ITP - CHAPTER 1, 2, 3 & 4

Sensation

The activation of receptors in various sense organs, leading to the perception of stimuli.

Sensory sensation

biological, activate neural nerves/sensory neurons

Sensory Receptors

Specialized forms of neurons that respond to different kinds of energy rather than neurotransmitters.

Transduction

The process of converting outside stimuli into neural activity.

Just noticeable difference (jnd)

The minimum difference between two stimuli that can be detected 50% of the time, also known as just noticeable difference (jnd).

Absolute threshold

the smallest amount of energy needed for a person to consciously detect a stimulus 50% of the time it is present

Subliminal Stimuli

Stimuli that are below the level of conscious awareness but can still activate sensory receptors.

Limin

threshold

sublimin

below the threshold

Habituation

The brain's tendency to stop attending to constant, unchanging information.

Sensory Adaptation

tendency of sensory receptors cells to become less responsive to a stimulus that is unchanging

Microsaccades

Constant movement of the eyes; tiny little vibrations that people do not notice consciously

Prevent sensory adaptation to visual stimuli

Saccadic Movements

Brightness

Determined by the amplitude of light waves; higher amplitude results in brighter light.

Color or Hue

Determined by the length of light waves; longer wavelengths correspond to red, while shorter wavelengths correspond to blue.

Saturation

The purity of a color; mixing with black or gray reduces saturation.

Cornea

The clear membrane covering the eye that focuses light and protects it.

Lasik

vision - improving techniques that make small incisions in the cornea to change the focus in the eye

Aqueous Humor

Visual layer below cornea

Clear, watery fluid that is continually replenished

Supplies nourishment to the eye

Pupil

Hole through which light from the visual image enters the interior of the eye

Iris

Round muscle (the colored part of the eye) in which pupil is located

Can change the size of the pupil, letting more or less light into the eye

Help focus the image (squinting)

Lens

A clear structure behind the iris that finishes the focusing process of light.

Visual Accommodation

The change in thickness of the lens as the eye focuses on objects at varying distances.

Vitreous humor

Jelly-like fluid that also nourishes the eye and gives it shape

Nearsightedness or Myopia

The shape of the eye causes the focal point to fall short of the retina

Farsightedness or hyperopia

The focus points is behind the retina

Retina

The final stop for light in the eye

Photoreceptors that respond to various light waves

Rods

Visual sensory receptors found at the back of the retina

Responsible for noncolor sensitivity to low levels of light

Cones

Visual sensory receptors found at the back of the retina

Responsible of color vision and sharpness of vision

Blind Spot

Area in the retina where the axons of the three layers of retina cells exit the eye to form the optic nerve; insensitive to light

Light passess through ______ and _______ until it reaches and stimulates the rods and cones. Nerve impulses from the rods and cones travel along a nerve pathway to the brain.

ganglion

bipolar cells

Dark Adaptation (rod)

The recovery of the eye’s sensitivity to visual stimuli in darkness after exposure to bright lights

Light Adaptation (cones)

The recovery of the eye's sensitivity to visual stimuli in light after exposure to darkness.

Trichromatic Theory

A theory of color vision proposing three types of cones:red, blue, and green.

Opponent-Process Theory

Theory of color vision that proposes four primary colors with cones arranged in pairs: red and green, blue and yellow

Afterimages

images that occur when a visual sensation persists for a brief time even after the original stimulus is removed

Monochrome Colorblindness

A condition in which a person’s eyes either have no cones or have cones that are not working at all

Red-Green Colorblindness

Either the red or the green cones are not working

Sex-linked inheritance

Gene for color-deficient vision is recessive

one recessive chromosome

male

two recessive chromosome

female

sound

vibration of molecule of air

Wavelength

Interpreted as frequency or pitch of sound.

Amplitude

Interpreted as the volume of sound.

Purity

Interpreted as timbre

Hertz

Cycle or waves per second, a measurement of frequency

Auditory Canal

The short tunnel leading from the outer ear to the eardrum.

pinna

visible, external parts of the ear

Eardrum

Thin section of skin that tightly covers the opening into the middle part of the ear

Smallest bones in the human being

hammer

anvil

stirrup

Cochlea

A snail-shaped structure in the inner ear filled with fluid.

Organ of Corti

Rests in the basilar membrane

Contains receptor cells for sense of hearing

Auditory Nerve

Bundle of axons from the hair cells in the inner ear

Receives neural messages from the organ of Corti

Transduction

Transformation of the vibration of sound into neural message

Pitch

Psychological experience of sound that corresponds to the frequency of the sound waves

Place Theory

Theory of pitch that states that different pitches are experienced by the stimulation of hair cells in different locations on the organ of Corti

Frequency Theory

Theory of pitch that states that pitch is related to the speed of vibrations in the basilar membrane

Volley Principle

Theory of pitch that states that frequencies from about 400 Hz up to 4000 Hz causes the hair cells (auditory neurons) to fire in a volley pattern, or take turns in firing

Cochlear Implant

A microphone implanted just behind the ear the picks up sound from the surrounding environment

Taste Buds

Taste receptor cells in mouth; responsible for sense of taste

Gustation

The sensation of a taste

Five basic tastes

Sweet, Sour, Salty, Bitter, Brothy or Umami

Taste

called as chemical sense because it works with molecules of food

Olfaction

The sense of smell

Olfactory bulbs

Areas of the brain located just above the sinus cavity and just below the frontal lobes that receive info from the olfactory receptor cells

Somesthetic Senses

The body senses consisting of the skin senses, the kinesthetic senses, and the vestibular senses

soma

body

esthetic

feeling

skin senses

sensation of touch, pressure, temperature, and pain

Sensory receptors in the skin

Gate-control theory

pain signal must pass through a “gate” located in the spinal cord

Kinesthetic Sense

Sense of the location of body parts in relation to the ground and each other

Proprioceptive receptors (proprioceptors)

Vestibular Senses

The sensations of movement, balance, and body position.

sense of balance

Sensory Conflict Theory

An explanation of motion sickness in which the info from the eyes conflicts with the info from the vestibular senses

Perception

method by which the sensations experienced at any given moment are interpreted and organized in some meaningful fashion

Size Constancy

tendency to interpret an object as always being the same actual size, regardless of its distance

Shape Constancy

tendency to interpret the shape of an object as being constant, even when its shape changes on the retina

Brightness Constancy

tendency to perceive the apparent brightness of an object as the same even when the light conditions change

Gestalt

Put them together to perceive as a whole

Figure-ground

The tendency to perceive objects, or figures, as existing on a background

Reversible figures

Visual illusion in which the figure and ground can be reversed

Proximity

perceive objects that are close to each other as part of the same groupings

Similarity

perceive things that look similar to each other as being part of the same group

Closure

Tendency to complete figures that are incomplete

Continuity

Tendency to perceive things as simply as possible with a continuous pattern rather than with a complex, broken up pattern

Contiguity

Tendency to perceive two things that happen close together in time being related

Depth Perception

The ability to perceive the world in three dimensions

Monocular Cues

Cues for perceiving depth based on one eye only

Linear perspective

tendency for parallel lines to appear to converge on each other

Relative size

Perception that occurs when objects that a person expects to be of a certain size appear to be small and are, therefore, assumed to be far away

Aerial (atmospheric) perspective

The haziness that surrounds objects that are farther away from the viewer, causing the distance to be perceived as greater

Texture gradient

tendency for textured surfaces to appear to become smaller and finer as distance from the viewer increases

Motion parallax

The perception of motion of objects in which close objects appear to move more quickly than objects that are farther away

ventriloquists

make vocalization without opening mouth

Binocular Cues

Cues for perceiving depth based on both eyes

Convergence

The rotation of the two eyes in their sockets to focus on a single object, resulting in greater convergence for closer objects and lesser convergence for closer objects and lesser convergence if objects are distant

Binocular disparity:

The difference in images between the two eyes, which is greater for objects that are close and smaller for distant objects

Hermann grid

Possibly due to the response of the primary visual cortex

Muller-Lyer illusion

Illusion of line length that is distorted by inward-turning or outward-turning corners on the ends of the lines, causing lines of equal length to appear to be different

Moon Illusion

The moon on the horizon appears to be larger than the moon in the sky

Autokinetic effect:

a small, stationary light in a darkened room will appear to move or drift bcs there are no surrounding cues to indicate that the light is not moving

Stroboscopic motion

Seen in motion pictures, in which a rapid series of still pictures will appear to be in motion

Individual features are put together