physiological psych ch 1

Introduction to Behavioral Neuroscience

• Behavioral Neuroscience Overview

  • Examines the relationship between the brain and behavior

  • Covers history and evolution of neuroscience

  • Highlights the importance of genetics in understanding behavior

Neurons and Brain Functionality

• Neuron Overview

  • The human brain contains over 80 billion neurons

  • Neurons connect in complex networks, forming thousands of connections with one another

• Operational Complexity

  • Simple models misrepresent the complexity of neuronal connections

  • Neurons can send messages to multiple others, leading to intricate communication pathways

  • Enables automatic behaviors, such as breathing or walking, without conscious thought

Brain Responsibilities

• The Brain in Control

  • The brain controls almost every aspect of functioning (memories, decision-making, reflexes, etc.)

  • Key brain structures include the brainstem and medulla, which manage essential functions like breathing

Definitions in Neuroscience

• Terms Explored

  • Physiological Psychology, Biopsychology, and Behavioral Neuroscience are largely interchangeable

  • Focus: how the brain influences behavior, mental illness, and addiction

• Neuroscience as a Broad Field

  • Encompasses multiple disciplines (chemistry, physics, pharmacology, etc.)

Mind-Brain Problem

• Conceptual Debate

  • Historical questions about the relationship between mind and brain

  • Mind as an abstract concept linked to brain functions (thoughts, memories, etc.)

  • Distinction between monism (one entity) and dualism (mind and brain as separate entities)

Historical Models of Brain Function

• Descartes' Hydraulic Model

  • Early intuition-based approach to brain function involving animal spirits and hydraulic systems

  • Lacked empirical evidence; relied on observational speculation

• Transition to Empiricism

  • Shift from intuition to systematic observation and evidence gathering in studying brain function

Advances in Understanding

• Electrical Stimulation Studies

  • Early experiments demonstrated the influence of electrical stimuli on muscle contractions

  • Showed the biological nature of neuronal communication

• Localization of Brain Function

  • Identification of specific brain areas responsible for certain functions or memories

  • Famous case studies highlighting brain function localization (e.g., Phineas Gage and Broca's area)

Limitations of Localization

• Lashley’s Research

  • Found that cutting small brain areas did not significantly disrupt learning or memory in rat studies

  • Suggested a need to consider broader brain networks rather than single localized areas

• Evolving Understanding of Brain Connectivity

  • Research shows that brain functions often involve multiple interconnected areas working in unison

Nature vs. Nurture Debate

• Key Question

  • How much do genetics (nature) vs. environment (nurture) influence behavior?

• Conclusion

  • Both factors are important; genetics may limit, but environment can also alter behavior

Genetic Foundations

• Understanding Genes

  • Genes transmit inherited characteristics, directing various biological processes

• Chromosomes Overview

  • Humans have 23 pairs of chromosomes; sex chromosomes determine biological sex

  • XX is female; XY is male

DNA Structure and Function

• DNA Basics

  • Contains coding information determining traits and observable characteristics

  • Genes vary and encode proteins that could influence behavior

• Definitions

  • Genotype: genetic makeup

  • Phenotype: observable characteristics resulting from genotype

Genetic Expression and Alleles

• Types of Alleles

  • Dominant and recessive alleles determine visible traits; one allele can suppress the expression of another

• Example: Blood type inheritance (ABO system)

Genetic Complexity in Behavior

• Complex Traits

  • Rarely determined by a single gene; often involve multiple genes and environmental influences

• Human Genome Project

  • Aimed to identify genes and their roles in health and disease

Epigenetics and Gene Expression

• Concept of Epigenetics

  • Environmental factors can influence gene expression positively or negatively

  • Changes can be passed to future generations.

Twin Studies in Genetics

• Analysis of Identical vs. Fraternal Twins

  • Identical twins share 100% genes; fraternal twins share 50%

  • Twin studies provide insight into the heritability of behaviors and disorders

Behavioral Disorders Evidence

• Comparison of Behavioral Disorders in Twins

  • Certain disorders show a strong genetic correlation;

  • Environmental factors and non-shared experiences also play critical roles

Summary of Key Points

• Basic Definitions Needed

  • Understand what chromosomes, genes, and alleles are as foundational knowledge

  • Focus on traits taught in class, emphasizing definitions and their implications

Recommendations for Study

• Preparing for Exams

  • Review flashcards and important definitions highlighted in the textbook for better retention of material.