Attention Flashcards
Outline two types of visual attention
- Overt attention: having the gaze upon what they are focused on
- Covert attention: seeing something peripherally but attending to something else
Why is attention important?
Attention is a perceptual system that helps prevent overloading of the brain. It has limited capacity and therefore it allows us to focus on specific parts of a scene at a time
Outline the two processes that direct our attention
- initial voluntary process: mediated by attentional capture where salient features (through colour contrast, size, orientation contrast, motion/flicker contrast)
- subsequent voluntary process: differs from person to person - fixation influenced by goals and expectations
Attentional capture
unintentional shift of focus to attend to another stimuli, interrupting the original processing
what captures our attention?
Colour contrast
Size
Orientation contrast
motion/ flicker contrast
How do expectations influence attention
Can determine fixations by causing it to last longer and occur more often
What is the binding problem?
Outlines how different aspects of a scene are seperately processed before it is combined into a single percept
How is visual infomation processed
- Lens focuses and creates an image that is relayed to the retina
- retina converts image into electrical signals which travel via the optic chiasm to the primary visual cortex where it is split into the dorsal or ventral stream
How does the feature integration theory link to the binding theory
FIT provides a solution to the binding problem suggesting that one object is processed at a time and thus preventing the binding of different objects
illusory conjunction
a prediction of the FIT where attention from different object will be incorrectly bounded together to create an image that doesnt exist when attention is inhibited (e.g a red flower and green leaf = green flower)
Dorsal and ventral stream
Also known as the what and where pathway, both are streams in the visual pathway.
Dorsal is invovled with motion after processing info, flows on top of the brain whereas the ventral stream is involved with visual perception after processing visual info and flows on the lower part of the brain
Why are conjunction searches predicted to be slow
visual search usually require binding of different components and becomes harder is target contain similar features as the distractor. FIT predicts that conjunction searches requires attention on each object until target is found