Lecture 12: Applied Cognitive Psychology Flashcards
What is change blindness?
- Change blindness is when a change in a visual stimulus is not detected even though you are looking for a change
- first considered in relation to eye saccades: people do not notice a change in a stimulus when moved eyes
What is often used to study change blindness?
Flicker paradigm” often used:
- introduces a large number of transients, not just the changing object
What is inattentional blindness?
Inattentional blindness is the failure to notice an object that is fully visible
How can inattentional blindness be minimized?
although inattentional blindness cannot be completely avoided, we can minimalize this by allocating our attention appropriately
- driving: allocate full attention to the task
- texting: do not text while driving…
- some technologies designed to aid may actually increase inattentional blindness (e.g., HUDs)
What are aircraft HUDs and why were they introduced?
- traditionally aircraft have head-down cockpits which means that pilots must look down and inside to read instruments
- HUDs introduced to maximize head-up, eyesout time.
- runway approaches
- low-level flight (helicopters)
- search and rescue
Do HUDs assist pilots?
- Yes: HUDs enhance performance in specific tasks (e.g., flight path maintenance, glide slope)
- However, HUDs may cause other problems…
What problems may HUDs cause?
Simulator-based studies have shown that pilots tend to miss (or be slow to respond) to events in the external scene when using a HUD.
- Example: runway incursions
- Not caused by visual clutter
What did the driving simulator study find?
- Compared: digital HUD vs. Standard instrument panel
- Speed monitoring (deviations)
- Lane deviations
- Good part: Speed HUD helped drivers keep to the posted speeds (speed decreased with HUD)
- Bad part: drivers showed larger deviations in lane position
What are the costs and benefits of a simple digital speed HUD?
- Benefit: better speed monitoring
- Cost: worse control of lane positioning
How do HUDs affect attention?
- HUD technologies may lead to inattentional blindness
- attention is focused on the HUD at expense of not attending to other information
- In the applied literature, inattentional blindness with HUDs has been called Cognitive Tunneling and this has been linked to object-based attention.
How do HUDs cause cognitive tunnelling?
- Focusing of attention onto a HUD. Why does this happen?
- HUD is a perceptual “object”
- HUD is a perceptual object that is separate from the external scene
- we know that attention is object-based: the HUD grabs and holds attention
What is object based attention?
Stage 1: elements are grouped into perceptual objects based on Gestalt principles
Stage 2: attention is allocated to perceptual objects
Key: Processing across objects requires moving attention from one object to another object
Does grouping by common fate support object-based attention?
Yes. Detection is better if targets appear on either the same object (moving or static), compared to when targets appear across these objects.
What do common fate tasks show?
- During common fate task two of the dots are going to change colour and our task is to respond as quickly as we can by pushing a button to say if they changed to the same colour or a different colour. Some dots are going to move, the colour changes either happen on the static dots or the moving dots (same object) OR one on a static and one on a moving (across objects)
- Do 1100 trials and look at accuracy and speed on same objects (either just moving dots or just static) vs. different objects (change on one moving dot and one static)
What is the perceptual mechanism (gestalt) that groups a HUD into an object?
Common fate
