L4 - active vision Flashcards
what is psychophysics?
the study of the relationship between physical stimuli + the perceptual experiences
what is the critical role of psychophysics?
establishes the limits of the sensory system e.g., smallest detectable change is colour, brightness etc.
What was the task in Posner’s (1980) study?
Ppts are asked to fixate on a central point on a screen.
A cue is presented - central (arrow pointing in a direction) or peripheral (brief brightening of an area on the screen).
After a short delay, a target appears in the location indicated by the cue (valid cue) or in a different location (invalid cue)
What where the 2 types of cue in this study?
Central cue
Peripheral cue
What is a central cue?
voluntary shift of attention
what is a peripheral cue?
automatic shift of attention
What’s a valid cue?
the cue correctly predicts where the target will appear
what’s an invalid cue?
the cue incorrectly predicts the location of the target
What were the findings of Posner’s (1980) study?
response times are faster when the cues are valid
visual attention spotlights illuminating regions of interest
What are the 2 types of covert attention?
Endogenous + Exogenous
What is endogenous covert attention?
a voluntary shift in attention from within
what’s exogenous covet attention?
an automatic shift in attention from external stimuli
What is the function of both types of covert attention?
speeds up simple reactions and improves perceptual discrimination
What are the 2 types of eye movements?
Saccades + Fixations
What are saccades?
accurate, high-velocity movements
