Binding neutral information to emotional contexts: Brain dynamics of long-term recognition memory

Abstract

There is abundant evidence in memory research that emotional stimuli are better remembered than neutral stimuli. However, effects of an emotionally charged context on memory for associated neutral elements is also important, particularly in trauma and stress-related disorders, where strong memories are often activated by neutral cues due to their emotional associations. In the present study, we used event-related potentials (ERPs) to investigate long-term recognition memory (1-week delay) for neutral objects that had been paired with emotionally arousing or neutral scenes during encoding. Context effects were clearly evident in the ERPs: An early frontal ERP old/new difference (300-500 ms) was enhanced for objects encoded in unpleasant compared to pleasant and neutral contexts; and a late centralparietal old/new difference (400-700 ms) was observed for objects paired with both pleasant and unpleasant contexts but not for items paired with neutral backgrounds. Interestingly, objects encoded in emotional contexts (and novel objects) also prompted an enhanced frontal early (180-220 ms) positivity compared to objects paired with neutral scenes indicating early perceptual significance. The present data suggest that emotional-particularly unpleasantbackgrounds strengthen memory for items encountered within these contexts and engage automatic and explicit recognition processes. These results could help in understanding binding mechanisms involved in the activation of trauma-related memories by neutral cues.

Local context influences memory for emotional stimuli but not electrophysiological markers of emotion-dependent attention

“…We propose, therefore, that an emotional stimulus retrieves its emotional context together with its temporal context, thereby helping the recall of further emotional items that share the same emotional context, while hindering recall of stimuli with a different (neutral) context (Polyn et al, 2009). This interpretation is directly supported by evidence that objects that have been paired just once with an emotional context are associated with enhanced LPP magnitude and enhanced old-new effects during a subsequent recognition test (Ventura-Bort, Low, et al, 2016;Ventura-Bort, Löw, et al, 2016). Further, this interpretation is also supported by findings that participants who recall mixed lists of emotional and neutral stimuli tend to recall emotional stimuli closely after other emotional stimuli, demonstrating semantic clustering effects around the emotional category (Long et al, 2015;Talmi et al, 2007).…”

Local context influences memory for emotional stimuli but not electrophysiological markers of emotion‐dependent attention

“…We propose, therefore, that an emotional stimulus retrieves its emotional context together with its temporal context, thereby helping the recall of further emotional items that share the same emotional context, while hindering recall of stimuli with a different (neutral) context (Polyn et al, ). This interpretation is directly supported by evidence that objects that have been paired just once with an emotional context are associated with enhanced LPP magnitude and enhanced old‐new effects during a subsequent recognition test (Ventura‐Bort, Low, Wendt, Dolcos et al, ; Ventura‐Bort, Löw, Wendt, Moltó et al, ). Further, this interpretation is also supported by findings that participants who recall mixed lists of emotional and neutral stimuli tend to recall emotional stimuli closely after other emotional stimuli, demonstrating semantic clustering effects around the emotional category (Long, Danoff, & Kahana, ; Talmi et al, ).…”

When neutral turns significant: brain dynamics of rapidly formed associations between neutral stimuli and emotional contexts

“…In another study, Dolcos & Cabeza () observed that enhanced elaborated processing during encoding, as indexed by LPP amplitude, predicted better long‐term memory performance for emotional information. Consistent with this, we have recently observed that objects paired with emotional, relative to neutral contexts, elicited enhanced electrophysiological correlates implicated in mnemonic retrieval processing (Ventura‐Bort et al ., ). The present study, thus, indicate that faster enhanced perceptual and elaborative processes of neutral information bound to emotional compared to neutral contexts might also promote memory storage (Dolcos & Cabeza, ; Weymar et al ., ; Ventura‐Bort et al ., ).…”

“…Each participant viewed three (out of six) different sets, consisting of a total of 144 neutral objects. Half of the neutral objects (144) were used in a recognition memory task that occurred 1 week later (published elsewhere, see Ventura-Bort et al, 2016). One hundred and forty-four background scenes -48 pleasant, 48 neutral and 48 unpleasantwere selected from the International Affective Picture System (IAPS; Lang et al, 2008) as UCS.…”