unit 1

Sensation

is the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. It involves the detection of physical energy and its conversion into neural signals.

Transduction

is the conversion of physical energy from stimuli into neural signals that the brain can interpret.

Perception

is the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.

Absolute Threshold

is the minimum stimulation needed to detect a particular stimulus 50% of the time.

Just noticeable difference

(JND) is the smallest difference in stimulation that a person can detect 50% of the time.

Weber’s Law

states that the just noticeable difference between stimuli is a constant proportion of the original stimulus. It explains how we perceive changes in different types of sensory input.

Synesthesia

is a condition in which stimulation of one sensory pathway leads to automatic, involuntary experiences in a second sensory pathway, such as seeing colors when hearing music.

Sensory Adaptation

is the reduced responsiveness of sensory receptors to constant stimulation over time, allowing individuals to focus on more relevant changes in their environment.

Lens

is a transparent structure in the eye that focuses light onto the retina, allowing for clear vision at various distances.

Retina

is a light-sensitive layer at the back of the eye that converts light into neural signals for visual processing.

Fovea

is a small pit on the retina that contains a high concentration of cones, providing the sharpest vision and color perception. R

Rods

are photoreceptor cells in the retina that are responsible for vision in low light conditions and do not detect color.

Cones

are photoreceptor cells in the retina that are responsible for color vision and function best in bright light.

Ganglion cells

are the final output neurons of the retina that transmit visual information to the brain via the optic nerve.

Blind spot

is the small area in the retina where the optic nerve exits the eye, resulting in a lack of light detection in that region.

nearsightedness

is a common vision condition where distant objects appear blurry while close objects can be seen clearly, caused by the eye being too long or the cornea having too much curvature.

Farsigthedness

is a vision condition where distant objects are seen clearly, but close objects appear blurry due to the eye's shape or lens issues.

Trichromatic

theory explains color vision based on three types of cones in the retina sensitive to red, green, and blue light.

Opponent Process

theory that describes how color perception is controlled by mechanisms that respond in opposite ways to different colors, specifically regarding pairs of color opposites like red-green and blue-yellow.

Color deficiency

is a visual impairment that affects an individual's ability to perceive colors accurately, often due to the absence or malfunction of certain types of cones in the retina.

Auditory System

the sensory system responsible for detecting sound and processing auditory information, involving the ear, auditory pathways, and brain regions.

Wavelength

is the distance between successive peaks of a wave, which determines the frequency and perceived color of light.

Amplitude

the height of a wave, indicating the strength or intensity of a sound or light wave.

Place Theory

is a theory that explains how we perceive different pitches of sound based on the location of activation along the basilar membrane in the cochlea.

Frequency theory

is a theory that explains how we perceive different pitches of sound based on the rate at which the auditory nerve fires. It suggests that the frequency of the sound wave corresponds to the frequency of the nerve impulses.

Volley theory

is a theory that explains how we perceive higher frequencies of sound by stating that multiple auditory neurons can fire in succession, working together to encode the frequency of a sound wave.

vestibular

system is a sensory system that contributes to balance and spatial orientation. It detects changes in motion and head position.

kinesthetic

system is a sensory system that helps perceive body position and movement through receptors in muscles, tendons, and joints.

pain

is the unpleasant sensory experience caused by actual or potential tissue damage, often leading to a protective reflex. It serves an important role in alerting the body to injury and prompting responses to avoid further harm.

gustation

is one of the five basic senses that allows the perception of flavors through specialized receptors on the tongue. It plays a crucial role in identifying sweet, sour, salty, bitter, and umami tastes.

olfaction

is the sensory system responsible for the sense of smell, detecting airborne molecules through receptors in the nasal cavity. It plays a vital role in flavor perception and emotional responses.

Circadian Rhythms

biological processes that follow a 24-hour cycle, influencing sleep-wake patterns and various physiological functions.

Beta Waves

brain waves associated with alertness and active thinking, typically present during awake states.

Alpha Waves

brain waves present during relaxed, calm states, often occurring when a person is awake but resting.

NREM 1

the lightest stage of sleep, where a person drift between wakefulness and sleep, often accompanied by muscle relaxation and slower brain waves.

NREM 2

a stage of sleep characterized by deeper relaxation and the presence of sleep spindles, where the body prepares for deeper sleep.

NREM 3

a stage of sleep characterized by slow-wave activity and deep restorative processes, where the body is least responsive to external stimuli.

Rapid Eye Movement

(REM) sleep is a sleep stage characterized by rapid movement of the eyes, increased brain activity, vivid dreams, and muscle atonia.

REM Rebound

the phenomenon where individuals experience increased REM sleep after being deprived of it, often resulting in more intense dreams.

Insomnia

a sleep disorder characterized by difficulty falling or staying asleep, leading to daytime fatigue and impaired functioning.

Narcolepsy

a neurological disorder that affects the control of sleep and wakefulness, leading to excessive daytime sleepiness and sudden sleep attacks.

Sleep Walking

a disorder that causes people to walk or perform other complex behaviors while still asleep, typically occurring during deep sleep.

REM Behavior Disorder

a sleep disorder in which individuals act out their dreams, often involving physical movements or vocalizations during REM sleep.

cerebellum

A region of the brain located at the back of the skull, responsible for coordinating voluntary movements, balance, and motor learning.

brainstem

The part of the brain that connects the cerebrum to the spinal cord, controlling vital functions such as breathing, heart rate, and blood pressure.

Medulla

oblongata, a section of the brainstem that regulates autonomic functions like heart rate, breathing, and reflexes.

reticular activating system

A network of neurons in the brainstem that regulates arousal, alertness, and the sleep-wake cycle.

cerebral cortex

The outer layer of the brain involved in various higher functions such as thought, perception, and decision-making.

Limbic System

A complex system of structures in the brain that is involved in emotions, memory, and motivation.

Amygdala

A structure in the limbic system that plays a key role in processing emotions, particularly fear and pleasure.

hippocampus

A major component of the limbic system, the hippocampus is essential for memory formation and spatial navigation.

hypothalamus

A small but crucial part of the brain that regulates vital functions such as temperature control, hunger, thirst, and the sleep-wake cycle, while also linking the nervous system to the endocrine system.

thalamus

The thalamus is a large mass of gray matter located near the center of the brain that acts as a relay station for sensory and motor signals to the cerebral cortex, playing a critical role in regulating sleep, consciousness, and alertness.

pituitary gland

A small endocrine gland located at the base of the brain, often referred to as the "master gland" because it regulates various hormonal functions by controlling other glands in the endocrine system.

occipital lobe

The occipital lobe is the rearmost part of the cerebral cortex, primarily responsible for processing visual information, including aspects such as color, light, and motion.

frontal lobe

The frontal lobe is located at the front of the cerebral cortex and is involved in higher cognitive functions such as reasoning, planning, problem-solving, and controlling behavior and emotions.

prefrontal cortex

The prefrontal cortex is the front part of the frontal lobe and is crucial for complex cognitive behavior, decision-making, and moderating social behavior.

motor cortex

The motor cortex is a region of the cerebral cortex located in the frontal lobe, responsible for planning, controlling, and executing voluntary movements.

parietal lobe

The parietal lobe is located near the center of the cerebral cortex and is primarily responsible for processing sensory information, including touch, temperature, and pain, as well as spatial awareness.

somatosensory cortex

A part of the parietal lobe that processes sensory information from the body, including touch, temperature, and pain.

temporal lobe

The temporal lobe is located on the sides of the cerebral cortex and is primarily involved in processing auditory information, memory, and emotional responses.

left hemisphere

The left hemisphere of the brain is responsible for language processing, analytical thinking, and controlling the right side of the body. It typically excels in tasks involving logic and reasoning.

Broca’s Area

a region in the left hemisphere associated with speech production and language processing.

Wernicke’s Area

a region in the left hemisphere involved in language comprehension and understanding.

corpus callosum

the large bundle of nerve fibers connecting the left and right hemispheres of the brain, facilitating communication between them.

split-brain experiments

studies investigating the effects of severing the corpus callosum to understand the lateralization of brain function.

brain plasticity

the brain's ability to reorganize itself by forming new neural connections throughout life, enabling adaptation to new experiences or injuries.

endocrine system

the collection of glands that produce hormones to regulate various bodily functions, including metabolism, growth, and mood.

pituitary gland

a pea-sized gland located at the base of the brain, often referred to as the "master gland" because it regulates other endocrine glands and controls growth, metabolism, and reproduction.

EEG

a test that detects electrical activity in the brain through electrodes placed on the scalp. It is commonly used to diagnose conditions such as epilepsy and sleep disorders.

fMRI

a functional neuroimaging technique that measures brain activity by detecting changes associated with blood flow, providing insights into brain function during cognitive tasks.

Lesion

a region in the brain that has been damaged due to injury, disease, or abnormality, often studied to understand brain function and behavior.

Multiple sclerosis

a chronic autoimmune disorder affecting the central nervous system, characterized by the degeneration of myelin sheaths around nerve fibers, leading to various neurological symptoms.

Myasthenia gravis

a chronic autoimmune neuromuscular disease that causes weakness in the skeletal muscles by disrupting the communication between nerves and muscles.

Prosopagnosia

a neurological condition characterized by the inability to recognize faces, often due to damage in the fusiform gyrus of the brain.

Broca’s aphasia

a type of expressive aphasia resulting from damage to Broca's area in the brain, causing difficulty in speech production but usually preserving comprehension.

Wernicke’s aphasia

a type of fluent aphasia caused by damage to Wernicke's area, leading to impaired language comprehension and the production of nonsensical speech.

Phantom limb pain

a painful sensation experienced in a limb that has been amputated, often resulting from the brain's representation of the missing limb.

Epilepsy

a neurological disorder characterized by recurrent seizures due to abnormal electrical activity in the brain.

Alzheimer’s

disease, a progressive neurodegenerative disorder characterized by memory loss, cognitive decline, and changes in behavior.

Neurotransmitters

Chemical messengers that transmit signals across synapses between neurons, playing a crucial role in communication within the nervous system.

Excitatory

neurotransmitters that increase the likelihood of firing an action potential in the receiving neuron.

Inhibitory

neurotransmitters that decrease the likelihood of firing an action potential in the receiving neuron.

GABA

Inhibitory neurotransmitter that reduces neuronal excitability throughout the nervous system.

Glutamate

Excitatory neurotransmitter that plays a key role in synaptic plasticity and cognitive functions such as learning and memory.

Dopamine

A neurotransmitter involved in reward, motivation, and motor control. It plays a crucial role in regulating mood and cognitive functions.

Serotonin

A neurotransmitter that helps regulate mood, sleep, and appetite. It is often linked to feelings of well-being and happiness.

Acetylcholine

A neurotransmitter that plays a key role in muscle activation, memory, and learning. It is involved in both the central and peripheral nervous systems.

Norepinephrine

A neurotransmitter involved in arousal, alertness, and stress response. It plays a role in regulating mood, attention, and certain physiological functions.

Endorphins

A group of neurotransmitters that act as natural pain relievers and are associated with feelings of pleasure and euphoria. They are often released during exercise, excitement, and pain.

Substance P

A neuropeptide that functions as a neurotransmitter and is involved in the transmission of pain signals.

Hormones

Chemical messengers that regulate various physiological processes and behaviors in the body, influencing growth, metabolism, and mood.

oxytocin

A hormone and neurotransmitter that plays a key role in social bonding, sexual reproduction, and during and after childbirth. Often referred to as the "love hormone" because of its involvement in maternal behaviors and bonding.

adrenaline

A hormone and neurotransmitter produced by the adrenal glands, involved in the body's fight-or-flight response by increasing heart rate, blood flow, and energy availability.

leptin

A hormone produced by adipose (fat) cells that helps to regulate energy balance by inhibiting hunger, thereby promoting satiety.

ghrelin

A hormone produced in the stomach that stimulates appetite, increases food intake, and promotes fat storage. It is often referred to as the "hunger hormone."

agonist

A substance that binds to a receptor and activates it, mimicking the action of a natural neurotransmitter.

Antagonist

A substance that binds to a receptor but does not activate it, blocking the action of a natural neurotransmitter.

Reuptake

The process by which neurotransmitters are reabsorbed by the presynaptic neuron after transmitting a signal across the synapse, effectively terminating the signal.

Depressants

Substances that reduce neural activity, leading to sedation and relaxation.