Adaptive Memory: Independent Effects of Survival Processing and Reward Motivation on Memory

Survival processing occupies the central bottleneck of cognitive processing: A psychological refractory period analysis

Words judged for relevance in a survival situation are remembered better than words judged for relevance in a nonsurvival context. This survival processing effect has been explained by selective tuning of human memory during evolution to process and retain information specifically relevant for survival. According to the richness-of-encoding hypothesis the survival processing effect arises from a domain-general mechanism-namely, a particularly rich and distinct form of encoding. This form of information processing is effortful and requires limited cognitive capacities. In our experiment, we used the well-established psychological refractory period framework in conjunction with the effect propagation logic to assess the role of central cognitive resources for the survival processing effect. Our data demonstrate that the survival memory advantage indeed relies on the capacity-limited central stage of cognitive processing. Thus, rating words in the context of a survival scenario involves central processing resources to a greater amount than rating words in a nonsurvival control condition. We discuss implications for theories of the survival processing effect.

Reward association impairs recognition of incidentally encoded negative information: Electrophysiological evidence

Previous studies investigating the effect of reward on emotional episodic memory have produced inconsistent results. In this study, through two experiments using event-related potentials (ERPs), we investigated the effect of reward association on the encoding and retrieval of incidentally encoded emotional information, and examined whether this effect changes over time. Participants in the two experiments were asked to discriminate the emotional valence of color images under reward or no-reward condition and incidentally encode them. Immediate (in Experiment 1) or 24-hour delayed (in Experiment 2) recognition after encoding was tested. In Experiments 1 and 2, reward (relative to no-reward) significantly improved the recognition of positive and neutral items, but significantly reduced the recognition of negative items. During encoding, the significant ERP reward effects (significantly more positive ERP amplitude for rewarded items than for non-rewarded ones) for positive and neutral images were widely distributed from 200 to 1500 ms after image onset, while those for negative stimuli occurred mainly from 200 to 500 ms. During retrieval, the significant ERP reward effects for positive and neutral items occurred in the two experiments, but the reversed ERP reward effects for negative items were found only in Experiment 1. The results of the present study suggest that reward association affects the encoding and retrieval of emotional images by enhancing memory processing efficiency of positive and neutral items, while impairing recognition of negative items, thus yielding a robust and sustained modulation over frontal/frontocentral or centroparietal/parietal areas where mechanisms of reward and emotion processing operate in conjunction.

Pre-associative item encoding influences associative memory: Behavioral and ERP evidence

It is unknown whether the manner with which an item is encoded in isolation, immediately before it is encoded into an inter-inter association, influences associative memory. We therefore presented the items of to-be-encoded associative pairings sequentially and manipulated how each first item of a pair was encoded (before associative encoding could begin). Furthermore, we recorded ERPs during memory encoding to investigate the neurocognitive processes that might relate pre-associative item encoding to subsequent associative memory performance. Behaviorally, we found that pre-associative item elaboration (vs. no elaboration) led to a memory tradeoff-enhanced item memory relative to impaired associative memory. This tradeoff likely reflected that item elaboration reduced cognitive resources for ensuing associative encoding, indexed by a reduced P300 and frontal slow wave at the time of associative encoding. However, frontal slow wave subsequent memory effects measured during pre-associative item encoding revealed that, for a given item, greater semantic elaboration was related to better item and associative memory while greater visual elaboration was related to better item and worse associative memory. Thus, there are likely two opposing ways in which pre-associative item encoding can influence associative memory: (1) by depleting encoding resources to impair associative memory and (2) by scaffolding inter-item associations to enhance associative memory. When item encoding occurs immediately before associative encoding, it appears that the temporary depletion of encoding resources is more important in determining later memory performance. Future research should compare the independent effects of resource depletion and encoding strategy during pre-associative item encoding.

Are the main effects of the will to exist, live, survive and fight on optimizing executive function due to its optimizing self-motivation? A longitudinal study

The study aims to identify the mechanisms underlying the findings that will to exist, live, survive and fight (WTELS-F) optimizes executive functions. Defining executive functions (EF) as having cold (working memory, inhibition, and cognitive flexibility) and hot (e.g., motivation) components, we hypothesized that WTELS-F affects executive functions positively via two pathways. The first pathway is through the hot executive function (motivation), and the second is via survival or existential processing. In a longitudinal study of 228 adult participants two times with ten weeks in between, we used measures for WTELS-F, working memory, inhibition, shift/cognitive flexibility, and self-motivation. We tested the structural validity of the four factors' executive function by exploratory factor analysis in time 1 data and confirmatory factor analysis in time 2 data. We conducted structural equation modeling WTELS-F change as a latent variable predicted by the change in its three components between times 1 and 2., affecting changes in self-motivation (the hot EF), and changes in the latent variable of cold EF as predicted by changes in working memory, inhibition, and shift. Results indicated that the model of EF fit the data well without modification. WTELS-F significantly affected self-motivation (the hot EF) and the cold EF longitudinally. It had further mediated effects on cold EF via its impact on self-motivation. The results provided evidence for the two pathways hypothesis of the effects of WTELS-F on EF. The conceptual and clinical implications of these findings were discussed.

Survival processing advantage demonstrated with virtual reality-based survival environment: A promising tool for survival processing research

Many studies have been conducted to demonstrate the survival processing advantage (SPA) as an evolutionary-oriented memory effect. But few studies were conducted to demonstrate this effect in real-life or simulated survival environments. This study tested whether the SPA could be replicated in a survival virtual reality environment (VRE). In Experiment 1, the SPAs were measured in VREs (survival grasslands, survival battlefield, nonsurvival moving) in which Experiment 1A used the standard long instructions and Experiment 1B used the modified short instructions. In Experiment 2, the SPAs were measured again with the scenarios corresponding to the VREs used in Experiment 1A. All experiments demonstrated typical SPAs, suggesting that the survival VRE is a reliable tool in designing and delivering a survival situation. The potential problems of applying survival VRE to survival processing research are discussed at the end.

Realistic context doesn't amplify the survival processing effect: Lessons learned from Covid-19 scenarios

Imagining being stranded in the grasslands of an unknown territory without basic survival materials and subsequently rating the relevance of words for this situation leads to exceptionally good memory for these words. This survival processing effect has received much attention, primarily because it has been argued to disclose the evolutionary foundations of human memory. So far, only fictitious scenarios were used to demonstrate this effect. To provide a fairer test of emotional response against richness-of-encoding explanations of the effect, we aimed at increasing everyday relevance and realism of the survival scenarios. For this purpose, we created two new Covid-19 scenarios, one focusing on emotional response (Covid-19-emotion) and the other on survival strategy (Covid-19-strategy). Both new scenarios were compared to the classical grassland and moving scenarios typically used to investigate the survival processing effect. In Experiment 1, we observed better memory for the grassland and Covid-19-strategy scenarios compared to the other two, but no significant difference between the former. A descriptively similar result pattern emerged in Experiment 2 for the number of ideas generated on how to use objects in the four scenarios. Theoretical implications are discussed.