transmits sensory input to the CNS from the outside world and directs motor output • Autonomic Nervous System • Controls glands and muscles of our internal organs – “automatic pilot”

  20. Autonomic Nervous System • Dual system: • Sympathetic Nervous System • Arouses the body • Parasympathetic Nervous System • Calms us down

  21. Neurons • Nerve cells (building blocks) – essentially identical to animals • Small samples of brain tissue from a person and a monkey are basically indistinguishable

  22. Endocrine System: Taking the slow lane • Unlike the speedy nervous system which zips messages from eyes to brain to hand in a fraction of a second, endocrine messages use the slow lane • May take several seconds or more as bloodstream carries a hormone from an endocrine gland to its target tissue

  23. Endocrine System • Hormones are chemical messengers • Influence all aspects of our lives – growth, metabolism, reproduction, moods, etc. • Strives for homeostasis (balance) by responding to stress, exertion, internal thoughts, etc.

  24. The Brain • Studying the brain: • Clinical observations • Manipulating the brain

  25. How does the brain govern behavior? • 3 Principle layers of the brain: • Brainstem • Limbic System • Hippocampus • Amygdala • Hypothalamus • Cerebral Cortex

  26. Brainstem (or Hindbrain) • The brain’s innermost region… • Begins where the spinal cord enters the skull and swells slightly forming the medulla • Towards the rear of the brainstem is the cerebellum – this is linked to memory and its major function is muscular control

  27. Limbic System

  28. Limbic System • Hippocampus • This structure plays a key role in allowing us to store new information • Problems here may cause Alzheimer's – these individuals have trouble processing declarative memories • Milner (1968): the classic case of H.M.

  29. Limbic System • Amygdala • Emotional control center of the brain – major influence on aggression and fear • Emotional memories as well • Alzheimer’s ??? • Kluver and Bucy (1939) • Demasio (1994)

  30. Limbic System • Hypothalamus • Major influence on hunger, thirst, body temperature, and sexual behavior • Olds and Milner (1954)

  31. Cerebral Cortex • Makes us distinctively human – much higher developed than in animals • Motor Cortex – involved in the conscious initiation of voluntary movements in specific parts of the body including hand, knee, foot and head • Fritsch and Hitzig (1870) • Delgado (1969) • Penfield (1975)

  32. Cerebral Cortex • Sensory Cortex • receives information from our senses • Visual cortex • visual info • Auditory cortex • auditory info • Somatosensory cortex • info from skin • Association cortex • involved in complex cognitive tasks associating words with images • Broca’s area (aphasia) • Wernicke’s area (aphasia)

  33. Neurotransmitters • Neurotransmitters are chemicals made by neurons and used by them to transmit signals to the other neurons • A chemical message telling the next cell to fire or not to fire its own action potential • More than 200 in our body all with different functions • Lets briefly discuss some of the most important ones…

  34. Serotonin • Facilitates a relaxed, sleepy feeling • Tryptophan an amino acid found in dairy products and turkey is converted into serotonin in the body • So, insomnia sufferers may be smart to listen to grandmother’s suggestion to drink a warm glass of milk before going to bed

  35. Some Illnesses Associated With Serotonin • Too low levels in depression and anxiety sufferers • Obesity may also be associated with low levels • Linked to aggression as well -- low levels in the brains of suicide victims

  36. Dopamine • High levels lead to pleasure • Makes person feel happy and active • Dopamine raises the body's temperature and increases metabolic rate • Gives you euphoric feelings and allows you to be active • Drug and alcohol abuse will block dopamine receptors and therefore a person needs to take more to get the same effect

  37. Illnesses Associated With Dopamine • Parkinson’s Disease • too low levels • Schizophrenia • too high levels • Tourette’s disorder • too high levels • Huntington’s disease • too high levels

  38. Norepinephrine • Plays a role in attention and arousal • Used by sympathetic nervous system to prepare us for action

  39. Illnesses Associated With Norepinephrine • Depression • chronic stress depletes this neurotransmitter and can lead to depression • Note: • Aerobic Exercise is found to protect the brain from this depletion – so go out and run a mile or two if your down in the dumps

  40. Epinephrine • Involved in energy and glucose metabolism

  41. Illnesses Associated With Epinephrine • Depression – too low levels

  42. Acetylcholine • Involved in voluntary movement, learning, memory, and sleep • Helps parasympathetic nervous system to slow our heart rate

  43. Illnesses Associated With Acetylcholine • Alzheimer’s disease – too low levels • Note: • Unfortunately, drugs used to increase acetylcholine to help restore normal levels appear to have small effects on improving memory

  44. GABA • Inhibits excitation and anxiety • Appears directly related to anxiety reduction

  45. Illnesses Associated With GABA • Anxiety disorders – too low levels • Huntington’s Disease – too low levels • GABA systems aren’t working and this allows dopamine systems to run wild • Huntington's disease is a hereditary disorder characterized by memory loss, abnormal movement and premature death • It affects 1 in 10,000 people, and children with an affected parent have a 50 percent chance of developing the disease • Epilepsy – too low levels

  46. Glutamate • Main excitatory neurotransmitter in the brain • Very important in learning and memory

  47. Illnesses Associated With Glutamate • Alzheimer’s disease • too low levels in hippocampus • Strokes • too high levels can cause neurons to die • ALS (Lou Gehrig’s Disease) • causes death in neurons in the spinal cord and brainstem

  48. Endorphins • Involved in pain reduction and pleasure • They enhance the release of dopamine • These natural opiates are released in response to pain and vigorous exercise

  49. Illnesses Associated With Endorphins • Use of artificial opiates can cause body to stop manufacturing its own – this can lead to drug addiction

More Related