Biological Psychology BRIDGING THE LEVELS OF ANALYSIS

1. 3 Biological Psychology BRIDGING THE LEVELS OF ANALYSIS Slides prepared by Matthew Isaak

2. Learning Objectives LO 3.1 Distinguish the parts of neurons and what they do. LO 3.2 Describe electrical responses of neurons and what makes them possible. LO 3.3 Explain how neurons use neurotransmitters to communicate with each other. LO 3.4 Describe how the brain changes as a result of development, learning, and injury. LO 3.5Identify what roles different parts of the central nervous system play in behavior.

3. Learning Objectives LO 3.6 Clarify how the somatic and autonomic nervous systems work in emergency and everyday situations. LO 3.7 Describe what hormones are and how they affect behavior. LO 3.8 Identify different brain-stimulating, -recording, and -imaging techniques. LO 3.9Evaluate results demonstrating the brain's localization of function.

4. Learning Objectives LO 3.10Describe genes and how they influence psychological traits. LO 3.11Explain the concept of heritability and the misconceptions surrounding it

5. Lecture Preview • Nerve cells and communication in the brain • The central and peripheral nervous systems • The endocrine system: glands and hormones • Mapping the mind: the brain in action • Nature and nurture

6. Biological Psychology LO 3.1 Distinguish the parts of neurons and what they do. • Neuroscientists have made huge strides in understanding how the brain works. • Bridging the gap between the nervous system and our behavior allows us to span multiple levels of analysis.

7. NeuronsLO 3.1 Distinguish the parts of neurons and what they do. • Neurons are brain cells that specialize in communication. • There are around 85 billion neurons, with around 160 trillion connections between them. • Oddly shaped compared to other cells in the body, they have a number of specific features.

8. Neuronal ComponentsLO 3.1 Distinguish the parts of neurons and what they do. • Cell body (soma) • Center of neuron; builds new cell components • Dendrites • Branchlike extension that receive information from other neurons

9. Neuronal ComponentsLO 3.1 Distinguish the parts of neurons and what they do. • Axons • "Tails" of the neuron that spread out from the cell body and transmit information

10. Figure 3.1 A Neuron with a Myelin Sheath.

11. Neuronal ComponentsLO 3.1 Distinguish the parts of neurons and what they do. • Axon terminal • Knob at the end of the axons that contains synaptic vesicles filled with neurotransmitters • Neurotransmitters (NTs) • Chemical messengers that allow neuron-to-neuron communication

12. Neuronal ComponentsLO 3.1 Distinguish the parts of neurons and what they do. • Synapse • Space between neurons through which NTs travel

13. Figure 3.2 The Axon Terminal.

14. Glial CellsLO 3.1 Distinguish the parts of neurons and what they do. • There are as many glial cells as neurons in the brain. Several types: • Astrocytes are the most abundant and increase reliability of neuronal transmission. • Ogliodendrocytes promote new connections and produce the myelin sheath around axons.

15. Electrifying Thought LO 3.2 Describe electrical responses of neurons and what makes them possible. • Neurons respond to NTs by generating electrical activity. • When there are no NTs acting on a neuron, it is at the resting potential. • When there is enough of a charge inside the neuron (threshold), an action potential will occur.

16. Action PotentialsLO 3.2 Describe electrical responses of neurons and what makes them possible. • Abrupt waves of electric discharge triggered by a change in charge inside the axon • This is the neuron "firing," an all-or-none response. • Originate near cell body and travel down the axon to the axon terminal, triggering NT release

17. Figure 3.3 The Action Potential. When a neuron is at rest there are positive and negative ions on both sides of the membrane. During an action potential, positive ions rush in and then out of the axon. This process recurs along the axon until the axon terminal releases neurotransmitters.

18. Action PotentialsLO 3.2 Describe electrical responses of neurons and what makes them possible. • Neurons can fire 100 to 1,000 times per second. • In between firings, there is a very brief absolute refractory period.

19. Neurotransmission LO 3.3 Explain how neurons use neurotransmitters to communicate with each other. • Inside neurons, communication is electrical, but between neurons, it is chemical via NTs. • When released, NTs bind with the next neuron's receptor sites. • This process is halted by reuptake, when NTs go back into the axon terminal.

20. Figure 3.5 The Lock-and-Key Model of Neurotransmitter Binding to Receptor Sites.

21. NeurotransmissionLO 3.3 Explain how neurons use neurotransmitters to communicate with each other. • Some NTs excite the nervous system, whereas other NTs inhibit the nervous system. • Each NT has specific roles and functions in brain and behavior.

22. Types of NeurotransmittersLO 3.3 Explain how neurons use neurotransmitters to communicate with each other. • Glutamate and GABA are the most common NTs in the central nervous system. • Glutamate is excitatory and increases the chance neurons will communicate; GABA is inhibitory. • Acetylcholine (Ach) influences arousal, selective attention, sleep, and memory.

23. Types of NeurotransmittersLO 3.3 Explain how neurons use neurotransmitters to communicate with each other. • Monoamines contain only one amino acid. • Norepinephrine (NE) and serotonin influence arousal. • Dopamine plays a role in our response to rewarding experiences.

24. Types of NeurotransmittersLO 3.3 Explain how neurons use neurotransmitters to communicate with each other. • Neuropeptides have specialized functioning (like endorphins for pain relief). • Anandamides bind to the same receptors as THC and influence eating, motivation, memory, and sleep.

25. Psychoactive DrugsLO 3.3 Explain how neurons use neurotransmitters to communicate with each other. • Psychoactive drugs impact mood, arousal, or behavior by acting as agonists or antagonists for NTs. • Agonists – increase NT activity • Antagonists – decrease NT activity

26. Agonists and AntagonistsLO 3.3 Explain how neurons use neurotransmitters to communicate with each other. Agonists • Opioids – mimic endorphins • Alcohol, Xanax – stimulate GABA receptors • Prozac, Paxil – block serotonin reputake Antagonists • Antipsychotics – block dopamine from receptors • Botox – blocks ACh

27. Neural Plasticity LO 3.4 Describe how the brain changes as a result of development, learning, and injury. • Plasticity – nervous system's ability to change over time • Neurons change in four ways during development: • Growth of dendrites and axons • Synaptogenesis • Pruning • Myelination

28. Neural PlasticityLO 3.4 Describe how the brain changes as a result of development, learning, and injury. • During learning, long-term potentiation occurs and makes synapses perform better. • There is only limited recovery following brain injury or serious illness.

29. Neural PlasticityLO 3.4 Describe how the brain changes as a result of development, learning, and injury. • Stem cell therapies may someday encourage plasticity after injury or degeneration. • Neurogenesis – creation of new neurons – does occur during adulthood.

30. The Brain-Behavior Network LO 3.5 Identify what roles different parts of the central nervous system play in behavior. • Sensory information comes into—and decisions come out of—the central nervous system (CNS). • The nerves outside the CNS are called the peripheral nervous system (PNS).

31. LO 3.5 Identify what roles different parts of the central nervous system play in behavior.

32. Figure 3.8 The Nervous System Exerts Control over the Body.

33. Central Nervous SystemLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • The CNS is divided into distinct systems based on location and function.

34. Figure 3.9 The Human Brain: A Simple Map.

35. Cerebral CortexLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • The forebrain is the most developed area of the human brain, giving us our advanced intellectual abilities. • Consists of two cerebral hemispheres corrected by the corpus callosum which allows communication between them.

36. Figure 3.10 The Cerebral Hemispheres and the Corpus Callosum.

37. LO 3.5 Identify what roles different parts of the central nervous system play in behavior. • The majority of the forebrain is composed of the cerebral cortex. • It can be divided into four lobes, each associated with a different function.

38. Figure 3.11 The Four Lobes of the Cerebral Cortex.

39. Frontal LobesLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • Oversee and organize most other brain functions (executive functioning) • The body is mapped onto the motor cortex. • The prefrontal cortex is responsible for thinking, planning, and language. • Broca's area – important in speech comprehension

40. Parietal LobeLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • Contains the somatosensory cortex, which is sensitive to touch, pain, and temperature • Helps track objects' locations in space • Communicates information to the motor cortex every time we reach, grasp, or move our eyes

41. Figure 3.12 Representation of the Body Mapped onto the Motor and Sensory Areas of the Cerebral Cortex. The brain networks with the body in a systematic way, with specific regions of both the motor and primary sensory cortex mapping onto specific regions of the body.

42. Temporal LobeLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • The lower part of the cerebral cortex, it plays a role in hearing, understanding language, and storing autobiographical memories. • Contains the auditory cortex and Wernicke's area, responsible for speech comprehension

43. Occipital LobeLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • Lies at the rear of the brain and is specialized for vision • When sensory information enters the brain, it first goes to that sense's primary sensory cortex, then to the association cortex.

44. Basal GangliaLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • Forebrain structure that helps control movement • Allows us to perform movements to obtain rewards and reinforcement • Damage can contribute to Parkinson's disease

45. Limbic SystemLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • The emotional center of the brain that also has a role in smell, motivation, and memory • Thalamus relays information from the sense organs to primary sensory cortex • Hypothalamus regulates and controls internal bodily states; controls the pituitary gland

46. Limbic SystemLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • Amygdala plays key roles in fear, excitement, and arousal • Hippocampus plays a role in spatial memory; damage causes inability to form new memories

47. Figure 3.14 The Limbic System. The limbic system consists mainly of the thalamus, hypothalamus, amygdala, and hippocampus.

48. Brain StemLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • Connects the cerebral cortex and spinal cord • Performs some basic bodily functions • Serves as a relay station between the cortex and rest of nervous system

49. Figure 3.15 The Brain Stem. The brain stem is located at the top of the spinal cord, below the cortex.

50. Brain StemLO 3.5 Identify what roles different parts of the central nervous system play in behavior. • Midbrain contributes to movement, tracking of visual stimuli, and reflexes triggered by sound • Reticular Activating System connects the forebrain and cerebral cortex and plays key role in arousal