Box 2. Models of Selective Memory Enhancements. There has been longstanding interest in the “memory trade-offs” that occur for emotional memories. Loftus et al. (1987) noted the “weapon focus effect,” whereby individuals remember a weapon but not details of the perpetrator or broader context. Similarly, Reisberg and Heuer (2007) described “emotional memory narrowing,” and Safer et al. (1998) discussed “tunnel memory.” Adolphs et al. (2001) described how emotion seemed to enhance the gist for what had happened but to impair memory for details, and Kensinger and colleagues (Kensinger et al., 2005; Kensinger & Schacter, 2006a) described how emotion can lead central details to be remembered at the expense of their peripheral context. The Arousal Biased Competition (ABC) theory (Mather & Sutherland, 2011) rooted these findings in the biased competition literature (Desimone & Duncan, 1995). Biased competition models essentially propose that there is a tug-of-war for attentional resources, with high-priority stimuli winning and low-priority stimuli losing. ABC suggests that in the presence of arousal, there is an amplification of this tug-of-war, such that the high-priority stimuli take even more of the resources and the low-priority stimuli are left with even less. Support for this model has come from behavioral studies, showing that when a shock or other arousing stimulus is presented, it leads to a greater discrepancy in processing and in memory for the high-priority stimuli (Sutherland & Mather, 2012). Additionally, a neuroimaging study showed that relative to a CS- control tone, when a CS+ tone (predicting a shock) was played, there was both enhanced visual activity for a high-priority visual stimulus and also reduced activity for the low-priority stimulus (Lee et al., 2014). These results suggest that arousal does not uniformly enhance perceptual processing but may do so specifically for high-priority content (see also Clewett & Murty, 2019). It has more recently been proposed, and formalized in the Glutamate Amplifies Noradrenergic Effects (GANE) model, that the neurobiological mechanism underlying this arousal-biased competition may be that “hot spots” are created by synergies between norepinephrine and glutamate release (Mather et al., 2016).