Chapter 5; Sensation and Perception

good continuation

(also, continuity) we are more likely to perceive continuous, smooth flowing lines rather than jagged, broken lines

peak

(also, crest) highest point of a wave

Why don't all sensations result in perception?

Although our perceptions are built from sensations, not all sensations result in perception.

afterimage

continuation of a visual sensation after removal of the stimulus

vestibular sense

contributes to our ability to maintain balance and body posture

transduction

conversion from sensory stimulus energy to action potential

binocular cue

cue that relies on the use of both eyes

monocular cue

cue that requires only one eye

lens

curved, transparent structure that provides additional focus for light entering the eye

hertz (Hz)

cycles per second; measure of frequency

congenital deafness

deafness from birth

Ruffini corpuscles

deep pressure and stretch

just noticeable difference

difference in stimuli required to detect a difference between the stimuli

place theory of pitch perception

different portions of the basilar membrane are sensitive to sounds of different frequencies

tympanic membrane

eardrum

perceptual hypothesis

educated guess used to interpret sensory information

cochlear implant

electronic device that consists of a microphone, a speech processor, and an electrode array to directly stimulate the auditory nerve to transmit information to the brain

Taste (gustation) and smell (olfaction) are chemical senses that

employ receptors on the tongue and in the nose that bind directly with taste and odor molecules in order to transmit information to the brain for processing. Our ability to perceive touch, temperature, and pain is mediated by a number of receptors and free nerve endings that are distributed throughout the skin and various tissues of the body.

conductive hearing loss

failure in the vibration of the eardrum and/or movement of the ossicles

inattentional blindness

failure to notice something that is completely visible because of a lack of attention

sensorineural hearing loss

failure to transmit neural signals from the cochlea to the brain

Gestalt psychology

field of psychology based on the idea that the whole is different from the sum of its parts

cochlea

fluid-filled, snail-shaped structure that contains the sensory receptor cells of the auditory system

The eye's lens focuses this light so that the image is focused on a region of the retina known as the

fovea. The fovea contains cones that possess high levels of visual acuity and operate best in bright light conditions. Rods

congenital insensitivity to pain (congenital analgesia)

genetic disorder that results in the inability to experience pain

taste bud

grouping of taste receptor cells with hair-like extensions that protrude into the central pore of the taste bud

amplitude

height of a wave

top-down processing

interpretation of sensations is influenced by available knowledge, experiences, and thoughts

wavelength

length of a wave from one peak to the next peak

In general, how does light wavelength affect sensation?

light wavelength is associated with perception of color

photoreceptor

light-detecting cell

retina

light-sensitive lining of the eye

decibel (dB)

logarithmic unit of sound intensity

trough

lowest point of a wave

Meissner's corpuscles

m

subliminal message

message presented below the threshold of conscious awareness

incus

middle ear ossicle; also known as the anvil

malleus

middle ear ossicle; also known as the hammer

stapes

middle ear ossicle; also known as the stirrup

absolute threshold

minimum amount of stimulus energy that must be present for the stimulus to be detected 50% of the time

sensory adaptation

not perceiving stimuli that remain relatively constant over prolonged periods of time

frequency

number of waves that pass a given point in a given time period

monaural cue

one-eared cue to localize sound

principle of closure

organize perceptions into complete objects rather than as a series of parts

closure

organizing our perceptions into complete objects rather than as a series of parts

neuropathic pain

pain from damage to neurons of either the peripheral or central nervous system

deafness

partial or complete inability to hear

linear perspective

perceive depth in an image when two parallel lines seem to converge

pitch

perception of a sound's frequency

proprioception

perception of body position

kinesthesia

perception of the body's movement through space

optic chiasm

point at which optic nerve fibers cross in the brain

blind spot

point where we cannot respond to visual information in that portion of the visual field

visible spectrum

portion of the electromagnetic spectrum that we can see

Ménière's disease

results in a degeneration of inner ear structures that can lead to hearing loss, tinnitus, vertigo, and an increase in pressure within the inner ear

figure-ground relationship

segmenting our visual world into figure and ground

olfactory receptor

sensory cell for the olfactory system

Sensation occurs when

sensory receptors detect sensory stimuli. Perception involves the organization, interpretation, and conscious experience of those sensations.

nociception

sensory signal indicating potential harm and maybe pain

inflammatory pain

signal that some type of tissue damage has occurred

binocular disparity

slightly different view of the world that each eye receives

interaural timing difference

small difference in the time at which a given sound wave arrives at each ear

fovea

small indentation in the retina that contains cones

pupil

small opening in the eye through which light passes

interaural level difference

sound coming from one side of the body is more intense at the closest ear because of the attenuation of the sound wave as it passes through the head

temporal theory of pitch perception

sound's frequency is coded by the activity level of a sensory neuron

timbre

sound's purity

cone

specialized photoreceptor that works best in bright light conditions and detects color

rod

specialized photoreceptor that works well in low light conditions

vertigo

spinning sensation

bottom-up processing

system in which perceptions are built from sensory input

umami

taste for monosodium glutamate

thermoception

temperature perception

basilar membrane

thin strip of tissue within the cochlea that contains the hair cells which serve as the sensory receptors for the auditory system

similarity

things that are alike tend to be grouped together

proximity

things that are close to one another tend to be grouped together

Ruffini corpuscle

touch receptor that detects stretch

Pacinian corpuscle

touch receptor that detects transient pressure and higher frequency vibrations

Merkel's disk

touch receptor that responds to light touch

Meissner's corpuscle

touch receptor that responds to pressure and lower frequency vibrations

cornea

transparent covering over the eye

binaural cue

two-eared cue to localize sound

pinna

visible part of the ear that protrudes from the head

perception

way that sensory information is interpreted and consciously experienced

sensation

what happens when sensory information is detected by a sensory receptor

signal detection theory

change in stimulus detection as a function of current mental state

pheromone

chemical message sent by another individual

opponent-process theory of color perception

color is coded in opponent pairs: black-white, yellow-blue, and red-green

trichromatic theory of color perception

color vision is mediated by the activity across the three groups of cones

iris

colored portion of the eye

Why are taste and smell considered chemical senses? When we describe a flavor of a food, what we are really describing?

Taste (gustation) and smell (olfaction) are called chemical senses because both have sensory receptors that respond to molecules in the food we eat or in the air we breathe. There is a pronounced interaction between our chemical senses. For example, when we describe the flavor of a given food, we are really referring to both gustatory and olfactory properties of the food working in combination.

Using the anatomical terms, explain how the physical sound is transformed into a signal in our brains.

The activation of hair cells is a mechanical process: the stimulation of the hair cell ultimately leads to activation of the cell. As hair cells become activated, they generate neural impulses that travel along the auditory nerve to the brain. Auditory information is shuttled to the inferior colliculus, the medial geniculate nucleus of the thalamus, and finally to the auditory cortex in the temporal lobe of the brain for processing.

How does wave frequency impact our perceptual experience of sound?

The frequency of a sound wave is associated with our perception of that sound's pitch. High-frequency sound waves are perceived as high-pitched sounds, while low-frequency sound waves are perceived as low-pitched sounds.

How does the amplitude of a sound wave impact our perceptual experience with respect to loudness?

The loudness of a given sound is closely associated with the amplitude of the sound wave.

Can you compare and contrast the theories of pitch perception?

The place theory of pitch perception suggests that different portions of the basilar membrane are sensitive to sounds of different frequencies.

What is the difference between top-down and bottom-up processes?

Top-down process; expectations are used to recognize stimuli Bottom-up process; sense basic features of the stimuli

What are the differences between rods and cones?

While cones are concentrated in the fovea, where images tend to be focused, rods, another type of photoreceptor, are located throughout the remainder of the retina.

optic chiasm

X-shaped structure that sits just below the brain's ventral surface; represents the merging of the optic nerves from the two eyes and the separation of information from the two sides of the visual field to the opposite side of the brain

pattern perception

ability to discriminate among different figures and shapes

depth perception

ability to perceive depth

electromagnetic spectrum

all the electromagnetic radiation that occurs in our environment

hair cell

auditory receptor cell of the inner ear

olfactory bulb

bulb-like structure at the tip of the frontal lobe, where the olfactory nerves begin

optic nerve

carries visual information from the retina to the brain