THE EFFECTS OF WEAPON FOCUS AND AROUSAL ON EYEWITNESS RECALL (AMNESIA, IDENTIFICATION)

Eyewitnesses to crimes frequently confront a perpetrator with a weapon, leading some investigators to label a less complete (or error-laden) recall of the perpetrator's features as "Weapon Focus." This research tested the hypothesis that the mere presence of a weapon in a mock crime scene is the principal explanation for poorer recall. In a series of studies involving the manipulation of weapon type, timing of onset and total exposure time, evidence was produced which significantly confirmed this hypothesis. The weapon focus effect on recall also occurred in the absence of arousal although arousal often accompanies a witness' response to the sight of a weapon in a crime situation. It was concluded that the weapon, a highly salient stimulus, competes with the features of the perpetrator for the total amount of viewing time and leads to the "Weapon Focus" decrement in feature accuracy recall. Investigation of the effect of arousal itself was done with a paradigm in which a highly shocking stimulus, a gruesome autopsy picture labeled as a police photo, was placed in a series of neutral pictures presented in a fixed order. In the control condition, the arousing effect of the same autopsy picture was reduced by attributing the source of the photo to a movie studio (M.G.M.). Contrary to previous research by Loftus and Burns (1983) showing a retrograde amnesia effect for stimuli preceeding the high-shock stimulus, the present studies produced an anterograde amnesia effect. The high arousal appears to disrupt the processing of the neutral stimuli which follow it.