Short-term memory reactivation of a weak CS–US association promotes long-term memory persistence in conditioned odor aversion

In conditioned odor aversion (COA), the association of a tasteless odorized solution (the conditioned stimulus [CS]) with an intraperitoneal injection of LiCl (the unconditioned stimulus [US[), which produces visceral malaise, results in its future avoidance. The strength of this associative memory is mainly dependent on two parameters, that is, the strength of the US and the interstimuli interval (ISI). In rats, COA has been observed only with ISIs of ≤15 min and LiCl (0.15 M) doses of 2.0% of bodyweight, when tested 48 h after acquisition (long-term memory [LTM]). However, we previously reported a robust aversion in rats trained with ISIs up to 60 min when tested 4 h after acquisition (short-term memory [STM]). Since memories get reactivated during retrieval, in the current study we hypothesized that testing for STM would reactivate this COA trace, strengthening its LTM. For this, we compared the LTM of rats trained with long ISIs or low doses of LiCl initially tested for STM with that of rats tested for LTM only. Interestingly, rats conditioned under parameters sufficient to produce STM, but not LTM, showed a reliable LTM when first tested for STM. These observations suggest that under suboptimal training conditions, such as long ISIs or low US intensities, a CS–US association is established but requires reactivation in the short-term in order to persist in the long-term.

The dynamic and malleable nature of memories is a well-studied phenomenon. Traditionally, for memory formation to occur, a set of processes collectively known as consolidation are thought to be needed in order to stabilize memories, making them susceptible to modification during this period (Dudai et al. 2015). More recently a slightly distinct theory, known as memory integration, was proposed according to which memories are rapidly formed during learning without the need for consolidation, but any relevant information around the event can be integrated modifying them (Gisquet-Verrier and Riccio 2019). Common to both theories though, is that memories alternate between an inactive and an active state and modifications can mostly occur during the active state, which lasts for some time after learning, or during its reactivation due to retrieval (Lee et al. 2017; Albo and Gräff 2018; Gisquet-Verrier and Riccio 2019). Thus, memory malleability is explained either because consolidation can be altered or because additional information can be integrated with the initial memory (Bailey et al. 1996; Dudai 2004; Wixted 2004; Alberini et al. 2006; Lee et al. 2008, 2017; McGaugh and Roozendaal 2009; Roesler and Schröder 2011; Dudai et al. 2015; Nader 2015; Crossley et al. 2019; Gisquet-Verrier and Riccio 2019).In conditioned odor aversion (COA), an odorized tasteless solution (conditioned stimulus, CS) whose ingestion is followed by gastrointestinal malaise (unconditioned stimulus, US) is rejected in future encounters (conditioned response, CR). In most COA studies, a robust aversion has been observed only when the interstimulus interval (ISI) is ∼5 min, and no significant aversion can be seen when the ISI is >15 min (Hankins et al. 1973; Palmerino et al. 1980; Ferry et al. 1995, 1996; Ferry and di Scala 1997; Ferry et al. 2006; Chapuis et al. 2007). This observation has been attributed to a short-lasting memory of the odor that becomes unavailable for its association with the US after ISI >15 min. However, in all these instances the CR was measured 48 h after conditioning (LTM test), leaving up the possibility that CS–US association was formed but somehow did not last till the long-term. In keeping with this possibility, we previously reported a significant aversion during a test performed 4 h after conditioning (i.e., STM test) in rats trained with ISIs up to 60 min, three times longer than previously described (Tovar-Díaz et al. 2011). The LTM, however, was not tested so no further insight was provided regarding its persistence due to STM reactivation.Thus, in the current paper we hypothesized that a STM test would reactivate the initial memory, allowing it to further consolidate/integrate the information and to persist in the LTM. To test this possibility, we trained independent groups of rats with reduced US intensities or prolonged ISIs in a standard two-bottle choice COA paradigm and tested them twice at 4 and 48 h after conditioning. Our findings suggest that COA takes place under milder US and longer ISIs than previously thought and reactivating this memory during the STM test promotes its persistence in the LTM test.     

Children’s attributions of beliefs to humans and God: cross-cultural evidence

The capacity to attribute beliefs to others in order to understand action is one of the mainstays of human cognition. Yet it is debatable whether children attribute beliefs in the same way to all agents. In this paper, we present the results of a false-belief task concerning humans and God run with a sample of Maya children aged 4-7, and place them in the context of several psychological theories of cognitive development. Children were found to attribute beliefs in different ways to humans and God. The evidence also speaks to the debate concerning the universality and uniformity of the development of folk-psychological reasoning.     

The Latent Threat of Community Violence: Indirect Exposure to Local Homicides and Adolescents’ Mental Health in Colombia

This study examines the relation between adolescents’ indirect exposure to local homicides and mental health disorders and post‐traumatic stress disorder (PTSD) symptoms. We employ a sample of 300 adolescents ( representative for Bogotá, Colombia, and geocoded data on violent crimes recorded by the national police. Findings show that one SD increment in local homicides is associated with increments by 0.17 SD in the mental health disorder index and a 0.14 SD increase in the PTSD score index, even after accounting for adolescents’ direct exposure to violence. The estimated effect for PTSD was larger for adolescents’ who were directly exposed to violence and for those living in multidimensionally poor households, whereas no detectable effects were found for adolescents who perceived their residential neighborhood as relatively safe.     

Anxiety and depression: Past,present, and future events

This article focuses on differences between anxiety and depression. The first study is concerned with the timing (past, present, future) of negative events associated with high levels of anxiety and depression in normal participants. Depression was associated more with past events than future events, whereas the opposite was the case with anxiety. These findings are consistent with those reported in several studies on clinical samples. In a second study, participants provided their emotional reactions to scenarios referring to negative events lying in the past or in the future with the future events being either uncertain or probable. Past events were associated with more depression and less anxiety than future events whether uncertain or probable. Probable future events were associated with more anxiety and depression than uncertain ones. Theoretical implications of these findings are discussed.     

Psychometric properties of the Portuguese version of the Alabama Parenting Questionnaire parent form

ABSTRACT

The Alabama Parenting Questionnaire parent form (APQ-P) is one of the most commonly used measures to assess parenting practices. The current study evaluated the psychometric properties of the APQ-P using a community sample of 499 Portuguese mothers of children and adolescents aged 10 to 17 years. Confirmatory factor analysis revealed adequate psychometric properties of a three-factor model (positive parenting, ineffective parenting, and poor monitoring) in a solution of 20-items. After comparing the three-factor model across children’s age groups (≤13 vs. ≥14), partial metric and partial scalar invariance were found. Items loadings were similar between groups for ineffective parenting and poor monitoring, and factor scores were similar between groups for positive parenting. The 20-item version can be an appropriate measure of parenting, relevant for research and intervention purposes. Future studies should validate the current findings in independent samples, and devote particular attention to different parenting practices across different children’s age groups.     

Team adaptability and task cohesion as resources to the non-linear dynamics of workload and sickness absenteeism in firefighter teams

ABSTRACT

The current study builds on the non-linear Dynamic Systems (NDS) perspective to test the assumption that change in sickness absenteeism is non-linear, and that such change is due to workload, team adaptability and task cohesion. Participants were 37 firefighter teams (n = 250 individuals) from a main European capital city. The research hypotheses were tested using SPSS and the “cusp” package, in the statistical software R. The results suggest that change in sickness absenteeism behaviours over time is non-linear, with the cusp catastrophe model predicting such behaviours better than the linear and logistic models. In our model, task cohesion functions as an asymmetry factor (i.e., the independent variable that determines the strength and discrepancy between the two stable states of the dependent variable) leading to a linear change in sickness absenteeism. Interestingly, both workload and team adaptability function as bifurcation (i.e., the independent variable that determines the change between the two stable states of the order parameter) and asymmetry factors leading to non-linear and linear change in sickness absenteeism over time. This study contributes to the growing evidence that incorporating the NDS perspective enables a better understanding of action teams, namely those working in extreme environments.