Chronic effect of copper on biology, immunity, and biochemical assessment of Helicoverpa armigera (Lepidoptera; Noctuidae) in laboratory bioassays.

Although copper is an essential element for any organism's well-being, it becomes toxic if present in excess. In the present study, copper was provisioned at 25, 50, and 75 mg/kg in an artificial diet and fed to juvenile larvae of cotton bollworm, Helicoverpa armigera (Lepidoptera; Noctuidae), for 4 generations. The results of this investigation exhibited shortening of larval life in the first 2 generations, but extended duration was observed in third and fourth generations compared to controls, and dietary copper caused reduced total hemocyte counts in all treatments. The number of immunocytes (i.e., granulocytes and plasmatocytes) were also significantly reduced. The changes in activities of certain important enzymes, including catalase, superoxide dismutase, and peroxidases, were seen. Furthermore, after treatment, an increase in the activity of 2 detoxifying enzymes, glutathione s-transferase and acetylcholinesterase, was observed. It is clear that metallothioneins are important in maintaining essential and nonessential metal ion homeostasis. While copper is typically regarded as an important essential metal in an organism's life, excessive amounts can have deteriorating effects. This heavy metal is being used as a nano-based pesticide. Therefore, the present investigation aims to determine the fate of Cu in insects receiving them in new formulations.

Corrigendum: Methylome changes in Lolium perenne associated with long-term colonisation by the endophytic fungus Epichloë sp. LpTG-3 strain AR37.

[This corrects the article DOI: 10.3389/fpls.2023.1258100.].

Neural representation of a one-week delay in remembering information after production and self-generated elaboration encoding strategy.

Many studies have confirmed the memory enhancement effect of production, generation and elaboration which can be effective after only one encoding. It is also known that greater memory enhancement effects can be obtained by combining multiple memory strategies during encoding. This study aimed to investigate whether the combination of production and self-generated elaboration enhances memory performance compared with production or generation alone. A total of 23 undergraduate and graduate students participated in this study. In the functional magnetic resonance imaging analysis, we explored the neural representation of remembering information after production and self-generated elaboration strategy. We set four encoding strategy conditions: (1) Read Silent (read without production), (2) Read Aloud (only production), (3) Add Silent (self-generated elaboration without production), (4) Add Aloud (production and self-generated elaboration). The retrieval performance and brain activity while retrieving the learned sentences after a one-week delay were examined. The behavioral results showed that the highest memory performance was for sentences encoded in Add Aloud. The interaction between production and self-generated elaboration was statistically significant. These results suggest that the memory enhancement effect of combining production and self-generated elaboration is not a simple addition nor synergistic facilitation effect. The imaging results showed that the following areas were related to the retrieval of the target encoded in the add aloud condition: the area related to integration of internal and external information (precuneus), area related to information rich stimuli (lateral occipital lobe), area related to self-involvement and inference of others' feelings (MPFC), area related to seen imagery (retrosplenial region) and area related to adjustment of movement (cerebellum). These results suggest that with an encoding strategy that combines production and self-generated elaboration, integrated auditory input of vocalizations and generated images, visual images of the scene, self-relevance, inference of other's feeling, movement by moving mouth are stored with the target and enhanced memory performance of AA.

Methylome changes in Lolium perenne associated with long-term colonisation by the endophytic fungus Epichloë sp. LpTG-3 strain AR37.

Epichloë spp. often form mutualistic interactions with cool-season grasses, such as Lolium perenne. However, the molecular mechanisms underlying this interaction remain poorly understood. In this study, we employed reduced representation bisulfite sequencing method (epiGBS) to investigate the impact of the Epichloë sp. LpTG-3 strain AR37 on the methylome of L. perenne across multiple grass generations and under drought stress conditions. Our results showed that the presence of the endophyte leads to a decrease in DNA methylation across genomic features, with differentially methylated regions primarily located in intergenic regions and CHH contexts. The presence of the endophyte was consistently associated with hypomethylation in plants across generations. This research sheds new light on the molecular mechanisms governing the mutualistic interaction between Epichloë sp. LpTG-3 strain AR37 and L. perenne. It underscores the role of methylation changes associated with endophyte infection and suggests that the observed global DNA hypomethylation in L. perenne may be influenced by factors such as the duration of the endophyte-plant association and the accumulation of genetic and epigenetic changes over time.

The influence of information generation on destination memory.

To remember to whom we transmit information, we rely on destination memory, with worse performance occurring when participants share personal facts (e.g., my age is . . .) compared with interesting ones (e.g., a shrimp's heart is in its head). When reporting personal information, the internal attentional focus decreases the attentional resources available to associate that information with recipients, resulting in worse destination memory. Given that the poorer destination memory when participants transmitted personal facts was always compared with the transmission of interesting facts, in Experiment 1 (between-participants design: 41 participants) and Experiment 2 (within-participants design: 30 participants), we compared the generation and transmission of personal facts with the transmission of familiar proverbs. Again, the generation and transmission of personal facts hampered destination memory. Besides the type of information (personal vs. familiar proverbs), the conditions differed regarding the type of process (generation vs. transmission of information). To clarify the influence of generation on destination memory, in Experiment 3 (N = 31), participants (1) transmitted and (2) generated and transmitted familiar proverbs, and significant differences in destination memory between the conditions was not observed. In general, our experiments seem to support the assumption that transmitting personal information leads to worse destination memory not because participants generated the information but because personal facts drive the attentional focus to the self.

Effects of Parental Dietary Restriction on Offspring Fitness in Drosophila melanogaster.

Dietary restriction (DR) is a well-established strategy to increase lifespan and stress resistance in many eukaryotic species. In addition, individuals fed a restricted diet typically reduce or completely shut down reproduction compared to individuals fed a full diet. Although the parental environment can lead to changes epigenetically in offspring gene expression, little is known about the role of the parental (F0) diet on the fitness of their offspring (F1). This study investigated the lifespan, stress resistance, development, body weight, fecundity, and feeding rate in offspring from parental flies exposed to a full or restricted diet. The offspring flies of the parental DR showed increases in body weight, resistance to various stressors, and lifespan, but the development and fecundity were unaffected. Interestingly, parental DR reduced the feeding rate of their offspring. This study suggests that the effect of DR can extend beyond the exposed individual to their offspring, and it should be considered in both theoretical and empirical studies of senescence.

Generative processing and emotional false memories: a generation "cost" for negative false memory formation but only after delay.

Previous research shows that manipulations (e.g. levels-of-processing) that facilitate true memory often increase susceptibility to false memory. An exception is the generation effect. Using the Deese/Roediger-McDermott (DRM) paradigm, Soraci et al. found that generating rather than reading list items led to an increase in true but not false memories. They argued that generation led to enhanced item-distinctiveness that drove down false memory production. In the current study, we investigated the effects of generative processing on valenced stimuli and after a delayed retention interval to examine factors that may lead to a generation effect that increases false memories. At the immediate test, false recognition rates for both negative and neutral valanced critical lures were similar across read and generate conditions. However, after a one-week delay, we saw a valence differentiation, with a generation effect for false recognition but only for negative stimuli. The roles of item-specific and relational processing during encoding and their interaction with long-term retention are discussed.

Episodic memory and ageing: the role of cognitive reserve factors and cognitive resources according to task difficulty.

BACKGROUND: Episodic memory is the memory system which is most affected by ageing. However, similar memory decline is not seen in all older adults. Various cognitive reserve factors, such as the Openness Personality Trait and level of educational attainment, and cognitive resources linked to these factors, such as executive control and crystallised knowledge, can predict older adults' memory performance. OBJECTIVE: This study examined the link between and the role of these variables in older adults' memory performances according to the difficulty of the task. METHODS: Forty participants (aged between 60 and 82) learned 24 paired words with two encoding conditions (reading and generation), and then performed a cued recall. They were asked for their level of educational attainment, and their openness, executive control and crystallised knowledge levels were respectively measured using a personality questionnaire (Big Five), an inhibition test (Stroop) and a vocabulary test (Mill Hill). RESULTS: Only crystallised knowledge predicts older adults' recall of generated words while openness and executive control predict and mediate the effect of level of education on older adults' recall of read words. CONCLUSION: Openness is a reserve factor and is an essential component, along with executive control, in difficult memory tasks.

Selecting effectively contributes to the mnemonic benefits of self-generated cues.

Self-generated memory cues support recall of target information more robustly than memory cues generated by others. Across two experiments, we tested whether the benefit of self-generated cues in part reflects a meta-mnemonic effect rather than a pure generation effect. In other words, can learners select better memory cues for themselves than others can? Participants generated as many possible memory cues for each to-be-remembered target as they could and then selected the cue they thought would be most effective. Self-selected memory cues elicited better cued recall than cues the generator did not select and cues selected by observers. Critically, this effect cannot be attributed to the process of generating a cue itself because all of the cues were self-generated. Further analysis indicated that differences in cue selection arise because generators and observers valued different cue characteristics; specifically, observers valued the commonality of the cue more than the generators, while generators valued the distinctiveness of a cue more than observers. Together, results suggest that self-generated cues are effective at supporting memory, in part, because learners select cues that are tailored to their specific memory needs.

[Episodic memory and aging: The role of cognitive reserve and cognitive resources according to task difficulty]. / Mémoire épisodique et vieillissement : rôle des facteurs de réserve et des ressources cognitives selon la difficulté de la tâche.

BACKGROUND: Episodic memory is the most affected memory system in aging. However, memory decline is not similar in every older adult. Various cognitive reserve factors, as Openness personality trait or educational level, and cognitive resources linked to these factors, as executive control and crystallized knowledge, can predict older adults' memory performance. OBJECTIVE: This study examined the link between and the role of these variables in older adults' memory performances according to the task difficulty. METHODS: Forty participants (60-82 years old) learned 24 paired words with two encoding conditions (reading and generation) and then performed a cued recall. Their educational level was asked, and their Openness, executive control and crystallized knowledge levels were respectively measured using a personality questionnaire (Big Five), an inhibition test (Stroop) and a vocabulary test (Mill Hill). RESULTS: Only crystallized knowledge predicts older adults' generated words recall while Openness and executive control predict and mediate educational level effect on older adults' read words recall. CONCLUSION: Openness is a reserve factor and is an essential component, along with executive control, in difficult memory tasks.

The "first-generation effect" on perceptions and academic performance of pharmacy students.

INTRODUCTION: The "first-generation effect" refers to familial educational attainment's role in first-generation student academic success. It often implies low academic achievements at associate and bachelor degree levels. Would this be true at the doctor of pharmacy (PharmD) level? This study assessed perceptions and first-professional (P1) year student academic performance of first-generation vs. non-first-generation PharmD cohorts at the Feik School of Pharmacy. METHODS: Perceptions (academic and personal support) were assessed via a 49-question survey at the start of the second- and third-professional years. Academic performance was assessed via measures of academic success (course grades, grade point average, supplemental instruction enrollments, and academic infractions) in P1 year. Statistical t-tests and F-tests were used to analyze differences in perceptions and academic performance for the two cohorts. RESULTS: From 132 eligible students, 128 completed the survey (97% response rate) and 58 (45%) were first-generation students. First-generation students had a lower perception of their academic success, and they perceived finances as one of their greatest barriers (86% vs. 64%). Fifteen P1 courses were reviewed for academic performance, and first generations had lower final course grades in only two courses (Anatomy and Physiology 1; Medical Microbiology and Immunology). For measures of academic success, no significant differences were noted. CONCLUSIONS: Overall, this study suggested that first-generation status may not be a hindrance to academic performance at the PharmD level, but that financial perceptions and a lower self-perception of academic success seem to be major barriers for first-generation PharmD students.

Examining the relationship between generation constraint and memory.

Self-generated information is often better remembered than read information (the generation effect). Recent research, however, has shown that generating information under fewer experimental constraints (i.e., fewer limitations on what can be generated) can increase the magnitude of the generation effect. This study systematically varied generation constraint to better understand the effects of constraint on memory. Participants encoded associated cue-target word pairs (above-below) on either the left or right side of a computer monitor. At encoding, generation constraint was manipulated by systematically varying the number of letters given to participants to generate the target word (i.e., above-below; option-choic_; bank-mon__; etc.). At retrieval, participants were given either a recognition, cued recall, or free recall test measuring both item (target word) and context memory (location on the computer monitor). Using mixed-effects logistic regression analyses to control for item-selection effects (e.g., participants producing idiosyncratic targets in some conditions relative to others), results indicated that generation constraint significantly influenced item, but not context (location) memory. The relationship between generation constraint and memory performance, however, differed by the type of memory test administered: Recognition data revealed a curvilinear relationship; cued recall showed a negative, linear relationship; and free recall showed no significant relationship. Overall, these findings provide more evidence that generation constraint has a strong yet complex effect on different aspects of memory, and further delineates some boundary conditions of the influence of generation constraint on memory.

Theories of the generation effect and the impact of generation constraint: A meta-analytic review.

The generation effect is the memory benefit for self-generated compared with read or experimenter-provided information. In recent decades, numerous theories have been proposed to explain the memory mechanism(s) and boundary conditions of the generation effect. In this meta-analysis and theoretical review, we analyzed 126 articles (310 experiments, 1,653 estimates) to assess 7 prominent theories to determine which theories are supported by the existing literature. Because some theories focus on item memory (memory for the generated target) and others focus on context memory (memory for details associated with the generated target), we examined memory effects for both types of details (item, context) in this meta-analysis. Further, we assessed the influence of generation constraint (how constrained participants are to generate a certain response), which recent work has shown affects the magnitude of the generation effect. Overall, the results of this meta-analysis support some theoretical accounts, but not others, as explanatory mechanisms of the generation effect. Results further showed that generation constraint significantly moderates the magnitude of the generation effect, suggesting that this factor should be rigorously investigated in future work. Overall, this meta-analysis provides a review and examination of generation effect theories, and reveals important areas of future research.

Fewer generation constraints increase the generation effect for item and source memory through enhanced relational processing.

Memory is often better for information that is self-generated versus read (i.e. the generation effect). Theoretical work attributes the generation effect to two mechanisms: enhanced item-specific and relational processing (i.e. the two-factor theory). Recent work has demonstrated that the generation effect increases when generation tasks place lower, relative to higher, constraints on what participants can self-generate. This study examined whether the effects of generation constraint on memory might be attributable to either mechanism of the two-factor theory. Across three experiments, participants encoded word pairs in two generation conditions (lower- and higher-constraint) and a read control task, followed by a memory test for item memory and two context memory details (source and font color). The results of these experiments support the idea that lower-constraint generation increases the generation effect via enhanced relational processing, as measured through both recognition and cued recall tasks. Results further showed that lower-constraint generation improves context memory for conceptual context (source), but not perceptual context (color), suggesting that this enhanced relational processing may extend to conceptually related details of an item. Overall, these results provide more evidence that fewer generation constraints increase the generation effect and implicate enhanced relational processing as a mechanism for this improvement.

Performance Expectancies Moderate the Effectiveness of More or Less Generative Activities Over Time.

We examined if the benefits of generation for long-term learning depend on individual differences in performance expectancies (PEs) prior to learning. We predicted that a greater generative activity (problem-solving) compared to less generative activity (worked-examples) should be more effective for pupils with higher PEs, especially in the long run. As a comparison group for problem-solving, we implemented a special type of worked-examples that decreased engaging in self-explanations, because our main prediction focused on PEs moderating the long-term effectivity of less versus greater generative activities. We tested students' immediate and delayed performance (after 3 months) using coherent curricular materials on linear functions in a sample of eighth graders (advanced school track). The results were partly in line with our predictions: Although we found no moderation of PE and generative activity, we obtained the predicted 3-way interaction of PE, generative activity, and time. Immediately, greater generative activity (problem-solving) was beneficial for pupils with higher PEs, while for pupils with lower PEs, problem-solving versus worked-examples did not differ. In the delayed test, this pattern reversed: for lower PEs, greater generative activity outperformed less generative activities, but there was no difference for higher PEs. Unexpectedly, the initial advantage of problem-solving for higher PEs could not be maintained, decreasing over three subsequent months, whereas the performance in the worked-example condition remained at a comparable level for higher PEs. The change in performance in the problem-solving condition for lower PEs was descriptively less pronounced than in the worked-example condition, but statistically not different. We further investigated the effects of problem-solving and worked-examples on changes in PEs after learning and after testing, hinting at gradual decrease in PEs and greater metacognitive accuracy in the problem-solving condition due to a reduction of overconfidence.

Slow naming of pictures facilitates memory for their names.

Speakers remember their own utterances better than those of their interlocutors, suggesting that language production is beneficial to memory. This may be partly explained by a generation effect: The act of generating a word is known to lead to a memory advantage (Slamecka & Graf, 1978). In earlier work, we showed a generation effect for recognition of images (Zormpa, Brehm, Hoedemaker, & Meyer, 2019). Here, we tested whether the recognition of their names would also benefit from name generation. Testing whether picture naming improves memory for words was our primary aim, as it serves to clarify whether the representations affected by generation are visual or conceptual/lexical. A secondary aim was to assess the influence of processing time on memory. Fifty-one participants named pictures in three conditions: after hearing the picture name (identity condition), backward speech, or an unrelated word. A day later, recognition memory was tested in a yes/no task. Memory in the backward speech and unrelated conditions, which required generation, was superior to memory in the identity condition, which did not require generation. The time taken by participants for naming was a good predictor of memory, such that words that took longer to be retrieved were remembered better. Importantly, that was the case only when generation was required: In the no-generation (identity) condition, processing time was not related to recognition memory performance. This work has shown that generation affects conceptual/lexical representations, making an important contribution to the understanding of the relationship between memory and language.

Generating Causal Relations in Scientific Texts: The Long-Term Advantages of Successful Generation.

A high level of text comprehension can be achieved by engaging learners in processes of organization and integration while reading a cohesive text. In the present study, we investigated the impact of an innovative generative technique on learning with scientific texts. The cohesion generation was implemented by means of explicit cohesion gaps. High school students (n = 199) were randomly assigned to either receive a fully cohesive scientific text (control condition) or a scientific text that required the selection of causal connectives, such as because, although, therefore, or however (generation condition). Learners in the generation condition were required to reflect on causal relations to complete the text. All students were tested immediately (T1) and 2 weeks after the learning phase (T2). Cognitive load was measured by a dual task and self-report measure. Contrary to our expectations, no differences were found in performance on inference questions (situation model). Learners in the generation condition performed worse on text-based questions at T1 but showed less forgetting from T1 to T2. The impact of condition on the situation model was moderated by reading skills. Remarkably, the generation success was highly predictive for learning outcomes even when controlling for learners' proficiencies. Consequently, learners who succeeded to employ effortful processes to overcome the difficulty showed a superior performance on both the text-base and situation-model questions compared to students reading the cohesive text. Moreover, in these learners, generative activity led to a sustainable learning performance 2 weeks later. Poor readers especially took advantage of generative activity, despite struggling to perform the cohesion task as indicated by the cognitive load measures. The results suggest that the activity of generating causal relations can augment inferential processing in learners who are not involved in inferential processing spontaneously. To successfully apply this generative learning technique, students require considerable instructional support.

The production effect and the generation effect improve memory in picture naming.

The production effect (better memory for words read aloud than words read silently) and the picture superiority effect (better memory for pictures than words) both improve item memory in a picture naming task (Fawcett, J. M., Quinlan, C. K., & Taylor, T. L. (2012). Interplay of the production and picture superiority effects: A signal detection analysis. Memory (Hove, England), 20(7), 655-666. doi: 10.1080/09658211.2012.693510 ). Because picture naming requires coming up with an appropriate label, the generation effect (better memory for generated than read words) may contribute to the latter effect. In two forced-choice memory experiments, we tested the role of generation in a picture naming task on later recognition memory. In Experiment 1, participants named pictures silently or aloud with the correct name or an unreadable label superimposed. We observed a generation effect, a production effect, and an interaction between the two. In Experiment 2, unreliable labels were included to ensure full picture processing in all conditions. In this experiment, we observed a production and a generation effect but no interaction, implying the effects are dissociable. This research demonstrates the separable roles of generation and production in picture naming and their impact on memory. As such, it informs the link between memory and language production and has implications for memory asymmetries between language production and comprehension.

Optimizing memory strategy use in young and older adults: The role of metamemory and internal strategy use.

We explored whether experiencing differential efficacy of reading and generation for memory in an initial learning trial led younger and older adults to improve recall of read items in a subsequent learning trial, leading to a reduction of the generation effect. In the first trial, generation improved the memory performance of both young and older adults. However, in Trial 2, the generation effect remained significant for older adults only, confirming that they did not change the way they processed read items, unlike the young adults. The older adults were also less spontaneously aware that generation led to better memory performance in the first trial, and, in contrast to the young adults, awareness did not result in a reduction of the generation effect. Moreover, the age-related differences in generation effect reduction were mediated by an independent measure of self-reported internal strategy use. However, when an appropriate environmental support was provided between both trials, older adults improved read items recall at the second trial as well as younger ones, leading to an elimination of the generation advantage for both groups. Environmental support reduced the implication of internal strategy use in the generation effect reduction, suggesting that age-related differences in the implementation of effective encoding processes in Trial 2 would be the consequence of a metamemory deficit, and reduced capacity to self-initiate internal strategies.