A meta-analysis of the survival-processing advantage in memory

Does source reliability moderate the survival processing effect? The role of linguistic markers as reliability cues

Adaptive memory retains information that would increase survival chances and reproductive success, resulting in the survival processing effect. Less is known about whether the reliability of the information interacts with the survival processing effect. From an adaptive point, information from reliable sources should lead to better encoding of information, particularly in a survival context. In Turkish, specific linguistic components called evidentiality markers encode whether the information presented is firsthand (direct) or not (indirect), providing insight into source reliability. In two experiments, we examined the effect of evidentiality markers on recall across survival and nonsurvival (moving) contexts, predicting that the survival processing effect would be stronger for information marked with evidentiality markers indicating direct information. Results of both experiments yielded a robust survival processing effect, as the sentences processed for their relevance to survival were better remembered than those processed for their relevance to nonsurvival events. Yet the marker type did not affect retention, regardless of being tested as a between- or within-subject factor. Specifically, the survival processing effect persisted even with evidentiality markers indicating indirect information, which suggests that the processing of survival-related information may be privileged even if potentially unreliable. We discuss these results in the context of recent studies of the interaction of language with memory.

The survival processing effect in episodic memory in older adults and stroke patients

In the present study, we tested whether processing information in the context of an ancestral survival scenario enhances episodic memory performance in older adults and in stroke patients. In an online study (Experiment 1), healthy young and older adults rated words according to their relevance to an ancestral survival scenario, and subsequent free recall performance was compared to a pleasantness judgment task and a moving scenario task in a within-subject design. The typical survival processing effect was replicated: Recall rates were highest in the survival task, followed by the moving and the pleasantness judgment task. Although older adults showed overall lower recall rates, there was no evidence for differences between the age groups in the condition effects. Experiment 2 was conducted in a neurological rehabilitation clinic with a sample of patients who had suffered from a stroke within the past 5 months. On the group level, Experiment 2 revealed no significant difference in recall rates between the three conditions. However, when accounting for overall memory abilities and executive function, independently measured in standardized neuropsychological tests, patients showed a significant survival processing effect. Furthermore, only patients with high executive function scores benefitted from the scenario tasks, suggesting that intact executive function may be necessary for a mnemonic benefit. Taken together, our results support the idea that the survival processing task - a well-studied task in the field of experimental psychology - may be incorporated into a strategy to compensate for memory dysfunction.

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.

Survival processing and directed forgetting: enhanced memory for both to-be-remembered and to-be-forgotten information

In a recently published study, (Parker, A., Parkin, A., & Dagnall, N. (2021). Effects of survival processing on list method directed forgetting. Memory (Hove, England), 29(5), 645-661) examined directed forgetting in a survival processing context using the list-method directed forgetting procedure. (Parker, A., Parkin, A., & Dagnall, N. (2021). Effects of survival processing on list method directed forgetting. Memory (Hove, England), 29(5), 645-661) found that the costs of directed forgetting were greater when engaging in survival processing than when making moving relevance or pleasantness ratings. However, according to most current accounts of directed forgetting, engaging in survival processing should not have enhanced the directed forgetting effect but rather should not have impacted the directed forgetting effect. In the present study, we further investigated how survival processing impacts directed forgetting using both the list (Experiment 1) and item method of directed forgetting (Experiment 2). In Experiment 1, we did not replicate the findings of (Parker, A., Parkin, A., & Dagnall, N. (2021). Effects of survival processing on list method directed forgetting. Memory (Hove, England), 29(5), 645-661) - that the directed forgetting effect is enhanced when engaging in survival processing. Rather, we demonstrated that making survival ratings and moving ratings yielded a similar cost of directed forgetting for List 1 items. In Experiment 2, survival processing provided an overall memory benefit (but not when recalling to-be-remembered and to-be-forgotten items in separate recall tests) but did not differentially impact to-be-remembered and to-be-forgotten words. Thus, we did not find evidence that survival processing influences directed forgetting.

Differing Effects of Nociception and Pain Memory on Isometric Muscle Strength in Participants With and Without a History of Injury: A Quasi-Experimental Study

OBJECTIVE

The goals of this study are to establish whether mechanical pressure pain, short-term memory recall of a painful stimulus, or long-term memory of a previous painful lower limb injury alters isometric muscle strength and whether there was a difference in responses between participants with and without a previous history of injury.

DESIGN

Fifty-nine pain-free participants (29 with previous injury and 30 without) participated in this study. Tibialis anterior isometric muscle strength was compared pre- and post-noxious mechanical stimulus with instructions to recall pain (short- and long-term).

RESULTS

Short- and long-term pain recall produced a significant reduction in muscle strength (short-term: F (1,57) = 160.472, P < 0.001; long-term: F (1,57) = 128.899, P < 0.001). A greater decrease was experienced with short- and long-term pain memory than exposure to mechanical pain (mechanical pain: -14.8% or -32.98 kg, 95% confidence interval [CI], -41.57 to -24.19; short-term: -24.1% or -52.70 kg, 95% CI = -60.98 to -44.34; long-term: -20.3% or -44.63 kg, 95% CI = -52.77 to -36.95). There was no significant difference in responses associated with an injury history.

CONCLUSIONS

Findings suggest that recalled pain memory can impact motor responses and calls attention to the role of past injury history in the rehabilitation process.

A direct replication and extension of Popp and Serra (2016, experiment 1): better free recall and worse cued recall of animal names than object names, accounting for semantic similarity

Introduction

Free recall tends to be better for names of animate concepts such as animals than for names of inanimate objects. In Popp and Serra's 2016 article, the authors replicated this "animacy effect" in free recall but when participants studied words in pairs (animate-animate pairs intermixed with inanimate-inanimate pairs) and were tested with cued recall, performance was better for inanimate-inanimate pairs than for animate-animate pairs ("reverse animacy"). We tested the replicability of this surprising effect and one possible explanation for the effect (semantic similarity).

Methods

Our Experiment 1 was a preregistered direct replication (N = 101) of Popp and Serra's Experiment 1 (mixed-lists condition). In a second preregistered experiment conducted in four different samples (undergraduate N = 153, undergraduate N = 143, online Prolific N = 101, online Prolific/English-as-a-first-language N = 150), we manipulated the within-category semantic similarity of animal and object wordlists.

Results

AIn Experiment 1, just as in Popp and Serra, we observed an animacy effect for free recall and a reverse animacy effect for cued recall. Unlike Popp and Serra, we found that controlling for interference effects rendered the reverse animacy effect non-significant. We took this as evidence that characteristics of the stimulus sets (e.g., category structure, within-category similarity) may play a role in animacy and reverse animacy effects. In Experiment 2, in three out of our four samples, we observed reverse animacy effects when within-category similarity was higher for animals and when within-category similarity was equated for animals and objects.

Discussion

Our results suggest that the reverse animacy effect observed in Popp and Serra's 2016 article is a robust and replicable effect, but that semantic similarity alone cannot explain the effect.

Surviving with story characters: What do we remember?

Readers simulate story characters' emotions, memories, and perceptual experiences. The current study consists of three experiments that investigated whether survival threat would amplify the mnemonic experience of a narrative. First, a replication study of Nairne et al. (Journal of Experimental Psychology: Learning, Memory, and Cognition, 33 (2), 263-273, 2007) was conducted with minor methodological alternations and yielded improved recall for participants imagining themselves in a survival scenario over a moving scenario (Experiment 1). In Experiments 2 and 3, participants read stories about a character either stranded in the grasslands or moving to a foreign land. Improved recall for objects included in the story (Experiments 2 and 3) and recognition of story details (Experiment 3) was found when the character was in a survival situation. The largest effects were observed when the reader was asked to imagine themselves as the story character (Experiment 3). Overall, readers remembered survival-relevant details as if they were experiencing the story character's plight. These results extend research showing that survival processing enhances memory for word lists (e.g., Nairne et al., Psychological Science, 19 (2), 176-180, 2008).

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.

Adaptive Education: Learning and Remembering with a Stone-Age Brain

Educators generally accept that basic learning and memory processes are a product of evolution, guided by natural selection. Less well accepted is the idea that ancestral selection pressures continue to shape modern memory functioning. In this article, I review evidence suggesting that attention to nature's criterion-the enhancement of fitness-is needed to explain fully how and why people remember. Thinking functionally about memory, and adopting an evolutionary perspective in the laboratory, has led to recent discoveries with clear implications for learning in the classroom. For example, our memory systems appear to be tuned to animacy (the distinction between living and nonliving things) which, in turn, can play a role in enhancing foreign language acquisition. Effective learning management systems need to align with students' prior knowledge, skill, and interest levels, but also with the inherent content biases or "tunings" that are representative of all people.

Memory for medicinal plants remains in ancient and modern environments suggesting an evolved adaptedness

Adaptive memory is the propensity of human memory to easily store and retrieve important information to deal with challenges related to the Pleistocene. Recent evidence shows that humans have had a multiregional evolution across the African continent, including the rainforests and deciduous forests; however, there is little evidence regarding the implications of these origins and the relevant and recurring challenges of these environments on survival processing advantage in memory. In this study, we conducted an experiment with volunteers to analyze whether adaptive memory operates in the retrieval of important information to solve challenges of using medicinal plants to treat diseases in the ancestral environments of the savanna, rainforests, and deciduous forests compared to the modern environments of desert, tundra, coniferous forest, and urban areas. We used simulated survival environments and asked volunteers (30 per simulated scenario) to imagine themselves sick in one of these environments, and needing to find medicinal plants to treat their disease. The volunteers rated the relevance of 32 words to solve this challenge, followed by a surprise memory test. Our results showed no ancestral priority in recalling relevant information, as both ancestral and modern environments showed a similar recall of relevant information. This suggests that the evolved cognitive apparatus allows human beings to survive and can create survival strategies to face challenges imposed in various environments. We believe that this is only possible if the human mind operates through a flexible cognitive mechanism. This flexibility can reflect, for example, the different environments that the first hominids inhabited and the different dangerous situations that they faced.

Survival processing modulates the neurocognitive mechanisms of episodic encoding

Memories formed in the context of an imagined survival scenario are more easily remembered, but the mechanisms underlying this effect are still under debate. We investigated the neurocognitive processes underlying the survival processing effect by examining event-related potentials (ERPs) during memory encoding. Participants imagined being either stranded in a foreign land and needing to survive, or in an overseas moving (control) scenario, while incidentally encoding a list of words. Words encountered in the survival context were associated with improved recall and reduced false-memory intrusions during a later memory test. Survival processing was associated with an increased frontal slow wave, while there was no effect on the overall P300 amplitude, relative to the control scenario. Furthermore, a subsequent memory effect in the P300 time window was found only in the control scenario. These findings suggest that survival processing leads to a shift away from lower level encoding processes, which are sensitive to motivation and stimulus salience and which were evident in the control scenario, to more active and elaborative forms of encoding. The results are consistent with a richness of encoding account of the survival processing effect and offer novel insights into the encoding processes that lead to enhanced memory for fitness-relevant information.

Effects of survival processing on list method directed forgetting

Two experiments examined the effects of directed (intentional) forgetting on information processed for its survival value. Experiment 1 used the list-method directed forgetting procedure in which items processed for their relevance to survival, moving house or pleasantness were followed by the cue to remember or forget. Following the encoding of a second list, free-recall of both lists showed that survival encoding brought about greater remembering (after the remember cue) and forgetting (after the forget cue). Experiment 2 also used the list-method and manipulated mental context reinstatement prior to recall. Although this manipulation was effective in enhancing memory, more directed forgetting was again shown in the survival condition. In both experiments the effects of survival processing were shown also in free-recall "remember" (vs. "know") responses, indicative of the retrieval of associative or contextual details. The mechanisms that might underpin these were evaluated and considered in relation to future work.

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

Humans preferentially remember information processed for their survival relevance, a memorial benefit known as the survival processing effect. Memory is also biased towards information associated with the prospect of reward. Given the adaptiveness of these effects, they may depend on similar mechanisms. We tested whether motivation drives both effects, with reward incentives that are known to boost extrinsic motivation and survival processing perhaps stimulating intrinsic motivation. Accordingly, we manipulated survival processing and reward incentive independently during an incidental-encoding task in which participants chose between pairs of words concerning their relevance for a scenario, and examined the effects on encoding event-related potentials (ERP) activity and later performance on a surprise recall test. We hypothesized that if survival processing fosters intrinsic motivation, it should reduce the beneficial effects of extrinsic motivation (reward incentive). In contrast to this prediction, we found that reward incentive and survival processing independently improved memory and that the P300, a measure of lower-level cognitive resource allocation, was increased by reward incentive independent of survival processing. Further, survival processing and reward incentive independently increased the frontal slow wave (FSW), a measure of higher-level elaboration. These findings suggest that while survival processing and reward incentive may both increase encoding elaboration, the memory-enhancing effect of survival processing does not depend on increased intrinsic motivation. Additionally, we replicated a recent finding whereby the survival processing effect generalizes to a choice-based encoding task and further showed that the beneficial effect of choice on memory likely does not interact with either survival processing or reward.

Surviving in a second language: survival processing effect in memory of bilinguals

Human memory likely evolved to serve adaptive functions, that is, to help maximise our chances of survival and reproduction. One demonstration of such adaptiveness is the increased retention of information processed in survival contexts, the so-called Survival Processing Effect (SPE). This study examined this effect in a native (L1) and in a second language (L2). This comparison is relevant to explore if emotionality is involved in the SPE, as emotional activation seems to be larger in L1 than in L2. Following the original survival processing procedure, participants rated the relevance of information to the survival and moving scenarios and performed a recognition (Experiment 1) or a free recall (Experiment 2) task in L1 or L2. In both experiments, the SPE was replicated in L1 but not in L2. The absence of the effect when emotional activation is less likely suggests that emotionality might play a role in the survival processing effect; nevertheless, additional studies are needed to further investigate this hypothesis.

Effects of Survival Processing on Item and Context Memory: Enhanced Memory for Survival-Relevant Details

Due to the natural selection pressure, certain aspects of memory may have been selected to give humans a survival advantage. Research has demonstrated that processing information for survival relevance leads to better item memory (i.e., the content of information) compared to control conditions. The current study investigates the effects of survival processing on context memory (i.e., memory for peripheral episodic details) and item memory to better understand when the survival processing memory advantage emerges. In this study, participants studied pictures of objects in either a survival or moving (control) condition. Objects were presented in either a plausible color, for example, a red apple, or in an implausible color, such as a green pie. We chose this color plausibility manipulation because color is a detail that conveys information about the fitness (and other diagnostic information) about an item. After studying items, participants made item memory judgments (did you see this item before?) and two context memory judgments: color context (in which color did you see this item?) and source context (in which condition did you see this item?). Results indicated better item memory for materials processed in the survival relative to moving condition. Critically, for color context, there was a condition by plausibility interaction, where memory was best for plausibly colored items in the survival processing condition. There was no difference, however, in source context memory between the survival and moving conditions. These results suggest the survival processing memory advantage extends to contextual details that particularly reflect the survival utility of items such as color.

Adaptive Memory: Generality of the Parent Processing Effect and Effects of Biological Relatedness on Recall

The adaptive memory framework posits that human memory is an evolved cognitive feature, in which stimuli relevant to fitness are better remembered than neutral stimuli. There is now substantial evidence that processing a neutral stimulus in terms of its relevancy to an imagined ancestral survival scenario enhances recall, although there is still disagreement concerning the proximate mechanisms responsible for this effect. Several other mnemonic biases have recently been discovered that similarly appear to reflect evolutionary pressures, including a bias to remember items relevant to an imagined parenting scenario. We tested the generality of this parent processing effect by varying the biological relatedness of the imagined child. We also varied the biological relatedness of a child during an imagined third-person survival processing scenario. Across four experiments, we found evidence that simply altering the described biological relatedness of a child in the parenting scenario and third-person survival processing scenario can affect recall, such that items are better remembered when made relevant to a biological child compared to an adopted child. How these findings inform the general adaptive memory framework is discussed.

A set of 750 words in Spanish characterized in two survival-related dimensions: avoiding death and locating nourishment

With the aim of finding quantitative indicators of the survival relevance for a set of concrete concepts, a subjective rating task was administered to a large sample of college students (N = 300). In the rating task, participants used a five-point scale to rate 750 concepts in one of two survival-relevant dimensions, providing their own judgment about the relevance of each concept in a situation in which either avoiding death (AD) or obtaining food (OF) was of importance. The subjective ratings showed high stability and reliability and showed varied patterns of association to potentially relevant concept-defining variables, with correlational analyses showing both commonalities and differences between the two rated dimensions. Regression analyses indicated that, while not likely to modulate word accessibility, survival ratings were related to certain conceptual properties that could be especially sensitive for threat detection. The collected data set provides normative information that can be of use in manipulating and controlling verbal stimuli in future research focusing on adaptive properties of episodic memory and other aspects of the human cognitive system. The complete norms are available for downloading at Open Science Framework ( https://osf.io/sf9mb/ ).

Paired-associate learning, animacy, and imageability effects in the survival advantage

The current study examined animacy and paired-associate learning through a survival-processing paradigm (Nairne et al. in Journal of Experimental Psychology: Learning, Memory, and Cognition, 33(2), 263-273, 2007; Schwartz & Brothers, 2014). English-speaking monolingual participants were asked to learn a set of new word translations to improve their chances of survival or to improve their study abroad experience. Animate and inanimate words were included in this task, to further examine animacy effects in cued recall paradigms (Popp & Serra in Journal of Experimental Psychology: Learning, Memory, and Cognition, 42(2), 186-201, 2016; VanArsdall et al. in Experimental Psychology, 60(3), 172-178, 2013). Across sentence-completion, matching, and picture-naming tasks, learning was facilitated by the survival context, relative to the study abroad context and an intentional learning condition. Scenario ratings indicated this survival advantage could also be a function of higher imageability ratings for the survival context than for the study abroad context. Replicating previous findings with cued recall, inanimate words were overall better remembered than animate words, across all three tasks, though survival processing facilitated language-learning for both animate and inanimate categories. This 'reverse animacy effect' replicated previous findings by Popp and Serra (Journal of Experimental Psychology: Learning, Memory, and Cognition, 42(2), 186-201, 2016), showing animate words can interfere with a participant's ability to create associations with their words, including those in a new language. These results are discussed with regards to the widely-reliable survival and animacy advantages, with a particular emphasis on the role of imageability in this paradigm.

Survival Processing in a Novel Choice Procedure

People remember information that has been processed for survival relevance particularly well, perhaps because our memory systems have been tuned by natural selection to retain information pertinent to inclusive fitness. In the standard procedure, people rate the relevance of single words or objects to an imagined survival scenario and then receive a surprise retention test for the rated items. Here we replicate the survival advantage in a novel choice procedure in which people are asked to choose which of two items would be most useful in a survival context or in a “moving” (Experiment 1) or “scavenger hunt” (Experiment 2) control context. Chosen items were remembered better than unchosen items, and the survival processing advantage did not interact with the choice effect. Experiment 2 replicates this pattern using the matched-scenario design first used by Nairne, Pandeirada, Gregory, and VanArsdall (2009). These experiments extend the generality of the survival advantage and provide diagnostic information about its underlying proximate mechanisms.

The Survival Processing Advantage of Face: The Memorization of the (Un)Trustworthy Face Contributes More to Survival Adaptation

Researchers have found that compared with other existing conditions (e.g., pleasantness), information relevant to survival produced a higher rate of retrieval; this effect is known as the survival processing advantage (SPA). Previous experiments have examined that the advantage of memory can be extended to some different types of visual pictorial material, such as pictures and short video clips, but there were some arguments for whether face stimulus could be seen as a boundary condition of SPA. The current work explores whether there is a mnemonic advantage to different trustworthiness of face for human adaptation. In two experiments, we manipulated the facial trustworthiness (untrustworthy, neutral, and trustworthy), which is believed to provide information regarding survival decisions. Participants were asked to predict their avoidance or approach response tendency, when encountering strangers (represented by three classified faces of trustworthiness) in a survival scenario and the control scenario. The final surprise memory tests revealed that it was better to recognize both the trustworthy faces and untrustworthy faces, when the task was related to survival. Experiment 1 demonstrated the existence of a SPA in the bipolarity of facial untrustworthiness and trustworthiness. In Experiment 2, we replicated the SPA of trustworthy and untrustworthy face recognitions using a matched design, where we found this kind of memory benefits only in recognition tasks but not in source memory tasks. These results extend the generality of SPAs to face domain.