Prefrontally-mediated alterations in the retrieval of negative events: Links to memory vividness across the adult lifespan

Abstract

Prior research has identified age-by-valence interactions in both behavior and neural recruitment; age has been associated with increased retrieval of positive relative to negative information as well as an increased tendency to recruit prefrontal regions during negative event retrieval and for this recruitment to correspond to decreased hippocampal connectivity. To date, the explicit relation between prefrontal recruitment and memory phenomenology has not been examined. The current study examined the link between these two measures by examining age-by-valence interactions in the relation between prefrontal recruitment and subjective ratings of memory vividness. Participants (ages 18–85) encoded visual images paired with verbal titles. During a scanned retrieval session, they were presented with titles and asked whether each had been seen with an image during encoding. Participants provided vividness ratings following retrieval of each image. Age was associated with greater prefrontally-mediated alterations in negative event phenomenology, with age-related increases in the relation between ventral prefrontal regions and negative event vividness and age-related decreases in the relation between dorsal prefrontal regions and negative event vividness. This analysis confirmed a critical role of PFC regions in age-by-valence interactions, where age reversed the relation between PFC recruitment and the subjective richness of retrieved memory representation. These findings are consistent with studies that reveal age-related enhancements in emotion regulation, and suggest that older adults may be engaging in these processes during retrieval of negative events.

Older adults use a prefrontal regulatory mechanism to reduce negative memory vividness of a highly emotional real-world event

“…No regions exhibited age-by-valence interactions on neural recruitment, meaning that no regions exhibited greater valence effects in young relative to older adults. Replicating prior episodic memory findings 3 , age-by-phase interactions were identified in posterior sensory regions (see Figure 1), driven by greater age-related decreases in recruitment during search relative to elaboration. In fact, conjunction analyses identified two sub-regions in which age was associated with significant decreases in recruitment during search and significant increases in recruitment during elaboration (Figure 1).…”

“…In this prior study of episodic retrieval, activation of the dorsomedial prefrontal cortex (dmPFC) was unrelated to positive event vividness across the adult lifespan, but showed age-related reversals for negative event vividness. In young adults, dmPFC recruitment was associated with increased vividness, suggesting a supportive role of this region in detail retrieval, but in older adults, recruitment was associated with decreased vividness ratings 3 . Functional connectivity analyses were conducted to examine a potential mechanism for age-related decreases in vividness.…”

“…The current research extends our prior findings by examining age-related effects during autobiographical memory retrieval. Specifically, the goal of the current analysis was to replicate prior findings from episodic memory research in support of a prefrontal regulatory mechanism 4 and arguing against a sensory deficit explanation 3 . To argue against a sensory deficit explanation, the current analysis would have to show a) that age was not associated with greater decreases in posterior sensory recruitment during negative relative to positive event retrieval, and b) that age-related decreases in recruitment were limited to the initial search phase of retrieval.…”

Prefrontal contributions to the stability and variability of thought and conscious experience

“…A gist disregards the low-level features of an event so that the relationships between multiple diverse stimuli may be made more salient [249], allowing behavior and cognition to become organized around higher-level properties of the world. In terms of emotional gist, increased neural activation in the dMPFC is associated with greater vividness of recollection when recalling negatively-valenced episodic memories in younger adults but positively-valenced episodic memories in older adults [266]. This may imply that the dMPFC helps to coordinate the recollection of a memory through its associated emotional gist, depending upon an observer's motivations or goals at the time of retrieval.…”

“…This may imply that the dMPFC helps to coordinate the recollection of a memory through its associated emotional gist, depending upon an observer’s motivations or goals at the time of retrieval. As age increases, motivational priorities tend to shift so that negatively-valenced emotional experiences are downregulated in favor of positively-valenced ones [ 267 ], potentially accounting for the age-dependent differences in valenced memory-retrieval associated with dMPFC activation [ 266 ].…”