🗓️Unit 03
Biopsychology

PSYC 181 – Intro to Psych

Emma Marshall – Instructor

University of Nebraska-Lincoln

July 19, 2024

Learning Objectives

1. Describe different historical and modern approaches to understanding the nature vs. nuture debate
2. Describe methods of assessing brain activity and function
3. Identify basic parts of a neuron, the nervous system, and brain structures and describe their primary functions
4. Explain the role of the endocrine system in regulating bodily functions

Evolution and Social Darwinism

Charles Darwin

Theory of Evolution

Proposed system of natural selection and survival of the fittest theory of evolution

Diagram from On the Origin of the Species (1859) shows how species change over generations

Social Darwinism and Eugenics

Francis Galton

The Decent of Man (1871)

Helped to start Eugenics movement but also developed some basic statistics

Attempts to control ‘natural selection’ through political or social means

Phrenology & Pseudoscience

First theory that brain regions control specific behaviors

Proposed by Gall and Spurzheim

Phineas Gage

• Case study demonstrating effects of frontal lobe damage on personality
• First scientific evidence of localized brain functions

Modern Psychophysiological Assessment

Study of the relationship between mental activity and biological responses

Common methods:

• Skin conductance
• Heart rate
• Muscle movements
• Brain imaging techniques

Brain Imaging Techniques

Category	Technique	Description
Radiation-based	CT Scan	Uses X-rays to create cross-sectional images of the brain
	PET Scan	Measures metabolic processes in the brain
Magnetic field-based	MRI	Produces detailed anatomical images of the brain
	fMRI	Shows brain activity by detecting changes in blood flow
Electrical activity-based	EEG	Records electrical activity of the brain

Radiation-based:

Magnetic Field-based:

Electrical activity-based:

UNL CB3

Nature vs. Nurture

Epigenetics

Epigenetics is an emerging area of scientific research that shows how environmental influences–children’s experiences–actually affect the expression of their genes.

This means the old idea that genes are set in stone has been disproven. Nature vs. nurture debate has arguably been resolved as –it nearly always both.

During development, the DNA that makes up our genes accumulates chemical marks that determine how much or little of the genes is expressed. This collection of chemical marks is known as the “epigenome” the different experiences children have rearrange those chemical marks. This explains why genetically identical twins can exhibit different behaviors, skills, health, and achievement.

Damage to the Frontal Lobe: Phineas Gage - While working as a railroad foreman, an accident caused an iron rod to penetrate through Gage’s skull and frontal lobe. After the accident, people noticed changes in his personality. - Before the accident - Well-mannered and soft-spoken. - After the accident - Started behaving in odd and inappropriate ways. - These changes were consistent with loss of impulse control (a function of the frontal lobe).

The Nervous System

Nervous System Structure

1. Central Nervous System (CNS)
   • Brain: Primary organ for processing information
   • Spinal cord: Conduit for information between brain and body
2. Peripheral Nervous System (PNS)
   • Somatic nervous system: Controls voluntary movements
   • Autonomic nervous system: Regulates involuntary functions
     • Sympathetic: “Fight or flight” response
     • Parasympathetic: “Rest and digest” functions

Brain Structure and Function

• Hemispheres: Left and right halves of the brain
• Lateralization: Specialization of functions in each hemisphere
• Corpus callosum: Fiber bundle connecting the hemispheres
• Forebrain, midbrain, and hindbrain: Major divisions of the brain

Cerebral Cortex

• Lobes of the cerebral cortex:
  • Frontal: Executive functions, motor control
  • Parietal: Sensory processing
  • Temporal: Auditory processing, memory
  • Occipital: Visual processing

Limbic System

Set of structures involved in emotion and memory

Regulates hormones

Fight or Flight

Memory processing

Nervous System Structure

Nervous System

Cells of the Nervous System

Neurons

Specialized cells that transmit nerve impulses

Glial Cells

Support cells for neurons

1. Neurons
   • Definition: Specialized cells that transmit nerve impulses
   • Structure: Cell body, axon, dendrites
   • Function: Conduct electrochemical signals
2. Glial cells
   • Definition: Support cells for neurons
   • Types: Oligodendrocytes, Schwann cells, astrocytes, microglia
   • Functions: Insulation, nutrition, waste removal, immune defense

Action Potential Process

Neuronal Communication

• Electrochemical process
• Membrane potential: Difference in electrical charge across the cell membrane
• Resting potential: Baseline electrical state of neurons (-70mV)
• Action potential: Rapid, temporary change in membrane potential

Neurotransmitters and Drugs

Chemical messengers released by neurons

Neurotransmitters

Major Neurotransmitters and How They Affect Behavior

Neurotransmitter	Involved in	Potential Effect on Behavior
Acetylcholine	Muscle action, memory	Increased arousal, enhanced cognition
Beta-endorphin	Pain, pleasure	Decreased anxiety, decreased tension
Dopamine	Mood, sleep, learning	Increased pleasure, suppressed appetite
Gamma-aminobutyric acid (GABA)	Brain function, sleep	Decreased anxiety, decreased tension
Glutamate	Memory, learning	Increased learning, enhanced memory
Norepinephrine	Heart, intestines, alertness	Increased arousal, suppressed appetite
Serotonin	Mood, sleep	Modulated mood, suppressed appetite

Edocrine System

Network of glands that produce and secrete hormones

Male Endocrine System

Female Endocrine System

Major glands: Pituitary, thyroid, adrenal, gonads, pancreas