Cognitive Semester 1 Week 4: Attention mechanisms and processes Flashcards
What is inattentional blindness?
Failure to notice a change in the environment that is in plain sight due to a lack of attention, not a problem with the visual system.
Example of inattentional blindness study
Chabris, Weinberger, Fontaine and Simons (2011) - participants given a task to follow runner maintaining a distance of 30ft. Then they were asked if they’d seen the fight along the route. 72% saw it in daylight, but when given a higher cognitive load such as asking them to count the number of times the runner touches their head, this decreased.
Stages of Broadbent’s Filter Model
1) Inputs
⇉ both attended and unattended information
2) Sensory buffer store - identifies physical characteristics. Unlimited capacity.
⇉ both attended and unattended information
3) Selective filter - Selects one input for further processing based on its physical characteristics. Unattended information cannot pass through.
→ only attended information
4) Higher level processing - extracts meaning from the input
→ only attended information
5) Working memory
Evidence for Broadbent’s model
Shadowing tasks
- A different auditory stimulus is played in each ear
- Participants only report the information they hear in one ear
- Participants struggle to recall the message played in the unattended ear
Stages of Treisman’s Attenuation Theory
1) Inputs
⇉ both attended and unattended information
2) Sensory buffer store - identifies physical characteristics. Unlimited capacity.
⇉ both attended and unattended information
3) Attenuating filter - same function as selective filter. However, unattended inputs still pass through, but only weakly.
⇉ both attended and a very small amount of unattended
4) Dictionary unit - Higher level processing. Inputs given a threshold value; low thresholds are more likely to capture attention even if they aren’t being attended to e.g. hearing your name called from another room.
⇉ both attended and a very small amount of unattended
5) Working memory
Example of the attenuation theory
The cocktail party effect
- Someone calls your name from across the room you will hear them
- Filter out extraneous noises to focus on conversations with your friends
- Some inputs make it through the filter even if we’re not attending to them
Evidence for the attenuation theory
Shadowing tasks - subjects told to attend to one ear, some participants mixed the inputs from both ears to make an output that makes sense.
Difference between filter theories
Broadbent - Inputs ignored based on physical characteristics
Treisman - Inputs attenuated based on physical characteristics
What is attention as a spotlight?
When viewing a visual scene, we focus on a particular part, which can be narrow or broad depending on the task or person.
Example of attention as a spotlight
In “Where’s Wally,” effectively searching a busy scene requires moving our attentional spotlight.
Target detection study (Laberge, 1983)
Easier to detect a target when it’s in the middle of the visual scene. Quicker reaction time for a target number positioned in the middle.
How can our attentional spotlight be shifted?
By environmental cues.
What is endogenous cueing?
- Symbolic of target location, indicated where a target may appear
- Slow, following is voluntary
- Centrally presented
- Driven by internal goals
What is exogenous cueing?
- Appears in the location of a target
- Automatically captures attention e.g. bear roar
- Peripherally presented
- Driven by external events in the environment
What is inhibition of return?
Recently attended locations are less likely to be attended again. Useful for efficient visual searching by encouraging attention to move to new locations.
Effect of a short delay or a long delay between cue and target appearance
Short delay = Quicker to find the target.
Long delay = we move our attention away from target location and inhibition of return delays attention returning to previous locations, so we’re slower to detect the target
What is the Feature Integration Theory?
Separate features identified based on physical characteristics (e.g., colour, shape, sound) are combined by attention to form a unified perception.
Example of Feature Integration Theory
Glancing at colourful objects, you notice features like red, round, and small.
Focusing on one object (e.g., a red apple) integrates these features to form the perception of the apple.
Why is the stroop task difficult according to the Feature Integration Theory?
When the stimulus is incongruent (the colour of the word is different to the word), the features don’t match up to form one perception.
Two types of visual search tasks
Parallel search tasks:
- Target has one distinct feature causing it to ‘pop out’
- can quickly and accurately identify objects
Conjunction search task:
- Target is defined by a combination of features
- More difficult to identify as it shares more features with distractors
What is local and global processing?
Local Processing:
- Small, fine details
- Narrow attentional spotlight
Global Processing:
- Large scale, big picture
- Broaden your attentional spotlight
The right posterior parietal cortex plays an important role in directing attention between local and global information.
What is the Navon task and how does it relate to local and global processing?
Large letter composed of smaller letters (e.g. an s made up of small Hs).
Local processing - attention on small Hs
Global processing - attention on one large S
