Simons and Chabris

Question 1

Define inattentional blindness.

Answer 1

The failure to see an event or object in your field of vision because you are so focused on other elements of what you can see.

Question 2

What was the background to Simons and Chabris’ study?

Answer 2

• Mack and Rock got participants to look at crosses and judge whether the horizontal or vertical line was longer. In one of the trials, an ‘unexpected event’ was present. 25% of participants didn’t notice this.
• Neisser showed participants a video where two teams passed basketballs between them and a woman carrying an umbrella walked across the screen for four seconds. This video was created by separately filming each team and the woman and then overlaying to create a transparent effect. 22 out of 28 participants failed to see the woman.

Question 3

What were the aims of Simons and Chabris’ study?

Answer 3

• To investigate if inattentional blindness would be more likely is the unexpected event was similar to the attended event.
• To find out if particularly unusual events would be more likely to be seen.
• To investigate whether participants would have trouble noticing the unexpected event when they were given a harder task.
• To investigate the effect of the ‘transparent’ video and compare if the same level of blindness would occurs in a more realistic ‘opaque’ video.

Question 4

What were the independent variables in Simons and Chabris’ study?

Answer 4

• The video being opaque or transparent.
• The ‘unexpected event’ being a gorilla or a woman carrying an umbrella.
• Participants counting passes made by the black t-shirt team or the white t-shirt team.
• Participants completing the easy task (counting the total number of passes made by ‘their team’) or the hard task (keeping two separate counts of the number of bounce passes and the number of aerial passes made by ‘their team’).

Question 5

What was the dependent variable in Simons and Chabris’ study?

Answer 5

Whether participants reported seeing the unexpected event or not.

Question 6

What was the sample in Simons and Chabris’ study?

Answer 6

• 228 participants (data was only analysed for 192 participants giving 12 per condition).
• Mostly undergraduate students at Harvard University.

Question 7

What was the procedure in Simons and Chabris’ study?

Answer 7

• Individually, each participant watched a short video which showed two teams playing basketball and also included the unexpected event.
• Participants were asked to record the number of passes ‘their team’ made in their head.
• Once the video had finished they were asked to write down the number of passes they counted and were asked a number of surprise questions.

Question 8

What results were found regarding the type of video in Simons and Chabris’ study?

Answer 8

Participants were more likely to notice the unexpected event when the video was opaque than when it was transparent.

Question 9

What results were found regarding the type of unexpected event in Simons and Chabris’ study?

Answer 9

Participants were more likely to notice the unexpected event when it was more usual (woman with the umbrella) than unusual (gorilla).

Question 10

What results were found regarding the similarity of the unexpected event to the attended event in Simons and Chabris’ study?

Answer 10

Participants were more likely to notice the unexpected event (gorilla) when it was similar to the attended event (counting the passes made by the black t-shirt team).

Question 11

What results were found regarding the difficulty of the counting task in Simons and Chabris’ study?

Answer 11

Participants were more likely to notice the unexpected event when competing an easier task (counting the total number of passes made by their team) than when completing an easier task (keeping two separate counts of the number of bounce passes and the number of aerial passes made by their team).

Question 12

What was the overall level of inattentional blindness in Simons and Chabris’ study?

[Percentage of participants who did not notice the unexpected event]

Answer 12

46%

Question 13

What were the conclusions made from Simons and Chabris’ study?

Answer 13

• Inattentional blindness occurs in dynamic events that are sustained.
• Since many participants missed the unexpected event in the opaque video, inattentional blindness can’t be accounted for as simply a response to a transparent video.