Hierarchical organization of a reference system in newborn spontaneous movements

In this paper, we studied spontaneous newborn movements regarding the coordination of the four limbs, arms and legs, from a dynamic perspective. We used the method of recurrence plots to analyse the kinematic data from audiovisual recordings of neonates. We identified temporal and spatial synchronization of the four limbs that resulted in high recurrence patterns of biomechanical reference configurations. Furthermore, we identified transitions between linear and nonlinear epochs in the movement behavior of newborns on different time scales by means of recurrence quantification analysis. Results are discussed in the context of the concept of a structural hierarchy, in which different time scales correspond to hierarchical levels of organization.     

Mobbing: a meta-analysis and integrative model of its antecedents and consequences

Although mobbing has been extensively studied, empirical research has not led to firm conclusions regarding its antecedents and consequences, both at personal and organizational levels. An extensive literature search yielded 86 empirical studies with 93 samples. The matrix correlation obtained through meta-analytic techniques was used to test a structural equation model. Results supported hypotheses regarding organizational environmental factors as main predictors of mobbing.     

Effects of spatial food distribution on search behavior in rats (Rattus norvegicus)

To analyze how search strategies are adapted according to the geometric distribution of food sources, the authors submitted rats to a search task in which they had to explore 9 food trays in an open field and avoid visiting already-depleted trays. Trays were spatially arranged in 4 independent configurations: a cross, a 3 x 3 matrix, 3 clusters of 3 trays each, and a random configuration. Rats exhibited differential search efficiency as a specific effect of the susceptibility of the configurations to being explored in a principled way: crosses were first, matrices or clusters were in the middle, and random configurations were last. Although no exhaustive searches or highly principled patterns were observed in any of the configurations, performances improved as the sessions went by. Thus, structural affordances of the environment influence the construction not only of search strategies but also of information linked to where the reward is.     

Learning reward expectations in honeybees

The aim of this study was to test whether honeybees develop reward expectations. In our experiment, bees first learned to associate colors with a sugar reward in a setting closely resembling a natural foraging situation. We then evaluated whether and how the sequence of the animals’ experiences with different reward magnitudes changed their later behavior in the absence of reinforcement and within an otherwise similar context. We found that the bees that had experienced increasing reward magnitudes during training assigned more time to flower inspection 24 and 48 h after training. Our design and behavioral measurements allowed us to uncouple the signal learning and the nutritional aspects of foraging from the effects of subjective reward values. We thus found that the animals behaved differently neither because they had more strongly associated the related predicting signals nor because they were fed more or faster. Our results document for the first time that honeybees develop long-term expectations of reward; these expectations can guide their foraging behavior after a relatively long pause and in the absence of reinforcement, and further experiments will aim toward an elucidation of the neural mechanisms involved in this form of learning.     

Memory retrieval time and memory capacity of the CA3 network: role of gamma frequency oscillations

The existence of recurrent synaptic connections in CA3 led to the hypothesis that CA3 is an autoassociative network similar to the Hopfield networks studied by theorists. CA3 undergoes gamma frequency periodic inhibition that prevents a persistent attractor state. This argues against the analogy to Hopfield nets, in which an attractor state can be used for working memory. However, we show that such periodic inhibition allows one cycle of recurrent excitatory activity and that this is sufficient for memory retrieval (within milliseconds). Thus, gamma oscillations are compatible with a long-term autoassociative memory function for CA3. A second goal of our work was to evaluate previous methods for estimating the memory capacity (P) of CA3. We confirm the equation, P = c/a(2), where c is the probability that any two cells are recurrently connected and a is the fraction of cells representing a memory item. In applying this to CA3, we focus on CA3a, the subregion where recurrent connections are most numerous (c = 0.2) and approximate randomness. We estimate that a memory item is represented by approximately 225 of the 70,000 neurons in CA3a (a = 0.003) and that approximately 20,000 memory items can be stored. Our general conclusion is that the physiological and anatomical findings of CA3a are consistent with an autoassociative function. The nature of the information that is associated in CA3a is discussed. We also discuss how the autoassociative properties of CA3 and the heteroassociative properties of dentate synapses (linking sequential memories) form an integrated system for the storage and recall of item sequences. The recall process generates the phase precession in dentate, CA3, and entorhinal cortex.     

An experimental test of a game‐theoretical model of reciprocity

In this contribution the norm of reciprocity is defined as a basic internal motivation. Using formal tools of game theory, a model of social utility function is presented. The reciprocity model predicts that social actors should reciprocate costs and benefits they receive, even when there are costs in conforming to the norm. Hypotheses about actors' behavior, expectations and evaluations are derived from the model. The hypotheses were tested in an experimental situation, the reciprocity game, consisting of a prisoner's dilemma game (PD) followed by a dictator game (DG). The sample was composed of 74 Italian undergraduate students. In line with the model's predictions, the experimental results showed that participants reciprocate the behavior of the opponent in the PD. In the DG, if the opponent cooperated, participants gave back an almost equal share, whereas if the opponent defected, participants gave a minimal amount. These reciprocity effects are modulated by individual differences in the concern for reciprocity. Copyright © 2000 John Wiley & Sons, Ltd.     

Exploring temporal aspects of social identity: the concept of possible social identities

In the social identity model of reactions to negative social identity (Tajfel & Turner, 1979, 1986), the concept of cognitive alternatives focuses on individual and group perceptions of the possibility of changing group memberships or improving existing ones. In the current paper, the under-researched concept of cognitive alternatives is expanded so as to better encompass issues relating to the temporal dimension of social identity maintenance. Markus and Nurius' (1986) possible selves perspective is used as a starting point for exploring the manner in which social identity maintenance is influenced by cognitions about, and social representations of, a group's past and possible future. It is proposed that the concept of cognitive alternatives be expanded to incorporate possible social identities, which represent individual and shared cognitions about possible past group memberships, possible future group memberships, and perceptions of the possible past and future for current group memberships. The consequences of perceiving positive and negative possible social identities are examined, and methodological issues which might facilitate their empirical study addressed. © 1998 John Wiley & Sons, Ltd.     

Can the chronic exclusion-resignation link be broken? An analysis of support groups within prisons

Social exclusion, especially when prolonged over time––has a strong impact on the individuals’ health and wellbeing. According to the Temporal Need-Threat Model (Williams, 2009), the experience of chronic social exclusion inescapably leads to a condition of resignation, characterized by feelings of alienation, depression, helplessness, and unworthiness. However, few empirical studies have tested this prediction and its potential moderating factors. In this research, we identified the prison as a prototypical condition of chronic social exclusion, and aimed at (a) empirically testing the link between chronic exclusion and the resignation stage, (b) investigating whether situational factors—such as attending a support group in prison—can reduce the adverse outcomes of the resignation, and (c) exploring the role of individual differences (e.g., psychological flexibility) in mediating the effect of the support group on the resignation. The study involved 136 participants—68 detainees (31 of them participated in a support group) and 68 free citizens. Results showed that prisoners without the support group showed the highest levels of feelings of resignation. By contrast, prisoners in the support group were no different from nonprisoners in terms of resignation stage outcomes, and this beneficial effect of the support group was mediated by higher levels of perceived social support and psychological flexibility. Overall, this study suggests that the link between chronic exclusion and the resignation stage could be moderated by intervening social factors, highlighting the potential benefits of group-based interventions to tackle the negative consequences of chronic exclusion in chronically excluded populations.     

Enabling Action: Reflections upon Inclusive Participatory Research on Health with Women with Disabilities in the Philippines

People with disabilities experience health disparities arising from social, environmental, and system-level factors. Evidence from a range of settings suggests women with disabilities have reduced access to health information and experience barriers to screening, prevention, and care services. This results in greater unmet health needs, particularly in relation to sexual and reproductive health. Women with disabilities are also more likely to experience physical and sexual violence than women without disabilities, further undermining their health. Community-based participatory research (CBPR) can generate knowledge and underpin action to address such health disparities and promote health equity. However, the potential and challenges of disability inclusion in CBPR, particularly in contexts of poverty and structural inequality such as those found in low- and middle-income countries, are not well documented. In this paper, we reflect on our experience of implementing and evaluating W-DARE, a three-year program of disability-inclusive CBPR aiming to increase access to sexual and reproductive health and violence-response services for women with disabilities in the Philippines. We discuss strategies for increasing disability inclusion in research and use a framework of reflexive solidarity to consider the uneven distribution of the benefits, costs, and responsibilities for action arising from the W-DARE program.