Psychology AS - Memory

In this experiment to test for accuracy of eye witness testimony Loftus and Palmer asked leading questions - an question which has a subtle suggestion tricking the eye witness into remebering the the misleading verb or information.

In this case participants were shown a video of a car crash and then asked questions about it. one group was asked "how fast were the cars as they bumped into each other" and another group "how fast were the cars as they crashed into each other"

The results were that:

Participants asked the 'bumped' question made a low speed estimate, and the participants asked the 'crashed' question made a high speed estimate!

Their stdy proved that leading questions and provvocative verbs can alter recollection

Participants were shown events leading up to a car accident. This included a slide showing a red sports car at a STOP or a Yield junction.

After watching the events leading up to the accident participants were asked a number of questions, including one question about the STOP or Yield junction sign.

finally participants were show both slides of the yield and stop sign junctions and were asked about which they had seen...

The trick was there were 2 conditions

CONSISTENT CONDITION

participants who saw the stop sign the first time were shown the stop sign 

participants who saw the yield sign the first time were shown the yield sign

INCONSISTENT CONDITION

participants who saw the first sign saw a different after

e.g saw stop shown yield and vice versa

Loftus and Palmer found...

75% of those given the consistent question gave a correct identification

41% were correct in the inconsistent condintion (where the post event info was misleading)

This suggests that...

...even when people are tested visually the accuracy is affected by misleading information.

...it is true that post event information alters a witness's memory for an event.