Chapter 3 - Neuroscience & Behavior

MODULE 3-1 (7) - Neurons

Structure of Neurons

Neurons: Nerve Cells

Consist of cell body that contains nucleus

Distinctive Feature of neurons

Dendrite - cluster of fibers at end of neuron that receives messages from other neurons

Axon - part of the neuron that carries messages destined for other neurons.

Terminal Buttons - sends messages

How Neurons Fire

Neurons follow an all-or-none law - rule that neurons are either on or off

Resting state - negative electrical charge of about -70 millivolts within a neuron

Before a neuron is triggered

Action potential - electric nerve

Speed of Transmission

Speed in which an action potential travels along an axon is determined by

Axon’s Size
Thickness of myelin sheath

Neurons differ in terms of

Quickness of impulse moving along axon
Potential firing rate

Intensity of stimulus determines fire rate

Mirror Neurons

Specialized Neurons that fire, when a person:

enacts a particular behavior

Discovery of mirror neurons suggest that humans’ capacity to mitate other may be a inbor behavior

Helps in explaining how and why humans have the capacity to understand others’ intentions

Possible basis for:

empathy feeling
development of language in humans

Where Neurons Meet: Bridging The Gap

Synapse: Space between 2 neurons when axon of sending neuron communicates dendrites of receiving neuron by using chemical messages

Neurotransmitters: Chemicals that carry messages across the synapse to the dendrite ( an sometimes the cell body) of receiving neuron

Not every neuron is capable of receiving chemical message carried by particular neurotransmitter

Successful chemical communication is possible only when neuro

Types of chemical messages delivered by neurotransmitters:

Excitatory message

If neurotransmitters remained at the side of the synapse, it would lead to:

Receiving nero's awash, in a continual chemical bath
Producing constant simulation of or coinhibilition of receiving neurons
Effective communications would no longer be possible

Reuptake: reabsorption of neurotransmitters by a terminal buttons

Understanding of reuptake has lead to development of certain
drugs that treat psychological disorders
- SSRIs (selective serotonin reuptake inhibitors)
- Reduces the symptoms of depression.

MODULE 3-2 (8): Nervous System and Endocrine System

Central/Peripheral Nervous System

Central Nervous System: parts of the nervous system that includes brain and spinal cord

Spinal Cords: Bundle of neurons that leave the brain an runs down the length of the back

Reflex: Automatic, involuntary response to an incoming stimulus

Kinds of neurons involved in reflexes:

Sensory Neurons (afferent)
Motor Neurons (efferent)

Peripheral Nervous Systems: made up of neurons with long axons and dendrites, it branches out from spinal cord and brain and reaching extremities of body

Includes

Somatic Division
Autonomic Division

Activating Divisions of Autonomic Nervous Systems

Autonomic Nervous system consists of

Sympathetic Division
Parasympathetic Division

Evolutionary Foundations of Nervous System

Evolutionary Psychology - identifies behavior patterns
Behavioral genetics - study of effects of heredity on behavior

Endocrine System: Chemicals/Glands

Endocrine system - chemical communication network that sends messages
Hormones - circulates through the blood
Pituitary gland - major component of endocrine system aka “master gland”
- Secretes hormones that control growth and other parts of endocrine system

MODULE 3-3 (9) - Brain

How do researchers identify the major parts and functions of the brain?
What are the major parts of the brain, and what behavior is each part responsible?
How do the 2 halves of the brain operate independently?
How can an understanding of the nervous system help us find ways to alleviate disease and pain?

Studying the Brain’s Structure and Functions: Spying on the Brain

Electroencephalogram (EEG)

Records electrical activity in the brain through electrodes placed on the outside of skull

Functional magnetic resonance imaging

Provides detailed, 3D computer-generated image of brain structures and activity by aiming a powerful magnetic field at the body

Positron emission tomography (PET)

Shows biochemical activity within the brain at a given moment
- Requires radioactive tracer injection

Transcranial magnetic stimulation (TMS)

Causes a momentary interruption of electrical activity by exposing a tiny region of the brain to a strong magnetic field

Central Core: “Old Brain”

Controls basic functions such as eating sleeping and is common to all vertebrates

Hindbrain contains:

Medulla: Controls critical body functions, such as breathing and heartbeat
Pons: Bridge in Hindbrain
- Acts as transmitter of motor information
- Involved in regulating sleep
Cerebellum: Part of the brain that controls bodily balance
Reticular Formation: Extends from medulla through the pons, passing through midbrain and forebrain
- Produces arousal of body
Thalamus: Part of brain located in middle of central core that acts primarily to rely information about the senses
Hypothalamus: Tiny part of brain, located below the thalamus
- Maintains homeostasis
- Produces and regulates behavior that is critical to the basic survival of species
  - Eating, self-protection, sex

Limbic System: Beyond Central Core

Limbic System: Part of the brain that controls eating, aggression, and reproduction

Includes amygdala and hippocampus
Plays important role in emotion, learning, and memory, along with hippocampus

Sometimes referred as “animal brain” due to similarities in structures and functions to those of other mammals

Cerebral Cortex: “New Brain”

Responsible for the most sophisticated information processing in the brain

Lobes: 4 major sections of cerebral cortex

Frontal
Parietal
Temporal
Occipital

Sulci: deep grooves in cortex that physically divides 4 sets of lobes

Motor Area of Cortex

Motor area: Responsible for body’s voluntary movement

Well mapped: researchers have identified amount and relative location of cortical tissue used for movement in specifics parts of body

Sensory Area of Cortex

Sensory area: Site in the brian of the tissue that corresponds to each sense with the degree of sensitivity related to amount of tissue

Example: somatosensory area: in parietal lobe; specific locations associated with the ability to perceive touch and pressure in particular location of body
Auditory area in temporal lobe
Visual Area in occipital lobe

Association Areas of Cortex

Association Areas: Site of higher mental processes

Thought, language, memory, speech

Example Phineas Gage, railroad worker accident

Damage to association area

Aphasia: result from injuries to association areas of the brain, and create problems with language

Broca’s aphasia
Wenicke’s aphasia

Neuroplasticity and Brain

Neuroplasticity

Changes in the brain related to the addition of new neurons that occur throughout the lifespan
New interconnections between neurons
Reorganizations of info-porcessions areas

Neurogenesis - Creation of new neurons in certain areas of the brain during adulthood

Specialization of Hemispheres: 2 Brains or 1?

Brain is divided into 2 roughly mirror-image halves
Hemispheres: Symmetrical left and right halves of the brain that control the side of the body opposite to their location
Lateralization: Dominance of one hemisphere of the brain in specific functions
- Language

Split Brain: Exploring 2 Hemispheres

Split-brain patients

Corpus callosum surgically cut
- Last resort treatment for severe epilepsy

END OF CHAPTER 3

	Created by Joshua Bishop over 4 years ago

All notes of Basic Psychology in Chapters 1, 2, and 3

Understanding Psychology: Chapter 1-3 Notes