Lecture 6.5

Question 1

Primary Sensory Cortex

Answer 1

Receives input from thalamus

Question 2

Secondary Sensory Cortex

Answer 2

Receives input from primary

Question 3

Association Cortex

Answer 3

Receives input from more than one sensory system

Input mostly from secondary

Question 4

Three characteristics of sensory systems

Answer 4

Hierarchical organization
Functional segregation
Parallel processing

Question 5

Ranking of hierarchical organization

Answer 5

Receptors –> Thalamic relay –> Primary sensory cortex –> Secondary –> Association
Each level receives input from lower levels and adds a level of analysis before passing up

Question 6

Damage to lower levels

Answer 6

Loss of function

Question 7

Damage to higher levels

Answer 7

Specific sensory deficit

Question 8

Sensation

Answer 8

Detection of stimuli

Question 9

Perception

Answer 9

Interpretation of stimuli

Question 10

Agnosias

Answer 10

Perceptual problems

Question 11

Functional segregation

Answer 11

Primary, secondary and association cortices are not functionally homogeneous
Different analysis within each hierarchical level
Do not act together to perceive sensation

Question 12

Parallel processing

Answer 12

Different levels of sensory hierarchy are not serial

Simultaneous analysis of a signal in different ways by multiple parallel pathways of neural networks

Question 13

Two types of parallel processing

Answer 13

Influence behaviour without conscious awareness

Influence behaviour by engaging conscious awareness

Question 14

Claustrum

Answer 14

Thin layer of neurons under neocortex

Receive input from all lower sensory areas to form perception

Question 15

Sound

Answer 15

Vibration of air molecules

Question 16

Range of frequencies heard by humans

Answer 16

20 to 20 000 Hz

Question 17

Amplitude of sound wave

Answer 17

Loudness

Question 18

Frequency of sound wave

Answer 18

Pitch

Question 19

Complexity of sound wave

Answer 19

Timbre

Question 20

Pure tone

Answer 20

Can't localize 
Generally uncomfortable 
Sine waves 
Do not occur naturally (computer or lab)
Close relationship between the tone and pitch

Question 21

Fourier analysis

Answer 21

Mathematically break down complex waves into component sine waves of different frequencies and amplitudes
Theory that fourier analysis occurs in the brain

Question 22

Outer ear

Answer 22

Sound waves travel down the auditory canal

Question 23

Tympanic membrane

Answer 23

Ear drum

Vibrations transferred to ossicles

Question 24

Ossicles

Answer 24

Malleus
Incus
Stapes
Trigger vibrations in oval window

Question 25

Inner ear

Answer 25

Transfers vibrations to endolymph of cochlea

Question 26

Cochlea

Answer 26

Long coiled tube with internal membrane to tip

Question 27

Organ of Corti

Answer 27

Each pressure change in the oval window travels along the organ of Corti as a wave

Question 28

Basilar membrane

Answer 28

Hair cells (auditory receptors) mounted

Question 29

Tectorial membrane

Answer 29

Rests on hair cells

Question 30

Round window

Answer 30

Dissipates vibrations

Question 31

Endolymph

Answer 31

High in K+
Surrounds the hair cells
Ionic imbalance = energy storage - no need for Na+/K+ pumps - trigger AP when hair cells move
Tight junctions between hair cells maintain ion imbalance