Counterfactual thinking induces different neural patterns of memory modification in anxious individuals.

Episodic counterfactual thinking (eCFT) is the process of mentally simulating alternate versions of experiences, which confers new phenomenological properties to the original memory and may be a useful therapeutic target for trait anxiety. However, it remains unclear how the neural representations of a memory change during eCFT. We hypothesized that eCFT-induced memory modification is associated with changes to the neural pattern of a memory primarily within the default mode network, moderated by dispositional anxiety levels. We tested this proposal by examining the representational dynamics of eCFT for 39 participants varying in trait anxiety. During eCFT, lateral parietal regions showed progressively more distinct activity patterns, whereas medial frontal neural activity patterns became more similar to those of the original memory. Neural pattern similarity in many default mode network regions was moderated by trait anxiety, where highly anxious individuals exhibited more generalized representations for upward eCFT (better counterfactual outcomes), but more distinct representations for downward eCFT (worse counterfactual outcomes). Our findings illustrate the efficacy of examining eCFT-based memory modification via neural pattern similarity, as well as the intricate interplay between trait anxiety and eCFT generation.

Expanding the Frontiers of nail product evaluation: Novel application of differential scanning calorimetry (DSC) for assessing crosslinking density and predicting nail brittleness and flexibility.

OBJECTIVE: While modern industry advancements have expanded nail beautification options, scientific literature primarily focuses on nail biology and medicine, with limited attention on cosmetic treatments. This study aimed to investigate human nail denaturation properties, including gender impact, blending nails to enlarge the sample pool, nail sensitization through bleaching, and active effectiveness testing. The objective was to understand the DSC and bending fatigue relationship, and define the consumer relevance of the DSC test. METHODS: Nail clippings were collected from adult female and male volunteers. The wet DSC was employed to validate sample preparation, explore the effects of gender, and assess the potential of using blended nails for claims substantiation testing. Nails were sensitized through bleaching using hydrogen peroxide. The effects were confirmed through DSC and nail flexure tests. Furthermore, the ability of actives to address concerns related to nail softness and brittleness was assessed using these techniques. RESULTS: The results confirmed the viability of equilibrating nails in water for up to 14 h as a standardized testing method. The denaturation temperature results were independent of gender and suitable for claims substantiation testing. Blending nails from different sources did not yield significant variations in denaturation properties. A preliminary study suggested that cadaver nails should be used with caution because they exhibited differences in denaturation temperature, influenced by the sampling location. Bending fatigue tests highlighted the significance of humidity, with higher humidity conditions (80%) enhancing nail flexibility and providing better resolution for claims substantiation. Sensitizing the nails with hydrogen peroxide induced alterations in both DSC and bending fatigue results. Proof-of-principle studies demonstrated an elevation in denaturation temperature and a decrease in the number of cycles to break, indicating a nail-hardening effect when formaldehyde was applied. The use of a nail softener led to an enhancement in nail fatigue resistance due to a notable reduction in nail crosslinking density. CONCLUSIONS: The measurement of crosslinking density proved to be a sensitive tool for assessing the effects of cosmetic treatments on nails, particularly in predicting outcomes related to nail brittleness and flexibility.

OBJECTIF: Si les progrès de l'industrie moderne ont multiplié les options d'embellissement des ongles, la littérature scientifique se concentre principalement sur la biologie et la médecine des ongles, en portant une attention limitée sur les traitements cosmétiques. Cette étude visait à étudier les propriétés de dénaturation des ongles humains, y compris l'impact en termes de genre, l'uniformisation des ongles pour élargir le pool d'échantillons, la sensibilisation des ongles par le biais d'un blanchiment et les analyses d'efficacité active. L'objectif était de comprendre la relation entre la DSC et la fatigue par flexion, définissant la pertinence du test par DSC pour le consommateur. MÉTHODES: Des coupes d'ongles ont été recueillies auprès de volontaires adultes de sexe féminin et masculin. L'analyse par DSC humide a été utilisée pour valider la préparation des échantillons, étudier les effets en lien avec le genre, et un potentiel d'utilisation d'ongles uniformisés pour les analyses de justification des allégations. Les ongles ont été sensibilisés à l'aide d'un blanchissement au peroxyde d'hydrogène. Les effets ont été confirmés par des analyses par DSC et des tests de flexion des ongles. En outre, la capacité des principes actifs à répondre aux préoccupations liées à la souplesse et à la fragilité des ongles a été évaluée à l'aide de ces techniques. RÉSULTATS: Les résultats ont confirmé la viabilité de l'équilibrage des ongles immergés dans de l'eau pendant une durée maximale de 14 heures comme méthode d'analyse standardisée. Les résultats de la température de dénaturation étaient indépendants du genre et adaptés aux analyses de justification des allégations. L'uniformisation des ongles provenant de différentes sources n'a pas entraîné de variations significatives des propriétés de dénaturation. Une étude préliminaire a suggéré que les ongles prélevés sur des cadavres doivent être utilisés avec prudence, car ils présentaient des différences de température de dénaturation, influencées par le site d'échantillonnage. Les tests de fatigue par flexion ont mis en évidence l'importance de l'humidité, notamment des conditions d'humidité plus élevées (80 %) améliorant la flexibilité de l'ongle et offrant une meilleure résolution pour la justification des allégations. La sensibilisation des ongles avec du peroxyde d'hydrogène a induit des modifications des deux résultats aux analyses par DSC et de fatigue par flexion. Des études de preuve de principe ont démontré une élévation de la température de dénaturation et une diminution du nombre de cycles à rompre, indiquant un effet durcissant de l'ongle lors de l'application de formaldéhyde. L'utilisation d'un émollient unguéal a permis d'améliorer la résistance à la fatigue des ongles en raison d'une réduction notable de la densité de réticulation des ongles. CONCLUSIONS: La mesure de la densité de réticulation s'est avérée être un outil sensible pour évaluer les effets des traitements cosmétiques sur les ongles, en particulier pour prédire les résultats liés à la fragilité et à la flexibilité des ongles.

Perceived plausibility modulates hippocampal activity in episodic counterfactual thinking.

Episodic counterfactual thinking (ECT) consists of imagining alternative outcomes to past personal events. Previous research has shown that ECT shares common neural substrates with episodic future thinking (EFT): our ability to imagine possible future events. Both ECT and EFT have been shown to critically depend on the hippocampus, and past research has explored hippocampal engagement as a function of the perceived plausibility of an imagined future event. However, the extent to which the hippocampus is modulated by perceived plausibility during ECT is unknown. In this study, we combine two functional magnetic resonance imaging datasets to investigate whether perceived plausibility modulates hippocampal activity during ECT. Our results indicate that plausibility parametrically modulates hippocampal activity during ECT, and that such modulation is confined to the left anterior portion of the hippocampus. Moreover, our results indicate that this modulation is positive, such that increased activity in the left anterior hippocampus is associated with higher ratings of ECT plausibility. We suggest that neither effort nor difficulty alone can account for these results, and instead suggest possible alternatives to explain the role of the hippocampus during the construction of plausible and implausible ECT.

Does hand position affect orienting when no action is required? An electrophysiological study.

Previous research has shown that attention can be biased to targets appearing near the hand that require action responses, arguing that attention to the hand facilitates upcoming action. It is unclear whether attention orients to non-targets near the hand not requiring responses. Using electroencephalography/event-related potentials (EEG/ERP), this study investigated whether hand position affected visual orienting to non-targets under conditions that manipulated the distribution of attention. We modified an attention paradigm in which stimuli were presented briefly and rapidly on either side of fixation; participants responded to infrequent targets (15%) but not standard non-targets and either a hand or a block was placed next to one stimulus location. In Experiment 1, attention was distributed across left and right stimulus locations to determine whether P1 or N1 ERP amplitudes to non-target standards were differentially influenced by hand location. In Experiment 2, attention was narrowed to only one stimulus location to determine whether attentional focus affected orienting to non-target locations near the hand. When attention was distributed across both stimulus locations, the hand increased overall N1 amplitudes relative to the block but not selectively to stimuli appearing near the hand. However, when attention was focused on one location, amplitudes were affected by the location of attentional focus and the stimulus, but not by hand or block location. Thus, hand position appears to contribute only a non-location-specific input to standards during visual orienting, but only in cases when attention is distributed across stimulus locations.

The Efficacy of Downward Counterfactual Thinking for Regulating Emotional Memories in Anxious Individuals.

Aversive autobiographical memories sometimes prompt maladaptive emotional responses and contribute to affective dysfunction in anxiety and depression. One way to regulate the impact of such memories is to create a downward counterfactual thought-a mental simulation of how the event could have been worse-to put what occurred in a more positive light. Despite its intuitive appeal, counterfactual thinking has not been systematically studied for its regulatory efficacy. In the current study, we compared the regulatory impact of downward counterfactual thinking, temporal distancing, and memory rehearsal in 54 adult participants representing a spectrum of trait anxiety. Participants recalled regretful experiences and rated them on valence, arousal, regret, and episodic detail. Two to six days later, they created a downward counterfactual of the remembered event, thought of how they might feel about it 10 years from now, or simply rehearsed it. A day later, participants re-rated the phenomenological characteristics of the events. Across all participants, downward counterfactual thinking, temporal distancing, and memory rehearsal were equally effective at reducing negative affect associated with a memory. However, in individuals with higher trait anxiety, downward counterfactual thinking was more effective than rehearsal for reducing regret, and it was as effective as distancing in reducing arousal. We discuss these results in light of the functional theory of counterfactual thinking and suggest that they motivate further investigation into downward counterfactual thinking as a means to intentionally regulate emotional memories in affective disorders.

Phenomenology of counterfactual thinking is dampened in anxious individuals.

Counterfactual thinking (CFT), or simulating alternative versions of occurred events, is a common psychological strategy people use to process events in their lives. However, CFT is also a core component of ruminative thinking that contributes to psychopathology. Though prior studies have tried to distinguish adaptive from maladaptive CFT, our study provides a novel demonstration that identifies phenomenological differences across CFT in participants with varying levels of trait anxiety. Participants (N = 96) identified negative, regretful memories from the past 5 years and created a better counterfactual alternative (upward CFT), a worse counterfactual alternative (downward CFT), or simply recalled each memory. Participants with high levels of trait anxiety used more negative language when describing their mental simulations, reported lower ratings of composition during upward CFT, and reported more difficulty in imagining the emotion they would have felt had negative events turned out to be better. Additionally, participants with high anxiety thought that upward CFT was less likely to occur relative to individuals with low anxiety. These results help to clarify how mental simulations of aversive life events are altered in anxiety and serve as a stepping stone to future research uncovering the mechanisms of ruminative thought patterns.

Differential contribution of anterior and posterior midline regions during mental simulation of counterfactual and perspective shifts in autobiographical memories.

Retrieving autobiographical memories induces a natural tendency to mentally simulate alternate versions of past events, either by reconstructing the perceptual details of the originally experienced perspective or the conceptual information of what actually occurred. Here we examined whether the episodic system recruited during imaginative experiences functionally dissociates depending on the nature of this reconstruction. Using fMRI, we evaluated differential patterns of neural activity and hippocampal connectivity when twenty-nine participants naturally recalled past negative events, shifted visual perspective, or imagined better or worse outcomes than what actually occurred. We found that counterfactual thoughts were distinguished by neural recruitment in dorsomedial prefrontal cortex, whereas shifts in visual perspective were uniquely supported by the precuneus. Additionally, connectivity with the anterior hippocampus changed depending upon the mental simulation that was performed - with enhanced hippocampal connectivity with medial prefrontal cortex for counterfactual simulations and precuneus for shifted visual perspectives. Together, our findings provide a novel assessment of differences between these common methods of mental simulation and a more detailed account for the neural network underlying episodic retrieval and reconstruction.

Spatial distancing reduces emotional arousal to reactivated memories.

Memories are able to update and adapt with new information about the world after they are reactivated. However, it is unknown whether the labile period following reactivation makes episodic memories more amenable to emotion regulation, an application that holds great clinical promise. Here, we investigated the efficacy of cognitive reappraisal to down regulate negative affect in response to reactivated memories. Healthy young adults (N = 119) rated the emotionality of negative pictures. After a partial reactivation of each picture 2 days later, participants voluntarily engaged in a spatial distancing regulation tactic by imagining the reactivated object extremely far away from them. Compared with no-regulation and no-reactivation controls, self-reported arousal for regulated pictures dropped significantly 2 days after the manipulation, despite no significant difference in memory accuracy or valence. These results open up a new line of work that capitalizes on reactivation-based lability to selectively alter enduring arousal responses to emotional memories.

What if? Neural activity underlying semantic and episodic counterfactual thinking.

Counterfactual thinking (CFT) is the process of mentally simulating alternative versions of known facts. In the past decade, cognitive neuroscientists have begun to uncover the neural underpinnings of CFT, particularly episodic CFT (eCFT), which activates regions in the default network (DN) also activated by episodic memory (eM) recall. However, the engagement of DN regions is different for distinct kinds of eCFT. More plausible counterfactuals and counterfactuals about oneself show stronger activity in DN regions compared to implausible and other- or object-focused counterfactuals. The current study sought to identify a source for this difference in DN activity. Specifically, self-focused counterfactuals may also be more plausible, suggesting that DN core regions are sensitive to the plausibility of a simulation. On the other hand, plausible and self-focused counterfactuals may involve more episodic information than implausible and other-focused counterfactuals, which would imply DN sensitivity to episodic information. In the current study, we compared episodic and semantic counterfactuals generated to be plausible or implausible against episodic and semantic memory reactivation using fMRI. Taking multivariate and univariate approaches, we found that the DN is engaged more during episodic simulations, including eM and all eCFT, than during semantic simulations. Semantic simulations engaged more inferior temporal and lateral occipital regions. The only region that showed strong plausibility effects was the hippocampus, which was significantly engaged for implausible CFT but not for plausible CFT, suggestive of binding more disparate information. Consequences of these findings for the cognitive neuroscience of mental simulation are discussed.

Neural activity associated with repetitive simulation of episodic counterfactual thoughts.

When people revisit past autobiographical events they often imagine alternative ways in which such events could have occurred. Often these episodic counterfactual thoughts (eCFT) are momentary and fleeting, but sometimes they are simulated frequently and repeatedly. However, little is known about the neural differences between frequently versus infrequently repeated eCFT. The current study explores this issue. In a three-session study, participants were asked to simulate alternative ways positive, negative, and neutral autobiographical memories could have occurred. Half of these eCFT were repeatedly re-simulated while the other half were not. Immediately after, participants were asked to simulate all these eCFT again while undergoing fMRI. A partial least squares analysis on the resultant fMRI data revealed that eCFT that were not frequently repeated preferentially engaged brain regions including middle (BA 21) and superior temporal gyri (BA 38/39), middle (BA 11) and superior frontal gyri (BA 9), and hippocampus. By contrast, frequently repeated eCFT preferentially engaged regions including medial frontal gyri (BA 10), anterior cingulate cortex, insula, and inferior parietal lobule (BA 40). Direct contrasts for each type of eCFT were also conducted. The results of these analyses suggest differential contributions of regions traditionally associated with eCFT, such as BA 10, anterior cingulate cortex, and hippocampus, as a function of kind of eCFT and frequency of repetition. Consequences for future research on eCFT and rumination are considered.

Emotional intensity in episodic autobiographical memory and counterfactual thinking.

Episodic counterfactual thoughts-imagined alternative ways in which personal past events might have occurred-are frequently accompanied by intense emotions. Here, participants recollected positive and negative autobiographical memories and then generated better and worse episodic counterfactual events from those memories. Our results suggest that the projected emotional intensity during the simulated remembered/imagined event is significantly higher than but typically positively related to the emotional intensity while remembering/imagining the event. Furthermore, repeatedly simulating counterfactual events heightened the emotional intensity felt while simulating the counterfactual event. Finally, for both the emotional intensity accompanying the experience of remembering/imagining and the projected emotional intensity during the simulated remembered/imagined event, the emotional intensity of negative memories was greater than the emotional intensity of upward counterfactuals generated from them but lower than the emotional intensity of downward counterfactuals generated from them. These findings are discussed in relation to clinical work and functional theories of counterfactual thinking.