Philosophy of Mathematics in the Warsaw Mathematical School

The aim of this paper is to present and discuss the philosophical views concerning mathematics of the founders of the so called Warsaw Mathematical School, i.e., Wac?aw Sierpiński, Zygmunt Janiszewski and Stefan Mazurkiewicz. Their interest in the philosophy of mathematics and their philosophical papers will be considered. We shall try to answer the question whether their philosophical views influenced their proper mathematical investigations. Their views towards set theory and its rôle in mathematics will be emphasized.     

Tits use amodal completion in predator recognition: a field experiment

Amodal completion enables an animal to perceive partly concealed objects as an entirety, and to interact with them appropriately. Several studies, based upon either operant conditioning or filial imprinting techniques, have shown that various animals (both mammals and birds) can perform amodal completion. Before this study, the use of amodal completion by untrained animals in the recognition of objects had not been considered. Using two feeders, we observed in a field experiment the reaction of tits to the torso of a sparrowhawk (partly occluded or an ‘amputated’ dummy) in two different treatments (sparrowhawk torso vs. complete dummy pigeon; and torso vs. complete dummy sparrowhawk). It is clear that the birds considered the two torso variants as predators and kept away from both of them when the second feeder offered a ‘pigeon’ instead. On the other hand, when a ‘complete sparrowhawk’ was present on the second feeder, the number of visits to the occluded torso remained low; while the number of visits to the amputated one increased threefold. Birds risked perching near what was clearly an amputated torso; while the fear of a “hiding” (occluded) torso remained unchanged, when the second feeder did not provide a safe alternative. Such discrimination between torsos requires the ability for amodal completion. Our results demonstrate that in their recognition process, the birds not only use simple sign stimuli, but also complex cognitive functions.     

Burnout predictors among prison officers: The moderating effect of temperamental endurance

The study investigates whether work stressors, coping styles, and work-related social support predict burnout among prison officers (N = 476). It was hypothesized that coping and social support would mediate the effects of work stressors on burnout and that these effects would be moderated by temperamental endurance. Results of structural equation modeling showed that emotion-oriented coping was positively related to emotional exhaustion, and negatively to personal accomplishment. Task-oriented coping was positively related to personal accomplishment. Social support from work was negatively related to emotional exhaustion. The effects of work stressors on burnout were mediated by work-related social support and by emotion-oriented coping. Additionally, some of these mediating effects were moderated by endurance. Work-related social support was negatively related to depersonalization only among participants with strong endurance. High level of work stressors predicted high emotion-oriented coping only among individuals with weak endurance.     

Does performance on the standard antisaccade task meet the co-familiality criterion for an endophenotype?

The “co-familiality” criterion for an endophenotype has two requirements: (1) clinically unaffected relatives as a group should show both a shift in mean performance and an increase in variance compared with controls; (2) performance scores should be heritable. Performance on the antisaccade task is one of several candidate endophenotypes for schizophrenia. In this paper we examine whether the various measures of performance on the standard version of the antisaccade task meet the co-familiality criterion for an endophenotype. The three measures of performance—reflexive saccade errors, latency of correct antisaccades, and gain—show a wide range of effect sizes and variance ratios as well as evidence of significant or near significant heterogeneity. The estimated mean effect sizes [Cohen’s d: error rate: 0.34 (SD: 0.29); latency: 0.33 (SD: 0.30); gain: 0.54 (SD: 0.38)] are significantly greater than 0, but the magnitude of the departures from 0 is relatively small, corresponding to modest effect sizes. The width of the 95% confidence intervals for the estimated effect sizes (error rate: 0.2–0.49; latency: 0.17–0.50; gain: 0.23–0.85) and the coefficients of variation in effect sizes (error rate: 85.3%; latency: 90.9%; gain: 68.4%) reflect heterogeneity in effect sizes. The effect sizes for error rate showed statistically significant heterogeneity and those for latency (P = .07) and gain (P = .09) showed a trend toward heterogeneity. These results indicate that the effect sizes are not consistent with a single mean and that the average effect size may be a biased estimate of the magnitude of differences in performance between relatives of schizophrenics and controls. Relatives of schizophrenics show a small but significant increase in variance in error rate, but the confidence interval is broad, perhaps reflecting the heterogeneity in effect size. The variance ratios for latency and gain did not differ in relatives of schizophrenics and controls. Performance, as measured by error rate, is moderately heritable. The data do not provide compelling support for a consistent shift in mean or variance in relatives of schizophrenia patients compared with nonpsychiatric controls, both of which are required for a major gene involved in co-familial transmission. This set of findings suggests that although intra-familial resemblance in antisaccade performance is due in part to genetic factors, it may not be related to a schizophrenia genotype. Based on the current literature, it would be premature to conclude that any of the measures of antisaccade performance unambiguously meets the co-familiality criterion for an endophenotype.     

Coping self-efficacy mediates the effects of negative cognitions on posttraumatic distress

Although cognitive distortions have predicted posttraumatic distress after various types of traumatic events, the mechanisms through which cognitive distortions influence posttraumatic distress remain unclear. We hypothesized that coping self-efficacy, the belief in one's own ability to manage posttraumatic recovery demands, would operate as a mediator between negative cognitions (about self, about the world, and self-blame beliefs) and posttraumatic distress. In the cross-sectional Study 1, data collected among 66 adult female victims of child sexual abuse indicated that coping self-efficacy mediated the effects of negative cognitions about self and about the world on posttraumatic distress. The same pattern of results was found in a longitudinal Study 2, conducted among 70 survivors of motor vehicle accidents. Coping self-efficacy measured at 1 month after the trauma mediated the effects of 7-day negative cognitions about self and about the world on 3-month posttraumatic distress. In both studies self-blame was not related to posttraumatic distress and the effect of self-blame on posttraumatic distress was not mediated by coping self-efficacy. The results provide insight into a mechanism through which negative cognitions may affect posttraumatic distress and highlight the potential importance of interventions aimed at enhancing coping self-efficacy beliefs.     

Centrifugal acceleration to 3Gz is related to increased release of stress hormones and decreased mood in men and women

It has been suggested that the central and peripheral neural processes (CPNP) are affected by gravitational changes. Based on the previous experiments during parabolic flights, central and peripheral changes may not only be due to the changed gravitational forces but also due to neuroendocrine reactions related to the psycho-physiological consequences of gravitational changes. The present study focuses on the interaction of neuroendocrine changes and the physical and mental states after acceleration to three-time terrestrial gravity (3Gz). Eleven participants (29.4+/-5.1 [SD] years (male (n=8): 30+/-5.1 years; female (n=3): 27.7+/-2.1 years) underwent a 15 min acceleration to 3Gz in a human centrifuge. Before and after the acceleration to 3Gz circulating stress hormone concentrations (cortisol, adrenocorticotropic hormone (ACTH), prolactin, epinephrine, norepinephrine) and perceived physical and mental states were recorded. A second control group of 11 participants underwent the same testing procedure in a laboratory session. Serum cortisol concentration during exposure to the centrifugal acceleration increased by 70%, plasma concentration of ACTH increased threefold, prolactin twofold, epinephrine by 70% and norepinephrine by 45%, whereas the perceived physical well-being decreased. These findings demonstrate that psycho-physiological changes have to be regarded as a relevant factor for the changes in CPNP during phases of hypergravity exposure.     

Beta-adrenergic receptor activation during distinct patterns of stimulation critically modulates the PKA-dependence of LTP in the mouse hippocampus

Activation of β-adrenergic receptors (β-ARs) enhances hippocampal memory consolidation and long-term potentiation (LTP), a likely mechanism for memory storage. One signaling pathway linked to β-AR activation is the cAMP-PKA pathway. PKA is critical for the consolidation of hippocampal long-term memory and for the expression of some forms of long-lasting hippocampal LTP. How does β-AR activation affect the PKA-dependence, and persistence, of LTP elicited by distinct stimulation frequencies? Here, we use in vitro electrophysiology to show that patterns of stimulation determine the temporal phase of LTP affected by β-AR activation. In addition, only specific patterns of stimulation recruit PKA-dependent LTP following β-AR activation. Impairments of PKA-dependent LTP maintenance generated by pharmacologic or genetic deficiency of PKA activity are also abolished by concurrent activation of β-ARs. Taken together, our data show that, depending on patterns of synaptic stimulation, activation of β-ARs can gate the PKA-dependence and persistence of synaptic plasticity. We suggest that this may allow neuromodulatory receptors to fine-tune neural information processing to meet the demands imposed by numerous synaptic activity profiles. This is a form of “metaplasticity” that could control the efficacy of consolidation of hippocampal long-term memories.The hippocampus importantly contributes to memory function in the mammalian brain (Zola-Morgan et al. 1986; Eichenbaum et al. 1990; Otto and Eichenbaum 1992; Phillips and LeDoux 1992; Remondes and Schuman 2004). It has reciprocal connections with numerous cortical areas, including those responsible for high-level integration of spatial and contextual data from the external environment (Lavenex and Amaral 2000). As such, the hippocampus is well positioned to receive and survey a broad range of information and select behaviorally salient data for long-term storage. Activity-dependent enhancement of hippocampal synaptic strength can store information carried in patterns of afferent neural activity (Bliss and Collingridge 1993; Moser et al. 1998; Nathe and Frank 2003; Whitlock et al. 2006). Substantial evidence suggests that long-term potentiation (LTP) of synaptic strength plays important roles in the formation of long-term memory (LTM) (Doyere and Laroche 1992; Bourtchuladze et al. 1994; Abel and Lattal 2001; Genoux et al. 2002). As such, mechanistic studies of LTP have shed valuable light on how the mammalian brain stores new information.The hippocampus receives dense noradrenergic projections from the locus coeruleus, a brain structure that can influence many vital brain functions, including attention, sleep, arousal, mood regulation, learning, and memory (Berridge and Waterhouse 2003). Both α- and β-adrenergic receptor subtypes are present on hippocampal neurons (Morrison and Foote 1986; Berridge and Waterhouse 2003), and noradrenaline (NA) acts on hippocampal β-adrenergic receptors (β-ARs) to facilitate the retention and recall of memory (Izquierdo et al. 1998; Ji et al. 2003; Murchison et al. 2004). In humans, stimulation of the noradrenergic neuromodulatory system enhances memory for emotional stimuli, and inhibition of β-ARs prevents this memory enhancement (Cahill et al. 1994; van Stegeren et al. 1998; O’Carroll et al. 1999).Consistent with the notion that selective enhancement of LTM may occur following β-AR activation, stimulation of β-ARs can also facilitate the persistence of LTP. In areas CA3 and CA1, β-AR activation facilitates the induction of long-lasting LTP when paired with certain patterns of electrical stimulation (Huang and Kandel 1996; Gelinas and Nguyen 2005). However, the mechanisms by which different patterns of stimulation control synaptic responsiveness to β-AR activation are unclear.β-ARs couple to guanine-nucleotide-binding regulatory Gs proteins to stimulate adenylyl cyclase activity and increase intracellular cAMP (Seeds and Gilman 1971; Maguire et al. 1977). A main target of cAMP signaling is activation of cAMP-dependent protein kinase (PKA), a kinase that is required for some forms of long-lasting LTP and for consolidation of hippocampal LTM (Frey et al. 1993; Abel et al. 1997; Nguyen and Woo 2003). Interestingly, the PKA-dependence of hippocampal LTP displays plasticity: Specific temporal patterns of synaptic stimulation, such as repeated and temporally spaced 100-Hz stimulation, elicit LTP that requires PKA for its expression (Woo et al. 2003). Also, spatial “enrichment” can increase the PKA-dependence of LTP in mice, and this is correlated with improved hippocampal memory function (Duffy et al. 2001). However, it is unclear whether activation of β-ARs can critically gate the PKA-dependence of LTP. In this study, we examine the effects of β-AR activation on LTP generated by various patterns of afferent stimulation in area CA1 of the hippocampus, and we determine the role of PKA in these β-AR-modulated forms of LTP.     

The role of protein synthesis in memory consolidation: progress amid decades of debate

A major component of consolidation theory holds that protein synthesis is required to produce the synaptic modification needed for long-term memory storage. Protein synthesis inhibitors have played a pivotal role in the development of this theory. However, these commonly used drugs have unintended effects that have prompted some to reevaluate the role of protein synthesis in memory consolidation. Here we review the role of protein synthesis in memory formation as proposed by consolidation theory calling special attention to the controversy involving the non-specific effects of a group of protein synthesis inhibitors commonly used to study memory formation in vivo. We argue that molecular and genetic approaches that were subsequently applied to the problem of memory formation confirm the results of less selective pharmacological studies. Thus, to a certain extent, the debate over the role of protein synthesis in memory based on interpretational difficulties inherent to the use of protein synthesis inhibitors may be somewhat moot. We conclude by presenting avenues of research we believe will best provide answers to both long-standing and more recent questions facing field of learning and memory.     

Parrots are "more human" than chickens

Analysis of an Internet database of pets' names showed owners were more likely to give anthropomorphic names to pets living within homes than those living outside.     

Variation in the serotonin transporter gene modulates selective attention to threat

The 5-HTTLPR is an insertion/deletion polymorphism in the promoter region of the serotonin transporter gene. Prior research has revealed associations between the short-allele variant of this polymorphism, enhanced self-reported negative emotionality, and hypersensitivity of fear relevant neural circuits. In a sample of 50 healthy women we examined the role of 5-HTTLPR for cognitive-affective processing of phylogenetical fear-relevant stimuli (spiders) in a dot probe task. In contrast to homozygote long-allele carriers (ll), participants carrying at least 1 short allele (ss and sl) selectively shifted attention toward pictures of spiders, when these were presented for a duration of 2,000 ms. These results argue for an involvement of 5-HTTLPR in cognitive processing of threatening stimuli and thus, underpin its general role for individual differences in negative affect.