Week 1: Introduction And Visual Processing

Question 1

What are the two reasons to study perception?

Answer 1

1. Perception as a gateway to psychology - viewing other people’s body language, behaviour and reactions allows us form a world view.
2. Perception as creation - our brain creates unique images; colour, depth, information is a figment of our imagination.

Question 2

State and explain each step of the perceptual process

Question 3

Differentiate between “top-down” and “bottom-up” processing.

Answer 3

Top-down processing involves making judgments about stimuli based on previous encounters/ previous knowledge whereas bottom-up processing is when incoming stimuli from the environment is interpreted.

Question 4

What is another name for “top-down” processing?

What is another name for “bottom-up” processing?

Answer 4

knowledge-based processing

Data-based processing

Question 5

Discuss the two levels of analysis of studying perception.

Answer 5

**Psychophysical and Physiological approaches.

Question 6

What are the three approaches to studying perception and what kind of relationship is observed?(PP, PH1, PH2)

Answer 6

PP: Psychophysical approach which observes the STIMULUS-PERCEPTION relationship.

PH1: Physiological approach 1 which observes the STIMULUS-PHYSIOLOGY relationship.

PH2: Physiological approach 2 which observes the PHYSIOLOGY-PERCEPTION relationship.

Question 7

What are the two methods of measurement for the psychophysical approach? Describe these methods.

Answer 7

1. Qualitative Methods
   - description: identifying the characteristics of stimuli (a.k.a phenomenological approach)

• recognition: categorising stimuli /recalling the name/ identity of stimuli.–> testing brain damage

2. Quantitative Methods
   - detecting
   - perceiving magnitude
   - searching

Question 8

List five different ways to study perception.

Answer 8

**??
Description 
Recognition 
Detecting
Perceiving Magnitude 
Searching

Question 9

Describe how cognitive processes can influence perception.

Question 10

Discuss what the phenomenological method is.

Answer 10

**A.K.A the qualitative method of “description”.

Emphasises subjective experience/ lived aspects of a particular construct – that is, how the phenomenon is experienced at the time that it occurs, rather than what is thought about this experience or the meaning ascribed to it subsequently.

Question 11

What is meant by the term, absolute threshold? How is it measured?

Contrast methods of limits, method of adjustment, method of constant stimuli.

Answer 11

Absolute threshold is a quantitative method of assessment of perception which indicates the smallest amount of energy required to detect a stimuli.

e.g. dimmest amount of light or quietest sound.

Measured by ‘method of limits’ (e.g. different intensities presented in ascending and descending order, cross-over point is threshold).

‘method of adjustment’ (e.g. turning dial on radio - intensity continuously adjusted)

Also measured by ‘method of constant stimuli’ Five to nine stimuli of different intensities are presented in random order, multiple trials are presented, threshold = intensity detected in 50% of trials.

Question 12

Define difference threshold.

Answer 12

Difference Threshold or Limen (DL) - smallest difference between two stimuli a person can detect.

As magnitude of stimulus increases, so does DL –

Weber’s Law describes this relationship
DL / S = K

Question 13

The difference threshold for an electric shock is 0.01 which is smaller than that of light intensity (0.08). What does this mean?

Answer 13

That we are more sensitive to changes in the electric shock than that of light intensity.
small change in pain intensity —> damage to body.
light intensity isn’t as important from an evolutionary perspective

Question 14

What is magnitude estimation (scaling)?

Answer 14

a psychophysical procedure in which participants make subjective judgments of the magnitude of stimuli by assigning numbers to them. The resulting scales often follow a power law (see Stevens law).

Results in a linear reaction, response compression or response expansion.

Question 15

State the difference between response compression and response expansion

Answer 15

In response compression, as the intensity increases, perceived magnitude increases more SLOWLY than the intensity. Whereas in response expansion, as the intensity increases, perceived magnitude increases FASTER than the intensity.

Question 16

An electric shock has been administered. Is response expansion or response compression more likely to occur? Why?

Answer 16

Response expansion is more likely to occur because individuals are more likely to report/ experience a bigger difference between the intensities of a shock.

Question 17

three major components of the perceptual process chart (Experience & action, Stimuli and Physiological processes).

Answer 17

PUT IMAGE HERE

Question 18

Under 1_____ , stimuli of different intensities are presented in ascending and descending order. The observer must then respond to 2_____

1. the method of detection.
   the method of magnitude.
   the method of limits.
2. A series of quantitative questions regarding the stimulus type.
   Whether they perceived the stimulus.
   How much energy they had to exert to detect that stimulus.

Answer 18

1. Method of limits
2. Whether they perceived the stimulus.

Under [The method of limits], stimuli of different intensities are presented in ascending and descending order. The observer must then respond to [Whether they perceived the stimulus ].

Question 19

True or false: Under the method of adjustment, the stimulus intensity is adjusted in discrete stages until the observer is able to detect it.

Answer 19

False.

intensity is adjusted CONTINUOUSLY.

Question 20

The ‘difference threshold’ is also called ___
. This increases as the magnitude of the stimulus __
, and has been described by __ ’s law.

Answer 20

1. limen
2. increases
3. Weber’s law

Question 21

Under the magnitude of estimation, response compression refers to how, as intensity increases, the perceived magnitude [____] [More ____] than the [___].

Answer 21

1. Increases
2. More slowly
3. Intensity

Under the magnitude of estimation, response compression refers to how, as intensity increases, the perceived magnitude [Increases] [More slowly] than the [Intensity].