Research by Sander and Grafman has suggested that the amygdala serves to not only process fear-inducing stimuli but also to determine which information is relevant for encoding. This suggests that the amygdala plays a role in determining what to pay attention to during the crime. In situations where a weapon is present, witnesses tend to focus on the object of arousal and miss peripheral details, like the identity of the perpetrator. This explanation relies on Easterbrook's (1959) theory that stress causes a reduction in mental resources, thus the range of cues a subject can attend to in this situation will be significantly reduced. In a dangerous situation where a weapon is present, survival becomes the most important facets and peripheral information is overlooked. This means that the witness has a heightened memory for the weapon, but may struggle to recall other information. Over time, research into the role of anxiety on weapon focus has produced inconsistent findings, causing researchers to look at alternative causes of the phenomenon. The relative contributions of both arousal and unusualness remain one of the primary theoretical issues in this literature, with some authors arguing for a contribution of both. Another potential cause of weapon focus is the "automatic capture" explanation. This suggests that the attention paid to a weapon is automatic and unintentional. Studies have been performed that show that even if a subject is asked to ignore specific stimuli they are unable to, thus indicating an automatic response. Remington et al. (1992) conclude that a participant might intend to ignore an event, but their attention is often automatically captured by it - as such, an eyewitness may not intend to solely focus on a weapon, but if their diversion of attention to it cannot be controlled, they possess little ability to ignore it. Yantis and Jonides (1996) suggest that it makes adaptive sense for humans to divert attention towards new objects, as a new representation has to be created for that object, presenting another explanation for the weapon focus phenomenon. However, they also conclude that attention focus is not automatic and can be directed on command, especially if attention is already focused somewhere specific. If attention is already focused away from a certain stimulus, then automatic capture is avoidable. Differences in weapon focus effects Differences in eyewitness memory can be attributed to whether the perpetrator holding a weapon is consistent with the eyewitness's schema.