Lecture 5

Question 1

What is psychophysics?

Answer 1

Describes the relationship between physical energy in the environment and psychological experience

Question 2

What is an absolute threshold?

Answer 2

The minimum amount of physical energy a sensory system can detect 50% of the time.

Question 3

Subliminal stimulation?

Answer 3

Below the absolute threshold - too weak to be detected

Question 4

Supraliminal stimulation?

Answer 4

Above the threshold - detected consistently

Question 5

What are the 3 approaches to perception?

Answer 5

Computational model, constructivist approach, ecological approach

Question 6

What is the computational model?

Answer 6

Determines the computation for how a computer would solve perceptual problems > i.e explain how computations of nervous system turn raw sensory info into a representation of the world.

Question 7

What is the constructivist approach?

Answer 7

That we construct a representation of reality from fragments of sensory information - strongly influenced by learning, expectations, interferences from past experiences, culture.

Question 8

What is the ecological approach?

Answer 8

Perception comes directly/solely from the environment - stiumlu gives us most of the information we need to make sense of the world.

Question 9

Signal detection theory of sensitivity?

Answer 9

• influenced by intensity of the signal, capacity of sensory systems, amount of background noise.

Question 10

Signal detection theory of Response criterion?

Answer 10

• A person’s willingness to respond to stimulus

- Influenced by motivation and expectancy,

Question 11

False Alarm?

Answer 11

Response criterion: No signal but individual decides that there was, and responds.

Question 12

Correct rejection?

Answer 12

Not reporting a signal when there is no signal/ none was given.

Question 13

Miss?

Answer 13

Signal occurs, but no detected

Question 14

Hit?

Answer 14

Signal occurs and the individual detects it.

Question 15

What is Weber’s law?

Answer 15

JND = KI

• The threshold for sensing stimuli increases as the intensity increases. It’s constant (K) for a particular sense.
• Does not hold when stimuli are very intense or very weak, but most generally, it does for the rest.

Question 16

hat is magnitude estimation?

Answer 16

The perception of stimulus intensity relative to stimulus strength

Question 17

What is Fechner’s law?

Answer 17

As the stimulus intensity constantly increases, this diminishes perceived magnitude estimation. E.g soft sound = easy detection for twice as loud sound. However, in rock concert - difficult to detect sound twice as loud.

Question 18

What is Steven’s power law?

Answer 18

Expanded on Feckner’s law - covers a wider array of stimuli.

Question 19

What is perceptual organisation?

Answer 19

Task performed by perceptual system to determine what stimuli go together to form an object.

Question 20

What is figure ground discrimination?

Answer 20

When perceptual system is faced with complex stimuli, automatically picks out certain features, objects, sounds to emphasise - ground is the less meaningful background.