Week 6

Question 1

Corollary Discharge Theory

Answer 1

Definition: movement perception depends on three signals:

Motor, Corollary discharge, image displacement

Question 2

Motor signal (MS)

Answer 2

signal sent to eyes to move eye muscles

Question 3

Movement is perceived when ____ (an evaluation unit) receives either a ___, ____.

Answer 3

comparator; CDS; IDS

Question 4

Corollary discharge signal (CDS)

Answer 4

identical copy of the motor signal
○ Informs the brain about the intentional eye movement.

Question 5

Image displacement signal (IDS)

Answer 5

movement of image stimulating receptors across the retina.

Question 6

Movement is perceived when we have either CDS or IDS. T or F

Answer 6

T

Question 7

STS Superior Temporal Sulcus

Answer 7

Biological motion is processed by sts and ffa

Question 8

Evidence for sts

Answer 8

Transcranial magnetic stimulation (TMS) applied to STS caused a decrease in ability to detect biological motion.
● Result: This temporary lesion interrupted brain functioning and decreased accuracy on the task.

Question 9

Sound

Answer 9

Sound is the experience we have when we hear.

Question 10

Physical definition of sound

Answer 10

● Sound is pressure changes in the air (or other medium).
● Condensation: Higher levels of local air pressure.
● Rarefaction: Decreased regions/ Lower levels of air pressure.
● Sound wave: The pattern of changes in pressure across a space.

Question 11

Timbre

Answer 11

• “quality” of a sound
• allows us to distinguish between different musical instruments playing the same pitch at the same loudness.

Question 12

Perception of timbre is influenced by

Answer 12

Attack: how quickly a note reaches its maximum volume after being played
- Fast attack (piano note) sounds more abrupt vs. Slow attack (bowing of a violin) sounds more gradual

Decay: How quickly the sound diminishes after the initial peak
- Guitar string (rapid decay) vs. Organ (long decay)

Different harmonics: Different instruments have different harmonic content for the same pitch

Question 13

Pure tones

Answer 13

• Perceived as a single note without any harmonics or overtones
• Simplest form of a sound wave

Question 14

Complex tones:

Answer 14

• A combination of multiple frequencies with various harmonics or overtones
• Give the tone its timbre

Question 15

Additive Synthesis:

Answer 15

• Constructs complex tones by adding together pure tones at different frequencies

Question 16

Signal Decomposition

Answer 16

Fourier Analysis: breaks down a complex waveform into a series of sine waves
that sum up to the original waveform.

Question 17

Fundamental frequency

Answer 17

• The lowest frequency in a complex tone
• Determines the pitch of the note

Question 18

Missing Fundamental Effect

Answer 18

• Perceived pitch: periodicity pitch; when a harmonic or the fundamental frequency is lost, the perceived pitch remains the same due to the effect of the missing fundamental.
• Consistent fundamental frequency
• The spacing of the harmonics and the repetition rate of the waveform carry the pitch information related to the fundamental frequency.

Question 19

Audibility Curve

Answer 19

• The minimum sound pressure level that the average human ear can detect at each frequency
• Humans are most sensitive to sounds in curve dips in the 2-5 kHz range

Question 20

Equal Loudness Curves:

Answer 20

• A set of curves that illustrate the ear’s sensitivity to different frequencies at various loudness levels
• The ear is less sensitive to very low and very high frequencies.

Question 21

In the sound stimulus, greater condensation of air molecules would correspond to

Answer 21

higher amplitude

Question 22

If a sound level meter measures 0 decibels (dB), this means no sound signal is present.

Answer 22

False

Question 23

The decibel scale relates physical pressure in the sound wave to the psychological experience of loudness. This scale demonstrates ____________________ as we attempt to estimate the magnitude of the physical stimulus.

Answer 23

response compression

Question 24

Perceived tone height corresponds to which of the following physical dimensions of sound?

Answer 24

Frequency

Question 25

What physical property of the sound signal does the perception of timbre correspond to most directly?

Answer 25

complexity

Question 26

The maximum frequency that a healthy, 20-year old person with normal hearing can detect is as high as:

Answer 26

20,000 Hz

Question 27

Sound amplitude is related to perceived loudness of a signal. If you play different frequencies at the same amplitude (intensity), they must have the same perceived loudness.

Answer 27

False

Question 28

Which of the ossicles is attached to the tympanic membrane?

Answer 28

Malleus

Question 29

Amplitude

Answer 29

Sound pressure level that corresponds to perceived loudness (for a given frequency).

Question 29

tone height

Answer 29

The perceptual experience of increasing pitch that happens when frequency is increased.

Question 30

Frequency

Answer 30

umber of cycles per second in which the sound pressure repeats corresponds to perceived pitch.