Simons and Chabris (1999) Visual inattention Flashcards
Change blindness
Change in the participantβs visual stimulus is introduced and respondent does not notice it: particularly if those objects are not the centre of interest in the scene.
Inattentional blindness/ perceptual blindness (Mack and Rock 1998)
Where a person doesnβt see the new and unexpected event in their visual field, even if it appears at fixation.
What causes the individual to miss unexpected, important things in their vicinity?
Excessive stimuli in their visual field
What is the correlation between distractions and performance (concentration), in terms of inattentional blindness?
Negative correlation: as the ppt becomes increasingly blind to their distractions, their performance (concentration) improves
Superimposition
the placing of one image on top of the other so you can see the second image through it
BACKGROUND CONTEXT - Describe Neisser et al (1979) experiment
- Observers had a task of focusing on a certain aspect of a dynamic visual scene whilst ignoring the others.
- During the task, an unexpected event occurred (umbrella/gorilla)
- 6 out of 28 of the observers did not see the unexpected event, but could see it when not engaged in the concurrent task.
How does Neisser et al (1979) experiment lead to Simon and Chabrisβ further investigation on inattentional blindness?
- Visually demanding tasks βoverload the brain with excessive stimuli: focus is heightened by ignoring irrelevant objects from the visual scene.
- Simon and Chabris further investigated the phenomena through various variables that affect it via naturalistic, dynamic events.
What was the general aim for the study?
To examine inattentional blindness for complex objects and events in dynamic scenes
What were the other three aims associated to the general aim of the study?
- To consider the role of task difficulty in detection
- Superimposed version vs live version
- To see whether the unusualness of the unexpected event has an effect on detection rates.
What type of experiment was used in the study?
Lab experiment
What was the experimental design used in this study?
Independent measures design
What were the IVs in the study?
- Transparent Umbrella Woman/Gorilla condition
- Opaque Umbrella Woman/Gorilla condition
Four unexpected conditions + task difficulty conditions: - White easy/hard
- Black easy/hard
Overall there was 16 conditions.
If the observers were given the easy or hard task, what did they have to do?
Easy: count the no. of bounce passes made by the attended team (white/black)
Hard: count the no. of bounce AND aerial passes made by the attended team (white/black)
What was the DV in the study?
How many ppts noticed the unexpected event
How many ppts were in the sample and who were they?
228 ppts (referred to as βobserversβ) and they were all undergraduate students.
How was the sample collected?
Volunteer sampling:
- without compensation
- received a candy bar
- paid a single fee in this, and another, unrelated experiment
What were the controls of the study? (DESIGN - MATERIALS)
- passing of basketball to team players in standardised order (P1 β> P2 β> P3 β> P1)
- four video tapes, duration 75 seconds
- passes either bounce or aerial passes + other typical movements i.e dribbling the ball
At what time during the video did the unexpected event occur and how long did the unexpected event last for?
After 44-48 seconds the unexpected event occurred, lasting a duration of 5 seconds
At what time during the video did the unexpected event occur and how long did the unexpected event last for?
After 44-48 seconds the unexpected event occurred, lasting a duration of 5 seconds
What were the two styles of the video?
- Transparent condition: each of the teams and the unexpected event were filmed separately, made partially transparent, then superimposed via digital software.
- Opaque condition: all seven actors filmed simultaneously + rehearsal before filming to eliminate collisions.
