A planner agent that tries its best in presence of nondeterminism

In many nondeterministic planning domains, an agent whose goal is to achieve φ may not succeed in finding a policy that can guarantee that all paths from the initial state lead to a final state where φ holds (strong solution). Nevertheless, if the agent is trying its best to achieve φ, it cannot give up. Instead, it may be inclined to accept weaker guarantees, such as having a path leading to φ from any intermediate state reached by the policy (strong-cyclic solution), or even less, such as having at least one path leading to φ from the initial state (weak solution). But the agent should choose among such different options based on their availability in each situation. Although the specification of this type of goal has been addressed before, in this paper we show how a planner based on the branching time temporal logic α-ctl can be used to plan for intuitive and useful goals of the form “try your best to achieve φ”.     

The NK3 receptor agonist senktide ameliorates scopolamine-induced deficits in memory for object, place and temporal order

Senktide, a potent neurokinin-3 receptor (NK₃-R) agonist, increases acetylcholine (ACh) release in the striatum, the prefrontal cortex (Schäble et al., 2011), the amygdala and hippocampus, presumably via postsynaptic mechanisms. A promnestic action of NK₃-R agonists has been described in a variety of learning/memory tasks. The memory-enhancing effects of NK₃-R agonists and their activating influence on ACh suggest a possible role of the NK₃-R in learning and memory via cholinergic modulation. Deterioration of the cholinergic system in the basal forebrain has been associated with learning and memory deficits and cholinergic agents have promnestic effects in a variety of learning paradigms. The anticholinergic drug, scopolamine, a muscarinic ACh receptor antagonist, incurs deficits in a variety of learning tasks and provides a useful tool to investigate the role of the cholinergic systems in mechanisms underlying learning and memory. The aim of this study was to ascertain the effect of the NK₃-R agonist, senktide, in the scopolamine-induced deficit model. We hypothesized that senktide treatment would attenuate scopolamine-induced (subcutaneous – s.c. 0.75 mg/kg) memory impairment in three novelty preference paradigms based on spontaneous object exploration: namely object recognition, object–place recognition and object recognition for temporal order. Administration of senktide reversed the scopolamine-induced memory deficits by re-establishing object recognition (s.c. 0.2 mg/kg), object–place recognition (0.2 and 0.4 mg/kg), as well as object recognition for temporal order (0.4 mg/kg) in adult Wistar rats. These results indicate memory enhancing effects of senktide in animals subjected to scopolamine-induced memory impairments and indicate that the promnestic action of NK₃-R agonists is mediated by muscarinic cholinergic mechanisms.     

The Relationships Among Parental Anxiety, Parenting, and Children’s Anxiety: The Mediating Effects of Children’s Cognitive Vulnerabilities

Theoretical models have emphasized the roles played by parental anxiety and behavior in the development of childhood anxiety problems. Little is known regarding the differential impacts of mothers and fathers or regarding the processes that mediate these influences. The present study examines the relationships between maternal and paternal trait anxiety, overprotection, and emotional support on the one hand and anxiety symptoms in children on the other hand. This study also explores the mediating role of children’s cognitive vulnerabilities to anxiety disorders in the relationship between parental variables and children’s anxiety. A sample of 80 children and their parents (fathers and mothers), selected from an initial screening of 905 school-aged children, participated in this study. The results indicate that both parents had unique influences on children’s anxiety symptoms: maternal trait anxiety and paternal overprotection and concern were found to independently and positively contribute to children’s anxiety. Furthermore, children’s interpretative biases mediated the relation between maternal trait anxiety and children’s anxiety symptoms. The results of this study underline the importance of considering both paternal and maternal factors in the development of children’s anxiety problems. These findings also have implications for theoretical models of the etiology of anxiety and for the treatment of these problems in children.     

AN ESSAY ON DREAMING,PSYCHICAL WORKING OUT AND WORKING THROUGH2

In this paper the author attempts to expand the idea put forward by Freud who considered dreams as a special form of unconscious thinking. It is the author's contention that the psychical working‐out function performed by dreams is a form of unconscious thinking, which transforms affects into memories and mental structures. He also attempts to clarify the way in which meaning is built and transformed in mental life. In that respect the unconscious internal world is seen as a form of unconscious thinking, a private theatre where meaning is generated and transformed. He focuses on what happens to feelings in dreams in connection with the meanings as a result of and an expression of the several stages of working through. The dream world is described as the setting where the mind gives expressive pictorial representation to the emotions involved in a conflict: a first step towards thinkability. The dreamwork also constitutes a process through which meaning is apprehended, built on and transformed at an expressive non‐discursive level, based on representation through figurative/pictorial images. The author draws on Meltzer's formulation to conjecture that the working‐through function of dreams, mainly in response to interpretations, is performed by a process of progression in formal qualities of the representations made available by dreaming in the form he has called affective pictograms. It is through progression in formal qualities of the representation that the thinking capabilities of the affective life develop and become part of the process of what is called metaphorically the metabolisation of emotional life. This process takes place through migration of meaning across various levels of mental process. In this perspective the analyst'sinterpretations of dreams effect what linguists call transmutation of the symbolic basis, a process that is necessary to help the mind to improve its capacity to think. Something expressed on the evocative plane and condensed into a pictographic image is then transformed into verbal language that expresses meaning. These conceptions are illustrated by a detailed clinical case.     

Exposure to novelty enhances retrieval of very remote memory in rats

Rats were trained in a one-trial step-down inhibitory avoidance task at the age of 3 months and tested for retention 1 day later, or 3, 6, 9, 12, 15, and 19 months later, i.e., when the animals were 3, 6, 9, 12, 15, 18, or 22 months of age. Retrieval performance declined with time and was undetectable in the last two age groups. Exposure to an unrelated novel environment (a square box lined with black plastic) 1 h before retention testing enhanced retrieval at all ages, regardless of the decline in the level of test session performance. The effect cannot be explained by an anxiogenic effect of the novelty box, or by an influence of novelty on locomotion or exploration, or by a nonspecific influence of exposure to novelty on step-down latency in the inhibitory avoidance apparatus.     

Forecasting “friends forever”: A longitudinal investigation of sustained closeness between best friends

Using data collected across 19 years, the chief goal of this study was to discover predictors of continued relational closeness between best friends. Participants were same‐sex and cross‐sex best friend pairs recruited from a small Midwestern college. In 1983, participants completed several tests and activities designed to assess facets of intimacy, with follow‐up studies in 1987 and 2002 measuring relational closeness. Regression analysis indicates that both manifest similarity and months of closeness in 1983 are associated with relational closeness in 2002. These results suggest that the investment of resources in the friendship and similarity between friends facilitate friendship longevity and that Kelley et al.’s (1983) conceptualization of closeness as related to interdependence is empirically robust.     

Spontaneous object recognition in capuchin monkeys: assessing the effects of sex,familiarization phase and retention delay

Animal Cognition - The spontaneous object recognition (SOR) task is a versatile and widely used memory test that was only recently established in nonhuman primates (marmosets). Here, we extended...     

Realism in energy transition processes: an example from Bohmian quantum mechanics

In this paper we study in details a system of two weakly coupled harmonic oscillators from the point of view of Bohm’s interpretation of quantum mechanics. This system may be viewed as a simple model for the interaction between a photon and a photodetector. We obtain exact solutions for the general case. We then compute approximate solutions for the case where one oscillator is initially in its first excited state (a single photon) reaching the other oscillator in its ground state (the photodetector). The approximate solutions represent the state of both oscillators after the interaction, which is not an eigenstate of the individual hamiltonians for each oscillator, and therefore the energies for each oscillator do not exist in the Copenhagen interpretation of Quantum Mechanics. We use the approximate solutions that we obtained to compute Bohmian trajectories and to study the energy transfer between the oscillators. We conclude that, even using the Bohmian view, the energy of each individual oscillator is not well defined, as the nonlocal quantum potential is not negligible even after the coupling is turned off.     

Chronic Illness and Child Behavior Problems in Low-SES Families: The Mediation of Caregivers’ Mental Health

Journal of Child and Family Studies - Childhood chronic illness is associated with deleterious effects on caregivers’ mental health and children’s socio-emotional development. This...     

Phase-oscillator computations as neural models of stimulus–response conditioning and response selection

The activity of collections of synchronizing neurons can be represented by weakly coupled nonlinear phase oscillators satisfying Kuramoto’s equations. In this article, we build such neural-oscillator models, partly based on neurophysiological evidence, to represent approximately the learning behavior predicted and confirmed in three experiments by well-known stochastic learning models of behavioral stimulus–response theory. We use three Kuramoto oscillators to model a continuum of responses, and we provide detailed numerical simulations and analysis of the three-oscillator Kuramoto problem, including an analysis of the stability points for different coupling conditions. We show that the oscillator simulation data are well-matched to the behavioral data of the three experiments.