Sensation and Perception

Flashcards covering sensation, perception, vision, hearing, touch, chemical senses, vestibular and kinesthetic senses, perception thresholds, perceptual theories, Gestalt rules, constancy, and depth cues.

Sensation

Experience of sensory stimulation; the activation of our senses.

Perception

Process of creating meaningful patterns from raw sensory information.

Cornea

The transparent protective coating over the front part of the eye.

Pupil

Small opening in the iris through which light enters the eye.

Iris

Colored part of the eye.

Lens

Transparent part of the eye inside the pupil that focuses light onto the retina.

Retina

Lining of the eye containing receptor cells that are sensitive to light.

Transduction

Process by which sensory signals are transformed into neural impulses.

Receptor cell

Specialized cell that responds to a particular type of energy.

Rods

Receptor cells in the retina responsible for night vision and perception of brightness.

Cones

Receptor cells in the retina responsible for color vision.

Fovea

Area of the retina that is the center of the visual field.

Optic nerve

The bundle of axons of ganglion cells that carries neural messages from each eye to the brain.

Blind spot

Place on the retina where the axons of all the ganglion cells leave the eye and where there are no receptors

Optic chiasm

Point near the base of the brain where some fibers in the optic nerve from each eye cross to the other side of the brain

Trichromatic theory

Theory of color vision that holds that all color perception derives from three different color receptors in the retina

Opponent-process theory

Theory of color vision that holds that three sets of color receptors respond in an either/or fashion to determine the color you experience

Colorblindness

Partial or total inability to perceive hues.

Trichromats

People who have normal color vision

Monochromats

People who are totally color blind

Dichromats

People who are blind to either red-green or yellow-blue

Amplitude

The height of the wave , determines the loudness of the sound, measured in decibels

Frequency

The number of cycles per second in a wave; in sound, the primary determinant of pitch

Hertz (Hz)

Cycles per second; unit of measurement for the frequency of waves

Pitch

Auditory experience corresponding primarily to frequency of sound vibrations, resulting in a higher or lower tone

Decibel

The magnitude of a wave; in sound the primary determinant of loudness of sounds

Ear canal

Also called the auditory canal

Hammer, anvil, stirrup

The three small bones in the middle ear that relay vibrations of the eardrum to the inner ear

Oval window

Membrane across the opening between the middle ear and inner ear that conducts vibrations to the cochlea

Round window

Membrane between the middle ear and inner ear that equalizes pressure in the inner ear.

Cochlea

Part of the inner ear containing fluid that vibrates which in turn causes the basilar membrane to vibrate.

Basilar membrane

Vibrating membrane in the cochlea of the inner ear; it contains sense receptors for sound

Organ of Corti

Structure on the surface of the basilar membrane that contains the receptors cells for hearing

Auditory nerve

The bundle of neurons that carries signals from each ear to the brain

Place theory

Theory that pitch is determined by the location of greatest vibration of the basilar membrane

Frequency theory

Theory that pitch is determined by the frequency with which hair cells in the cochlea fire

Conductive Hearing Loss

Sound vibrations from the tympanic membrane to the inner ear are blocked.

Sensorineural Hearing Loss

Occurs when there is damage to the vestibulocochlear (auditory) nerve.

Presbycusis

Occurs because of changes in the inner ear; common in older age.

Tinnitus

People with tinnitus hear a constant ringing or roaring sound.

Gate control theory

Theory that a ‘neurological gate in the spinal cord controls the transmission of pain messages to the brain

Papillae

Humans sense four different tastes: sweet, salty, sour, and bitter

Umami

A fifth basic taste that occurs when foods with glutamate (like MSG) are eaten.

Taste bud

The actual organ of taste.

Olfactory epithelium

Nasal membranes containing receptor cells sensitive to odors

Pheromone

Chemical that communicates information to other organisms through smell

Semicircular canals

Structure in the inner ear particularly sensitive to body rotation.

Vestibular sacs

Sacs in the inner ear that are responsible for sensing gravitation and forward, backward, and vertical movement

Stretch receptors

Receptors that sense muscle stretch and contraction

Golgi tendon organs

Receptors that sense movement of the tendons, which connect muscle to bone.

Absolute threshold

The least amount of energy that can be detected as a stimulation 50 percent of the time

Subliminal

Stimuli below our absolute threshold

Difference threshold

The smallest change in stimulation that can be detected 50 percent of the time

Just-noticeable difference

The smallest amount of change needed in a stimulus before we detect a change

Weber’s Law

The principle that the just noticeable difference for any given sense is a constant proportion of the stimulation being judged.

Signal detection theory

Investigates the effects of the distractions and interference we experience while perceiving the world.

Top-Down Processing

We perceive by filling in gaps in what we sense

Bottom-up Processing

We use only the features of the object itself to build a complete perception

Size constancy

Perception of an object as the same size regardless of the distance from which it is viewed

Shape constancy

Tendency to see an object as the same shape no matter what angle it is viewed from

Brightness constancy

Perception of brightness as the same, even though the amount of light reaching the retina changes

Monocular cues

Visual cues requiring the use of one eye

Interposition

Monocular distance cue in which one object, by partly blocking a second object, is perceived as being closer.

Linear perspective

Monocular cue to distance and depth based on the fact that two parallel lines seem to come together at the horizon

Binocular cues

Visual cues requiring the use of both eyes

Retinal disparity

Binocular distance cue based on the difference between the images

Convergence

Cast on the two retinas when both eyes are focused on the same object

Stereoscopic vision

Combination of two retinal images to give a three-dimensional perceptual experience.