What is visual attention? What does it do for us? What are some of its limitations?
A form of top-down processing that allows us to filter incoming information by highlighting what’s important and ignoring unimportant things
- allows us to briefly hold onto information
- however, there’s only so much that we can pay attention to at a time, leading to a capacity-limited bottleneck effect (the brain must pick what to prioritize)
Selective Attention
Restricting attention to a subset of stimuli amongst a larger assortment
- can also be thought of as searching for signal amongst noise
Divided Attention
Splitting attention across multiple stimuli at the same time (or attempting to)
Sustained Attention
Continuously monitoring ONE stimulus over time
- aka vigilance
Overt Attention
In vision, this can be thought of whatever stimulus your eye is directed at
Covert attention
In vision, this can be thought of as attending to something in your periphery (that is, without fixating on it)
How do we measure attention?
Generally we care about response time (how long it takes someone to respond) rather than accuracy
What is the Posner Cuing Paradigm used for? What kind of attention does it measure? What are the different cues it can use?
A way of measuring attention in which we manipulate cues (stimuli that indicate what to attend to, or where in the visual field a target may appear) and SOA, then measure how it affects RT
- mainly measures covert, selective attention
- cues can be valid or invalid, and peripheral or symbolic (or neutral)
What is SOA? How does it affect RT?
The time between the instruction (cue) and the onset of the stimuli (target)
In general, a longer SOA = slower RT
What is a valid cue? How does it affect RT compared to no cue?
A cue that accurately leads you to the direction of the target (ex: cue appears on left, target appears on left)
- can be either peripheral or symbolic
- this drives attention in a general spatial direction, leading to faster RT
What is the only case in which a valid cue would produce an RT slower than having no cue at all?
Really long SOA can leads to Inhibition of Return, in which attention drifts from the location of the cue and struggles to return to it later
- makes processing slower when the signal actually does appear
- only applies to valid cues
What is an invalid cue? How does it affect RT compared to no cue or neutral cue?
A cue that misleads you to the direction of the target (ex: cue appears on left, target appears on right)
- can be either peripheral or symbolic
- attending to the wrong location will lead to the slowest RT (slower than no cue)
What is a neutral cue? How does it affect RT?
Cue informs you that an item is coming, but doesn’t inform location
- leads to a RT somewhere in between valid and invalid
What is a peripheral cue? How does it affect RT?
Cue appears in the periphery, at the site of where the target should appear
- immediately bringing attention to the area = faster RT
- the fastest RT that can occur in a posner cuing paradigm generally happens with valid peripheral cues
What is a symbolic cue? How does it affect RT compared to peripheral ones?
Cue signifies location of the target without using that space
- processing is slower here than with peripheral cues
What does the posner cuing paradigm tell us about attention?
Covert attention is SPATIAL in nature
If you are attending to a different area in space (invalid cue), it takes longer to attend to the real target
Spotlight Model of Attention
Attention is restricted to space and must be moved from one point to the next in our visual field
Zoom Lens Model of Attention
The region of space we attend to can “shrink” and “grow” depending on what the goal is
Ex: “zooming in” would be more useful when attending to small details in a scene
What is a visual search task?
Another common way of testing attention because it’s an everyday task
- Searching for a target item among distractors (ex: Where’s Waldo?)
What variables can we manipulate in a visual search task?
Set Size (# of items), Distractor similarity, and Target complexity
- changing how salient that target is among the distractors will affect RT
What is a Feature Search?
When the target differs from distractors on one key feature, it’s quick to identify despite set size
- item’s uniqueness makes it salient (appears to pop out among distractors)
What is a Serial Self-Terminating Search?
Items are searched one by one until the target is found, done when the target and distractors share similar basic features
- unlike feature searches, increasing set size will make the task more difficult b/c no one feature defines the target
- requires more time overall
What are the two parts of Feature Integration Theory?
Parallel Search (aka feature search aka pre-attentive): individual features are automatically processes all at once, with little effort
Serial Search (aka conjunction search aka selective attention): conjunctions of features are processed slowly, one at a time, and require more effortful attention
What is the Binding Problem?
For conjunction (or serial) searches, we need to bind & unbind individual features to differentiate between target and distractor
- this can be especially difficult if the features are processed by different brain regions or cells
