AP Psych Unit 1: Biological Bases of Behavior

Psychology

Scientific study of behavior and mind.

Nature

Biological/genetic influences on behavior.

Evolutionary Perspective

Behavior shaped by survival and reproduction.

Natural Selection

Beneficial traits passed through generations.

Behavior Genetics

Study of genes and environment on behavior.

Mutations

Random genetic changes.

Environment

Every external influence on behavior.

Heredity

Genetic transmission from parents.

Genes

Units of hereditary information.

Genome

Complete genetic material of an organism.

Nurture

Environmental influence on behavior.

Eugenics

Controversial idea of improving genetics.

Identical (Monozygotic) Twins

Same egg, genetically identical.

Fraternal (Dizygotic) Twins

Two separate eggs, like siblings.

Interaction

Genes and environment influence together.

Epigenetics

Gene expression changes without DNA changes.

Nervous System

Body’s electrochemical communication network.

Central Nervous System

Brain and spinal cord.

Peripheral Nervous System

Nerves outside CNS.

Nerves

Bundles of axons carrying info.

Reflex

Automatic response to stimulus.

Autonomic Nervous System

Controls involuntary body functions.

Somatic Nervous System

Controls voluntary muscle movements.

Sympathetic Nervous System

Fight or flight response.

Parasympathetic Nervous System

Calms body after stress.

Neurons

Nerve cells transmitting information.

Cell Body

Main part of neuron.

Dendrites

Receive messages from other neurons.

Axon

Sends messages away from neuron.

Myelin

Insulates axons, speeds signals.

Synapse

Junction between neurons.

Glial Cells

Support and nourish neurons.

Reflex Arc

Simple path from stimulus to response.

Sensory Neurons

Carry info to brain/spinal cord.

Motor Neurons

Carry info from brain to muscles.

Interneurons

Connect sensory and motor neurons.

Action Potential

Electrical signal traveling down axon.

All-or-Nothing Principle

Neuron fires fully or not.

Depolarization

Neuron becomes less negative inside.

Reuptake

Reabsorption of neurotransmitters.

Multiple Sclerosis

Disease damaging myelin sheaths.

Neurotransmitters

Chemicals that transmit signals.

Excitatory Neurotransmitters

Increase chance of neuron firing.

Inhibitory Neurotransmitters

Decrease chance of neuron firing.

Dopamine

Linked to movement, pleasure.

Norepinephrine

Alertness, arousal, fight/flight.

Serotonin

Mood, hunger, sleep regulation.

GABA

Main inhibitory neurotransmitter.

Glutamate

Main excitatory neurotransmitter.

Endorphins

Painkillers, produce euphoria.

Substance P

Sends pain messages.

Acetylcholine

Movement and memory.

Hormones

Chemical messengers via bloodstream.

Leptin

Regulates hunger, reduces appetite.

Ghrelin

Stimulates hunger, increases appetite.

Melatonin

Regulates sleep cycles.

Oxytocin

Bonding and social connection.

Refractory Period

Neuron can’t fire immediately again.

Resting Potential

Neuron is polarized, ready.

Threshold

Minimum stimulation to fire.

Myasthenia Gravis

Disease disrupting muscle control.

Endocrine System

Gland system releasing hormones.

Adrenaline

Epinephrine; boosts fight-or-flight.

Biological Psychology

Links between biology and behavior.

Biopsychosocial Approach

Combines biological, psychological, social influences.

Levels of Analysis

Different views to analyze behavior.

Brain Plasticity (Neuroplasticity)

Brain’s ability to reorganize itself.

EEG

Electrical activity of brain.

MEG

Magnetic fields from brain activity.

MRI

Detailed brain structure scan.

CT

X-ray images of brain.

PET

Displays brain activity via glucose.

fMRI

Function and structure of brain.

Lesions

Destroyed brain tissue for study.

Brain Stem

Controls survival functions.

Hindbrain

Basic survival (medulla, cerebellum).

Midbrain

Sensory processing and movement.

Forebrain

High-level thinking (cerebral cortex, limbic).

Medulla Oblongata

Breathing and heart rate.

Reticular Activating System

Arousal and attention.

Cerebellum

Balance and coordination.

Cerebral Cortex

Complex thinking, outer brain layer.

Limbic System

Emotion and memory center.

Thalamus

Sensory relay station.

Hypothalamus

Hunger, thirst, body temp.

Pituitary Gland

Master gland; controls hormones.

Hippocampus

Processes memories.

Amygdala

Emotions, especially fear.

Corpus Callosum

Connects brain hemispheres.

Split Brain

Corpus callosum is severed.

Broca’s Area

Speech production.

Wernicke’s Area

Language comprehension.

Cortex Specialization

Areas for specific functions.

Contralateral Hemispheric Organization

Left brain → right body, vice versa.

Aphasia

Language impairment.

Occipital Lobe

Visual processing.

Temporal Lobe

Auditory processing.

Parietal Lobe

Touch, spatial info.

Frontal Lobe

Thinking, planning, movement.

Prefrontal Cortex

Decision-making, personality.