Princeton Review Psychology Gre - Chapter 10 (Sensation)

Front 1

Reception

Back 1

- Takes place when receptors for a particular sense detect a stimulus.
- The RECEPTIVE FIELD is the part of the world that triggers a particular neuron.

Front 2

Sensory Transduction

Back 2

- the process in which physical sensation is changed into electrical messages that the brain can understand.
- The heart of sensation

Front 3

Light

Back 3

- Composed of PHOTONS and WAVES measured by brightness and wavelengths.
- HUE (color) is the dominant wavelength of light. Brightness is the physical intensity.

Front 4

Cornea

Back 4

- the clear protective coating on the outside of the eye

Front 5

Lens

Back 5

- located behind the cornea
- CILIARY MUSCLES allow it to bend (ACCOMODATE) in order to focus an image onto the retina

Front 6

Retina

Back 6

- located on the back of the eye
- receives light images from the lens
- is composed of about 132 million photoreceptor cells and of other cell layers that process information

Front 7

Receptor cells (rods and cones)

Back 7

- are responsible for sensory transduction
- this happens through the chemical alteration of PHOTOPIGMENTS

Front 8

Rods

Back 8

- are particularly sensitive to dim light and night vision
- concentrated along the edges of the retina

Front 9

Cones

Back 9

- concentrated in the center of the retina (FOVEA)
- particularly sensitive to colro and daylight vision
- cones see better than rods because there are fewer cones per ganglion cell than rods per ganglion cell

Front 10

Fovea

Back 10

- the area of the retina with the greatest visual acuity

Front 11

What happens to light after it passes through the receptors?

Back 11

- it travels through the HORIZONTAL CELLS to the BIPOLAR CELLS to the AMACRINE CELLS
- some information processing probably takes place along the way
- finally, the information heads to the GANGLION CELLSm which make up the optic nerves

Front 12

Visual Pathway

Back 12

- consists of one optic nerve connecting each eye to the brain
- along the pathway is the OPTIC CHIASM in which half of the fibers from the optic nerve of each eye cross over and join the optic nerve from the other eye
- after the optic chiasm the information travels through the STRIATE CORTEX to the VISUAL ASSOCIATION AREAS of the cortex

Front 13

Opponent-Color (opponent-process)

Back 13

- proposed by EWALD HERING
- suggests that two types of color-sensitive cells exist: cones that respond to blue-yellow and those that respond to red-green
- when one color of hte pair on a cone is stimulated, the other is inhibited

Front 14

Tri-Color theory

Back 14

-proposed by Thomas Young and Herman von Helmholtz
- suggests that there are three types of receptors in the retina: red, blue, or green

Front 15

Opponent-Color vs Tri-Color

Back 15

- research shows that opponent-process theory seems to be at work in the LATERAL GENICULATE BODY, whereas the Tri-Color theory seems to be at work in the RETINA.

Front 16

Lateral inhibition

Back 16

- allows the eye to see contrast and prevents repetitive information from being sent to the brain
- this complex process is the idea that once one receptor cell is stimulated the others nearby are inhibited

Front 17

Hermann von Helmholtz

Back 17

- famous for a theory of color blindness

Front 18

Daivd Hubel and Torsten Wiesel

Back 18

- discovered that cells in the visual cortex are so complex and specialized that they respond only to certain types of stimuli
- e.g. some cells respond only to vertical lines, whereas some respond only to right angles and so on

Front 19

Amplitude

Back 19

- physical intensity of a sound wave that largely determines LOUDNESS

Front 20

Frequency

Back 20

- the pace of vibrations or sound waves per second for a particular sound that determines PITCH
- frequency is measured in hertz (Hz), and humans best hear frequencies around 1,000 Hz

Front 21

Timbre

Back 21

- comes from the complexity of the sound wave

Front 22

Outer ear

Back 22

- consists of PINNA and the AUDITORY CANAL

Front 23

Middle ear

Back 23

- begins with the tympanic membrane (also known as the ear-drum), which is stretched across the auditory canal
- behind this membrane are the ossicles (three small bones - malleus, incus and stapes)
- sound vibrations bump against the tympanic membrane, causing the ossicles to vibrate

Front 24

Inner ear

Back 24

- responsible for both hearing and balance
- begins in the OVAL WINDOW, which is tapped upon by the stapes
- these vibrations then active the fluid-filled, snail-shell-like COCHLEA, which contains the ear parts for hearing (the BASILAR MEMBRANCE and the ORGAN OF CORTI)
- the movement of the coclear fluid activate steh hair-cell receptors on the basilar membrance and the organ of corti
- this movement is called the TRAVELING WAVE

Front 25

Vestibular sacs

Back 25

- part of the inner ear
- sensitive to tilt and provide our sense of balance

Front 26

Auditory system that leads to the auditory cortex

Back 26

- consists of the OLIVARY NUCLEUS, the INFERIOR COLLICULUS, and the MEDIAL GENICULATE BODY

Front 27

Hermann von Helmholtz and hearing

Back 27

- famous for the PLACE-RESONANCE THEORY of sound perception, in which different parts of the basilar membrane respond to different frequencies

Front 28

Sound localization

Back 28

- is achieved in different ways
- the degree to which one of our ears hears a sound prior to and more intensely than the other can give us information about the origin of sound
- specifically, high-frequency sounds are localized by intensity differences, whereas low-frequency sounds are localized by phase differences

Front 29

Olfaction

Back 29

- small is an extremely primitive sense
- hair receptors in the nostrils send their messages to the olfactory bulb, which lies at the base of the brain
- smell has been strongly connected to memory and the perception of taste

Front 30

Gustation

Back 30

- humans distinguish four basic tastes: sweet, bitter, sour, and salt
- saliva mixes with food, so that the flavor can flow easily into the tongue's taste receptors
- taste receptors are called taste buds (or PAPILLAE)

Front 31

Free nerve endings

Back 31

- in the skin they detect pain and temperature changes

Front 32

Meissner's corpuscles

Back 32

- receptors in skin that detect touch or contact

Front 33

Two-point threshold

Back 33

- for touch it is the shortest space between to points of contact that can be detected
- is largely determined by the density and layout of nerves in the skin

Front 34

Physiological zera

Back 34

- the temperature that is sensed as neither warm nor cold

Front 35

Ronald Melzack and Patrick Wall's GATE CONTROL THEORY OF PAIN

Back 35

- looks at pain as a process rather than just a simple sensation goverened in one center in the brain
- Melzack and Wall assert that pain perception is related to the interaction of large and small nerve fibers that run to and from the spine
- pain may or may not be perceived depending on different factors, including cognition

Front 36

Endorphins

Back 36

- neuromodulators that kick in to reduce or eliminate the perception of pain

Front 37

Orienting reflex

Back 37

- the tendency to turn toward an object that has touched you

Front 38

Kinesthetic sense (proprioception)

Back 38

- information from receptors in joints and muscles that tells us about the positioning of our own body

Front 39

Osmoreceptors

Back 39

- deal with thirst