Sensation
The process of receiving and processing sensory information from the environment.
Bottom-up Processing
The processing of sensory information starting from the basic features and building up to a complete perception.
Top-down Processing
The processing of sensory information using prior knowledge and expectations to interpret and make sense of the input.
Thresholds
Different levels of stimulation required for a sensory experience to be detected or recognized.
Absolute Threshold
The minimum amount of stimulation needed for a sensory experience to be detected 50% of the time.
Just Noticeable Difference (JND)
The smallest difference in stimulation that can be detected between two stimuli.
Weber's Law
The principle that the JND between two stimuli is proportional to the magnitude of the stimuli.
Subliminal
Below the threshold of conscious awareness.
Signal Detection Theory
A theory that explains how we make decisions about weak or ambiguous stimuli in the presence of background noise.
Gestalt Grouping
The tendency to perceive elements as organized wholes rather than individual parts.
Depth Perception
The ability to perceive the distance and three-dimensional characteristics of objects.
Monocular Depth Cues
Depth cues that can be perceived with one eye, such as relative size, texture gradient, and linear perspective.
Binocular Depth Cues
Depth cues that require both eyes, such as retinal disparity and convergence.
Nearsightedness
A condition in which nearby objects can be seen clearly, but distant objects appear blurry.
Farsightedness
A condition in which distant objects can be seen clearly, but nearby objects appear blurry.
Retina
The light-sensitive layer at the back of the eye that contains photoreceptor cells.
Fovea
The central area of the retina that is responsible for sharp central vision.
Rods
Photoreceptor cells in the retina that are responsible for different aspects of vision. Rods are more sensitive to dim light and are responsible for peripheral vision, while cones are responsible for color vision and visual acuity.
Bipolar & Ganglion Cells
Cells in the retina that transmit visual information from the photoreceptor cells to the optic nerve.
Color Vision Theories
Different theories that explain how we perceive and process color.
Trichromatic Theory
The theory that suggests that color vision is based on three types of cones that are sensitive to different wavelengths of light (red, green, and blue).
Opponent-Process Theory
The theory that suggests that color vision is based on three pairs of opposing color receptors (red-green, blue-yellow, black-white) that work in opposition to each other.
Theories of Hearing
Different theories that explain how we perceive and process sound.
Frequency vs
The theory that suggests that pitch is determined by the frequency of sound waves.
Hearing Loss
The partial or complete inability to hear sounds.
NIHL (Noise-Induced Hearing Loss)
Hearing loss caused by exposure to loud noises.
Conduction Deafness
Hearing loss caused by problems with the transmission of sound waves from the outer to the inner ear.
Sensorineural Deafness
Hearing loss caused by damage to the hair cells or auditory nerve.
Gustation
The sense of taste.
Olfaction
The sense of smell.
Somatic Sense
The sense of touch, including pressure, temperature, vibration, and pain.
Vestibular Sense
The sense of balance and spatial orientation.
Kinesthesis
The sense of body position and movement.
Perception of Movement
The ability to perceive and understand the motion of objects.
Stroboscopic Effect
The perception of motion in a rapid series of slightly different images.
Phi Phenomenon
The illusion of movement created by the rapid succession of stationary images.
Perceptual Constancy
The tendency to perceive objects as maintaining their size, shape, color, and brightness, despite changes in the sensory input.
Size Illusions
Illusions that distort our perception of the size of objects.
Ponzo Illusion
An illusion that makes two identical lines appear to be different lengths due to the presence of converging lines.
Muller-Lyer Illusion
An illusion that makes two identical lines appear to be different lengths due to the presence of arrow-like figures.
Moon Illusion
An illusion that makes the moon appear larger when it is near the horizon compared to when it is higher in the sky.
Perceptual Set
The tendency to perceive and interpret sensory information based on preexisting expectations and experiences.
Schema
Mental frameworks or structures that help organize and interpret incoming information.