AP Psychology Unit 1b Vocab

Sensation

the process by which our sensory receptors and nervous system receive and represent raw stimulus energy from our environment

Psychophysics

the quantitative study of the relationship between physical stimuli in the world and the psychological sensations and perceptions they produce

Sensory Receptors

specialized cells in the nervous system that detect environmental stimuli and convert them into neural signals

Signal Detection Theory

a psychological model that predicts how and when we detect a faint stimulus (signal) amidst background distraction (noise), based on personal factors like motivation, expectations, fatigue, and experience rather than a fixed biological absolute threshold

Absolute Threshold

the minimum intensity of a stimulus needed for a person to detect it 50% of the time

Just-Noticeable Difference

(Difference Threshold)

the minimum amount of change in a physical stimulus that a person can detect 50% of the time.

Weber’s Law

the just-noticeable difference (JND) between two stimuli is always a constant proportion of the original stimulus intensity

Sensory Adaptation

the diminished sensitivity to a constant, unchanging stimulus over time

Sensory Interaction

the principle that one sense can influence, affect, or work together with another sense to shape our overall perception

Synesthesia

a neurological condition where the activation of one sensory or cognitive pathway causes an automatic, involuntary experience in a different sensory or cognitive pathway

Embodied Cognition

the psychological theory that human thoughts, feelings, and learning are deeply shaped by physical bodily experiences and sensorimotor interactions with the environment

Subliminal

any sensory stimulus that falls below one’s absolute threshold for conscious awareness

Priming

an unconscious process where exposure to one stimulus affects how you respond to a later, related stimulus

Wavelengths

the distance from the peak (crest) of one light or sound wave to the peak of the next

Hue

the dimension of color determined by the wavelength of light

Intensity

the amount of energy in a light or sound wave, which is determined by the wave's amplitude (its height) and is perceived as brightness in vision or loudness in hearing

Cornea

the clear, protective outer layer on the front of the eye that bends light to help focus it

Pupil

the adjustable opening in the center of the eye through which light enters

Iris

the ring of muscle tissue that forms the colored portion of the eye and controls the size of the pupil opening

Retina

the light-sensitive inner surface at the back of the eye containing receptor cells (rods and cones) and layers of neurons that process visual information

Blind Spot

the point where the optic nerve leaves the eye, creating a small gap in vision because there are no receptor cells (rods or cones) located there

Visual Nerve (optic nerve)

the bundle of ganglion cell axons that carries neural impulses (visual information) from the retina of the eye to the brain

Lens

the transparent, flexible structure located behind the pupil that changes shape to focus light images onto the retina

Accommodation

modifying an existing mental framework—called a schema—or creating a brand-new one when new information does not fit what you already know

Nearsightedness

a vision condition where nearby objects appear clear, but distant objects look blurry because light focuses in front of the retina

Farsightedness

a vision condition where distant objects are seen clearly, but near objects appear blurry because images focus behind the retina instead of directly on it

Fovea

the central focal point in the retina of the eye around which cone cells cluster

Photoreceptors

specialized light-sensitive neurons located in the retina that convert light energy into neural impulses

Transduction

the process where specialized sensory receptors convert physical or chemical energy from the environment into electrochemical neural impulses that the brain can understand

Rods

photoreceptor cells located in the retina of the eye that detect black, white, and gray, and are essential for peripheral and night vision

Cones

photoreceptor cells in the retina that process color and sharp, detailed central vision in bright light

(Young-Helmholtz)

Trichromatic Theory

the retina contains three types of cone photoreceptors—each most sensitive to either short (blue), medium (green), or long (red) wavelengths of light

Opponent-Process Theory

the color vision theory stating that the visual system processes color in three opposing pairs: red-green, blue-yellow, and black-white

Feature Detectors

specialized nerve cells in the brain's visual cortex that respond to specific, individual features of a visual stimulus

Afterimages

a visual sensation that continues to appear in your vision after the original physical stimulus has been removed

Ganglion Cells

specialized neurons in the retina that receive visual signals from bipolar cells and bundle their axons together to form the optic nerve, which carries information to the brain

Dichromatism

a form of partial color blindness where a person has only two types of functional cone photoreceptors in the retina instead of the normal three, making it difficult to distinguish certain colors

Monochromatism

a rare form of total color blindness where an individual can only perceive the world in black, white, and shades of gray