Lecture 4

Question 1

What is sensation?

Answer 1

The process by which info is gathered from environment and transmits to the brain for processing

Question 2

What is perception?

Answer 2

The process by which the brain interprets and organises this sensation (sensory info).

Question 3

What is the first principle of sensation and perception?

Answer 3

There is no one-to one correspondence between physical and psychological reality. Measuring this different perception of stimuli is psychophysics.

Question 4

What is the second principle of sensation and perception?

Answer 4

Both are active processes. Actively involve ourselves in stimulus e.g name spoken and we turn to listen /hear.

Question 5

What is the third principle of sensation and perception?

Answer 5

Sensation and perception are adaptive e.g smell of yuck food = disgust because we should steer clear.

Question 6

What is the progress of the sensory system towards perception

Answer 6

• Accessory structure modifies energy
• Receptor will transduce energy
• Sensory info transferred to CNS
• Initial processing in thalamus (except for smell) and relays to cerebral cortex
• Processing in cerebral cortex produces perception

Question 7

How do we sense the environment with the 5 senses?

Answer 7

• Detecting physical energy (light/colour waves)
• Transduction on the basis of intensity and quality of sensory info
• Intensity: Number of neurons and frequency at which they fire
• Quality : Type of receptor involved, i.e colour, pitch, taste, temp

Question 8

What are thresholds in sensory systems?

Answer 8

Requiring the minimum amount of energy required to activate system e.g tip toeing cant be heard until intensity increases when they are closer

Question 9

What is decision making in sensory systems?

Answer 9

Determining which environmental stimuli is meaningful or not e.g dog braking outside at night (no response), however a smashing window may require a decision to evoke response.

Question 10

Provide an example of level changes in stimulation levels? (sensory systems)

Answer 10

Going from a first attempt squat to a second attempt squat by 10kg.

Question 11

Why do sensory system tune out redundant information?

Answer 11

For more efficient sensory information processing. Turning down the volume on other stuff.

Question 12

What is encoding?

Answer 12

Translation of a stimulus’ physical properties into pattern of neural activity that specifically identify those properties.

Question 13

What is nerve specific energy doctrine?

Answer 13

Stimulation of a particular sensory nerve, provides codes for that one sense. e.g rubbing your eyeball with produce light.

Question 14

What are the two types of stimulus codes?

Answer 14

Temporal code: changes in the timing of firing of neurons.

Spatial code: provides info about stimulus by identifying location of firing neurons relative to their neighbours.

Question 15

What is sound?

Answer 15

Repetitive fluctuations in the pressure of a medium e.g air.

Question 16

Distinguish between vibration and wave

Answer 16

Vibration: Requires an object to produce fluctuations in pressure to create sound.
Wave: Repetitive, rhythmic variation in pressure that spreads in all directions.

Question 17

How and what are the two dimensions in which a wave form is characterised?

Answer 17

Amplitude: intensity - difference in airpressure from it’s baseline to peak.
Wavelength: Distance from one peak to the next.
Frequency (Hz): Number of complete waveforms/cycles that pass every second.

wavelength and frequency are related - longer wavelength = lower frequency

Question 18

Psychological dimensions of sound - Loudness

Answer 18

• Amplitude

- Measured in dB

Question 19

Psychological dimensions of sound - Pitch

Answer 19

• Frequency

- Higher or lower tone

Question 20

Psychological dimensions of sound - Timbre

Answer 20

• Wave patterns added o the lowest/most fundamental wave frequency
• Depends on specialised neurons

Question 21

Pinna?

Answer 21

• Crumpled part of outer ear

- Collects and shapes sound down to ear canal

Question 22

Ear canal

Answer 22

The passage by which transfers sound from pinna to middle ear.

Question 23

Middle ear

Answer 23

• Tightly stretch membrane known as tympanic membrane (eardrum).
• Vibrations from tympanic membrane transferred to three tiny bones - Malleus (hammer ), incus (anvil) and stapes (stirrup).

Question 24

Inner Ear

Answer 24

• Bones amplify changes in pressure produced by original sounds focusing vibrations of tympanic membrane of oval window - via semi circular canals. Incl. cochlea.

Question 25

Components of inner ear;

Answer 25

• Cochlea (transduction)
• Basilar membrane
• Organ of corti
• Hair cells
• Acoustic nerve

Question 26

What is conduction deafness?

Answer 26

• Middle ear bones fuse (Malleus, incus, stapes) and cannot properly amplify vibrations.

Question 27

What is nerve deafness?

Answer 27

• Results from damage to acoustic nerve and hair cells.

- Occurs with age or through exposure to loud sounds overtime.

Question 28

What constitutes visible light on an electromagnetic spectrum?

Answer 28

From just under 400 nanometres to about 750 nanometres

Question 29

What does light intensity vs light wavelength?

Answer 29

• Intensity refers to how much energy the light contains and determines brightness
• Light wavelength depends on what colour you see, with different wavelength producing sensations of different colours.

Question 30

What are the major structures of the eye?

Answer 30

• Cornea, Iris, Pupil, Lens, Muscles, Retina, Blind Spot

Question 31

Psychological dimensions of light (Hue)?

Answer 31

• Colour (besides white, black, grey)

Question 32

Psychological dimensions of light (Colour saturation?)

Answer 32

• Purity of colour

Question 33

Psychological dimensions of light (Brightness)?

Answer 33

• Intensity of wavelengths

Question 34

What is the Trichromatic (Young-Helmhotz) theory?

Answer 34

• Short, medium and long wavelengths -visual elements to the eye, each sensitive to different wavelengths.
  Short: Sensitive to blue (440 nm) Medium sensitive to green (510 nm) and Long sensitive to reddish - yellow.

Question 35

What is the Opponent -Process theory of colour vision?

Answer 35

Colour sensitive elements in eye grouped in pairs that oppose each other. One activates when other is no longer stimulated. Red/Green Blue/Yellow Black/White

• Explains afterimages and complementary colours.

Question 36

What part of brain are sen information from the olfactory bulb?

Answer 36

• Frontal lobe

- Amyglada

Question 37

(TRUE/FALSE) - Olfactory bulb sends information through the thalamus.

Answer 37

FALSE

Question 38

What happens if there is a loss of olfactory sense?

Answer 38

Could indicate certain brain diseases that affect memory and emotion.

Question 39

What are the taste sensations?

Answer 39

Astringent, Bitter, Sweet, sour, salty, Umami

Question 40

What is papillae?

Answer 40

Grouped taste buds in mouth and throat

Question 41

What is the cutaneous sense (intensity of the stimulus) encoded by?

Answer 41

Firing rate of individual neurons and the number of neurons stimulated

Question 42

What are warm fibres?

Answer 42

Increase their firing rates when temperature changes int he range of 95-115 degrees F. Temperatures above this range are painful and stimulate the cold fibres in efforts to remain homeostatic.