Biological Bases of Behavior Overview
Interaction of Heredity and Environment
Heredity: The genetic transmission of characteristics from parents to offspring. It refers to the genetic material inherited from the parents that shapes an individual’s traits.
Nature: The influence of genetic inheritance on behavior and development. This refers to the biological factors that affect an individual’s growth and functioning.
Nurture: The environmental influences that shape an individual's development. This includes upbringing, culture, social interactions, and life experiences.
Genetic Predisposition: An inherited genetic trait or tendency that increases the likelihood of developing a certain condition or behavior, but it does not guarantee it.
Evolutionary Perspective: An approach in psychology that looks at how natural selection has shaped behavior. It suggests that behaviors that promote survival and reproduction are more likely to be passed on.
Natural Selection: The process by which traits that increase an organism’s chances of survival and reproduction are more likely to be passed on to future generations.
Eugenics: The study of or belief in improving the human race by selective breeding or other forms of genetic manipulation to encourage desirable traits.
Twin Studies: Research studies that compare twins, particularly identical and fraternal twins, to understand the relative influence of heredity and environment.
Family Studies: Studies that investigate the resemblance of traits among family members to determine the genetic and environmental influences on behavior.
Adoption Studies: Research involving children who were adopted at an early age to compare the influence of biological vs. adoptive families.
2. Overview of the Nervous System
Central Nervous System (CNS): Comprises the brain and spinal cord, responsible for processing information and directing responses.
Peripheral Nervous System (PNS): Includes all the nerves outside the CNS, connecting the brain and spinal cord to the rest of the body.
Autonomic Nervous System: Controls involuntary bodily functions like heart rate, digestion, and respiratory rate.
Sympathetic Nervous System: Activates the body’s fight or flight response, preparing the body for stressful or emergency situations.
Parasympathetic Nervous System: Counteracts the sympathetic nervous system, promoting rest and digestion.
Somatic Nervous System: Controls voluntary movements of skeletal muscles.
3. The Neuron and Neural Firing
Neurons: Specialized cells that transmit electrical and chemical signals throughout the nervous system.
Glial Cells: Cells that provide structural support, nourishment, and insulation to neurons.
Reflex Arc: The automatic pathway of a reflex, bypassing the brain for quicker response.
Sensory Neurons: Neurons that carry incoming sensory information from the body to the CNS.
Motor Neurons: Neurons that carry outgoing signals from the CNS to muscles and glands.
Interneurons: Neurons that connect sensory and motor neurons, facilitating communication within the CNS.
Neural Transmission: The process by which neurons communicate with each other through electrical impulses and neurotransmitters.
Action Potential: The electrical charge that travels along the axon of a neuron.
All-or-Nothing Principle: The concept that once a neuron’s threshold is reached, the action potential will always fire at full strength.
Depolarization: The process during an action potential when the neuron’s membrane potential becomes more positive.
Refractory Period: A brief period after firing during which a neuron cannot fire again.
Resting Potential: The state of a neuron when it is not actively firing, with a negative charge inside relative to the outside.
Reuptake: The process by which neurotransmitters are reabsorbed into the presynaptic neuron after transmitting a signal.
Threshold: The level of stimulation required to trigger an action potential.
Multiple Sclerosis: A disease that causes the immune system to attack the myelin sheath of neurons, disrupting neural transmission.
Myasthenia Gravis: A condition where the immune system attacks acetylcholine receptors, leading to muscle weakness.
Excitatory Neurotransmitters: Chemicals that increase the likelihood of a neuron firing, such as glutamate.
Inhibitory Neurotransmitters: Chemicals that decrease the likelihood of a neuron firing, such as GABA.
Dopamine: A neurotransmitter associated with reward, motivation, and movement control.
Serotonin: A neurotransmitter involved in mood regulation, sleep, and appetite.
Norepinephrine: A neurotransmitter involved in arousal and alertness.
Glutamate: The most abundant excitatory neurotransmitter, involved in learning and memory.
GABA: The major inhibitory neurotransmitter, involved in calming the nervous system.
Endorphins: Natural painkillers produced by the brain.
Substance P: A neurotransmitter involved in the transmission of pain.
Acetylcholine: A neurotransmitter that plays a role in muscle contraction and memory.
Hormones: Chemical messengers that regulate physiological processes.
Adrenaline: A hormone released during stress that increases heart rate and energy levels.
Leptin: A hormone involved in regulating energy balance and fat storage.
Ghrelin: A hormone that stimulates hunger.
Melatonin: A hormone involved in regulating the sleep-wake cycle.
Oxytocin: A hormone involved in social bonding and childbirth.
Psychoactive Drugs: Substances that alter mood, perception, or behavior.
Agonists: Substances that enhance the action of neurotransmitters.
Antagonists: Substances that block or reduce the effects of neurotransmitters.
Reuptake Inhibitors: Drugs that block the reuptake of neurotransmitters, increasing their effects.
Stimulants: Drugs that increase brain activity, such as caffeine and cocaine.
Depressants: Drugs that decrease brain activity, such as alcohol.
Hallucinogens: Drugs that alter perception, such as marijuana.
Opioids: Drugs that relieve pain, such as heroin.
Tolerance: The need for increasing amounts of a drug to achieve the same effect.
Addiction: A compulsive need for a substance or behavior despite harmful consequences.
Withdrawal: Symptoms that occur when a person stops using a substance to which they have developed a dependence.
4. The Brain
Brain Stem: The part of the brain responsible for basic life functions such as breathing and heart rate.
Medulla: Controls involuntary functions like heartbeat and breathing.
Reticular Activating System: Regulates wakefulness and arousal.
Reward Center: Brain areas that are activated by pleasurable experiences.
Cerebellum: Coordinates voluntary movements and balance.
Cerebral Cortex: The outer layer of the brain, responsible for higher cognitive functions like thinking and decision-making.
Limbic System: A group of structures involved in emotions, motivation, and memory.
Thalamus: The relay station for sensory and motor signals.
Hypothalamus: Regulates essential functions like temperature, hunger, and hormones.
Pituitary Gland: The master gland that regulates other endocrine glands.
Hippocampus: Involved in memory formation.
Amygdala: Involved in emotion, particularly fear and aggression.
Corpus Callosum: A bundle of nerves that connects the two hemispheres of the brain.
Occipital Lobes: Responsible for visual processing.
Temporal Lobes: Involved in auditory processing and memory.
Parietal Lobes: Involved in sensory processing and spatial awareness.
Association Areas: Areas of the cortex involved in higher mental functions.
Somatosensory Cortex: Processes sensory information from the body.
Frontal Lobes: Involved in reasoning, planning, and motor control.
Linguistic Processing: Language-related processes in the brain.
Higher-Order Thinking: The ability to think critically and solve complex problems.
Executive Functioning: Cognitive processes involved in decision-making, planning, and impulse control.
Prefrontal Cortex: Involved in decision-making, social behavior, and higher cognitive functions.
Motor Cortex: Controls voluntary muscle movements.
Split Brain Research: Studies that examine the functions of the two hemispheres of the brain by severing the corpus callosum.
Hemispheric Specialization: The theory that each hemisphere of the brain is specialized for different tasks.
Broca’s Area: A region in the frontal lobe involved in speech production.
Wernicke’s Area: A region in the temporal lobe involved in language comprehension.
Aphasia: A language disorder resulting from brain damage. Broca’s aphasia affects speech production, while Wernicke’s aphasia affects comprehension.
Contralateral Hemispheric Organization: The principle that each hemisphere of the brain controls the opposite side of the body.
Plasticity: The brain’s ability to reorganize and form new connections in response to damage or learning.
EEG: A test that measures electrical activity in the brain.
fMRI: A neuroimaging technique that measures brain activity by detecting blood flow.
Lesioning: The process of damaging specific brain areas to study their function.
5. Sleep
Consciousness: The state of being aware of and able to respond to one's environment.
Circadian Rhythm: The 24-hour cycle of biological processes, including the sleep-wake cycle.
Jet Lag: A temporary sleep disorder caused by traveling across multiple time zones, disrupting the circadian rhythm.
Shift Work: A work schedule that disrupts the natural sleep-wake cycle, often leading to sleep disturbances and health issues.
NREM Sleep: Non-rapid eye movement sleep, which includes three stages:
Stage 1: Light sleep, with hypnagogic sensations (the sensation of falling).
Stage 2: Deeper sleep, characterized by sleep spindles and K-complexes.
Stage 3: Deep, restorative sleep (slow-wave sleep).
REM Sleep: Rapid eye movement sleep, the stage of sleep associated with vivid dreaming and memory consolidation.
REM Rebound: The tendency for REM sleep to increase after periods of deprivation.
Activation-Synthesis Theory (Dreams): The theory that dreams are the brain’s attempt to make sense of random neural activity during sleep.
Consolidation Theory (Dreams): The theory that dreams help consolidate memories and emotional experiences.
Memory Consolidation: The process by which short-term memories are converted to long-term storage during sleep.
Restoration of Resources: The theory that sleep restores energy and repairs bodily systems.
Insomnia: A sleep disorder characterized by difficulty falling or staying asleep.
Narcolepsy: A disorder characterized by excessive daytime sleepiness and sudden sleep attacks.
REM Sleep Behavior Disorder: A condition where individuals act out their dreams during REM sleep.
Sleep Apnea: A disorder where breathing repeatedly stops and starts during sleep.
Somnambulism: Sleepwalking, usually occurring during NREM sleep.