F1000Research F1000Research 2046-1402 F1000 Research Limited London, UK 10.12688/f1000research.146863.2 Brief Report Articles The retrieval of neutral and positive autobiographical memories: a pilot study

[version 2; peer review: 2 approved]

 Su Xinning Conceptualization Data Curation Formal Analysis Investigation Methodology Resources Software Validation Visualization Writing – Original Draft Preparation https://orcid.org/0000-0002-6264-5221 a 1 Midorikawa Akira Conceptualization Funding Acquisition Project Administration Supervision Writing – Review & Editing b 1 Department of Psychology, Chuo University, Tokyo, Japan sosinnei@gmail.com green@tamacc.chuo-u.ac.jp

No competing interests were disclosed.

 22 10 2024 2024 13 285 16 10 2024 Copyright: © 2024 Su X and Midorikawa A 2024 This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background

Several studies have shown that the retrieval of positive memories may play a role in emotional regulation. However, it is unclear whether the effects of neutral and positive autobiographical memories differ. It is necessary to confirm whether genuinely neutral autobiographical memories can be retrieved without bias when prompted to recall neutral memories.

 Methods

In this pilot study, using “home” and “study” as cue words, we investigated whether participants were able to retrieve appropriate autobiographical memories when asked to recall a limited number of neutral or positive memories.

 Results

Although participants were asked to recall neutral autobiographical memories, they tended to recall positive memories.

 Conclusions

Our results support the concept of positive memory bias and suggest that future work should consider combining neutral and positive autobiographical memories by asking participants to recall neutral–positive memories.

 autobiographical memories emotional valence positive memory bias neutral–positive memories Chuo University Grant for Special Research Chuo University Grant for Special Research The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Amendments from Version 1

Based on the reviewers' comments, we have provided a clearer explanation of the research background and objectives, and accordingly revised the content of the discussion. Additionally, we have adjusted Figure 1 to make it more concise and clear, and added the distribution of individual scores.

 Introduction

Autobiographical memory is defined as memory for information relating to the self ( Brewer, 1986). It is believed to play a role in shaping an individual’s self-awareness and identity over time ( Conway, 2005; Conway & Pleydell-Pearce, 2000; Tulving, 2002). Autobiographical memory is strongly linked to emotion ( Holland & Kensinger, 2010). Several studies have shown that individuals with emotional disorders, such as depression ( King et al., 2010) and anxiety ( Krans et al., 2014), exhibit autobiographical memory biases. For example, these individuals tend to recall more negative autobiographical memories compared to control participants. While individuals may recall past negative experiences to learn from their mistakes, excessive recall of negative events often leads to rumination, a maladaptive cognitive process associated with the onset and perpetuation of depression ( Nolen-Hoeksema & Morrow, 1991; Nolen-Hoeksema et al., 2008). This suggests a need for strategies to mitigate the negative impact of such memories.

Harris et al. (2010) found that repeated retrieval of positive autobiographical memories can lead to forgetting negative memories associated with the same cue word. This finding implies that positive memory retrieval can inhibit the recall of unwanted negative autobiographical memories. However, in addition to autobiographical memories with positive or negative valence, memories can also be neutral ( D’Argembeau et al., 2003). Regarding whether neutral memory retrieval can also inhibit the recall of negative memories, evidence from recent studies on semantic memory indicates that retrieving neutral semantic memories can lead to forgetting related negative memories ( Greer et al., 2024). Considering that autobiographical and semantic memories share overlapping neural bases ( Graham et al., 2003), and negative autobiographical memories are more strongly associated with emotional disorders ( King et al., 2010; Krans et al., 2014), it is worth investigating whether the effects observed with neutral semantic memories might also apply to neutral autobiographical memories. Should neutral autobiographical memories function similarly to positive ones, this could extend the findings of Harris et al. (2010), offer new insights into the mechanisms of memory and emotion, and suggest alternative strategies for mitigating the effects of negative memories.

However, before we extend the findings of Harris et al. (2010), a pilot study is necessary to determine whether genuinely neutral autobiographical memories can be retrieved without bias when prompted to recall neutral memories. Previous studies have shown that participants tend to recall more positive autobiographical events when asked to recall as many memories as possible ( Berntsen, 1996; Clark et al., 2013; Marsh et al., 2019). Additionally, recall order is influenced by the emotional content of memories, with emotional memories often recalled before neutral ones ( Nusser & Zimprich, 2021; Zimprich & Nusser, 2023). This phenomenon, known as positive memory bias ( Adler & Pansky, 2020; Skowronski, 2011; Walker et al., 2003), suggests that neutral memories may not be the primary focus unless specifically cued. The self-memory system ( Conway, 2005) suggests that autobiographical memory retrieval is influenced by an individual’s current beliefs, active goals, and self-image, which tend to be positive. As a result, people may unconsciously gravitate toward recalling positive autobiographical memories.

However, most previous studies did not limit the number or valence of recalls. According to the procedure of Harris et al. (2010), participants were explicitly asked to recall a limited number of specified emotional events associated with each cue word. Since our ultimate aim is to extend the findings of Harris et al. (2010), in the present pilot study, we adopted the same cue words as Harris et al. (2010), namely “home” and “study”, to investigate whether appropriate autobiographical memories when asked to recall a limited number of neutral or positive memories.

 Methods Participants and study design

In total, 10 students (five men and five women) participated in this study (mean age = 21.90 years; range: 19–24 years). All participants were enrolled in a preparatory school in Tokyo, Japan, and were recruited in a classroom setting.

The experiment had a 2 × 2 mixed design. The between-subjects factor was valence (positive/neutral), and the within-subjects factor was cue (home/study).

 Ethics approval and informed consent

This study was conducted in line with the Declaration of Helsinki. It was approved by the ethics committee of Chuo University, on 4 August 2020, vide approval number 2020-02. Written informed consent was obtained from all individual participants included in the study.

 Procedure

Participants were divided into positive and neutral groups. The cue words used by Harris et al. (2010) were “home” and “work”, likely chosen due to the wide age range of their participants (17–42 years old). For the cue word “work”, Harris et al. (2010) asked participants to recall autobiographical memories related to study or work. Given that all of our participants were college students of similar age, the cue words in our experiment were “home” and “study”, presented to each group. Participants were asked to generate five positive or five neutral autobiographical memories for each cue. Researchers informed the participants that the “study events” should be associated with study or work, whereas the “home events” should be related to home or family.

After retrieving autobiographical memories for each cue word, participants briefly reported the context of the recalled events verbally, and a researcher recorded their descriptions. Then, as in Harris et al.’s (2010) methodology, after they had reported the events, participants were asked to rate the valence of those events (1 = Very negative, 7 = Very positive).

 Results One-sample t-tests

On a 7-point Likert response scale, the neutral score (i.e., 4) was regarded as the baseline; differences between self-rated scores for the four memory types (i.e., home memories in the positive group, study memories in the positive group, home memories in the neutral group, and study memories in the neutral group) and the neutral score were calculated. One-sample t-tests were used to determine whether differences between the scores for each memory type and the neutral score were significant. We found significant differences between scores for all memory types and the neutral score (home memories in the positive group, t (4) = 5.06, p < 0.01, d = 2.26; study memories in the positive group, t (4) = 3.50, p = 0.03, d = 1.57; home memories in the neutral group, t (4) = 3.92, p = 0.02, d = 1.75; and study memories in the neutral group, t (4) = 7.20, p < 0.01, d = 3.22) ( Figure 1).

Box-and-whisker plot for the four memory types.

Dashed line is the neutral score (baseline), and error bars represent standard deviation.

 Analysis of variance (ANOVA)

As shown in Figure 1, a 2 (valence group: positive/neutral) × 2 (cue: home/study) mixed ANOVA for event valence was conducted. There was no main effect of valence group ( F (1,8) = 3.30, p = 0.11, η p 2 = 0.29), no main effect of cue ( F (1,8) = 2.27, p = 0.17, η p 2 = 0.22), and no interaction effect ( F (1,8) = 3.35, p = 0.10, η p 2 = 0.30).

 Discussion

In this study, we used the cue words “home” and “study” to determine whether appropriate autobiographical memories could be retrieved by participants who were asked to recall a limited number of neutral or positive memories. We found a bias toward recalling positive events in both the neutral and positive groups, even though participants were asked to recall neutral events. Moreover, there were no significant differences in memory ratings between the two groups.

One explanation for these results is positive memory bias ( Adler & Pansky, 2020; Skowronski, 2011; Walker et al., 2003). The self-memory system ( Conway, 2005) suggests that autobiographical memory retrieval is influenced by people’s current beliefs, active goals, and self-image, which tend to be positive. As a result, people may unconsciously tend to recall positive autobiographical memories. Several studies have shown that more positive autobiographical events are generally recalled, whether voluntarily or involuntarily, compared with neutral or negative events ( Berntsen, 1996; Clark et al., 2013; Marsh et al., 2019). However, unlike previous studies, we limited the number of recalled memories, asking participants to generate five positive or five neutral autobiographical memories for each cue. Thus, the neutral and positive groups did not differ in the number of recalls; nevertheless, they showed emotional valence bias.

This study had some limitations. First, since our ultimate aim is to extend the findings of Harris et al. (2010), the methods and cue words employed in this pilot study align with those described by Harris et al. (2010). While this approach is appropriate for the present study’s purposes, it would be beneficial to incorporate more neutral cue words to broaden the results further. Second, we adopted self-rating valence as per the methodology of Harris et al. (2010). However, self-ratings may be biased by various factors, including participants’ subjective interpretation of what constitutes a neutral event and their current mood ( Chiorri & Vannucci, 2024). Given the potential for subjective bias, future studies should incorporate both subjective self-ratings and objective assessments by independent raters to ensure a more accurate categorization of recalled events. This will allow for better verification of whether neutral memories are indeed perceived as neutral or if a bias toward positivity has occurred.

In conclusion, despite some limitations, we found that when limiting the number of recalls, participants tended to recall positive events even when asked to recall neutral autobiographical memories. Previous studies have found that retrieval of neutral semantic memories leads to forgetting of negative semantic memories ( Greer et al., 2024), while retrieval of positive autobiographical memories leads to forgetting of negative autobiographical memories ( Harris et al., 2010). Therefore, it is necessary to extend the findings of Harris et al. (2010) to examine whether neutral autobiographical memories can also inhibit the recall of negative memories. However, before extending the findings of Harris et al. (2010), we conducted this pilot study to determine whether genuinely neutral autobiographical memories can be retrieved without bias when prompted to recall neutral memories. Based on the results of this pilot study, it will be necessary to continue refining our understanding. Additionally, we can propose innovative ideas, such as exploring whether future work could integrate neutral and positive autobiographical memories, by asking participants to recall neutral–positive memories. We look forward to further research investigating whether, similar to the effects of retrieving positive memories ( Burton & King, 2004; Burton & King, 2009; Harris et al., 2010), retrieving neutral–positive memories may also inhibit the recall of negative memories or enhance positive emotions. Such studies could provide valuable insights for developing emotional regulation strategies.

Ethics approval and informed consent

This study was conducted in line with the Declaration of Helsinki. It was approved by the Ethics Committee of Chuo University, on 4 August 2020, vide approval number 2020-02. Written informed consent was obtained from all individual participants included in the study.

 Data availability statement Underlying data

This study contains the following underlying data:

Fighsare, Data for “the retrieval of neutral and positive autobiographical memories: a pilot study” https://doi.org/10.6084/m9.figshare.24939264.v1 ( Su, 2024).

Data are available under the terms of the Creative Commons Attribution 4.0 International license (CC-BY 4.0).

 References Adler O Pansky A : A “rosy view” of the past: Positive memory biases. Cognitive biases in health and psychiatric disorders: Neurophysiological foundations. Elsevier Academic Press;2020; pp.139–171. 10.1016/B978-0-12-816660-4.00007-6 Berntsen D : Involuntary autobiographical memories. Appl. Cogn. Psychol. 1996;10(5):435–454. 10.1002/(SICI)1099-0720(199610)10:5<435::AID-ACP408>3.0.CO;2-L Brewer WF : What is autobiographical memory? Autobiographical memory. Cambridge University Press;1986; pp.25–49. 10.1017/CBO9780511558313.006 Burton CM King LA : The health benefits of writing about intensely positive experiences. J. Res. Pers. 2004;38(2):150–163. 10.1016/S0092-6566(03)00058-8 Burton CM King LA : The health benefits of writing about positive experiences: the role of broadened cognition. Psychol. Health. 2009;24(8):867–879. 20205032 10.1080/08870440801989946 Chiorri C Vannucci M : The Subjective Experience of Autobiographical Remembering: Conceptual and Methodological Advances and Challenges. J. Intell. 2024;12(2):21. 38392177 10.3390/jintelligence12020021 PMC10890313 Clark IA Mackay CE Holmes EA : Positive involuntary autobiographical memories: you first have to live them. Conscious. Cogn. 2013;22(2):402–406. 23416539 10.1016/j.concog.2013.01.008 PMC3675682 Conway MA : Memory and the self. J. Mem. Lang. 2005;53(4):594–628. 10.1016/j.jml.2005.08.005 Conway MA Pleydell-Pearce CW : The construction of autobiographical memories in the self-memory system. Psychol. Rev. 2000;107(2):261–288. 10789197 10.1037/0033-295x.107.2.261 D’Argembeau A Comblain C Van der Linden M : Phenomenal characteristics of autobiographical memories for positive, negative, and neutral events. Appl. Cogn. Psychol. 2003;17(3):281–294. 10.1002/acp.856 Graham KS Lee AC Brett M : The neural basis of autobiographical and semantic memory: new evidence from three PET studies. Cogn. Affect. Behav. Neurosci. 2003;3(3):234–254. 14672158 10.3758/cabn.3.3.234 Greer J Ali A Laksman C : Effortful retrieval of semantic memories induces forgetting of related negative and neutral episodic memories. Cognition. 2024;251:105908. Advance online publication. 10.1016/j.cognition.2024.105908 Harris CB Sharman SJ Barnier AJ : Mood and retrieval-induced forgetting of positive and negative autobiographical memories. Appl. Cogn. Psychol. 2010;24(3):399–413. 10.1002/acp.1685 Holland AC Kensinger EA : Emotion and autobiographical memory. Phys. Life Rev. 2010;7(1):88–131. 20374933 10.1016/j.plrev.2010.01.006 PMC2852439 King MJ MacDougall AG Ferris SM : A review of factors that moderate autobiographical memory performance in patients with major depressive disorder. J. Clin. Exp. Neuropsychol. 2010;32(10):1122–1144. 20544462 10.1080/13803391003781874 Krans J Bree J de Bryant RA : Autobiographical memory bias in social anxiety. Memory. 2014;22(8):890–897. 10.1080/09658211.2013.844261 Marsh L Edginton T Conway MA : Positivity bias in past and future episodic thinking: Relationship with anxiety, depression, and retrieval-induced forgetting. Q. J. Exp. Psychol. 2019;72(3):508–522. 29364056 10.1177/1747021818758620 Nolen-Hoeksema S Morrow J : A prospective study of depression and posttraumatic stress symptoms after a natural disaster: The 1989 Loma Prieta earthquake. J. Pers. Soc. Psychol. 1991;61(1):115–121. 1890582 10.1037/0022-3514.61.1.115 Nolen-Hoeksema S Wisco BE Lyubomirsky S : Rethinking Rumination. Perspect. Psychol. Sci. 2008;3(5):400–424. 26158958 10.1111/j.1745-6924.2008.00088.x Nusser L Zimprich D : Order effects in the recall of autobiographical memories: Evidence for an organisation along temporal and emotional features. Memory. 2021;29(3):379–395. 33706675 10.1080/09658211.2021.1896735 Skowronski JJ : The positivity bias and the fading affect bias in autobiographical memory: A self-motives perspective. Handbook of self-enhancement and self-protection. The Guilford Press;2011; pp.211–231. Su X : The retrieval of neutral and positive autobiographical memories: a pilot study. figshare.2024. 10.6084/m9.figshare.24939264.v1 Tulving E : Chronesthesia: Conscious awareness of subjective time. Principles of frontal lobe function. Oxford University Press;2002; pp.311–325. 10.1093/acprof:oso/9780195134971.003.0020 Walker WR Skowronski JJ Thompson CP : Life is Pleasant—and Memory Helps to Keep it that Way! Rev. Gen. Psychol. 2003;7(2):203–210. 10.1037/1089-2680.7.2.203 Zimprich D Nusser L : Output order effects in autobiographical memory in old age: further evidence for an emotional organisation. Mem. Cognit. 2023;51(1):23–37. 35641847 10.3758/s13421-022-01312-3 PMC9945544 10.5256/f1000research.173083.r333848 Reviewer response for version 2 Maksimovskiy Arkadiy 1 Referee https://orcid.org/0000-0001-6696-7853 Howard Hughes Medical Institute - Harvard Medical School, Boston, Massachusetts, USA

Competing interests: No competing interests were disclosed.

 11 12 2024 Copyright: © 2024 Maksimovskiy A 2024 This is an open access peer review report distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. recommendation approve

All comments were successfully addressed.

Is the work clearly and accurately presented and does it cite the current literature?

Yes

If applicable, is the statistical analysis and its interpretation appropriate?

No

Are all the source data underlying the results available to ensure full reproducibility?

Yes

Is the study design appropriate and is the work technically sound?

Partly

Are the conclusions drawn adequately supported by the results?

Partly

Are sufficient details of methods and analysis provided to allow replication by others?

Yes

Reviewer Expertise:

Cognitive neuroscience and memory research.

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

 10.5256/f1000research.173083.r333847 Reviewer response for version 2 Shen Xinxu 1 Referee https://orcid.org/0000-0001-7319-641X Temple University, Philadelphia, Pennsylvania, USA

Competing interests: No competing interests were disclosed.

 4 11 2024 Copyright: © 2024 Shen X 2024 This is an open access peer review report distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. recommendation approve

I think the revised version is good for indexing.

Is the work clearly and accurately presented and does it cite the current literature?

Yes

If applicable, is the statistical analysis and its interpretation appropriate?

Partly

Are all the source data underlying the results available to ensure full reproducibility?

Yes

Is the study design appropriate and is the work technically sound?

Partly

Are the conclusions drawn adequately supported by the results?

Partly

Are sufficient details of methods and analysis provided to allow replication by others?

Yes

Reviewer Expertise:

episodic memory, decision making

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.

 10.5256/f1000research.160988.r298790 Reviewer response for version 1 Shen Xinxu 1 Referee https://orcid.org/0000-0001-7319-641X Temple University, Philadelphia, Pennsylvania, USA

Competing interests: No competing interests were disclosed.

 29 7 2024 Copyright: © 2024 Shen X 2024 This is an open access peer review report distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. recommendation approve-with-reservations

The pilot study by Xinning Su and Akira Midorikawa explores whether participants can retrieve genuinely neutral autobiographical memories using the cue words "home" and "study." Despite being asked to recall neutral memories, participants showed a positive memory bias, often recalling positive events instead. This study addressed an important question, but I have some concerns about the motivation behind the study and the methods. see below:

The authors discuss how the repeated retrieval of positive autobiographical memories could potentially inhibit the recall of negative autobiographical memories. However, before delving into the specifics of their study and the underlying motivations (particularly the question of whether neutral and positive autobiographical memories contribute similarly to emotion regulation), it would be beneficial to examine prior research on the impact of retrieving neutral autobiographical memories. Specifically, it's essential to investigate whether the retrieval of neutral autobiographical memories can also inhibit the recall of negative memories.

The authors should provide a clear rationale for the selection of specific cue words used in their study. This includes explaining why these particular words were chosen and how they align with the study's objectives. Additionally, it would be beneficial to consider incorporating a broader range of neutral cue words. This diversity could ensure a more comprehensive examination of the effects of neutral memory retrieval on the inhibition of negative memories and provide a more robust dataset for analysis.

The use of self-rated valence to score autobiographical memories can introduce bias, as individuals may perceive and rate their memories subjectively. To mitigate this issue, it would be advantageous to have an independent rater evaluate the memories. This approach could provide a more objective assessment of the valence of memories, reducing the potential for self-report biases and enhancing the reliability of the study's findings.

The statement "People generally retrieve autobiographical memories consistent with their self-image and beliefs, which tend to be positive" appears abruptly without prior mention of self-image or beliefs. It is crucial to introduce and discuss the concept of self-image and beliefs earlier in the manuscript. Providing a theoretical framework or citing relevant literature on how self-image and beliefs influence memory retrieval could offer context and support for this assertion. This would help integrate the statement more seamlessly into the discussion and strengthen the argument.

The conclusion suggesting that future research should consider combining neutral and positive autobiographical memories by asking participants to recall neutral–positive memories is not well-supported by the current study. There is insufficient evidence to indicate that neutral and positive autobiographical memories function similarly, despite the observation that individuals tend to recall neutral memories more positively. To substantiate this conclusion, the authors should present stronger empirical evidence or theoretical justification demonstrating the potential benefits and similarities of combining these types of memories in emotion regulation and memory inhibition studies.

Is the work clearly and accurately presented and does it cite the current literature?

Yes

If applicable, is the statistical analysis and its interpretation appropriate?

Partly

Are all the source data underlying the results available to ensure full reproducibility?

Yes

Is the study design appropriate and is the work technically sound?

Partly

Are the conclusions drawn adequately supported by the results?

Partly

Are sufficient details of methods and analysis provided to allow replication by others?

Yes

Reviewer Expertise:

episodic memory, decision making

I confirm that I have read this submission and believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.

Su Xinning Psychology, Chuo University, Hachioji, Tokyo, Japan

Competing interests: No competing interests were disclosed.

 15 10 2024

Response to Dr. Xinxu Shen:

We would like to express our sincere gratitude to the reviewers for your insightful comments on our manuscript. Your valuable comments have significantly contributed to enhancing the quality of our work.

 

Comment 1: The authors discuss how the repeated retrieval of positive autobiographical memories could potentially inhibit the recall of negative autobiographical memories. However, before delving into the specifics of their study and the underlying motivations (particularly the question of whether neutral and positive autobiographical memories contribute similarly to emotion regulation), it would be beneficial to examine prior research on the impact of retrieving neutral autobiographical memories. Specifically, it's essential to investigate whether the retrieval of neutral autobiographical memories can also inhibit the recall of negative memories.

Response: Thank you for this insightful comment. Previous research involving expressive writing has indeed explored the use of neutral content. For example, Sheerin et al. (2018) asked participants to write about neutral events, such as “what you did today”, and found that neutral writing also contributed to emotion regulation. However, due to paradigm differences, we did not include these studies in our current discussion. As for whether the retrieval of neutral autobiographical memories can inhibit the recall of negative memories, to our knowledge, no studies have specifically investigated this. However, a recent study found that retrieving neutral semantic memories can inhibit the recall of negative memories. We have added the following description to address this point (Paragraph 2 of the Introduction, lines 5-16):

Regarding whether neutral memory retrieval can also inhibit the recall of negative memories, evidence from recent studies on semantic memory indicates that retrieving neutral semantic memories can lead to forgetting related negative memories (Greer et al., 2024). Considering that autobiographical and semantic memories share overlapping neural bases (Graham et al., 2003), and negative autobiographical memories are more strongly associated with emotional disorders (King et al., 2010; Krans et al., 2014), it is worth investigating whether the effects observed with neutral semantic memories might also apply to neutral autobiographical memories. Should neutral autobiographical memories function similarly to positive ones, this could extend the findings of Harris et al. (2010), offer new insights into the mechanisms of memory and emotion, and suggest alternative strategies for mitigating the effects of negative memories.

Comment 2: The authors should provide a clear rationale for the selection of specific cue words used in their study. This includes explaining why these particular words were chosen and how they align with the study's objectives. Additionally, it would be beneficial to consider incorporating a broader range of neutral cue words. This diversity could ensure a more comprehensive examination of the effects of neutral memory retrieval on the inhibition of negative memories and provide a more robust dataset for analysis.

Response: Thank you for this pertinent feedback. We have added the following explanation to clarify why these particular words were chosen. (Paragraph 1 of the Procedure, lines 1-9)

The cue words used by Harris et al. (2010) were “home” and “work”, likely chosen due to the wide age range of their participants (17–42 years old). For the cue word “work”, Harris et al. (2010) asked participants to recall autobiographical memories related to study or work. Given that all of our participants were college students of similar age, the cue words in our experiment were “home” and “study”, presented to each group. Participants were asked to generate five positive or five neutral autobiographical memories for each cue. Researchers informed the participants that the “study events” should be associated with study or work, whereas the “home events” should be related to home or family.

In addition, we have included your advice in the Discussion section of the revised version of the article. (Paragraph 3 of the Discussion, lines 1-5)

This study had some limitations. First, since our ultimate aim is to extend the findings of Harris et al. (2010), the methods and cue words employed in this pilot study align with those described by Harris et al. (2010). While this approach is appropriate for the present study’s purposes, it would be beneficial to incorporate more neutral cue words to broaden the results further.

Comment 3: The use of self-rated valence to score autobiographical memories can introduce bias, as individuals may perceive and rate their memories subjectively. To mitigate this issue, it would be advantageous to have an independent rater evaluate the memories. This approach could provide a more objective assessment of the valence of memories, reducing the potential for self-report biases and enhancing the reliability of the study's findings.

Response: Thank you for this insightful feedback. As you rightly pointed out, having an independent rater evaluate the memories is essential. Therefore, to address this limitation, we have added the following statement to the Discussion section. (Paragraph 3 of the Discussion, lines 5-11)

This study had some limitations. ……Second, we adopted self-rating valence as per the methodology of Harris et al. (2010). However, self-ratings may be biased by various factors, including participants’ subjective interpretation of what constitutes a neutral event and their current mood ( Chiorri & Vannucci, 2024). Given the potential for subjective bias, future studies should incorporate both subjective self-ratings and objective assessments by independent raters to ensure a more accurate categorization of recalled events. This will allow for better verification of whether neutral memories are indeed perceived as neutral or if a bias toward positivity has occurred.

Comment 4: The statement "People generally retrieve autobiographical memories consistent with their self-image and beliefs, which tend to be positive" appears abruptly without prior mention of self-image or beliefs. It is crucial to introduce and discuss the concept of self-image and beliefs earlier in the manuscript. Providing a theoretical framework or citing relevant literature on how self-image and beliefs influence memory retrieval could offer context and support for this assertion. This would help integrate the statement more seamlessly into the discussion and strengthen the argument.

Response: Thank you for your valuable feedback. In response to your suggestion, we have added the following note to the Introduction. (Paragraph 3 of the Introduction, lines 10-13)

The self-memory system (Conway, 2005) suggests that autobiographical memory retrieval is influenced by an individual’s current beliefs, active goals, and self-image, which tend to be positive. As a result, people may unconsciously gravitate toward recalling positive autobiographical memories.

Comment 5: The conclusion suggesting that future research should consider combining neutral and positive autobiographical memories by asking participants to recall neutral–positive memories is not well-supported by the current study. There is insufficient evidence to indicate that neutral and positive autobiographical memories function similarly, despite the observation that individuals tend to recall neutral memories more positively. To substantiate this conclusion, the authors should present stronger empirical evidence or theoretical justification demonstrating the potential benefits and similarities of combining these types of memories in emotion regulation and memory inhibition studies.

Response: Thank you for your insightful feedback. In response to your suggestion, we have added the following note to the Discussion. (The last paragraph of the Discussion)

In conclusion, despite some limitations, we found that when limiting the number of recalls, participants tended to recall positive events even when asked to recall neutral autobiographical memories. Previous studies have found that retrieval of neutral semantic memories leads to forgetting of negative semantic memories (Greer et al., 2024), while retrieval of positive autobiographical memories leads to forgetting of negative autobiographical memories (Harris et al., 2010). Therefore, it is necessary to extend the findings of Harris et al. (2010) to examine whether neutral autobiographical memories can also inhibit the recall of negative memories. However, before extending the findings of Harris et al. (2010), we conducted this pilot study to determine whether genuinely neutral autobiographical memories can be retrieved without bias when prompted to recall neutral memories. Based on the results of this pilot study, it will be necessary to continue refining our understanding. Additionally, we can propose innovative ideas, such as exploring whether future work could integrate neutral and positive autobiographical memories, by asking participants to recall neutral–positive memories. We look forward to further research investigating whether, similar to the effects of retrieving positive memories (Burton & King, 2004; Burton & King, 2009; Harris et al., 2010), retrieving neutral–positive memories may also inhibit the recall of negative memories or enhance positive emotions. Such studies could provide valuable insights for developing emotional regulation strategies.

Once again, we sincerely thank you for your helpful comments and look forward to further comments on our manuscript.

 10.5256/f1000research.160988.r294508 Reviewer response for version 1 Maksimovskiy Arkadiy 1 Referee https://orcid.org/0000-0001-6696-7853 Howard Hughes Medical Institute - Harvard Medical School, Boston, Massachusetts, USA

Competing interests: No competing interests were disclosed.

 16 7 2024 Copyright: © 2024 Maksimovskiy A 2024 This is an open access peer review report distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. recommendation reject

This pilot study tackled an important question by investigating whether participants were able to retrieve appropriate autobiographical memories when asked to recall a limited number of neutral or positive memories. ​ The study found that although participants were asked to recall neutral memories, they tended to recall positive memories. ​ This is intended to support the concept of positive memory bias. However, several limitations need to be addressed before the intended conclusion can be reached.

1. The word ‘study’ was not used in the original procedure outlined by Harris (2010). Please explain why it was selected. Additionally, the terms ‘study’ and ‘home’ might overlap in our day and age. Please further explain the distinction.

2. “In addition to autobiographical memories with positive or negative valence, memories can be neutral (D’Argembeau et al., 2003). It is unclear whether neutral and positive autobiographical memories contribute similarly to emotion regulation. However, before that question can be answered…”

Please explain why neutral memories might contribute in the same way as positive memories. Why is this an important question? What are the mechanisms behind it?

3. “However, most previous studies did not limit the number of recalls, which varied among events according to emotional valence. Notably, it is unclear whether participants can recall genuinely neutral memories when prompted if the number of recalls is limited.”

It is unclear how neutral memory might be linked to the number of recalls.

4. Figure 1: Why are two plots (box and whisker as well as bar graph) used to illustrate the same concept?

Figure 1a: Please provide a distribution of scores for each participant. From the figure, it appears that ‘Positive study’ did not significantly differ from the neutral condition (contrary to the description), and the other positive category (i.e., ‘positive home’) barely (if at all) differed from neutral conditions. Please provide a distribution of individual scores and explain.

5. If you’re asking participants to recall neutral events, but they recalled positive events, there is the possibility that participants did not see their ratings as neutral, which means the manipulation did not work (rather than a bias provided by authors). Please provide an explanation and further evidence as to how this is interpreted as a positive memory bias and whether any manipulation checks were done to ensure that neutral memories could be recalled.

6. Thank you for providing original data. I ran a quick one-tailed t-test and am not seeing differences between the conditions (T-statistic: 1.82; P-value: 0.11). The code in python is below – please explain why this insignificant finding is consistent with your provided interpretation of the data:

# Filter data for positive and neutral groups

positive_data = data[data['group'] == 'positive']['valence_mean']

neutral_data = data[data['group'] == 'neutral']['valence_mean']

# Perform a t-test

t_stat, p_value_two_tailed = stats.ttest_ind(positive_data, neutral_data)

# Adjust the p-value for a one-sided test

p_value_one_tailed = p_value_two_tailed / 2 if t_stat > 0 else 1 - p_value_two_tailed / 2

# Display the results

print(f'T-statistic: {t_stat}')

print(f'P-value: {p_value}')

Is the work clearly and accurately presented and does it cite the current literature?

Yes

If applicable, is the statistical analysis and its interpretation appropriate?

No

Are all the source data underlying the results available to ensure full reproducibility?

Yes

Is the study design appropriate and is the work technically sound?

Partly

Are the conclusions drawn adequately supported by the results?

Partly

Are sufficient details of methods and analysis provided to allow replication by others?

Yes

Reviewer Expertise:

Cognitive neuroscience and memory research.

I confirm that I have read this submission and believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above.

Su Xinning Psychology, Chuo University, Hachioji, Tokyo, Japan

Competing interests: No competing interests were disclosed.

 15 10 2024

Respons to Dr. Arkadiy Maksimovskiy:

We would like to express our sincere gratitude to the reviewers for your insightful comments on our manuscript. Your valuable comments have significantly contributed to enhancing the quality of our work.

Comment 1: The word ‘study’ was not used in the original procedure outlined by Harris (2010). Please explain why it was selected. Additionally, the terms ‘study’ and ‘home’ might overlap in our day and age. Please further explain the distinction.

Response: Thank you for this pertinent feedback. The cue words used by Harris et al. (2010) were ‘home’ and ‘work’, which may have been due to the wide age range of their participants (17–42 years). For the cue word ‘work’, Harris et al. (2010) asked participants to recall autobiographical memories related to study or work . Given that our participants were similarly aged college students (19–24 years), the cue words in our experiment were ‘home’ and ‘study.’ The researcher told participants that the ‘study events’ should be related to study or work, and the ‘home events’ should be related to home or family. Therefore, we believe that although the words presented on the computer screen differed, in combination with the verbal instructions, we used the same cue words as Harris et al., (2010). For this reason, we have added the following description to the Introduction (The last paragraph of the Introduction, lines 3-6)

Since our ultimate aim is to extend the findings of Harris et al. (2010), in the present pilot study, we adopted the same cue words as Harris et al. (2010), namely “home” and “study”, to investigate……

In addition, we added the following description to the Procedure. (Paragraph 1 of the Procedure, lines 1-9)

The cue words used by Harris et al. (2010) were “home” and “work”, likely chosen due to the wide age range of their participants (17–42 years old). For the cue word “work”, Harris et al. (2010) asked participants to recall autobiographical memories related to study or work. Given that all of our participants were college students of similar age, the cue words in our experiment were “home” and “study”, presented to each group. Participants were asked to generate five positive or five neutral autobiographical memories for each cue. Researchers informed the participants that the “study events” should be associated with study or work, whereas the “home events” should be related to home or family.

Comment 2: “In addition to autobiographical memories with positive or negative valence, memories can be neutral (D’Argembeau et al., 2003). It is unclear whether neutral and positive autobiographical memories contribute similarly to emotion regulation. However, before that question can be answered…” Please explain why neutral memories might contribute in the same way as positive memories. Why is this an important question? What are the mechanisms behind it?

Response: Thank you for this insightful feedback. We appreciate the opportunity to clarify these important points.

To address the first question: Why might neutral memories contribute in the same way as positive memories? We have added the following explanation in the revised manuscript. (Paragraph 2 of the Introduction, lines 5-8)

Regarding whether neutral memory retrieval can also inhibit the forgetting of negative memories, evidence from recent studies on semantic memory indicates that retrieving neutral semantic memories can lead to forgetting related negative memories (Greer et al., 2024).

To address the second question: Why is this an important question? We have added the following explanation. (Paragraph 2 of the Introduction, lines 11-16)

……it is worth investigating whether the effects observed with neutral semantic memories might also apply to neutral autobiographical memories. Should neutral autobiographical memories function similarly to positive ones, this could extend the findings of Harris et al. (2010), offer new insights into the mechanisms of memory and emotion, and suggest alternative strategies for mitigating the effects of negative memories.

To address the third issue: What are the mechanisms behind it? As well as link semantic and autobiographical memories. We have added the following clarification. (Paragraph 2 of the Introduction, lines 8-16)

Considering that autobiographical and semantic memories share overlapping neural bases (Graham et al., 2003), and negative autobiographical memories are more strongly associated with emotional disorders (King et al., 2010; Krans et al., 2014), it is worth investigating whether the effects observed with neutral semantic memories might also apply to neutral autobiographical memories. Should neutral autobiographical memories function similarly to positive ones, this could extend the findings of Harris et al. (2010), offer new insights into the mechanisms of memory and emotion, and suggest alternative strategies for mitigating the effects of negative memories.

Comment 3: “However, most previous studies did not limit the number of recalls, which varied among events according to emotional valence. Notably, it is unclear whether participants can recall genuinely neutral memories when prompted if the number of recalls is limited.” It is unclear how neutral memory might be linked to the number of recalls.

Response: Thank you for this pertinent feedback. Since our ultimate aim is to extend the findings of Harris et al. (2010), the pilot study conducted before this (i.e., the current study) needed to consider Harris’s procedures. Therefore, we limited the number of recalls and emotional valence. To clarify this issue, we added the following explanation.

However, before we extend the findings of Harris et al. (2010), a pilot study is necessary to determine whether genuinely neutral autobiographical memories can be retrieved without bias when prompted to recall neutral memories.…… (Paragraph 3 of the Introduction, lines 1-3)

However, most previous studies did not limit the number or valence of recalls. According to the procedure of Harris et al. (2010), participants were explicitly asked to recall a limited number of specified emotional events associated with each cue word. Since our ultimate aim is to extend the findings of Harris et al. (2010), in the present pilot study, we adopted the same cue words as Harris et al. (2010), namely “home” and “study”, to investigate whether appropriate autobiographical memories when asked to recall a limited number of neutral or positive memories. (Paragraph 4 of the Introduction)

Comment 4: Figure 1: Why are two plots (box and whisker as well as bar graph) used to illustrate the same concept? Figure 1a: Please provide a distribution of scores for each participant. From the figure, it appears that ‘Positive study’ did not significantly differ from the neutral condition (contrary to the description), and the other positive category (i.e., ‘positive home’) barely (if at all) differed from neutral conditions. Please provide a distribution of individual scores and explain.

Response: Thank you for this insightful feedback. Based on your advice, we removed the bar graph, kept only the box-and-whisker plot and added the distribution of individual scores. (Figure 1)

Comment 5: If you’re asking participants to recall neutral events, but they recalled positive events, there is the possibility that participants did not see their ratings as neutral, which means the manipulation did not work (rather than a bias provided by authors). Please provide an explanation and further evidence as to how this is interpreted as a positive memory bias and whether any manipulation checks were done to ensure that neutral memories could be recalled.

Response: Thank you for raising this important point. As we followed Harris et al.’s (2010) methodology for the present study, we used self-rating valence and did not conduct explicit manipulation checks to confirm whether participants recalled neutral events as instructed. To make this clearer, we revised the Procedure as follows: (Paragraph 2 of the Procedure, lines 3-5)

Then, as in Harris et al.’s (2010) methodology, after they had reported events, participants were asked to rate the valence of those events (1 = Very negative, 7 = Very positive).

However, as you point out, this is a limitation of the current study. we have therefore added the following clarification to the Discussion section. (Paragraph 3 of the Discussion, lines 5-11)

This study had some limitations. ……Second, we adopted self-rating valence as per the methodology of Harris et al. (2010). However, self-ratings may be biased by various factors, including participants’ subjective interpretation of what constitutes a neutral event and their current mood (Chiorri & Vannucci, 2024). Given the potential for subjective bias, future studies should incorporate both subjective self-ratings and objective assessments by independent raters to ensure a more accurate categorization of recalled events. This will allow for better verification of whether neutral memories are indeed perceived as neutral or if a bias toward positivity has occurred.

Comment 6: Thank you for providing original data. I ran a quick one-tailed t-test and am not seeing differences between the conditions (T-statistic: 1.82; P-value: 0.11). The code in python is below – please explain why this insignificant finding is consistent with your provided interpretation of the data:

# Filter data for positive and neutral groups

positive_data = data[data['group'] == 'positive']['valence_mean']

neutral_data = data[data['group'] == 'neutral']['valence_mean']

# Perform a t-test

t_stat, p_value_two_tailed = stats.ttest_ind(positive_data, neutral_data)

# Adjust the p-value for a one-sided test

p_value_one_tailed = p_value_two_tailed / 2 if t_stat > 0 else 1 - p_value_two_tailed / 2

# Display the results

print(f'T-statistic: {t_stat}')

print(f'P-value: {p_value}')

Response: Thank you for confirming our data and running the t-test. This t-test analysed whether there was a difference in self-reported valence ratings between the different valence groups (positive or neutral). The result was that there was no significant difference. This result is consistent with the ANOVA results we provided in the article. We conducted a 2 (valence group: positive/neutral) × 2 (cue: home/study) mixed ANOVA on self-reported valence ratings. The results revealed a nonsignificant main effect of the valence group. Therefore, thank you for validating our results. Although the result is negative (nonsignificant), it is still valuable to report for its potential contribution to understanding the topic.

Once again, we sincerely thank you for your helpful comments and look forward to further comments on our manuscript.