unit 4 psych terms

sensation

process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

transduction

conversion of sensory stimuli into neural impulses that can be understood by the brain

perception

process of organizing and interpreting sensory information to make sense of the world around us. it involves the brains interpretation of sensory inputs, which can be influenced by past experiences, expectations, and context

absolute threshold

the minimum amount of stimulation required for a stimulus to be detected by a sensory system. it represents the point at which a stimulus becomes noticeable to an individual at least 50% of the time.

just-noticeable difference

the smallest change in a stimulus that can be detected by an individual. its the minimal difference needed for a person to perceive that a change has occurred.

sensory adaptation

the process by which sensory receptors become less receptive to constant stimuli overtime

webers law

the perceived difference in a stimulus must be proportional to the original intensity of the stimulus

synesthesia

a condition in which stimulation of one sensory pathway leads to automatic, involuntary experiences in another sensory pathway

retina

the light-sensitive inner surface of the eye containing photoreceptor cells that convert light to neural signals

blind spot

area on the retina where the optic nerve exists the eye, lacking photoreceptor cells. its a spot where vision is absent, as there are no light-sensitive cells to detect visual stimuli

visual nerve

a bundle of more than one million nerve fibers that connects the retina of the eye to the brain. it acts as a one-way cable carrying visual signals from the eyes photoreceptors and retinal ganglion cells to the brains visual cortex

lens

transparent structure in the eye that focuses light onto the retina. it adjusts its shape to help the eye properly refract light, enabling clear vision at different distances

accommodation

the process by which the lens of the eye changes its shape to focus on objects at different distances, it allows for clear vision of both nearby and distant objects by adjusting the curvature of the lens

nearsightedness

a common vision condition where close objects appear clear, but distant objects appear blurry. it occurs when the eyeball is too long, or the cornea is too curved, causing light to focus in front of the retina instead of on it

farsightedness

a vision condition where distant objects are seen more clearly than close ones. it happens when the eyeball is too short or the cornea is too flat, causing light to focus behind the retina rather than directly on it

photoreceptors

specialized sensory neurons located in the retina at the back of the eye that converts light into electrical and chemical signals for the brain

rods

photoreceptor cells in the retina responsible for vision in the low light conditions and detecting motion. they provide black-and-white vision and are highly sensitive to light, allowing us to see in dim environments

cones (blue, green,red)

photoreceptor cells in the retina responsible for color vision and detail in bright light they enable us to perceive colors and fine visual details, such as regarding text or distinguishing between different hues

trichromatic theory

a theory proposing that color vision is based on three types of cone receptors, each sensitive to different wavelengths of light. the brain combines signals from these cones to create the perception of a wide range of colors

opponent-process theory

a theory proposing that color vision is based on pairs of opposing color processes

fovea

central area of the retina responsible for sharp visual center it contains a high concentration of cone cells (no rods), enabling detailed and color vision

afterimages

visual sensations that persist after a stimulus is removed they occur due to temporary overstimulation of cone cells in the retina, resulting in a brief perception of an inverted or complementary image

ganglion cells

neurons in the retina that receive visual information from bipolar cells and transmit it to the brain via the optic nerve. they play a crucial role in processing visual signals and relaying them to the brain for further interpretation

dichromatism

type of color vision deficiency where an individual has only two types of functioning cone cells instead of the normal three. this condition typically results in difficulty distinguishing between certain colors especially reds and greens

monochromatism

a rare form of color blindness where an individual has only one type of functioning cone cell, or none at all. this results in the inability to perceive colors, seeing the world in shades of gray

prosopagnosia

a neurological condition characterized by the inability to recognize familiar faces including ones own face, despite intact vision and intellect. its often referred to as face blindness

blindsight

a phenomenon where individuals with damage to their visual cortex can respond to stimuli without consciously perceiving them. it suggests that some visual processing can occur unconsciously by passing traditional pathways in the brain

wavelength

the distance between sound wave peaks shorter wavelengths mean higher-pitched sounds. while longer wavelengths mean lower-pitched sounds

pitch

the highness or lowness of a sound, determined by the frequency of its vibrations

amplitude

the measure of the intensity or loudness of a sound wave, represented by the height of its peaks. greater amplitude corresponds to louder sounds, while lower amplitude indicates softer sounds

loudness

the subjective perception of sound pressure and the attribute of the human ear and brain that orders sounds on a scale from quiet to loud

pitch perception

the brains interpretation of the frequency of sound waves, determining whether a sound is high or low in tone. higher frequencies are perceived as higher pitches while lower frequencies are perceived as lower pitches

place theory

idea that different parts of the inner ear detect different sound frequencies. high pitches are sensed near the entrance, low pitches at the end

volley theory

a theory of pitch perception proposing that groups of auditory neurons fire in rapid successions or “voileys” to encode the frequency of sounds above 1000 HZ. this allows the brain to perceive pitches that exceed the firing rate of individual neurons

frequency theory

a theory of pitch perception proposing the frequency of a sound wave directly corresponds to the rate at which auditory nerve fibers fire. higher frequency sounds lead to faster firing rates, resulting in higher perceived pitches

sound localization

the brains ability to determine the location of sound source in space. it relies on cues such as differences in arrival time and intensity between the ears. as well as spectral cues to accurately locate sound

conduction deafness

hearing impairment caused by problems with the outer or middle ear. such as damage to the ear canal, eardrum, or middle ear bones. it typically results in difficulty hearing soft sounds and can often be treated medically

sensorineural deafness

hearing loss caused by damage to the inner ear or auditory nerve. it results in difficulty hearing soft sounds and understanding speech and its often permanent common causes include aging, exposure to loud noise, and certain medical conditions

olfactory system

responsible for smell, special receptors in the nose detect smells and send signals to the brain via the olfactory nerve the thalamus helps process this information, allowing us to identify different odors

thalamus

a large, egg-shaped structure of gray matter located deep inside the center of the brain above the brainstem

pheromones

chemical substances released by animals, including humans that trigger social or behavioral responses in other of the same species

gustation

the sense of taste, involving receptors on the tongue that detect different flavors

sweet, sour, salty, bitter, umami, oleogustus

the five established basic tastes and the proposed sixth taste represent the primary chemical signaling systems detected by human taste receptors

taste receptors

specialized cells located on the tongue and in the mouth that detect different tastes

supertasters

highly sensitive to taste, experiencing flavors more intensely, especially bitterness

medium tasters

have an average sensitivity to taste, experiencing flavors moderately

nontasters

less sensitive to taste, experiencing flavors less intensely than others

sensory interaction

the interdependency and collective functioning of the senses to create a complete representation of the environment

warm/cold receptors

specialized sensory neurons in the skin that detect changes in temperature. warm receptors respond to increase in temperature while cold receptors respond to decreases. they help us perceive and regulate our body’s temperature

pain

a more difficult concept than others. it is in fact not a sensation but an emotional response to stimuli

gate control theory

a theory proposing that the experience of pain is modulated by a neural “gate” in the spinal cord this gate can open to allow pain signals to be transmitted to the brain or close to block them

phantom limb

sensation of pain or other feelings in a missing limb. it occurs due to the brains continued perception of the limb even though its no longer there. sensations can range from tingling to intense pain and are thought to result from the process of plasticity in the somatosensory cortex following amputation

vestibular sense

the sense of body orientation and movement, including balance and spatial awareness, it relies on receptors in the inner ear that detect changes in head position and movement, helping to maintain stability and coordinate bodily movements

semicircular canals

fluid-filled structures in the inner ear that detect rotational movements of the head. they play a crucial role in the vestibular sense, helping to maintain balance and coordination by sending signals to the brain about changes in head position and movement

kinesthesis

the sense of body movement and position, including the awareness of muscle joint sensations, it allows us to perceive and control our bodies movements, providing feedback to the brain about the position and orientation of body parts