Perception

Question 1

Describe rationalism.

Answer 1

Some propositions are knowable by intuition, and others knowable by deduction through intuition.

Question 2

Describe empiricism.

Answer 2

We have no source of knowledge other than sense experience.

Question 3

What essential concept was introduced by Alhazen?

Answer 3

Critical evaluation.

Question 4

Describe metamers.

Answer 4

Stimuli that are physically different but perceived to be identical.

Question 5

Describe the central idea in colour vision theory.

Answer 5

The trichromacy of colour mixing is due to the fact that we have 3 types of photoreceptor.

Question 6

How are so many different colours gauged using only 3 light detectors?

Answer 6

Colours are represented by the amplitude of responses.

Question 7

What is understood from L+M opponent processing?

Answer 7

Luminance (black/white).

Question 8

What is understood from L-M opponent processing?

Answer 8

The red/green channel.

Question 9

What is understood from S - (L+M) opponent processing?

Answer 9

The blue/yellow channel.

Question 10

What are 2 potential reasons trichromacy evolved in primates?

Answer 10

For frugivory and identifying edible foliage.

Question 11

What is motion parallax?

Answer 11

Depth from motion.

Question 12

Describe saccadic suppression.

Answer 12

Reduction of visual sensitivity when one makes a saccadic eye movement.

Question 13

Describe the role of the “comparator” in seeing movement.

Answer 13

It receives an “efferent copy” of orders to move the eyes, so it can compensate for eye movement in discriminating motion.

Question 14

What is akinetopsia?

Answer 14

No perception of motion.

Question 15

What are 3 ways the Sapir-Whorf hypothesis claim language influences thought?

Answer 15

Primes, constrains and alters.

Question 16

What are the “unique hues” in opponent processing?

Answer 16

Red vs. Green and Blue vs. Yellow.

Question 17

Describe motion aftereffect.

Answer 17

The illusion of a stationary object after long exposure to a moving object.

Question 18

What is interoccular transfer?

Answer 18

The transfer of an effect from one eye to the other.

Question 19

Define psychophysics.

Answer 19

The scientific study of the relationship between physical stimuli and psychological effects.

Question 20

In psychophysics, what is a threshold?

Answer 20

The minimum stimulus intensity for a person to exceed some performance level.

Question 21

Summarise Weber’s Law.

Answer 21

The just noticeable difference is a fixed percentage of the stimulus level.

Question 22

What are the 4 types of answers used to characterise detection performance?

Answer 22

Hit, miss, false alarm and correct reject.

Question 23

Describe the volley principle.

Answer 23

Multiple neurons can provide a temporal code for frequency if they have staggered firing rates.

Question 24

What is azimuth?

Answer 24

The direction of sound, determined using ILD bad ITD.

Question 25

What are cones of confusion?

Answer 25

Regions in space where all sounds produce the same time and intensity differences.

Question 26

What is inverse-square law?

Answer 26

Decrease in intensity is distance squared.

Question 27

Describe how spectral composition of sounds helps people identify their distance.

Answer 27

Higher frequencies decrease in energy more than lower frequencies as sound waves travel from source to one ear.

Question 28

What is auditory stream segregation?

Answer 28

Perceptual organisation of a complex acoustic signal into separate auditory events for which each stream is heard as a separate event.

Question 29

Which mechanoreceptors respond best to steady, downward pressure, fine spatial details and low frequency vibrations?

Answer 29

Slow Adapting I

Question 30

Which mechanoreceptors respond best to sustained pressures and particular skin stretch?

Answer 30

Slow Adapting II

Question 31

Which mechanoreceptors respond best to vibrations between 5 - 50 Hz?

Answer 31

Fast Adapting I

Question 32

Which mechanoreceptors respond best to vibrations between 50 - 700 Hz?

Answer 32

Fast Adapting II

Question 33

Which reflexes are out of conscious control?

Answer 33

Monosynaptic

Question 34

Which reflexes can be consciously moderated?

Answer 34

Polyaynaptic

Question 35

What stimulates A - delta fibre nocioreceptors?

Answer 35

Strong pressure or heat.

Question 36

What stimulates C fibre nocioreceptors?

Answer 36

Intense stimulation: pressure, heat, cold, chemicals.

Question 37

What type of pain is associated with A - delta nocioreceptors?

Answer 37

Quick, shallow pain.

Question 38

What type of pain is associated with C fibre nocioreceptors?

Answer 38

Throbbing pain.

Question 39

Which type of nocioreceptors are myelinated?

Answer 39

A - delta fibres.

Question 40

What are some problems with shape theory of odours?

Answer 40

Scientists are bad at predicting smell from structure of molecules, rats can smell differences between isotopes and sometimes altering shape doesn’t alter smell.

Question 41

How do we recognise so many smells with only 300 receptor types?

Answer 41

They generate a pattern of activation in the cortex, which we learn to associate with a smell.

Question 42

What did Sobel et al. find regarding ‘blind smell’?

Answer 42

There was brain activation to smells not noticeable to participants.

Question 43

Why does the VNO appear not to function in humans?

Answer 43

It is just pseudogenes and degenerate structures in humans.

Question 44

How do you become anosmic?

Answer 44

The cribiform plate is pushed backwards and all OSN axons are sheared.

Question 45

What is retronasal flow?

Answer 45

How olfactory molecules from the mouth are brought to the nasal cavity.

Question 46

What is orthonasal olfaction?

Answer 46

Smells coming from the front.

Question 47

What is retronasal olfaction?

Answer 47

Smells coming from the mouth behind the palate (responsible for taste).

Question 48

Which basic tastes require G-coupled proteins to be sensed?

Answer 48

Sweet and bitter compounds.

Question 49

Describe the labelled lines theory of taste coding.

Answer 49

Each taste fibre carries a particular taste quality.

Question 50

Describe a second theory of taste coding.

Answer 50

There are patterns of activity across many different taste neurons.

Question 51

Where in the mouth is stimulated by fat molecules?

Answer 51

The trigeminal nerve.

Question 52

Why do we need gain control?

Answer 52

Neurons have to code things hat have large dynamic ranges.

Question 53

How does contrast gain control work?

Answer 53

Neuronal inputs are divided by the sum of the local average response.

Question 54

What are 4 signatures of cortical gain control?

Answer 54

Long range, tuning, slowness and complex features.

Question 55

How does the Nachmia and Sansbury’s ‘dipper function’ not follow Weber’s law?

Answer 55

As contrasted decreases, people get better at detecting difference before they get worse.

Question 56

What is p-value hacking?

Answer 56

Adjusting variables until there is a significant result.

Question 57

What is the Texas Sharpshooter Fallacy?

Answer 57

Defining success after getting the results.

Question 58

What is the file drawer problem?

Answer 58

When ‘bad’ data is not included in a study.

Question 59

What is a problem with doing multiple comparisons (and tests)?

Answer 59

One result is significant by chance.

Question 60

Describe a psychometric curve.

Answer 60

It characterises the relationship between a physical stimulus parameter and the probability of detecting the stimulus.

Question 61

The firing rate of cells to code low frequency tones is (faster/slower) than high frequency tones.

Answer 61

Slower.

Question 62

Give 3 attributes that all touch receptors have.

Answer 62

Type of stimulation it responds to, size of receptive field and rate of adaptation.

Question 63

How is information about taste sent to the brain?

Answer 63

Via cranial nerves.