Biological Psychology: Genes, Nervous System, and Brain Function

Biological Psychology: Core Concepts

Key Terminology in Biological Psychology

Understanding biological psychology requires familiarity with foundational terms related to genetics, evolutionary theory, neural anatomy, and physiological processes.

• Gene: A segment of DNA that codes for a specific protein, influencing traits and behaviors.

• Evolutionary Psychology: The study of how evolutionary principles such as natural selection shape behavior and mental processes.

• Nerve Cell (Neuron): The basic unit of the nervous system, specialized for transmitting information.

• Hormone: Chemical messengers released by glands, affecting various bodily functions and behaviors.

• Nervous System: The network of neurons and supporting cells that coordinate sensory input, motor output, and cognitive functions.

• Methods of Measuring Brain Activity: Techniques such as EEG (electroencephalography), fMRI (functional magnetic resonance imaging), and PET (positron emission tomography) used to study brain function.

Example: The hormone cortisol is released in response to stress and can influence memory and attention.

Genes and Behavior: Twin and Adoption Studies

Twin and adoption studies are essential for disentangling the effects of genetics and environment on behavior.

• Twin Studies: Compare identical (monozygotic) and fraternal (dizygotic) twins to estimate genetic influence on traits.

• Adoption Studies: Examine similarities between adopted children and their biological versus adoptive families to assess environmental effects.

• Heritability: The proportion of variation in a trait attributable to genetic factors.

Example: If identical twins raised apart show similar intelligence scores, this suggests a strong genetic component.

Neural Communication and Brain Function

Neurons communicate via electrical and chemical signals, and studies of brain injuries provide insight into brain organization.

• Neural Communication: Neurons transmit signals through action potentials and synaptic transmission.

• Action Potential: A rapid change in electrical charge that travels along the neuron’s axon.

• Synapse: The junction between two neurons where neurotransmitters are released.

• Split-Brain Patients: Individuals with severed corpus callosum, revealing lateralization of brain functions.

• Brain Lesions: Damage to specific brain areas used to study function and behavior.

Equation:

$V_{m} = V_{rest} + \Delta V$

Example: Studies of split-brain patients show that language is typically processed in the left hemisphere.

Effects of Drugs and Brain Injuries

Biological psychology helps predict how substances and injuries affect mental and physical abilities.

• Psychoactive Drugs: Chemicals that alter brain function, affecting mood, perception, and behavior.

• Brain Injuries: Trauma or disease can impair specific abilities depending on the affected region.

• Application: Understanding neurotransmitter systems aids in predicting drug effects.

Example: Damage to Broca’s area impairs speech production, while drugs like SSRIs increase serotonin to treat depression.

Neuroplasticity and Recovery from Brain Damage

Neuroplasticity refers to the brain’s ability to reorganize and form new connections after injury.

• Neuroplasticity: The capacity of the nervous system to change its structure and function in response to experience or damage.

• Rehabilitation: Therapies that harness neuroplasticity to restore lost abilities.

• Critical Periods: Times when the brain is especially receptive to change.

Example: Stroke patients may regain movement through intensive physical therapy that promotes neuroplastic changes.

Additional info: Academic context and definitions have been expanded to ensure the notes are self-contained and suitable for exam preparation.