Some Sensation and Perception for review

Sensation

the initial steps in the perceptual process, whereby physical features of the environment are converted into electrochemical signals that are sent to the brain for processing

senses

physiological functions for converting particular environmental features into electrochemical signals

Perception

the later steps in the perceptual process, whereby the initial sensory signals are used to represent objects and events so they can be identified, stored in memory, and used in thought and action.

representations

information in the mind and brain used to identify objects and events, to store them in memory, and to support thought and action

Stimuli

the objective and events that are perceived (distal stimuli) and the physical phenomena they produce (proximal stimuli)

neurons

cells of the nervous system that produce and transmit information carrying signals

sensory receptors

Specialized cells unique to each sense organ that respond to a particular form of sensory stimulation.

top-down information

an observer's knowledge, expectations, and goals, which can affect perception

bottom-up information

the information contained in neural signals from receptors, the actual neural information that is processed as perception

Psychophysics

a field of study concerned with relating psychological experience to physical stimuli

human senses

vision, audition (hearing), tactile perception (touch), proprioception (body perception), nocioception (pain perception), Thermoreception (temperature perception), balance, body movment, olfaction (smell), gustation (taste)

Synapse

a tiny gap between the axon terminal of one neuron and the dendrite or cell body of another neuron

absolute threshold

the minimum intensity of stimulation that must occur before you experience a sensation

difference threshold (just noticeable difference)

the minimum difference between two stimuli that allows an observer to perceive that the two stimuli are different

Weber's Law

a statement of the relationship between the intensity of a standard stimulus and the size of the just noticeable difference (JND = kI, where i is the intensity of the standard stimulus and the k is a constant that depends on the perceptual dimension being measured)

acuity

a measure of how clearly fine detail is seen by the eye.

retina

the inner membrane of the eye, made up of neurons, including the photoreceptors that convert the light entering the eye into neural signals

cornea

a transparent mebrane at the front of the eye; light enters the eye by first passing through the cornea, which sharply refracts the light

iris

the colored part of the eye- a small circular muscle with an opening in the middle middle (the pupil) through which light enters the eye.

lens

a transparent structure near the front of the eye that refracts the light passing through the pupil so that the light focuses properly on the retina. elpitical due to zonule fibers streching it and reound when taken out.

ciliary muscle

tiny muscles attached to the choroid; they relax and contract to control how the choroid pulls on the zonule fibers to change the shape of the lens

accommodation

adjustment of the shape of the lens so light from objects at different distances focuses correctly on the retina

retinal image

a clear image on the retina of the optic array

Rods

one of the two human photo receptors, named for their distinctive shape.

provide Light sensitivity and "black-and-white" vision in dim light

120,000,000 Rods in your retina.

fovea

a region in the center of the retina where the light from objects at the center of our gaze strikes the retina; contains no rods and a very high density of cones

Cateracts

a progressive 'clouding' of the lens that can, if left untreated, lead to blindness

Continuity

we perceive smooth, continuous patterns rather than discontinuous ones

Gestalt

Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes.

Schema

a concept or framework that organizes and interprets information

Perception

the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

Gustation

the sensation of taste

Olfaction

our sense of smell

olfactory bulb

the first brain structure to pick up smell information from the nasal cavity

olfactory epithelium

a thin layer of tissue, within the nasal cavity, that contains the receptors for smell

semicircular canals and vestibule

sensory organs of balance; provides sensory information about the body's position to maintain equilibrium

cochlea

a coiled, bony, fluid-filled tube in the inner ear through which sound waves trigger nerve impulses

Cones

concentrated near the center of the retina (fovea) and that function in daylight or in well-lit conditions. detect fine detail and give rise to color sensations. "Color, Clarity, and in the Center" only 6 to 7 million cones (far fewer than rods)

Fovea

the central focal point in the retina, where the eye's cones are clustered

Rods

Specialized visual receptors that play a key role in night vision and peripheral vision. detect light

Nocioceptors

nerve ending responsive to the sense of "pain"

Timbre

quality of sound

pitch

How "high" or "low" a sound is perceived

decibel

A unit used to compare the loudness of different sounds.

Frequency

the number of complete wavelengths that pass a point in a given time

selective attention

the focusing of conscious awareness on a particular stimulus

sensory adaptation

diminished sensitivity as a consequence of constant stimulation

sensory restriction

The loss of the use of one or more of the senses.

Saccades

quick eye movements from one fixation point to another

trichromatic theory

theory of color vision that proposes three types of cones: red, blue, and green

binocular cues

depth cues, such as retinal disparity and convergence, that depend on the use of two eyes

monocular cues

depth cues, such as interposition and linear perspective, available to either eye alone

sound localization

we can locate sounds based on which ear they strike first

endorphines are

released during exercise and pain; block the perception of pain (endogenous morphine)

kinesthesis

the sense of movement and body position

Extra sensory perception (ESP)

the controversial claim that perception can occur apart from sensory input; includes telepathy, clairvoyance, and precognition

percentage of people colorblind (statistically)

8% male; 1% female

Red-Green Colorblind

The most common form of colorblindness

Yellow-Blue Colorblind

Very rare colorblindness.

specific hair cells (in inner ear) that are stimulated

The place theory of pitch suggests that pitch is determined by the ________.

anosmia

inability to smell.

somatic senses

senses of touch, temperature, pain, and kinesthesia

Pinna

outer ear

Pappilae

taste buds