Lecture Overview• Our Genetic Inheritance• Neural Bases of Behavior• Nervous System Organization• A Tour Through the Brain
Our Genetic Inheritance• Behavioral Genetics: study of the relative effects of heredity & environment on behavior & mental processes
Our Genetic Inheritance • Evolutionary Psychology: studies how natural selection & adaptation help explain behavior & mental processes
Our Genetic Inheritance • Neuroscience: scientific study of the biology of behavior & mental processes
Our Genetic Inheritance: Genes & DNA • The nucleus of every cell contains genes, which carry the code for hereditary transmission. These genes are arranged along chromosomes (strands of paired DNA).
Our Genetic Inheritance• Malnourished children may not reach their full genetic potential, which demonstrates how environmental factors interact with genetic factors.
Pause & Reflect: Critical Thinking• Given that height has one of the highest heritability estimates (around 90%), what other factors might help explain the height differences in this mother & daughter?
Neural Bases of Psychology • Our nervous system consists of neurons (cells responsible for receiving & conducting electrical impulses from the brain).
Neural Bases of Psychology: The Structure of a Neuron
Neural Bases of Psychology: Neural Communication• Within a neuron, communication results from an action potential (a neural impulse that carries information along the axon of a neuron).
Neural Bases of Psychology:Neural Communication (Continued)• Between neurons, communication occurs through transmission of neural information across a synapse by neurotransmitters (chemicals released by neurons that alter activity in other neurons).
Neural Bases of Psychology:Neural Communication (Continued)• Receiving neurons receive multiple messages from other neurons. These multiple messages then determine if an action potential occurs or not.
Neural Bases of Psychology:Neural Communication (Continued)• Note how the axon terminals of sending neurons almost completely cover the cell body of the receiving neuron.
Pause & Reflect: Assessment• What happens to excess neurotransmitters or to those that do not “fit” into the adjacent receptor sites? (Answer appears on the next slide.)
Pause & Reflect:• The sending Assessment neuron normally reabsorbs the excess neurotransmitters (called “reuptake) or they are broken down by special enzymes.
Neural Bases of Psychology• Endocrine System: collection of glands that manufacture & secrete hormones into the bloodstream
Neural Bases of Psychology• Hormones: chemicals manufactured by endocrine glands & circulated in the bloodstream to produce bodily changes or to maintain normal bodily function.
Why Do We Need Two CommunicationSystems--Neurotransmitters + Hormones?
Pause & Reflect: Assessment1. _____ receive information from other neurons. The _____ carries the neuron’s messages to other body cells.2. How does neural communication within neurons differ from communication between neurons?
Nervous System Organization • Central Nervous System (CNS): brain & spinal cord • Peripheral Nervous System (PNS): all nerves & neurons connecting CNS to the rest of the body – PNS is subdivided into the somatic & autonomic nervous systems – Autonomic nervous system subdivided into sympathetic & parasympathetic nervous systems
Central Nervous System: Important Terms• Neuroplasticity: brain’s lifelong ability to reorganize & change its structure & function throughout the life span• Neurogenesis: division & differentiation of nonneuronal cells to produce neurons• Stem Cells: precursor (immature) cells with the potential to develop into almost any type of cell
Pause & Reflect: Critical Thinking• Understanding neurogenesis, neuroplasticity, & stem cells helps make us better informed consumers of scientific research & more knowledgeable participants in political debates. Can you explain why?
Nervous System Organization: Central Nervous System (CNS)• Brain• Spinal Cord: transmits information into & out of the brain
Nervous System Organization:Central Nervous System (CNS) • The spinal cord is also responsible for involuntary, automatic behaviors called reflexes.
Nervous System Organization: Peripheral Nervous System (PNS)• PNS connects CNS to the rest of the body; subdivided into: – Somatic Nervous System (SNS): connects sensory receptors & controls skeletal muscles – Autonomic Nervous System (ANS): controls involuntary bodily functions; subdivided into: »Sympathetic Nervous System (arouses) »Parasympathetic Nervous System (calms)
Nervous System Organization Anatomy & functions of the sympathetic (arouses)& parasympathetic (calms) nervous systems
Pause & Reflect:1. You touch a hot stove & then Assessment pull away. This immediately & reflexively action was controlled by _____.2. After being startled by the sight & sound of a fierce dog rushing toward you, it is most likely that your _____ is dominant.
A Tour Through the Brain• Lower-level brain structures: – Hindbrain – Midbrain – Parts of the Forebrain
A Tour Through The Brain: Hindbrain• Key structures & functions of the hindbrain: – Medulla: life survival functions – Pons: respiration, movement, waking, sleeping, & dreaming – Cerebellum: coordination of fine muscle movement, balance, & some aspects of perception & cognition
A Tour Through The Brain (Continued)• Midbrain: collection of brain structures in the middle of the brain; coordinates movement patterns, sleep, & arousal• Reticular Formation: runs through the hindbrain, midbrain, & brainstem; filters incoming information & controls arousal
A Tour Through The Brain (Continued)• Forebrain: collection of upper-level brain structures, including the thalamus, hypothalamus, limbic system, & cerebral cortex – Thalamus: relays sensory messages to the cerebral cortex – Hypothalamus: responsible for drives, hormones, & regulating the body’s internal environment
A Tour Through The Brain (Continued)• Limbic System: interconnected group of forebrain structures involved with emotions, drives, & memory
Structures of the Forebrain
Pause & Reflect:1. What are the three key structures of the Assessment hindbrain?2. The _____ includes the thalamus, hypothalamus, & limbic system.
Pause & Reflect:Assessment
A Tour Through The Brain: Cerebral Cortex• Cerebral Cortex: thin surface layer on the left & right cerebral hemispheres; regulates most complex behavior, including sensations, motor control, & higher mental processes
A Tour Through The Brain:Lobes of the Cerebral Cortex
A Tour Through The Brain: Lobes of the Cerebral Cortex•Frontal Lobes: receive &coordinate messagesfrom other lobes;responsible for motorcontrol, speechproduction, & higherfunctions, such asthinking, personality,emotion, & memory
Pause & Reflect: Critical Thinking• Do you recall from Chapter 1 Phineas Gage’ s mining accident, which sent a 13- pound tamping iron through his frontal lobes? How did this affect his short- & long- term behavior & mental processes?
A Tour Through The Brain: Lobes of the Cerebral Cortex (Cont.)• Parietal Lobes: located at thetop of the brain directly behindthe frontal lobes; responsible forinterpreting bodily sensations• Temporal Lobes: located oneach side of the brain above theears; responsible for audition,language comprehension,memory, & some emotionalcontrol
A Tour Through The Brain:Lobes of the Cerebral Cortex (Cont.) • Occipital Lobes: located at the back of the brain; responsible for vision & visual perception
A Tour Through The Brain:Motor Cortex & Somatosensory Cortex
Pause & Reflect: Critical Thinking• Why are the hands & face on this drawing so large? What do they represent?
A Tour Through The Brain: Split-Brain Research• Severing thecorpus callosum,for medicalreasons, alsoprovidesinformation onthe role &functions of theleft & righthemispheres.
A Tour Through The Brain: Split-Brain Research
A Tour Through The Brain: Lateralization• The left & righthemispheresspecialize inparticular (but oftenoverlapping)operations.
Pause & Reflect:1. What are the major functions of the four Assessment lobes of the brain?2. The _____ hemisphere is primarily responsible for language, & it controls the right side of the body.
End of CHAPTER 2Neuroscience& BiologicalFoundations