AP Psychology Unit 1: Biological Bases of Behavior

evolutionary perspective

the study of how psychological traits and behaviors have evolved over time to enhance survival and reproductive success

natural selection

the process by which organisms with advantageous traits pas those on to future generations

nature

“genes” are the inherent biological and genetic factors that influence an individual’s psychological development, traits, behaviors, and cognitive abilities

nurture

“environment”; the environmental influences and experiences that shape an individual’s psychological development, traits, behaviors, and cognitive abilities

twin studies

examines similarities and differences between identical (monozygotic) and fraternal (dizygotic) twins to assess the relative influence of generics and environment on traits and behaviors

adoption studies

investigates similarities between adopted children and their biological and adoptive families to asses the impact of genetics vs environment on various traits and behaior

family studies

analyzes comparisons among family members to understand the interplay of genetics and environment in shaping traits and behaviors within a family unit

heredity

the transmission of genetic info from biological parents to offspiring

genetic predisposition

the inherited likelihood of developing specific traits/conditions due to genetic factors from biological parents

eugenics

the belief in improving the genetic quality of the human population by controlling reproduction to increase desirable traits and decrease undesirable ones

cerebral cortex

the outer layer of the brain; responsible for higher-level cognitive functions, including: thinking, perceiving, and decision-making. It’s highly folded to increase its surface area.

lobes of the brain

the four main regions into which the cerebral cortex (the outer layer of the brain) is divided

association areas

parts of the brain that take info from all over the place—like what we see, hear, smell, and touch—and put it together to help us understand the world around us

frontal lobes

located at the front of the brain and are involved in higher-level cognitive functions like: decision-making, problem-solving, planning, and personality expression

prefrontal cortex

a region of the brain located in the frontal lobe; responsible for higher level cognitive and executive functioning (cognitive processes that enable individuals to: plan, organize, manage time, regulate emotions, and focus attention)

motor cortex

a region of the brain in the frontal lobe; responsible for planning, executing, and controlling voluntary movements of the body through sending signals to muscles

parietal lobes

located at the top of the brain; primarily responsible for processing sensory info like touch, temperature, and spatial awareness

somatosensory cortex

region of the brain located in the parietal lobe; responsible for interpreting touch, pressure, temperature, and pain signals, allowing us to perceive and respond to sensory stimuli

occipital lobes

located at the back of the brain; contains the primary visual cortex, responsible for processing shapes, colors, and motion

temporal lobes

located on the sides of the brain; contains the auditory cortex, which interprets sound signals to process language for memory formation

corpus callosum

thick band of nerve fibers that connects the left and right hemispheres of the brain; facilitates info sharing between the two hemispheres

brainstem

the oldest and most primitive part of the brain; responsible for basic life-sustaining functions such as breathing, heart rate, and sleep-wake cycles; serves as a pathway for neural signals, connecting the cerebral cortex and spinal cord

medulla

vital structure at the base of the brainstem, regulating autonomic functions such as heartbeat, breathing, and blood pressure

reticular activating system

a network of neurons located in the brainstem that plays a critical role in regulating arousal, attention, and consciousness

cerebellum

located at the back of the brain, below the cerebral hemispheres; responsible for coordinating movement, balance, and posture

limbic system

located beneath the cerebral cortex; a set of brain structures involved in emotions, memory, and motivation

reward center

network of brain structures, primarily located in the limbic system; processes pleasurable experiences and reinforces behavior associated with them

thalamus

a relay station in the brain that processes and relays sensory info such as sight, sound, touch, and taste to the cerebral cortex

hypothalamus

a small but powerful structure located below the thalamus; responsible for aiding in homeostasis by regulating: hunger, thirst, body temperature, sleep-wake cycle

pituitary gland

aka “master gland”; small, pea-sized gland located at the base of the brain; plays a central role in regulating hormone production and secretion

hippocampus

curved structure located within the brain’s temporal lobes; primarily responsible for forming and consolidating new memories

amygdala

small, almond-shaped, located within the brain’s temporal lobes; involved in processing emotions like fear and aggression

the nervous system

the body’s communication network; includes nerves, neurons, specialized cells

central nervous system (CNS)

consists of the brain and spinal cord; serves as the command center of the body

peripheral nervous system (PNS)

consists of all the nerves and ganglia outside the brain and spinal cord; communicates info to the CNS

autonomic nervous system

part of the PNS, consists of two main branches: sympathetic nervous system and parasympathetic nervous system; regulates involuntary bodily functions

sympathetic nervous system

activates the body’s “fight or flight” response in times of stress or danger

parasympathetic nervous system

promotes relaxation and restoring the body to a calm state after experiencing stress or danger

somatic nervous system

part of the peripheral nervous system (PNS); controls voluntary movements and relaying sensory info from the body to the CNS

neurons

building block of the nervous system, has 3 main parts: the cell body (soma), dendrites, axon; transmits electrical and chemical signals throughout the body

glial cells

provides structural support, insulation, and nourishment to neurons; play essential roles in maintaining brain health and supporting neuronal funcion

motor neurons

nerve cells that transmit signals from the CNS to muscles, glands, and organs; initiates and controls voluntary and involuntary movement

sensory neurons

nerve cells that transmit info from sensory receptors like those in the skin, muscles, and organs to the CNS; detect various stimuli like touch, temperature, and environmental changes, converting these into electrical signals to be processed by the brain

interneurons

nerve cells that serve as connectors within the CNS; relays signals between sensory and motor neurons

reflex arc

neutral pathway that controls reflex actions; allows for rapid, autonomic responses to sensory stimuli without conscious thought (primitive reflexes)

neural transmission

the process by which neurons communicate with each other through electrical and chemical signals

threshold

the level of stimulation required to trigger an action potential in a neuron, producing a response

action potential

brief electrical impulse that travels along the axon of a neuron; occurs when the neuron receives a stimulus that causes the inside of the cell to become more positively charged than the outside

all-or-nothing principle

once a neuron reaches its threshold of excitation, it will fire an action potential at full strength

depolarization

phase of action potential where the inside of the neuron becomes less negative compared to the outside; this occurs due to the influx of positively charged ions, such as sodium, through ion channels in the cell membrane; triggers the neuron to fire an action potential

refractory period

brief period following an action potential during which a neuron is unable to generate another action potential; occurs because the neuron’s sodium channels are temporarily inactivated and the cell membrane returns to its resting state

resting potential

the stable, negative electrical charge that exists across the cell membrane of a neuron when it is not actively transmitting signals; maintained because there are more positive sodium ions outside the cell and more negative potassium ions inside

reuptake

process where neurotransmitters that have been released into the synapse are reabsorbed by it

multiple sclerosis (MS)

chronic autoimmune disease that affects the CNS; occurs when the immune system mistakenly attacks the protective myelin sheath (a fatty substance that insulates nerve fibers), causing inflammation and damage

myasthenia gravis

chronic autoimmune disorder that occurs when the immune system produces antibodies that block or destroy the receptors for acetycholine, a neurotransmitter that stimulates nerve impulses and transmits them to muscles (this process is called neuromuscular junction)

neurotransmitters

chemical messengers that transmit signals between neurons; released from presynaptic neurons into synaptic cleft, where they bind to specific receptor sites on postsynaptic neurons, initiating or inhibiting a neural impulse

excitatory neurotransmitters

chemicals released by neurons that increase the likelihood of an action potential occurring in the postsynaptic neuron

glutamate

the primary excitatory neurotransmitter in the CNS; plays a key role in synaptic transmission and neuronal communication; involved in various brain functions like: learning, memory, neural plasticity

inhibitory neurotransmitters

chemicals released by neurons that decrease the likelihood of an action potential occurring

GABA

a neurotransmitter that acts as the primary inhibitory neurotransmitter in the CNS; promotes relaxation and reduces anxiety

dopamine

a neurotransmitter that plays a crucial role in regulating mood, reward, motivation, and movement; the brain’s key reward system

serotonin

a neurotransmitter that plays a vital role in regulating mood, sleep, appetite, and stress; essential for mental health

endorphins

neurotransmitters produced by the brain and CNS that act as natural pain relievers and mood enhancers; released in response to stress, pain, intense physical activity

substance p

a neurotransmitter involved in transmitting pain signals in the nervous system; binds to specific receptors on nerve cells in the spinal cord and brain

acetylcholine

a neurotransmitter that plays a fundamental role in both the CNS and PNS; involved in various functions, including: muscle contraction, memory, learning

hormones

chemical messengers produced by glands in the endocrine system that travels through the bloodstream to target cells or organs, where they regulate various physiological processes and behaviors

ghrelin

aka “hunger hormone”; a hormone produced primarily by the stomach and small intestine that stimulates appetite and promotes hunger

leptin

a hormone produced primarily by fat cells that regulates energy, balance, and appetite. It acts on the hypothalamus in the brain to suppress appetite and increase energy expenditure.

melatonin

a hormone that regulates the sleep-wake cycle and circadian rhythm in the body

oxytocin

aka the “love hormone” or “bonding hormone”; a hormone and neurotransmitter that plays a key role in social bonding; helps form emotional connections, trust, and intimacy

adrenaline

a hormone and neurotransmitter that plays a key role in the body’s stress response; helps the body adapt to challenging circumstances; surges in stress, fear, or excitement

norepinephrine

a neurotransmitter and hormone; it is involved in the body’s “fight or flight” response, regulating arousal, attention, and stress; helps increase heart rate, blood pressure, and alertness during times of stress or danger

plasticity

the brain’s ability to reorganize and adapt throughout life in response to experiences, learning, and environmental changes

split brain research

research that studies individuals who have undergone a surgical procedure called corpus callostomy, which disconnects the two hemispheres of the brain (mainly done for severe epilepsy)

contralateral hemispheric organization

the phenomenon where each hemisphere of the brain controls the opposite side of the body

hemispheric specialization

explored through split brain research; refers to the concept that each hemisphere of the brain has specialized functions and abilities

linguistic processing

the complex cognitive processes involved in understanding and producing language

Broca’s Area

located in the left hemisphere of the brain, specifically the frontal lobe; responsible for speech production and language processing; helps correct sentences and the coordination of the muscles involved in speech

Broca’s Aphasia

language disorder caused by damage to Broca’s Area, often resulting from stroke or brain injury; causes difficulty producing fluent speech and forming grammatically correct sentences, speech may be slow, effortful, and characterized by shortened phrases or words

Wernicke’s Area

a region located in the left hemisphere of the brain, specifically in the temporal lobe; involved in language comprehension and understanding spoken and written language

Wernicke’s Aphasia

located in the left hemisphere of the brain; a language disorder caused by damage to Wernicke’s Area, typically resulting from stroke or brain injury

electroencephalogram “EEG”

non-invasive neuroimaging technique used to record the electrical activity of the brain; involves placing electrodes on the scalp to detect and measure electrical signals from the brain; commonly used to diagnose and monitor various conditions, such as: epilepsy, sleep disorders, and brain injuries

functional magnetic resonance imaging “fMRI”

neuroimaging technique used to measure brain activity by detecting changes in blood flow and oxygen levels; allows researchers to observe which areas of the brain are active during specific tasks or stimuli

lesioning

a research technique used to study brain function by intentionally damaging or destroying specific areas of the brain in experimental animals; can be achieved through: surgical removal, chemical injection, or electrical stimulation