[Deck 4 - Vision and sound]

Question 1

How do optic flow calculations affect our speed perception?

Answer 1

If you’re walking faster (treadmill) than you’re actually moving (tractor) –> distances seem further away

Question 2

How do bees use optic flow?

Answer 2

~ to tell other bees where the food is @
~ closer to ground = more optic flow –> affects dance
~ uses sun’s position to give directions to food + take into account sun’s movement

Question 3

What % of our body weight is the rain and what % energy does it use?

Answer 3

2% weight

20% energy usage

Question 4

Self-Optimisation

Answer 4

the unconscious change of behaviour to become more efficient and reduce energy consumption
e.g. gait transition

Question 5

What is the optimum gradient of mountain paths?

Answer 5

~ 15 degree hill = 15 degree zig zag

~ hill < 15 degree = just go straight up

Question 6

Frequency

Answer 6

rate of air pressure modulation
~ related to pitch (more wave = higher)
~ no. of cycles per second

Question 7

Amplitude

Answer 7

sound pressure level
~ related to loudness (higher waves = louder)
~ distance between wave peak & atmospheric pressure (middle)

Question 8

What type of wave represents a sound wave>

Answer 8

Sin wave (0,0)

Question 9

Transduction

Answer 9

the method by which we transform physical stimulus into a neural signal

Question 10

The longer the cochlea…

Answer 10

… the more frequencies heard

Question 11

Which part of the cochlea detects high frequencies?

Answer 11

near the oval window

scarf demo

Question 12

Which part of the cochlea detects low frequencies?

Answer 12

near the end

scarf demo

Question 13

How does the cochlea implant work?

Answer 13

~ it stimulates the auditory nerve where the hair cell would have
~ sound processor outside of ear
~ internal implant wich has electrode running through cochlea

Question 14

What’s a safe noise level?

Answer 14

85 decibels for 8hrs a day = busy traffic

Question 15

What range of sound can humans hear?

Answer 15

20-20,000 Hz

Question 16

Which animals can hear ultrasound?

Answer 16

Elephants, bats & dolphins

40,000-160,000Hz

Question 17

Which animals can hear infrasound?

Answer 17

Elephants & moles

0-20Hz

Question 18

How does out brain differentiate between the different auditory streams?

Answer 18

Using auditory gestalts

Question 19

How are the stream segregated?

Answer 19

using time & pitch

Question 20

How many streams can we hear at once?

Answer 20

One

~ attention fluctuating between streams –> never hear the same song twice