EWT: anxiety

• how does anxiety have a negative effect on recall ?

  Johnson and Scott had participants believe they were in a lab study. While in the waiting room one group of participants overheard a casual conversation and after saw a man walk out with a pen and grease. The other group overheard a heated argument and saw a man walk out with a knife covered in blood. The participants were told to identify the person seeing 50 photos.49% could identify the man holding the pen whereas 33% could identify the man holding the knife. This is because they were focused on the weapon.
• how does anxiety have a positive effect on recall?

  Yuville and Cutshall used an actual shooting in a gun shop and there were 21 witnesses and 13 took part in a study. They were interviewed 4 or 5 months after the incident. The accuracy was based on the details and they were asked who stressed they were during the incident.The witnesses were all very accurate and there was a little change in accuracy. Those who were the most stressed were most accurate. This is because anxiety may have enhanced recall.
• what is a limitation for anxiety ?

  The reason the participants focused on the weapon was because they were surprised rather than scared. This suggests that weapon focus effect is due to unusualness rather than anxiety/threat and therefore tells us nothing specifically about the  effects of anxiety on EWT
• what support is there for negative effect ?

  Valentine and Mesout supports the research on weapon focus, finding negative effects in recall. The researchers used an objective measure(heart rate) to divide participants into low and high anxiety groups. In this study anxiety disrupted the participants ability to recall details about the actor in the London Dungeons labyrinth. This suggests that a high level of anxiety does have  a negative effect on recall 
• what is support for positive effects?

  Christiansen and Hubinette interviewed 58 witnesses to actual bank robberies. Recall was more than 75% accurate across all witnesses. Direct victims were more accurate.Confirms anxiety does not reduce accuracy of recall 
• what is a limitation for positive effects ?

  They interviewed their participants several months after the event. The researchers had no controls over what had happened during that time. The effects of anxiety could have been overwhelmed by these other factors. A lack of confounding variables may be responsible for these findings invalidating their support