Lecture 5 Flashcards
What is psychophysics?
Describes the relationship between physical energy in the environment and psychological experience
What is an absolute threshold?
The minimum amount of physical energy a sensory system can detect 50% of the time.
Subliminal stimulation?
Below the absolute threshold - too weak to be detected
Supraliminal stimulation?
Above the threshold - detected consistently
What are the 3 approaches to perception?
Computational model, constructivist approach, ecological approach
What is the computational model?
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.
What is the constructivist approach?
That we construct a representation of reality from fragments of sensory information - strongly influenced by learning, expectations, interferences from past experiences, culture.
What is the ecological approach?
Perception comes directly/solely from the environment - stiumlu gives us most of the information we need to make sense of the world.
Signal detection theory of sensitivity?
- influenced by intensity of the signal, capacity of sensory systems, amount of background noise.
Signal detection theory of Response criterion?
- A person’s willingness to respond to stimulus
- Influenced by motivation and expectancy,
False Alarm?
Response criterion: No signal but individual decides that there was, and responds.
Correct rejection?
Not reporting a signal when there is no signal/ none was given.
Miss?
Signal occurs, but no detected
Hit?
Signal occurs and the individual detects it.
What is Weber’s law?
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.
hat is magnitude estimation?
The perception of stimulus intensity relative to stimulus strength
What is Fechner’s law?
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.
What is Steven’s power law?
Expanded on Feckner’s law - covers a wider array of stimuli.
What is perceptual organisation?
Task performed by perceptual system to determine what stimuli go together to form an object.
What is figure ground discrimination?
When perceptual system is faced with complex stimuli, automatically picks out certain features, objects, sounds to emphasise - ground is the less meaningful background.
