Final: Lectures

Question 1

equation for spatial frequency

Answer 1

1/ ___ cpd (cycles per degree).

Question 2

Equation for contrast of sinusoidal grating

Answer 2

(Imax-Imin)/(Imax + Imin)

Question 3

Equation for contrast sensitivity

Answer 3

S = 1/T

Question 4

What are factors that might develop that would underly the improvement in infant contrast sensitivity seen over time?

Answer 4

cones, ability to accommodate
and converge, ability to attend, changes in cortical neurons

Question 5

a condition that leads to abnormal flow of
information from the eyes to visual cortex - all of the signals from each eye reach the
hemisphere on the same side of the head, and overlapping retinotopic maps for the two sides of the visual field develop in each hemisphere

Answer 5

Achiasma

Question 6

How is sound transmitted?

Answer 6

Sound is transmitted via an oscillating pressure wave through a medium (air/water).

Question 7

logarithm decibel scale to specify sound
pressure

Answer 7

dB = 20 * log10 (p/p 0 )

Question 8

How loud a sound is perceived as goes up with its pressure amplitude.

Answer 8

Perceived loudness

Question 9

How can a sound waveform be formed?

Answer 9

as a sum of sinusoidal sound waves
of varying frequency, amplitude, and timing.

Question 10

We call as sinusoidal sound wave a _____________.

Answer 10

pure tone

Question 11

How are pure tones characterized?

Answer 11

by its frequency and amplitude

Question 12

The lowest frequency tone is called the ?

Answer 12

fundamental or sometimes the first harmonic.

Question 13

How is the timbre of a sound determined?

Answer 13

The timbre of a sound of this sort is determined by the relative intensities of the fundamental and the various harmonics

Question 14

The perceived pitch of a pure tone is determined ?

Answer 14

by its frequency.

Question 15

the structure of the inner ear that transduces vibration into neural signals. It is filled with fluid, and when the fluid transmits a sound wave it causes vibration in the basilar membrane.

Answer 15

The cochlea

Question 16

Equation for computing ITD

Answer 16

ITD = rsin(theta) + rtheta
The second term, theta must be in radians
(radians = 2pidegs/360),

Question 17

What are social cues for distance?

Answer 17

sound level, attenuation of high frequencies, movement parallax, fraction of sound that is reflected (most useful indoors)

Question 18

the ability to focus on a single stimulus, such as a conversation, while filtering out other sounds in a noisy environment

Answer 18

cocktail party phenomenon

Question 19

The shortest sound segments that convey
meaning, are distinguished by place of articulation, whether the sound is
voiced or not, and the voice onset time (VOT)

Answer 19

Phonemes

Question 20

TRUE OR FALSE: Infants can make
the phonemic distinctions used in all languages, but then lose the ability to make those that aren’t relevant as they learn their native language(s)

Answer 20

TRUE

Question 21

actively amplify signals in the cochlea and
sharpen frequency tuning. One aspect of hearing loss is caused by damage to outer
hair cells, which leads to less frequency tuning of auditory nerves.

Answer 21

Outer hair cells

Question 22

Deafness can be ameliorated by inserting electrodes into the cochlea to electrically stimulate auditory nerve fibers - an auditory prosthesis

Answer 22

Cochlear implants

Question 23

Signals from each type of taste cell tend to
produce percepts of the corresponding taste

Answer 23

Fundamental tastes

Question 24

These mice prefer normally bitter tasting substances more than normal mice. This supports the idea that signals coming out of individual taste cells are driving very specific tastes

Answer 24

Transgenic mice with bitter receptors in sweet taste cells

Question 25

The miraculin in mBerries binds to sweet receptors without activating them directly, but activates these receptors when a normally sour tastant is ingested. We tried this and found that a sour lemon tasted quite sweet after eating the mBerry. This also supports the idea that signals coming out of individual taste cells are driving very specific tastes

Answer 25

mBerry demonstration

Question 26

Causes taste dysfunction. It appears to infect cells that support the taste cells and causes the taste cells to function less well or not at all. However, after recovery, taste receptors regenerate and in most cases taste is restored.

Answer 26

COVID 19

Question 27

Humans can follow a scent trail, and get better at it with practice. We do this better when we can use both nostrils, suggesting that our ability to localize scents is mediated in part by comparing signals from the two nostrils.

Answer 27

Odor localization

Question 28

- Fast adaptation - Small receptive field - RA1 = FA I

Answer 28

Meissner corpuscles

Question 29

- Slow adaptation - Small receptive field - SA1 = SA I

Answer 29

Merkel cell complexes

Question 30

- Slow adaptation - Large receptive field - SA2 = SA II

Answer 30

Ruffini endings

Question 31

- Fast adaptation - Large receptive field - RA 2 = FA II

Answer 31

Pacinian Corpuscles

Question 32

- continuously signal pressure - responding to presence of pressure

Answer 32

slow adapting

Question 33

- responding to changes in pressure - better at sensing vibration

Answer 33

fast adaptation

Question 34

Known for fine acuity

Answer 34

Merkel disks

Question 35

- thought to be related to hand control - slow motion across skin

Answer 35

Meissner corpuscles

Question 36

known to be about how skin is stretching as we move

Answer 36

Ruffini endings

Question 37

- sensitive to vibration - bulb absorbs continuous pressure but transmits rapid vibration

Answer 37

Pacinian Corpuscles

Question 38

Thought to mediate social touch

Answer 38

Hair cell receptors

Question 39

TRUE OR FALSE: negative decibels correspond to vibration amplitudes less than the reference amplitude

Answer 39

TRUE

Question 40

The Merkel receptors appear to mediate detection at __________ frequencies

Answer 40

low

Question 41

Meissner appear to mediate detection receptors at ___________ frequencies

Answer 41

intermediate

Question 42

The Pacinian appear to mediate detection at ___________ frequencies

Answer 42

high

Question 43

Equation for sensitivity

Answer 43

S = 1 / T where T is the threshold amount of force

Question 44

How can tactile acuity be measured?

Answer 44

by determining two-point threshold, smallest separation where you can tell two points from one

Question 45

Where is tactile acuity highest? where is it the lowest?

Answer 45

highest on the tips of the fingers and lower on the arms and trunk of the body.

Question 46

Signals go to spinal cord, then the thalamus, and then cortical area S1. S1 is right next to primary motor cortex. There is a somatotopic organization of sensation in S1 (somatosensory homunculus), meaning that nearby parts of the body are represented in nearby parts of S1. There is also a magnification of the cortical representation of some parts of the body (e.g., hands, lips), corresponding roughly to the variation in density of mechanoreceptors

Answer 46

Pathways for touch

Question 47

Part of the somatosensory system is proprioceptive receptors that detect tension in muscles and tendons as well as joint positions. These are critical for us to control our body movements. There are proprioceptive spinal reflexes that (e.g.) cause is to tighten a muscle when a tendon is pulled.

Answer 47

Proprioception

Question 48

Perception of pain is critical for avoiding bodily harm.

Answer 48

Pain