Chapter 5: Sensation and Perception

Question 1

What is sensation?

Answer 1

The process of receiving, converting, and transmitting informaiton from the outside world to the brain

Question 2

What is perception?

Answer 2

The process of slecting, organizing, and interpreting sensory data

Question 3

What are sensory receptors and transduction?

Answer 3

Sensory receptors:
Neurons that detect and convert their energy into neural impulses

Transduction:
The process of converting energy into a neural impulse

Question 4

What are absolute and difference sensory thresholds?

Answer 4

Absolute threshold:
The minimum amount of stimulation that a person can detect

Difference threshold:
The minimum amount of change in stimulation that can be detected
* Sometimes known as “just noticeable difference.”

Question 5

What is a subliminal message?

Answer 5

Messages that are present below the threshold for coscious awareness

Question 6

What are bottom-up and top-down processing?

Answer 6

Bottom-up:
when we sense basic features of stimuli and then integrate them
* listening to a friend until a crashing sound draws attention

Top-down:
when previous experience and expectations are used to recognize a stimuli
* Looking for yellow items because you lost your yellow keys

Question 7

What is sensory adaptation?

Answer 7

We often don’t perceive stimuli that remain relatively constant over prolonged periods of time

Question 8

What is inattentional blindness?

Answer 8

The failure to notice something that is completely visible because the person was attending to something else and not paying attention

Question 9

What is the signal detection theory

Answer 9

The inability to identify a stimulus when it is embedded in a distracting background

Thinking your phone rang while you were in the shower, but it didn’t

Question 10

What are the stimulus and receptors for sight?

Answer 10

Stimulus:
Electromagnetic energy (ex. light energy)

Receptors:
Photoreceptors (rods, cones)

Question 11

What are the photoreceptors in the eye?

Answer 11

Cones
* 7-8 million
* center (fovea) of retina
* low sensitivity
* sensitive to color

Rods
* 120-125 million
* periphery of retina
* high sensitivity
* not sensitive to color

Question 12

What is the optic nerve?

Answer 12

Carries visual information from the retina to the brain

Question 13

What is the optic chasm?

Answer 13

Where the optic nerve in both eyes cross at the front of the brain
It’s where informaiton from the right visual field (in both eyes) is passed to the left side of the brain, etc.

Question 14

What is the face module?

Answer 14

There may be a “face module” in the right temporal lobe that responds maximally to faces

Question 15

What are the trichromatic and opponent-process theories of color vision?

Answer 15

Trichromatic theory of color vision:
All colors in the spectrum can be produced by combining red, green, and blue cones
* Each of the three types of cones are receptive to one of the colors

Opponent-process theory:
color is coded in opponent pairs
* Black-white
* Yellow-blue
* Green-red
* This theory suggests that some cells of the visual system are excited by one of the opponent colors, and inhibited by the other
* Afterimage: the continuation of a visual sensation after removal of the stimulus

Question 16

What is gestalt psychology?

Answer 16

The brain creates a perception that is more than simply the sum of available sensory inputs

Question 17

What is the figure-ground relationship and the perceptual hypothesis?

(Gestalt)

Answer 17

Figure-ground relationship:
we tend to segment our visual world into figure and ground
* Figure is the object or person that is in focus of the visual field, while the ground is the background

Perceptual hypotheses:
educated guesses that we make while interpreting sensory information

Question 18

What are the different ideas of Gestalt?

(Prox., similarity, law of cont., principle of closure, pattern percep.)

Answer 18

Proximity:
things close together tend to be grouped together

Similarity:
similar things tend to be grouped together

Law of continuity:
we are more than likely to perceive continuous, smooth flowing lines rather than jagged, broken lines

Principle of closure:
we organize our perceptions into complete objects rather than a series of parts

Pattern perception:
our ability to discriminate among different figures and shapes

Question 19

How does touch work?

Answer 19

Neural impulses from the skin go to the thalamus (relay station) and then to the somatosensory cortex of the brain.

Question 20

How does touch sensitivity work?

Answer 20

Touch sensitivity depends on the concentration of receptors (such as lips or fingertips)

Question 21

What are the two types of pain?

Answer 21

Inflammatory pain:
pain that signals some type of tissue damage
Neuropathic pain:
pain that results from damage to neurons of either the peripheral or central nervous system.
As a result, signals that are sent to the brain are exaggerated

Question 22

What is congenital analgesia?

Answer 22

a genetic condition where a person cannot feel pain

Question 23

What are the main pain receptors?

Answer 23

A-delta fibers that carry sharp or prickling pain.
C-fibers that carry dull or burning pain.

Question 24

What are bradykinin and glatamate’s relationship to pain?

Answer 24

Bradykinin:
A chemical substance that accumulates at the site of an injury or inflammation

Glutamate:
Neurotransmitter that affects pain receptors in the brain, the spinal cord, and the body.

Question 25

What is the gate control theory? | (pain)

Answer 25

* Pain impulses must get through the "gate" located in the spinal cord * Pain messages are either blocker or alowed to proceed to the brain * The brain can control the gate

Question 26

What is the periaqueductal gray area?

Answer 26

is an important pain inhibiting center. It releases enkephalin (a natural analgesic).

Question 27

What are pain control methods?

Answer 27

**Acupucture:** * Inserting needles into various sites * may affect endorphins and/or the limbic system **Transcutaneous electral nerve stimulation (TENS):** * Might relieve pain by stimulating endorphines and/or inhibit activity at the pain gate **Hypnosis:** * Does not appear to work via stimulating endorphins * Blocks pain impulses at the spinal cord pain gate

Question 28

What are the stimulus and receptors for hearing?

Answer 28

**Stimulus:** Sound waves **Receptors:** hair cells on the basilar membrane in the inner ears

Question 29

What is the hearing process?

Answer 29

1. **Neural impulse** is sent via **auditory nerve** to the **brainstem** 2. Then it goes to the **midbrain** 3. Then it goes to the **thalamus** 4. Finally, to the **primary auditory cortex (temporal lobe)**

Question 30

How is loudness measured?

Answer 30

Measured via decibels: 30 = quiet library 60 = conversation 100 = chain saw

Question 31

How it pitch measured?

Answer 31

Measured in hertz: High frequency sound waves = high pitched sounds The audible range of sound frequencies is between 20 and 20,000 Hz

Question 32

What is the basilar membrane?

Answer 32

A thin strip of tissue within the cochlea

Question 33

What is timbre?

Answer 33

The quality/purity of a sound

Question 34

What are the temporal/frequency theory of pitch perception and the place theory of pitch perception?

Answer 34

**Frequency/temporal theory of pitch perception:** The entire basilar membrane is stimulated and the analysis of it occurs in the auditory cortex **Place theory of pitch perception:** Different frequencies and intensities affect different places on the basilar membrane AND the analysis of it occurs in the auditory cortex * **High-pitch receptors:** base of the basilar membrane * **Low-pitch receptors:** the tip of the basilar membrane

Question 35

What is sound localization?

Answer 35

The auditory system uses monaural (one-eared) and binaural (two-eared) cues to localize sound **Interaural level difference:** the fact that a sound coming from the right side of your body is more intense at your right ear than at your left ear because of the attenuation of the sound wave as it passes through your head **Interaural timing difference:** small difference in the time at which a given sound wave arrives at each ear

Question 36

What are the types of hearing loss? | (congenital, conductive, sensorineural, meniere's)

Answer 36

**Deafness:** the partial or complete inability to hear **Congenital deafness:** being born without hearing **Conductive hearing loss:** hearing loss due to a problem delivering sound energy to the cochlea **Sensorineural hearing loss:** can be caused by many factors such as aging, head trauma, infections and diseases, medications, noise exposure, tumors, and toxins * Most common type of hearing loss **Meniere’s disease:** results in a degeneration of the inner ear structures that can lead to hearing loss, tinnitus, vertigo, and an increase in pressure within the inner ear

Question 37

What are the taste stimulus and receptors?

Answer 37

**Stimulus:** Chemical substances dissolved in saliva **Receptors:** Taste buds on the tongue * Taste buds only last 10-14 days

Question 38

What are the five tastes?

Answer 38

Sweet, salty, sour, bitter and (potentially) umami (Japanese word for yummy) (MSG)

Question 39

What is the process of taste?

Answer 39

1. **taste buds** --> to the 7th, 9th, and 10th **cranial nerves** 2. then goes to the **medulla** and into the **pons** (taste area) 3. then goes to the **thalamus** 4. finally, it goes to the **frontal lobes**

Question 40

What are the stimulus and receptors for smell (olfaction)

Answer 40

**Stimulus:** Chemical substances in the air **Receptors:** Olfactory receptor cells in the nasal mucosa

Question 41

What is the smell process?

Answer 41

1. from the top of the nasal cavity, **neural impulses** are sent to the **olfactory bulbs** 2. then to the **olfactory cortex (forebrain)** 3. then to the **amygdala, olfactory tubercle, septal area, hippocampus, and reticular formation**

Question 42

What are pheromones?

Answer 42

substances/chemical messages believed to cause sexual stimulation especially in animals

Question 43

What are proprioception and kinesthesia?

Answer 43

**Proprioception:** perception of body position **Kinesthesia:** perception of the body’s movement in space

Question 44

What is the vestibular sense?

Answer 44

contributes to our ability to maintain balance and body pressure (sense of body orientation) * Vestibular sacs and semicircular canals in the inner ear