Unit 2 AP Psychology Terms

Sensation

• Process by which our sensory receptors and nervous system receive + represent stimulus energies from environment

Perception

• Process of organizaing and interpreting sensory info to make sense of the world

• Brain interprets sensory inputs

• Can be influenced by past experiences, expectations, and context

Transduction

• Conversion of sensory stimuli into neural impulses that can be understood by brain

• Physical energy → electrochemical signals

• Allows brain to interpret and perceive sensory information

Absolute Threshold

• Minimum amount of stimulation for stimuli to be detected by sensory system

• Point at which stimulus becomes noticeable (at least 50% of the time)

Just-Noticeable Difference (JND)

• Smallest change in stimulus that one can detect

• Minimal difference needed for a person to perceive that a change has occurred

Weber’s Law

• Perceived difference in stimulus must be proportional to original intensity of stimulus

• Bigger something is, more you need to change it to notice a difference

Sensory Adaptation

• Process where sensory receptors become less responsive to constant stimulus over time

Synesthesia

• Condition where stimulation of one sensory pathway leads to automatic, involuntary experiences in another sensory pathway

Retina

• Light-sensitive inner surface of the eye

• Contains photoreceptor cells that convert light → neural signals

Rods

• Photorecepor cells in the retina

• Responsible for vision in low light conditions and detecting motion

• Provides black-and-white vision and is highly sensitive to light

Cones

• Photoreceptor cells in the retina

• Responsible for color vision and detail in bright light

• Enables us to perceive colors and fine visual details (reading and distinguishing different hues)

Fovea

• Central area of the retina

• Responsible for sharp central vision

• Contains high concentration of cone cells but no rods

• Enables detailed and colored vision

Blind Spot

• Area on retina where optic nerve exits the eye

• Lacks photoreceptor cells

• Spot where vision is absent due to no light-sensitive cells to detect visual stimuli

Ganglion Cells

• Neurons in the retina that receives visual information from bipolar cells

• Transmits them to the brain via optic nerve

• Helps process visual signals

• Sends visual signals to brain for further interpretation

Lens

• Transparent structure in the eye

• Role is to focus light onto the retina

• Adjusts shape to help eye properly refract light, enabling clear vision

Accommodation

• Process by which lens of the eye changes shape to focus on objects at different distances

• Allows for nearby and distant clear vision

• Adjusts curvature of the lens

Nearsightedness

• Common vision condition where close objects appear clear & distant objects appear blurry

• Happens when eye is too long or cornea is too curved

• Causes light to focus in front of the retina instead of on it

Farsightedness

• Vision condition where distant objects are more clear than close ones

• Happens when eyeball is too short or cornea is too flat

• Causes light to focus behind the retina instead of on it

Trichromatic Theory

• Theory proposing that color vision is based on 3 types of cone receptors

• Each are sensitive to different light wavelengths

• Brain combines signals from these cones to create perception of wide range of colors

Opponent-Process Theory

• Theory proposing that color vision is based on pairs of opposing color process

  • (Blue + yellow, red + green, black + white)

• Activation of one color inhibits the other

• Leads to perception of color afterimages

• Explains certain aspects of color vision

Afterimages

• Visual sensations that persist after a stimulus is removed

• Occur due to temporary overstimulation of cone cells in retina

• Results in brief perception of inverted/complementary images

Dichromatism

• Type of color vision defiency

• Individuals affected only have 2 types of functioning cone cells (instead of 3)

• Results in difficulty distinguishing between certain colors

Monochromatism

• Rare form of color blindness

• Individual only has one type of functioning cone cell or none at all

• Results in inability to perceive colors

• Sees the world in shades of gray

Blindsight

• Phenomenon affecting individuals with damaged visual cortex

• They can respond to visual stimuli without consciously perceiving them

• Suggests that visual processing can occur unconsciously

• Bypasses traditional pathways in the brain

Prosopagnosia

• Neurological condition characterized by the inability to recognize familiar faces

• Happens despite intact vision and intellect

• Referred to as face blindness

Wavelength

• Distance between sound wave peaks

• Shorter wavelengths → higher-pitch

• Longer wavelengths → lower-pitch

Amplitude

• Measure of intensity/loudness of a sound wave

• Represented by height of its peaks

• Greater amplitudes → louder sounds

• Lower amplitudes → softer sounds

Pitch Perception

• Brain’s interpretation of frequency of sound waves

• Determines if sound is high/low in tone

• Higher frequencies → higher pitches

• Lower frequencies → lower pitches

Place Theory

• Idea that different parts of inner ear detect different sound frequencies

• High pitches sensed near entrance

• Low pitches sensed near the end

Frequency Theory

• Theory proposing that frequency of sound wave directly corresponds to rate at which auditory nerve fibers fire

• Higher frequency → faster firing rates

Volley Theory

• Theory proposing that groups of auditory neurons fire in rapid succession (“volleys”)

• Allows brain to encode frequencies above 1000Hz

Sound Localization

• Brain’s ability to determine location of sound source in a space

• Relies on cues like differences in arrival time, intensity between the ears, and spectral cues

Conduction Deafness

• Hearing impairness caused by problems to outer or middle ear

• Damage to ear canal, eardrum, or middle ear bones

• Results in difficulty hearing soft sounds and can be treated medically/surgically (temporary)

Sensorineural Deafness

• Hearing loss caused by damage to inner ear or auditory nerve

• Results in difficulty hearing soft sounds and understanding speech

• Often permanent

• Caused by aging, exposure to loud noises, and certain medical conditions