Sensation and perception colour

Question 1

what is the difference between sensation & perception?

Answer 1

• Sensation: Conversion of external stimuli into electrochemical signals in our brain. Through evolution, organisms have evolved sensor mechanisms to process these signals. These systems are referred to as senses.
• Perception: This is how these electrochemical signals are interpreted and represented.

Question 2

what are the dimensions of colour?

Answer 2

• Hue: This is the property that we normally use describe colour, like blue, green and red.
• Saturation: This corresponds to how intensely the hue is expressed.
• Brightness: This is the perceived amount of light reaching your eye.

Question 3

what is the trichromatic colour vision?

Answer 3

• Palmer (1777): Three different types of light sensor, each processing a specific wavelength.
• Young (1802) and von Helmholtz (1852): Three sensors but each are sensitive over a range of wavelengths, but maximally for red, green and violet.

Question 4

what are the colour vision channels?

Answer 4

• Ewald Hering (1892)
• proposed the opponent-process theory in colour vision to explain that colour perception is not simply a matter of cone receptors summating their responses, but that there are in fact three opponent dimensions that come together to produce colour vision.
• achromatic & chromatic

Question 5

what is colour mixing?

Answer 5

• Isaac Newton (1672)
• showed that when white light travels through a prism, it is decomposed into a rainbow of light. When the colours were focused back together using a magnifying class, a white light was produced.
• He concluded that (1) white light was a combination of all colours, and (2) colours can be combined to generate new ones.
• This is called additive mixing.

Question 6

what is additive colour mixing?

Answer 6

• Light energy is increased when two sources are combined:

Question 7

what is subtractive colour mixing?

Answer 7

• Light energy is reduced when two sources are combined:

Question 8

what is colour contrast?

Answer 8

• Chevreuil (1839) noticed that colours appeared different depending on what colours surrounded them.
• He developed the theory of “simultaneous colour contrast”.

Question 9

what is the stained glass illusion?

Answer 9

• This is another phenomenon that shows how the colours we perceive are affected by their surroundings.

Question 10

how does time and lighting impact images?

Answer 10

• This same scene looks very different at different times of the day, but we still recognise that the “true” colour of objects have not changed.
• For example, the shed is white and the grass is green.
• Granzier & Valsecchi 2014

Question 11

what are colour constancies and ratios?

Answer 11

• 1. Present participants with reference where surround is 3x as bright as central patch
• 2. Ask participants to adjust central patch to match reference central patch
• 3. Participants do not select the identical shade
• 4. They picked the shade that was a third the brightness of surround
• Wallach (1948) found that colours (including brightness) is perceived in relation to their surroundings

Question 12

what are the theories for colour constancy?

Answer 12

• Nascimento and Foster (1997) and Foster (2011) suggested the differences and ratios in excitation between cone types enable us to perceive colours as being stable despite lighting conditions.
• Hulbert (2007) suggest that adaptation, knowledge of colour of objects and memory of colours also come into play.

Question 13

what is the evolution of colour vision?

Answer 13

• Osorio and Vorobyev (1996)
• found that the dichromat’s eye is almost as good as a trichromat’s when identifying fruit and leaves, but the trichromat has an advantage for detecting fruit against a background of leaves.

Question 14

what is the purpose of colours nowadays?

Answer 14

• Bramao et al. (2011) showed that colour is important for object recognition, especially in term of diagnosticity.
• Colour information triggers the recognition of objects from our long-term visual memory.
• Objects in our memory are stored in their typical colour format, so colour deviations can be used as a diagnostic tool.

Question 15

how does colour express emotions?

Answer 15

• Dael, et al. (2016) showed that we associate certain colours with certain emotions. They showed participants videos of an actor expressing happiness or panic.
• Colours along the red–yellow spectrum were deemed more appropriate for joy expressions.
• Colours along the cyan–bluish hues were deemed more appropriate for fear expressions.

Question 16

what is the difference between colour patches vs colour words?

Answer 16

• Jonauskaite, et al. (2020) examined emotion-colour associations using colour terms or patches.
• RED: positive and negative emotions (i.e., love, anger, and hate
• BLUE: Positive emotions (natural experiences of a clear sky or clean water? Palmer & Schloss, 2010). Not generally associated with any negative emotion, except sadness by some.
• White – exclusively positive emotions
• PINK: exclusively positive emotions (i.e., love, joy, and pleasure; see also Fugate & Franco, 2019)
• TURQUOISE: Joy and pleasure
• YELLOW AND ORANGE: joy and amusement
• BROWN: Disgust
• Black and grey – exclusively negative emotions.

Question 17

what is the colour black associated with?

Answer 17

• Black was was associated with almost all negative emotions (i.e., sadness, guilt, regret, disappointment, fear, disgust, contempt, hate, and anger).
• When presented the word “black”, negative associations were stronger and more intense, especially with hate, anger, regret, and sadness.
• Colour words are more than a colour label and can carry deeper/stronger associations.

Question 18

what emotions can be elicited from colours?

Answer 18

• Valdez and Mehrabian (1994)
• demonstrated that people found bright and saturated colours more pleasurable, and saturation was directly correlated to physiological arousal.

Question 19

how does colour influence consumer behaviour?

Answer 19

• Babin et al. (2003) examined the effects of cool (blue) vs. warm (orange) interiors on shopping behaviour.
• For a blue store: bright lights resulted in higher price fairness perceptions.
• For the orange store: soft lights resulted in higher price fairness perceptions.
• They also reported that when the lights are bright, a cool/blue setting is more effective than a warm/orange setting in eliciting purchasing behaviour.
• Blue store + Bright lights
• Perceptions of fairness for higher prices.
• More effective at eliciting purchasing behaviour.

Question 20

how does colour impact appetite?

Answer 20

• Wang (2020)
• reported that the warm incandescent light (red) significantly increased appetite compared to cooler colours.

Question 21

how does colour impact marketing?

Answer 21

• Pelet (2010)
• showed that increased levels of brightness and saturation can increase intention to buy and memory of a website’s content.