AP Psych Unit 1 VOCAB: Biological basis of Behavior

Biopsychology

definition: the scientific study of how the brain and nervous system influence behavior

ex) relationship between neurological processes and psychological functions like thinking, learning, feeling, sensing, and perceiving

(exploring how brain activity manifests in observable behaviors.)

Neuroscience

definition: the scientific study of the brain and nervous system, examining how their structure and function influence behavior, cognition, and emotions.

ex) investigating how specific brain regions are involved in memory formation, studying the neural pathways related to decision-making, or analyzing brain activity during emotional responses

my ex) how to build helmets for NASA that improve neurostimulation in space, (too much caffeine can cause overstimulation; seizures)

Neuroplasticity

definition: the brain's ability to change and adapt in response to new experiences and environmental stimuli. It's a process that allows the brain to grow and meet new demands.

ex) learning a new language is an example of neuroplasticity.

Neurons

definition: the basic units of the brain and nervous system. They send and receive signals that allow us to move, feel, think, and more.

ex) sensory neurons: respond to stimuli like touch, sound, or light. They send signals to the brain or spinal cord.

Dendrites

definition: a branching, tree-like extension of a neuron that receives signals from other neurons, acting as the primary input point for a nerve cell, essentially where a neuron "listens" to incoming information from other cells in the nervous system.

ex) Their primary role is to receive electrical signals (neurotransmitters) from other neurons across synapses and transmit them to the cell body of the neuron for further processing

Axon

definition: a long, thin fiber extending from a neuron's cell body that transmits electrical impulses (action potentials) away from the cell body to other neurons, muscles, or glands; essentially acting as the "sending" part of the neuron, carrying information to other cells in the nervous system

ex) axons are responsible for sending electrical signals generated by the neuron to other cells. 

Myelin Sheath

definition: a fatty, insulating layer that wraps around the axon of a neuron, allowing for faster transmission of electrical impulses along the nerve fiber

ex) its primary role is to speed up the transmission of electrical signals (action potentials) along the axon by facilitating "saltatory conduction," where the signal jumps between gaps in the myelin called Nodes of Ranvier.

Synapse

definition: the space between neurons where they communicate with each other.

ex) Brain to body: synapses connect neurons in the brain to neurons in the rest of the body. For example, when you intend to move your arm, the synapse translates that intention into movement.

Action Potential

defintion: how neurons "fire" to communicate with each other, and occurs as a result of ions moving across the cell membrane, following an "all-or-none" principle where the signal either reaches threshold and fires fully, or doesn't fire at all.

ex) action potentials enable neurons to transmit information throughout the nervous system by sending electrical signals to other neurons, muscles, or glands.

Resting Potential

definition: typically registering as a negative voltage (around -70 millivolts) with the inside of the cell being more negative than the outside.

ex) When a neuron receives a stimulus, it undergoes a rapid change in membrane potential, called an "action potential," where the inside of the cell becomes temporarily positive. After the signal is transmitted, the neuron quickly returns to its resting potential to be ready for the next signal.

Threshold

definition: the minimum level of stimulation needed for a person to detect a stimulus, essentially the point at which a sensation becomes perceptible.

ex) Vision: The dimmest light a person can see in a dark room.

Hearing: The quietest sound a person can hear.

Taste: The smallest amount of salt needed to taste a difference on a food item.

Touch: The lightest touch on the skin that can be felt.

Refractory Period

definition: the reaction time to the second stimulus is delayed because they are still processing the first one.

ex) difficulty of reacting to a sudden danger while already focused on another task, like talking on the phone while driving and needing to brake quickly at a red light.

Neurotransmitter

definition: chemical messengers in the body. Their function is to transmit signals from nerve cells to target cells. These signals help regulate bodily functions ranging from heart rate to appetite.

ex) serotonin: Associated with mood regulation, sleep, and appetite

dopamine: Plays a role in, reward, motivation, and movement

Receptor Sites

definition: a specific location on a neuron or cell membrane where a neurotransmitter or other signaling molecule (like a hormone) can bind and trigger a cellular response, essentially acting like a lock that only a specific key (the signaling molecule) can fit into.

ex) adrenergic receptors: activated by norepinephrine (noradrenaline) and epinephrine (adrenaline), involved in the "fight or flight" response

Acetylcholine (ACh)

definition: a neurotransmitter that plays a role in memory, learning, attention, and involuntary muscle movement.

ex) helps with memory, learning, and attention and with muscle contractions, blinking, and stomach and heart movements

Dopamine

definition: It is a neurotransmitter that plays a role in the brain's reward system, giving us feelings of pleasure and motivation. It's known as the "feel-good" hormone.

ex) winning a game (sense of urgency)

Serotonin

definition: a chemical messenger that affects mood and other psychological functions. It's sometimes called the "happy" chemical because it contributes to feelings of happiness and well-being.

ex) reading a good, impactful book. (long lasting and brings happy calm).

Norepinephrine

definition: a neurotransmitter primarily associated with the "fight or flight" response, playing a key role in regulating, attention, alertness, and mood, essentially preparing the body for stressful situations by increasing heart rate, blood pressure, and focus

ex) when someone encounters a sudden threat, their body releases a surge of norepinephrine, causing their heart rate to increase, pupils to dilate, and their senses to become heightened, allowing them to quickly react to the danger.

GABA

definition: is a neurotransmitter that slows down brain activity and is associated with a calming effect.

ex) Can help modulate mood by slowing down the transition of messages between neurons.

Glutamate

definition: it is a neurotransmitter that plays a key role in cognitive processes like learning and memory. It's also important for regulating mood and sleep.

ex) physical activity can increase levels, which can help you feel energized and focused.

Endorphins

definition: neurotransmitters released by the pituitary gland and hypothalamus in the brain. As natural hormones, they can alleviate pain, lower stress, improve mood, and enhance your sense of well-being.

ex) if you participate in a relatively high-stress activity, such as sky-diving, you'll experience a spike in endorphins both before and after the activity. The endorphins counter the stress of your initial anticipation and then relieve the stress afterward.

Oxytocin

definition: a hormone that affects human behavior and social interactions

ex) helps people form relationships and long-term emotional attachments. 

Central Nervous System (CNS)

definition: a processing center that manages everything that your body does, from your thoughts and feelings to your movements

ex) made up of the brain and spinal cord. The CNS is the body's processing center. The brain controls most of the body's functions, including awareness, movement, thinking, speech, and the 5 senses.

Peripheral Nervous System (PNS)

definition: acting as the communication link between the brain and the rest of the body

ex) The brain sends signals through — to your leg muscles, enabling you to move your legs and walk.

Sympathetic Nervous System

definition: refers to the part of the autonomic nervous system that activates the "fight or flight" response, triggering physiological changes like increased heart rate, dilated pupils, and rapid breathing when faced with a perceived threat or stressful situation

ex) if you suddenly encounter a dangerous animal, your sympathetic nervous system would kick in, preparing your body to either confront the threat or flee

Parasympathetic Nervous System

definition: refers to the part of the autonomic nervous system responsible for the "rest and digest" response, essentially calming the body down after a stressful situation by regulating functions like digestion, heart rate, and pupil constriction

ex) feeling your body relax and your heart rate slow down after finishing a stressful task, allowing you to digest a meal comfortably.

Medulla

definition: part of the brainstem that controls vital involuntary bodily functions like breathing, heart rate, blood pressure, swallowing, and vomiting, essentially acting as the central hub for autonomic nervous system regulation

ex) automatic response to cough when something irritates your throat

Thalamus

definition: a part of the brain that relays sensory and motor information to the cerebral cortex. It also plays a role in consciousness, sleep, and alertness.

ex) The thalamus helps the brain decide what to pay attention to and what to ignore.

Hippocampus

definition: a part of the brain that plays a key role in learning and memory. It's located in the temporal lobe and is part of the limbic system.

ex) The hippocampus helps you store facts, dates, times, names, and locations. For example, learning how to memorize a speech or lines in a play.

my ex) a taxi driver’s grows when he learns the routes of london

Amygdala

definition: a part of the brain primarily responsible for processing emotions, particularly fear, and is often associated with the "fight or flight" response

ex) If you are walking down a dark alley and suddenly hear a loud noise, your amygdala would rapidly activate, triggering a feeling of fear and potentially causing you to jump or run away, even before your conscious mind fully processes the situation as a threat.