Sensory Methods and Signal Detection Theory

Question 1

Psychophysical measure of olfaction

Answer 1

Odour identification and odour naming

Odour detection

Intensity differentiation

Question 2

method of adjustment

Answer 2

Participant adjusts the stimulus until detectable based on criterion

Question 3

Method of limits

Answer 3

Stimulus intensity is presented in increased or decreased thresholds

Question 4

Method of constant stimuli

Answer 4

Random presentation of stimuli at various intensities.
- reduces bias

Question 5

name the four sensory differences tests

Answer 5

yes/no
2n alternative forced choice task
3n alternative forced choice task
same/different task

Question 6

yes/no test

Answer 6

Identifying the presence or absence of a stimulus.

Question 7

2-alternative forced choice task

Answer 7

Choosing between two presented options

Question 8

3-alternative forced choice task

Answer 8

Choosing between three presented options.

Question 9

Same/different task

Answer 9

Identifying if two stimuli are the same or different.

Question 10

relationship between normal distribution and perception

Answer 10

Perceptual strength of the same stimulus follows a normal distribution.

Question 11

percentage correct

Answer 11

correct trials/trials
- follows an S Curve

Question 12

normal distribution criterion

Answer 12

set halfway between chance and perfect performance

Question 13

signal detection theory and decision making

Answer 13

• Used to quantify how people make decisions under uncertainty
• Distinguished between an observer’s sensitivity to a stimulus and their decision making criteria

Question 14

what are the two things that SDT measures

Answer 14

sensitivity and decision making

Question 15

what is signal and noise

Answer 15

Signal: Relevant information being detected.

Noise: Irrelevant background information.

Question 16

what is D’ (d prime)

Answer 16

Sensitivity measure, the distance between two distributions.

Recognises perceptual variation, pure sensitivity measure, measures response bias.

Question 17

what do the two curves in the normal distribution represent

Answer 17

noise (no signal present)
signal (signal present)

Question 18

what are the four possible outcomes of SDT

Answer 18

Hit: Correctly detecting a signal when it’s present.
Miss: Failing to detect a signal when it’s present.
False Alarm: Mistakenly detecting a signal when only noise is present.
Correct rejection: Correctly identifying that no signal is present.

Question 19

What happens when the decision threshold is moved to the right

Answer 19

Fewer false alarms
More misses

Question 20

What happens when the decision threshold is moved to the left

Answer 20

Fewer misses
More false alarms ⬆️

Question 21

Cross modal sensory interactions

Answer 21

Where one function of one sense is changed by stimulation of another sense
e.g
- odour and taste
- audio and speech

Question 22

McGurk Effect

Answer 22

Audiovisual speech perception

baa baa baa vs faa faa faa

Question 23

Below threshold tastant + below threshold odorant

Answer 23

above threshold flavour
e.g vanilla and sucrose

Question 24

factors influencing sensory interactions

Answer 24

previous experience: Familiar pairings enhance perception.

familiarity: Stronger effects with known combinations.

congruency: Stronger enhancement when taste and odour match.

Question 25

how does colour influence taste

Answer 25

brighter food seems more intense in flavour vs dull food

Question 26

Blackwell (1955) Juice example

Answer 26

orange juice, blackberry juice - changed colours to see if people could still identify what they were - found that the colour was rather important for identification

Question 27

Synaesthesia

Answer 27

Perceptual phenomenon in which stimulation of one sensory or cognitive pathway leads to involuntary experiences in a second sensory or cognitive pathways - E.g pairing colours and numbers

Question 28

not cross modal

Answer 28

- Temperature: could change physical elements of stimulus so could be introducing new sensation - Viscosity: changing the availability of molecules e.g spread - Fat content: influence physical property of food, so will change its flavour

Question 29

thermal taster

Answer 29

Thermally induced taste sensations may be elicited when the tongue is thermally stimulated in the absence of gustatory stimulus - About 25% of the population have this