Sensation and Perception: Color, Depth, Hearing, and Chemical Senses

Vocabulary practice flashcards covering color vision theories, depth cues, auditory physiology, and the chemical senses of taste and smell based on lecture notes.

Newton’s Prism Experiment

An experiment determining that prisms do NOT change or create the color of light but only separate the wavelengths; Findings showed light angles bend differently, supporting the presence of wavelengths.

Selective Reflection

Wavelengths that are reflected off of solid objects within a certain band of visible light wavelengths.

Selective Transmission

Light that passes through liquid, representative of a certain band of visible light wavelengths.

Subtractive Color Mixing

Occurs when an object reflects major wavelengths and absorbs (subtracts) others; for example, mixing blue (subtracts large wavelengths) and yellow (subtracts small wavelengths) leaves only the medium wavelength, which is green.

Additive Color Mixing

The mixing of light on light where adding all colors results in white light because it encompasses all wavelengths.

Spectral Colors

Colors produced by a SINGLE wavelength; includes red, orange, yellow, green, blue, and violet.

Color Saturation

The intensity of color; intensity is decreased by adding white.

Color Value

The relative lightness or darkness of a color.

Munsell Color System

A system featuring a ring of color hues (spectral colors) where the y axis represents saturation and the x axis represents color value.

Trichromatic Theory of Color

The Young-Helmoholtz theory stating that color vision depends on three different photoreceptors/cones with short, medium, and long wavelength sensitivity.

Maxwell’s Color Matching Experiment

An experiment where adjusting the amounts of three primary wavelengths allowed any color to be created from a reference light.

Microspectrophotometer

A device that allows the measurement of the number of action potentials from one photoreceptor from a specific wavelength of light.

Red Wavelength

Long wave sensitivity measuring approximately $558\,nm$.

Green Wavelength

Medium wavelength sensitivity measuring approximately $531\,nm$.

Blue Wavelength

Short wavelength sensitivity measuring approximately $419\,nm$.

Foveal Cone Mosaic

A structural arrangement of cones reactive to certain sizes of wavelengths; for white light, all three cone types fire at the same time.

Monochromatism

A genetic disorder characterized by having NO functioning cones, perceiving only shades of grey, and having NO fovea, requiring reliance on the periphery.

Dichromats

Individuals with only two types of cones; most common in males as it is associated with the X chromosome and is recessive.

Ishihara Plates

Circles with colored numbers used to test for color blindness and identify which cone type is missing.

Protranopia

A form of color blindness where the LONG wavelength pigment is missing, making the individual unable to see red and green.

Deuteranopia

A form of color blindness where the MEDium wavelength pigment is missing, resulting in an inability to see reds and greens.

Tritanopia

A form of color blindness where the SHORT wavelength pigment is missing, resulting in an inability to see yellows and greens.

Opponent Process Theory

Theory stating that color vision is based on pairs of opposite colors (Red-green, yellow-blue) via opponent neurons that are excitatory for one color and inhibitory for the other.

Afterimage Illusions

Illusions occurring because photoreceptor cells become temporarily fatigued or desensitized due to overstimulation.

Color Constancy

A perceptual mechanism allowing the brain to recognize an object's true color regardless of changes in light conditions.

Oculomotor Cues

Information about object distance derived from eye muscle tension and eye position.

Convergence

The inward movement of the eyes that occurs when looking at close objects.

Accommodation

The process by which the lens changes shape to focus on objects at different distances (depth).

Monocular Cues (MC)

$2D$ depth cues that only require one eye to function.

Binocular Cues (BC)

$3D$ depth cues requiring both eyes, utilized because each eye sees a different perspective (retinal disparity).

Pictorial Cues (PC)

Cues used by artists to provide a sense of depth in flat images.

Occlusion

A Monocular/Pictorial Cue where a partially hidden object appears farther away.

Relative Height

A Monocular/Pictorial Cue where objects higher up on the ground or lower in the sky are perceived as farther away; the closer to the horizon, the farther the object.

Relative Size

A Monocular/Pictorial Cue where, if two objects are assumed to be the same size, the one appearing smaller is perceived as farther away.

Familiar Size

A Monocular/Pictorial Cue where knowledge of an object's actual size influences depth judgment.

Perspective Convergence

A Monocular/Pictorial Cue where parallel lines appear to converge at far distances.

Atmospheric Perspective

A Monocular/Pictorial Cue where close objects appear sharp and detailed, while farther objects appear hazy due to air particles.

Texture Gradient

A Monocular/Pictorial Cue where equally spaced objects appear more densely packed as they get farther away.

Motion Parallax

A depth cue where closer objects appear to fly by quickly while farther objects move slower or seem to move with you.

Deletion and Accretion

The covering and uncovering of objects as they move, providing depth information.

Retinal Disparity

A Binocular Cue involving the difference between images received by both eyes, which identifies depth through stereoscopic vision.

Horopter

An imaginary semi-circle where images fall on corresponding points of the two retinas.

Uncrossed Disparity

Occurs when images are farther behind the horopter and do NOT cross the fovea in the difference of angles between retinas.

Crossed Disparity

Occurs when images are in front of the horopter and DO cross the fovea.

Binocular Depth Cells

Neurons in V1 and MT of monkeys that receive input from both retinas and fire in response to retinal disparity.

Size Constancy

Top-down processing where the perceived size of an object remains constant irrespective of distance when depth cues are available.

Muller-Lyer Illusion

An illusion where lines of equal length appear different due to depth cues, leading to differing perceived distances despite identical retinal images.

Ponzo Illusion

An illusion of size based on converging lines representing depth.

Sound (Physical Description)

Pressure changes in the air.

Amplitude

The height of the soundwave which indicates perceived loudness; non-linear and requires large differences to be perceived.

Decibels ($db$)

The physical measurement unit of loudness.

Frequency

The number of waves per second that determines pitch.

Hertz ($Hz$)

The measurement of frequency, defined as $1\,Hz$ = $1$ cycle per second.

Fourier Analysis

A process that breaks down complex waves into simple pure tone sound waves to identify which pure tones are present.

Harmonics

The breakdown of complex sounds into their component frequencies.

Fundamental Frequency

The lowest frequency of a complex periodic sound, such as 'middle C'.

Audibility Curve

The threshold of hearing representing the quietest sound level required to hear a specific frequency.

Threshold of Feeling

Sound levels so loud they cause pain and potential damage; immediate hearing loss occurs at $>120\,db$.

Timbre

The perceptual quality of a sound.

Resonance

The function of the ear canal as an acoustic chamber that amplifies specific sound frequencies.

Tympanic Membrane

Also known as the eardrum; it vibrates and causes the ossicles to vibrate.

Ossicles

Three bones (Stapes, Incus, Malleus/not listed) that enhance vibrations to transfer them to the liquid in the cochlea to move hair cells.

Organ of Corti

Structure inside the cochlea responsible for auditory mechanotransduction, converting mechanical vibrations into electrical nerve impulses.

Base of Cochlea

The part of the cochlea closest to the ossicles; it is stiff/ridged and reacts to higher frequencies.

Apex of Cochlea

The part of the cochlea farthest from the ossicles; it is flexible/soft and reacts to lower frequencies.

Cilia

Fine hairs that bend; bending to the right ONLY causes action potentials.

Bekey’s Place Theory of Hearing

The theory that frequency is determined by the maximum firing rate of specific locations on the cochlea (tonotopic map).

Superior Olivary Nucleus

Part of the auditory pathway in the brain stem where cochlear information from each ear is connected for sound location.

Presbycusis

Hearing loss caused by hair cell damage due to noise exposure and age; most prominent at highest frequencies and affects males more.

Neurogenesis

The process by which neural stem cells divide and differentiate to produce new functional neurons.

Anosmia

The lack of the ability to smell.

Papillae

Ridges and valleys on the tongue's surface (not the tastebuds themselves).

Fungiform Papillae

Mushroom-shaped papillae located on the tips and sides of the tongue that hold tastebuds on top.

Filiform Papillae

Papillae covering the entire tongue that do NOT contain tastebuds.

Taste Buds

Approximately $10,000$ structures located on the tongue, each containing $50-100$ taste cells.

Chorda Tympani Nerve

Transmits taste signals from the front and sides of the tongue (fungiform and foliate papillae).

Supertasters

Individuals with a higher density of taste buds.

Microsmatic

Having a less keen sense of smell, typical of humans who can identify $~100,000$ smells.

Macrosmatic

Having a highly keen sense of smell, typical of dogs ($10,000\times$ more sensitive than humans).

Olfactory Mucosa

A region in the nasal cavity containing receptors; mucus and hairs trap most particles before they reach here.

Olfactory Receptor Neurons (ORN)

Receptors for olfaction where transduction occurs; there are approximately $400$ different kinds.

Glomeruli

Small structures in the olfactory bulb that each receive input from $10,000$ ORN axons of one specific type.

Pheromones

Chemicals that cause a reaction in other members of the same species.

Amygdala

A limbic system area involved in emotional responses, located near the olfactory bulb, allowing for evolutionary-relevant avoidance behaviors.