Vision and Chemoreception (Psych 2113 Exam 2)

Sensory Transduction

The fundamental process by which specialized sensory receptor cells convert physical energy—such as light, sound, pressure, or chemical stimuli—into electrical neural signals (receptor potentials) that the brain can interpret

Sclera

The dense, opaque, white outer layer of the eyeball (It is crucial for nonverbal communication, acting as a "gaze signal" to indicate emotion, health, and social focus)

Iris

The colored, muscular disc surrounding the pupil (Controls the amount of light entering the eye by contracting or relaxing to adjust pupil size)

Pupil

The black circle in the center of the eye (Regulates the amount of light entering the eye)

Cornea

The transparent dome on the surface of the eye (Protects the eye from dirt, debris, and infections)

Lens

A transparent structure behind the iris and pupil (Focuses light onto the retina)

Accomodation

The cognitive process of modifying existing mental frameworks (schemas) or creating new ones to incorporate new information or experiences that do not fit into existing knowledge

Retina

The light-sensitive, neural tissue lining the back of the eye that acts as the initial stage of visual processing

Fovea

A small, central pit in the retina responsible for sharpest, high-acuity, and color vision

Optic Disc

The anatomical, light-insensitive spot on the retina where ganglion cell axons gather to form the optic nerve and exit the eye (Because it lacks photoreceptors (rods/cones), it creates a physiological blind spot in each eye's visual field)

Optic Nerve

A bundle of over one million retinal ganglion cell axons that transmits visual information (including brightness, color, and contrast)

Rods

Are highly sensitive to low light, enabling night and peripheral vision

Cones

Are concentrated in the fovea, responsible for color vision, high-acuity, and daylight vision

Scotopic Vision

The ability to perceive surroundings in low-light or dark conditions (below 0.01 cd/m²) using only the rod photoreceptors in the retina

Photopic

High-acuity, color-sensitive vision mediated by cone photoreceptors in the retina under bright light conditions (daylight)

Myopia

A common refractive vision condition where close objects appear clear, but distant objects are blurry

Hyperopia

A common refractive vision condition where distant objects are usually seen clearly, but close objects appear blurry

Cataracts

An age-related or traumatic clouding of the eye's normally transparent lens, resulting in, or risking, significant vision impairment or blindness

Retinitis Pigmentosa

A group of rare, inherited genetic eye disorders characterized by the progressive degeneration of photoreceptor cells (rods and cones) in the retina

Trichromatic Theory

Human eye has three different types of cone photoreceptors, each sensitive to different wavelengths of light

Opponent Process Theory

The perception of color is based on three opposing pairs (Red vs. green, blue vs. yellow, and black vs. white)

Primary Visual Cortex

Located in the occipital lobe around the calcarine sulcus; responsible for the initial processing of visual information

Ventral Stream

Runs to the temporal lobe, specializing in object recognition, shape, color, and form

Dorsal Stream

Runs to the parietal lobe, focusing on motion, spatial location, and guiding actions like reaching and grasping

Prosopagnosia

A neurological and cognitive disorder characterized by a severe inability to recognize familiar faces, including those of close friends, family, or one's own reflection

Olfactory Epithelium

A specialized, pseudo-stratified sensory tissue located in the roof of the nasal cavity, responsible for detecting odors and initiating the sense of smell

Olfactory Bulbs

A neural structure in the forebrain that acts as the brain's first processing center for smell

Mitral Cells

The primary projection neurons and main output channels of the olfactory bulb in the mammalian brain

Olfactory Glomeruli

Spherical, dense neuropil clusters in the olfactory bulb acting as the first processing stage for smell

Primary Olfactory Cortex

A largely three-layered region of the brain's temporal lobe (primarily the piriform cortex) that acts as the initial cortical destination for odor signals directly from the olfactory bulb

Pyriform/Piriform Cortex

The largest component of the primary olfactory cortex, primarily responsible for odor perception, identification, and the neural coding of scent

Papillae

Small, raised structures on the tongue's surface that contain taste buds, playing a vital role in gustatory perception (taste)

Taste Buds

Primarily located on the tongue's papillae that contain receptor cells, which detect chemical molecules in food and drink to enable the perception of 5 basic tastes

Insula Operculum

It is considered a crucial brain hub for interoception (the sense of the body’s internal state) subjective feelings, self-awareness, and emotion regulation

Frontoparietal Operculum

It functions as a, cortical region that integrates sensory input with motor output and cognitive control