A formalisation of violation, error recovery, and enforcement in the bit transmission problem

The design of complex multi-agent systems is increasingly having to confront the possibility that agents may not behave as they are supposed to. In addition to analysing the properties that hold if protocols are followed correctly, it is also necessary to predict, test, and verify the properties that would hold if these protocols were to be violated. We illustrate how the formal machinery of deontic interpreted systems can be applied to the analysis of such problems by considering three variations of the bit transmission problem. The first, an example in which an agent may fail to do something it is supposed to do, shows how we deal with violations of protocols and specifications generally. The second, an example in which an agent may do something it is not supposed to do, shows how it is possible to specify and analyse remedial or error-recovery procedures. The third combines both kinds of faults and introduces a new component into the system, a controller, whose role is to enforce compliance with the protocol. In each case the formal analysis is used to test whether critical properties of the system are compromised, in this example, the reliable communication of information from one agent to the other.     

Recovery of memory from infantile amnesia is developmentally constrained

Episodic memories formed during infancy are rapidly forgotten, a phenomenon associated with infantile amnesia, the inability of adults to recall early-life memories. In both rats and mice, infantile memories, although not expressed, are actually stored long term in a latent form. These latent memories can be reinstated later in life by certain behavioral reminders or by artificial reactivations of neuronal ensembles activated at training. Whether the recovery of infantile memories is limited by developmental age, maternal presence, or contingency of stimuli presentation remains to be determined. Here, we show that the return of inhibitory avoidance memory in rats following a behavioral reactivation consisting of an exposure to the context (conditioned stimuli [CS]) and footshock (unconditioned stimuli [US]) given in a temporally unpaired fashion, is evident immediately after US and is limited by the developmental age at which the reactivations are presented; however, it is not influenced by maternal presence or the time interval between training and reactivation. We conclude that one limiting factor for infantile memory reinstatement is developmental age, suggesting that a brain maturation process is necessary to allow the recovery of a “lost” infantile memory.

Hippocampus-dependent episodic memories formed early in life are rapidly forgotten. This process of forgetting is evolutionarily conserved and is associated with infantile amnesia, the inability of adults to recall early-life memories (Campbell and Spear 1972; Rovee-Collier 1999; Hayne 2004; Josselyn and Frankland 2012; Callaghan et al. 2014; Madsen and Kim 2016; Alberini and Travaglia 2017).Although they are rapidly forgotten, early-life experiences influence brain functions throughout life (Jacobs and Nadel 1985; Meaney et al. 1988; Sroufe et al. 1990; Brunson et al. 2005; Pryce et al. 2005; Mineka and Zinbarg 2006; Bale et al. 2010; Poulos et al. 2014; Perry and Sullivan 2014) and produce long-lasting biological changes in the brain. For example, aversive early-life experiences regulate the expression of hippocampal glucocorticoid receptor and hypothalamic–pituitary–adrenal (HPA) functions in a persistent fashion (Champagne and Curley 2009). Moreover, threatening experiences in early life can predispose individuals to psychopathologies such as post-traumatic stress disorder (PTSD) and mood and anxiety disorders (Heim and Nemeroff 2001). Consistent with this long-lasting influence on behavior, studies in rodent models have shown that, in contrast to what was previously believed, memories formed in infancy (at postnatal days 16–18 [PN16–PN18]) although not expressed, are not lost. Rather, they are stored over the longer term in a latent form and can reemerge at later times, up to adulthood, following behavioral reactivations or artificial stimulation of the neuronal ensembles activated at learning (Travaglia et al. 2016; Guskjolen et al. 2018; Bessières et al. 2020).In our previous studies based on rat inhibitory avoidance (IA), a paradigm in which the animal learns to avoid a context previously paired with a footshock, we confirmed that an infantile episodic learning event given at PN17 resulted in the typical rapid forgetting. We then found that, however, this memory was stored long term in a latent form, as demonstrated by the observation that it could reemerge following a behavioral reactivation consisting of exposure to the training context (conditioned stimulus [CS]) and a later time footshock of the same intensity that was used during training (unconditioned stimulus [US]) but now given in a distinct context. Reexperiencing either the context or the footshock alone failed to reinstate the infantile memory (Travaglia et al. 2016), suggesting that the return of infantile memory is limited by certain boundaries.Several questions about the conditions for the recovery of latent, infantile episodic memories remain to be addressed. First, is infantile memory reinstatement following the unpaired US presentation temporally regulated? Second, is there an age limit for memory reinstatement? Third, given that other types of learning, such as non-hippocampus-dependent cued conditioning, are regulated by the maternal presence during infancy (Moriceau and Sullivan 2006), is infantile episodic memory reinstatement limited or regulated by the presence of the mother? In this study, we set out to address these questions using IA in infant rats.     

Misprojection of landmarks onto the spatial map

It has been suggested that neglect patients misrepresent the metric spatial relations along the horizontal axis (anisometry). The "fabric" of their internal spatial medium would be distorted in such a way that physically equal distances appear relatively shorter on the contralesional side (canonical anisometry). The case of GL, a 76-year-old lady with left neglect on visual search tasks, is presented. GL showed severe relative overestimation on the left (contralesional) side on two independent tasks evaluating the metrics of her internal representation. A qualitatively similar pattern was found in two out of 10 other neglect patients who performed the second task. This behavior cannot be accounted for by the canonical anisometry hypothesis. Nevertheless, GL produced a relative left overextension (underestimation) when trying to set the endpoints of a virtual line given its midpoint (Endpoints Task). An interpretation of these results is offered in terms of a misprojection of relevant landmarks onto the internal representation without assuming distortion of its "fabric."     

Dissociation between the mental rotation of visual images and motor images in unilateral brain-damaged patients

Deficits in the mental rotation of body parts and of external objects can be doubly dissociated (Rumiati, Tomasino, Vorano, Umiltà, & De Luce, 2001; Sirigu & Duhamel, 2001; Tomasino, Rumiati, & Umità, in press). The aim of this study was to replicate this finding and to then investigate the relevance of the specific hemispheres in these deficits. Nine patients with unilateral lesions (five in the Left Hemisphere and four in the Right) and 20 control subjects, performed a single task requiring mental rotation of hands, and two tasks requiring mental rotation of external objects. RH patients were impaired in the rotation of external objects, but showed intact performance on the rotation of hands; the opposite pattern was found for LH patients. These results support the view that the LH contributes to the mental rotation of hands, recruiting processes specific to motor preparation, while the RH is specialized for mental rotation of external objects.     

Factors Associated with Providers’ Work Engagement and Burnout in Homeless Services: A Cross‐national Study

The complexity of homeless service users’ characteristics and the contextual challenges faced by services can make the experience of working with people in homelessness stressful and can put providers’ well‐being at risk. In the current study, we investigated the association between service characteristics (i.e., the availability of training and supervision and the capability‐fostering approach) and social service providers’ work engagement and burnout. The study involved 497 social service providers working in homeless services in eight different European countries (62% women; mean age = 40.73, SD = 10.45) and was part of the Horizon 2020 European study “Homelessness as Unfairness (HOME_EU).” Using hierarchical linear modeling (HLM), findings showed that the availability of training and supervision were positively associated with providers’ work engagement and negatively associated with burnout. However, results varied based on the perceived usefulness of the training and supervision provided within the service and the specific outcome considered. The most consistent finding was the association between the degree to which a service promotes users’ capabilities and all the aspects of providers’ well‐being analyzed. Results are discussed in relation to their implications for how configuration of homeless services can promote social service providers’ well‐being and high‐quality care.     

Instigation to aggress and escalation of aggression examined from a personological perspective: The role of irritability and of emotional susceptibility

Two studies were conducted using Buss hostility machine paradigm to investigate the role of individual differences in irritability and emotional susceptibility on the instigation to aggress by a self-esteem lowering manipulation and on the hypothesized escalation of aggression over trials. The role of sex was also examined. In the first study, 60 highly irritable and 60 low irritable subjects were given the opportunity to deliver electric shocks to an experimental confederate, half after being provoked by a negative judgement on their performance in a learning task, half without such an experience. Each group of subjects was divided equally between males and females. It was found that highly irritable subjects, both males and females, delivered higher shocks after provocation than low irritable subjects under similar circumstances. An upward drift of shock level over trials was found only in provoked males and only in highly irritable females. In the second study, 60 highly emotionally susceptible and 60 low emotionally susceptible males and females were given the opportunity to deliver electric shocks to an experimental confederate, half after experiencing provocation, half without such an experience. It was found that provoked subjects delivered higher shocks than unprovoked subjects and that highly emotionally susceptible subjects delivered higher shocks than low emotionally susceptible subjects. Whereas an upward drift of shock levels over trials was found only in provoked males, the same effect was found in females, whether provoked or not. These findings are discussed in terms of the importance of stable personality characteristics that may mediate aggressive response.     

Predicting Perceived Risk of Crime: a Multilevel Study

With a sample of Italians selected from 71 Italian counties (N = 1,868), we performed two multilevel analyses aimed at predicting the perceived risk of crime at local (i.e., in the participants' county of residence) and at societal (i.e., in the context of Italian society) levels. A significant proportion of the variation in local risk perception was at the county level. The following individual variables predicted higher levels of this variable: indirect victimization, the perception of social and physical disorder, being a woman, being poorly educated, and being an older person. Among the ecological predictors, the crime rate and unemployment rate predicted higher levels of local crime risk perception, while the immigrant rate did not. Perceived risk of crime at the societal level did not show significant variation at the county level. Education, being a man, trusting people, and adhesion to post‐materialistic values predicted lower levels of societal crime risk perception, while number of sons/daughters and exposure to television news increased it. The limitations and possible development of this study are discussed.