Previous studies have demonstrated that double phosphorylation of a protein can lead to bistability if some conditions are fulfilled. It was also shown that the signaling behavior of a covalent modification cycle can be quantitatively and, more importantly, qualitatively modified when this cycle is coupled to a signaling pathway as opposed to being isolated. This property was named retroactivity. These two results are studied together in this paper showing the existence of interesting phenomena—oscillations and bistability—in signaling cascades possessing at least (...) one stage with a double-phosphorylation cycle as in MAPK cascades. (shrink)

en las últimas décadas la bioética se ha vuelto un tema crucial para la Iglesia. La dinámica propia de la técnica, que se auto-propulsa y avanza con independencia de criterios éticos, amenaza de modo inminente la dignidad humana. En la actualidad ya existe la posibilidad de producir artificialmente seres humanos, incluso sin la mediación de gametos. Pero lo que no existe son los índices para reconocer cuándo una célula intervenida sigue siendo sólo una célula -eventualmente pluripotencial y por tanto con (...) grandes promesas terapéuticas; o cuando ya es una célula totipotencial, un cigoto, un organismo humano: una persona. Ciencia, filosofía y teología, como se mostrará en este artículo, se unen en la reflexión bioética para encontrar de modo urgente esas señales; puesto que la biotecnología sigue avanzando, y hay de tomar posición sobre sus descubrimientos. La Iglesia no puede callar frente a una posible producción artificial, instrumentalización y destrucción de personas; que aunque estén en su fase unicelular y hayan llegado al mundo como artefactos, siguen siempre siendo el reflejo del Rostro de Dios. (shrink)

In this article, the right to health is discussed as a social right and an essential requisite in the construction and guarantee of human rights, more precisely human dignity, considering this right as a complex but effective process in the transformation of the social reality. In the first place, the activities of the public power and its difficulties to guarantee universal access to health are highlighted. This scenario ends up inhibiting the practice of the right to health and prevents users (...) from enjoying and using it. In that sense, this article challenges and explores some alternatives to solidify and put in practice the right to health in Brazil. Departing from the analysis of the Unified Health System and social participation in Brazil, this article discusses the judicialization of health in the country, highlighting the difficulties the State faces to equitably offer universal healthcare to society. This context offers an opportunity for reflection and a paradigm change, from the “judicialization of health” to the “judicialization of health policies.” Finally, the public health policies adopted by other countries are emphasized, in the attempt to construct the empowerment of human beings in the practice of their rights, particularly social participation and the discussion about the States’ responsibility to put their citizens’ right to health in practice. In conclusion, the political and collective construction of the right to health needs to be encouraged, distinguishing the legitimate interests of the different interlocutors involved. (shrink)

It is long known that facial configurations play a critical role when inferring mental and emotional states from others. Nevertheless, there is still a scientific debate on how we infer emotions from facial configurations. The theory of constructed emotion (TCE) suggests that we may infer different emotions from the same facial configuration, depending on the context (e.g. provided by visual and lexical cues) in which they are perceived. For instance, a recent study found that participants were more accurate in inferring (...) mental and emotional states across three different datasets (i.e. RMET, static and dynamic emojis) when words were provided (i.e. forced-choice task), compared to when they were not (i.e. free-labelling task), suggesting that words serve as contexts that modulate the inference from facial configurations. The goal of the current within-subject study was to replicate and extend these findings by adding a fourth dataset (KDEF-dyn), consisting of morphed human faces (to increase the ecological validity). Replicating previous findings, we observed that words increased accuracy across the three (previously used) datasets, an effect that was also observed for the facial morphed stimuli. Our findings are in line with the TCE, providing support for the importance of contextual verbal cues in emotion perception. (shrink)

The Ontology for Biomedical Investigations (OBI) is an ontology that provides terms with precisely defined meanings to describe all aspects of how investigations in the biological and medical domains are conducted. OBI re-uses ontologies that provide a representation of biomedical knowledge from the Open Biological and Biomedical Ontologies (OBO) project and adds the ability to describe how this knowledge was derived. We here describe the state of OBI and several applications that are using it, such as adding semantic expressivity to (...) existing databases, building data entry forms, and enabling interoperability between knowledge resources. OBI covers all phases of the investigation process, such as planning, execution and reporting. It represents information and material entities that participate in these processes, as well as roles and functions. Prior to OBI, it was not possible to use a single internally consistent resource that could be applied to multiple types of experiments for these applications. OBI has made this possible by creating terms for entities involved in biological and medical investigations and by importing parts of other biomedical ontologies such as GO, Chemical Entities of Biological Interest (ChEBI) and Phenotype Attribute and Trait Ontology (PATO) without altering their meaning. OBI is being used in a wide range of projects covering genomics, multi-omics, immunology, and catalogs of services. OBI has also spawned other ontologies (Information Artifact Ontology) and methods for importing parts of ontologies (Minimum information to reference an external ontology term (MIREOT)). The OBI project is an open cross-disciplinary collaborative effort, encompassing multiple research communities from around the globe. To date, OBI has created 2366 classes and 40 relations along with textual and formal definitions. The OBI Consortium maintains a web resource providing details on the people, policies, and issues being addressed in association with OBI. (shrink)

The objective of this study was to develop and determine the psychometric properties of an instrument designed to detect traits and behavior that are associated with predatory violent behavior, which is defined as a determined, planned, controlled, and proactive aggression. The sample was comprised of 546 students, mostly in their last year of high school or in their first year of college. The initial instrument had 78 items, ultimately resulting in 15 with good internal consistency (α =.825). Factor analysis showed (...) four factors: anger-in, appeal for weapons, suicidal ideation, and the tendency to take justice into one’s own hands. Said factors showed significant correlations of convergent validity. Data shown here allows inferring that the instrument is a novel and concise tool that evaluates and detects the potential of predatory violent behavior. (shrink)

Given its non-invasive nature, there is increasing interest in the use of transcutaneous vagus nerve stimulation across basic, translational and clinical research. Contemporaneously, tVNS can be achieved by stimulating either the auricular branch or the cervical bundle of the vagus nerve, referred to as transcutaneous auricular vagus nerve stimulation and transcutaneous cervical VNS, respectively. In order to advance the field in a systematic manner, studies using these technologies need to adequately report sufficient methodological detail to enable comparison of results between (...) studies, replication of studies, as well as enhancing study participant safety. We systematically reviewed the existing tVNS literature to evaluate current reporting practices. Based on this review, and consensus among participating authors, we propose a set of minimal reporting items to guide future tVNS studies. The suggested items address specific technical aspects of the device and stimulation parameters. We also cover general recommendations including inclusion and exclusion criteria for participants, outcome parameters and the detailed reporting of side effects. Furthermore, we review strategies used to identify the optimal stimulation parameters for a given research setting and summarize ongoing developments in animal research with potential implications for the application of tVNS in humans. Finally, we discuss the potential of tVNS in future research as well as the associated challenges across several disciplines in research and clinical practice. (shrink)

Given its non-invasive nature, there is increasing interest in the use of transcutaneous vagus nerve stimulation across basic, translational and clinical research. Contemporaneously, tVNS can be achieved by stimulating either the auricular branch or the cervical bundle of the vagus nerve, referred to as transcutaneous auricular vagus nerve stimulation and transcutaneous cervical VNS, respectively. In order to advance the field in a systematic manner, studies using these technologies need to adequately report sufficient methodological detail to enable comparison of results between (...) studies, replication of studies, as well as enhancing study participant safety. We systematically reviewed the existing tVNS literature to evaluate current reporting practices. Based on this review, and consensus among participating authors, we propose a set of minimal reporting items to guide future tVNS studies. The suggested items address specific technical aspects of the device and stimulation parameters. We also cover general recommendations including inclusion and exclusion criteria for participants, outcome parameters and the detailed reporting of side effects. Furthermore, we review strategies used to identify the optimal stimulation parameters for a given research setting and summarize ongoing developments in animal research with potential implications for the application of tVNS in humans. Finally, we discuss the potential of tVNS in future research as well as the associated challenges across several disciplines in research and clinical practice. (shrink)

Background In August 2017, Chile lifted its complete ban on abortion by permitting abortion in three limited circumstances: 1) to save a woman’s life, 2) lethal fetal anomaly, and 3) rape. The new law allows regulated use of conscientious objection in abortion care, including allowing institutions to register as objectors. This study assesses medical and midwifery students’ support for CO, following legal reform. Methods From October 2017 to May 2018, we surveyed medical and midwifery students from seven universities located in (...) Santiago, Chile. Universities included 4 secular and 3 private religiously-affiliated universities; all offering medical degrees with a specialization in obstetrics and gynecology and five offering midwifery degrees. We used generalized estimating equations to identify characteristics associated with student support for CO, intentions to use CO to refuse to care for someone seeking abortion, and support for CO at the institutional level. Results 333 of the 413 eligible students who opened the survey, completed the questions on conscientious objection; 26% were seeking medical degrees with an ob-gyn specialty, 25% were seeking midwifery degrees, and 49% were seeking medical degrees and had not yet decided their specialty. While nearly all endorse requirements for conscientious objecting clinicians to inform and refer abortion-seeking patients, a minority would personally use conscientious objection to avoid caring for a patient seeking abortion. About half of religious-university students and one-fifth of secular-university students support objections at the institutional level. Conclusions Most students support the regulated use of CO which preserves patients’ access to abortion care. Religious-university student views on the use of conscientious objection in abortion care are discordant with those of their institutions which currently support institutional-level objections. (shrink)

Recent studies in social endocrinology have explored the effects of social relationships on female reproductive steroid hormones—estradiol and progesterone—investigating whether they are suppressed in partnered and parous women. Results have been mixed for these hormones although evidence is more consistent that partnered women and women with young children have lower levels of testosterone. These studies were sequential to earlier research on men, based on Wingfield’s Challenge Hypothesis, which showed that men in committed relationships, or with young children, have lower levels (...) of testosterone than unpartnered men or men with older or no children. The study described here explored associations between estradiol and progesterone with partnership and parity among women from two different ethnicities: South Asian and white British. We hypothesized that both steroid hormones would be lower among partnered and/or parous women with children ≤3 years old, regardless of ethnicity. In this study we analyzed data from 320 Bangladeshi and British women of European origin aged 18 to 50 who participated in two previous studies of reproductive ecology and health. Levels of estradiol and progesterone were assayed using saliva and/or serum samples and the body mass index calculated from anthropometric data. Questionnaires provided other covariates. Multiple linear regressions were used to analyze the data. The hypotheses were not supported. We argue here that, unlike links between testosterone and male social relationships, theoretical foundations for such relationships with female reproductive steroid hormones are lacking, especially given the primary role of these steroids in regulating female reproductive function. Further longitudinal studies are needed to explore the bases of independent relationships between social factors and female reproductive steroid hormones. (shrink)

In this paper we prove the equivalence between the Gentzen system G LJ*\c , obtained by deleting the contraction rule from the sequent calculus LJ* (which is a redundant version of LJ), the deductive system IPC*\c and the equational system associated with the variety RL of residuated lattices. This means that the variety RL is the equivalent algebraic semantics for both systems G LJ*\c in the sense of [18] and [4], respectively. The equivalence between G LJ*\c and IPC*\c is a (...) strengthening of a result obtained by H. Ono and Y. Komori [14, Corollary 2.8.1] and the equivalence between G LJ*\c and the equational system associated with the variety RL of residuated lattices is a strengthening of a result obtained by P.M. Idziak [13, Theorem 1].An axiomatization of the restriction of IPC*\c to the formulas whose main connective is the implication connective is obtained by using an interpretation of G LJ*\c in IPC*\c. (shrink)

El artículo presenta una reflexión sobre la manera en que en los últimos veinte años la promoción de un determinado tipo de solidaridad en Chile ha contribuido a la conformación de una gubernamentalidad liberal avanzada, necesaria para la instalación de un programa neoliberal. La reflexión se enmarca en los aportes teóricos de Michel Foucault y tiene por objeto empírico piezas de publicidad de promoción de la solidaridad emitidas en Chile entre los años 2009 y 2010, que han sido analizadas en (...) el contexto del proyecto Fondecyt 1090534. Se presentan tres tipos de resultados: (a) se describen los sectores sociales que se construyen como agentes de la solidaridad, (b) se reflexiona sobre las prácticas solidarias más promovidas y (c) se indaga en la forma en que se interpela a los sujetos a ser solidarios. (shrink)

Mucho se ha escrito sobre la influencia de las sabidurías orientales en la filosofía de Arthur Schopenhauer, y muy poco sobre la impronta de éste en uno de los pensadores peor reconocidos en el ámbito de la filosofía académica como es Carl Gustav Jung. El presente artículo trata de dar con algunos puntos de encuentro en la obra de los dos autores, estrechando paralelismos y matizando distancias entre la «voluntad» schopenhaueriana y el «inconsciente» de Jung, a la par que ahonda (...) en el elemento central que vincula, a nuestro juicio, el pensamiento de ambos: el problema del mal y su diversas concepciones en las tradiciones religiosas de Oriente y del Occidente cristiano. (shrink)

We study by means of a laboratory experiment the role of individuals’ empathy in the Vote-with-the-Wallet Game. Our main purpose is to analyze the impact of the ability to empathize on participants’ behavior when asked to choose between two specific types of product: a cheaper conventional good and a more expensive one which, however, produces a positive externality for the other participants. We consider three manipulations: a) a redistribution mechanism where the expensive product is subsidized by the buyers of the (...) cheaper one; b) a framed version of the game where the expensive good is described as produced by a socially responsible company; c) a treatment where information about other participants’ behavior are made public. We find that all the manipulations increase the rate of contribution to the public good with respect to the baseline treatment and that the effects are stronger among participants who show higher levels of empathy. (shrink)

El objetivo del presente papel de trabajo es el de examinar los problemas derivados de la diferenciación entre matemáticas y dialéctica en República VI-VII. Se trata de una lectura problemática de los pasajes donde se expone el método dialéctico en este diálogo, a saber, el símil de la línea (509c-511e). Todo ello lo pretendemos abordar a la luz de las implicaciones a) epistemológicas, b) ontológicas y c) metodológicas. Mostraremos las dificultades que se derivan de las tres perspectivas propuestas, en torno (...) a la relación de identidad o diferencia entre matemática y dialéctica. Palabras clave: Platón; República; Matemáticas; Dialéctica; UnidadThe aim of this paper is to examine the problems derived from differentiating between Mathematics and Dialectics in Republic VI-VII. We undertake a problematic reading of the passages where dialectic method is expounded in this dialogue, namely, the simile of the line (509c-511e). We intend to approach all of this in the light of implications of these sorts: a) epistemological, b) ontological, and c) methodological. We will show the difficulties, derived from the three perspectives proposed, regarding the relation of identity or difference between Mathematics and Dialectics. Keywords: Plato; Republic; Mathematics; Dialectics; Unity. (shrink)

Cooperative learning (CL) is one of the pedagogical models that has had more application in the area of Physical Education (PE) in recent years, being highly worked in the initial training of teachers. The aim of the study is to check to what extent future PE teachers are able to apply in the classroom the PE training they have received at university, deepening their fears, insecurities and problems when carrying it out. Thirteen future PE teachers (7 girls and 6 boys) (...) aged 20.87±1.43 participated and, after having been trained in CL in various subjects, applied it in the classroom during their internship. A qualitative methodology was used, being the interviews, the teaching diaries and the seminars with the tutor the instruments of data collection used. Three categories of analysis were used: a) initial expectations in the application of the CL; b) problems encountered in its implementation; c) reflection about its application in the future. The results showed how the future teachers did not see their expectations of success fulfilled, encountering resistance from both students and teachers in PE. Furthermore, they reflect the need to continue training in a model that has infinite nuances so that it can be implemented satisfactorily. It is necessary to continue researching a pedagogical model with so many possibilities in the area of PE and with so much transversality on a social level. (shrink)

RESUMO Neste artigo, propomos estratégias de captação de regiões polêmicas em corpus produzido a partir de publicações do Twitter, partindo de quadro teórico que enfatiza a perspectiva dialógica. Com base nessas estratégias, fornecemos entradas para a análise da materialidade oriunda do universo tecnodiscursivo em circulação em ambientes digitais. Em razão da produção do corpus da investigação, avançamos na compreensão de traços que compõem imagens discursivas em torno de Diego Maradona em circulação no Twitter por ocasião de seu falecimento. Para tanto, (...) explicitamos e problematizamos técnicas de captação e produção de um corpus digital de pesquisa, através da delimitação de um espaço discursivo no Twitter que circundou a morte de Maradona. Os resultados obtidos se dirigem tanto às condições de utilização dessas plataformas por analistas do discurso, quanto à cartografia das regiões do dizer que se configuram nesse espaço e dos embates que nelas ganham consistência. ABSTRACT In this article, we propose strategies for capturing polemical regions in a corpus of posts from Twitter, setting out from a theoretical framework that emphasises a dialogic perspective. Based on these strategies, we provide entry points for analysing the materiality of the techno-discursive universe that circulates in digital environments. By producing this research corpus, we acquired a clearer understanding of elements that compose discursive images surrounding Diego Maradona in circulation on Twitter following the player’s death. Towards this aim, we formulated and critically considered techniques for extracting and producing a digital research corpus by delimiting a discursive space on Twitter surrounding Maradona’s death. The results obtained pertain to the conditions for use of these platforms by discourse analysts, the cartography of the regions configured in this space and the clashes that become consolidated within them. (shrink)

La atención es uno de los fenómenos psicológicos más presentes en la obra orteguiana y, a la vez, uno de los más desatendidos por la crítica. Habitualmente el fenómeno ha quedado eclipsado por ideas tradicionalmente más nodales como la de “perspectiva”, sin embargo, no podemos ignorar que ideas como esta hallan su fundamento precisamente sobre el fenómeno de la atención, lo que le otorga una importancia a considerar. En el presente libro, mediante una revisión crítica de los textos orteguianos, se (...) despliega y reúne un conjunto de argumentos con los que defender la centralidad de la atención en el pensamiento orteguiano ofreciendo, con ella, uno de los elementos cardinales en la estructuración sistemática de su obra, pues, como veremos, es en la atención donde el autor halla el fundamento para edi car su método perspectivista y, a su vez, donde descansa cierta posibilidad de cristalizar su doctrina raciovitalista. (shrink)

Volume 19, Issue 3, December 2023, Page 359-363.

Pregnancy presents some interesting challenges for the philosophy of embodied cognition. Mother and fetus are generally considered to be passive during pregnancy, both individually and in their relation. In this paper, we use the enactive operational concepts of autonomy, agency, individuation, and participation to examine the relation between mother and fetus in utero. Based on biological, physiological, and phenomenological research, we explore the emergence of agentive capacities in embryo and fetus, as well as how maternal agency changes as pregnancy advances. (...) We show that qualitatively different kinds of agency have their beginnings already in utero, and to what extent fetal and maternal movement modulate affectivity and individuation in pregnancy. We thus propose that mother and fetus are both agents who participate in pregnancy. Pregnancy then emerges as a relational developmental organization that anchors and holds its developing participants. We end the paper with reflections on ethical implications of this proposal, and suggestions for future research. (shrink)

En este artículo se presenta un análisis cualitativo preliminar de los contratos laborales firmados entre cuatro músicos de Europa del este y la dirección de la Orquesta Sinfónica de Antioquia en 1949, mientras dichos músicos estaban en los campos de refugiados europeos donde los sobrevivientes de la guerra fueron congregados para su atención y rehabilitación. Con este análisis se pretende problematizar la inserción de estos personajes como agentes de modernización cultural en Medellín, haciendo énfasis en las condiciones políticas y socioculturales (...) que caracterizaban a Colombia a comienzos de la década de 1950. La nacionalidad de estos músicos (tres checos y un rumano) era objeto de sospecha desde la legislación migratoria colombiana, que desde la década de 1920 establecía un catálogo de extranjeros que no debían entrar al país, pues podían traer ideologías contrarias a la defensa de la propiedad privada. Al contrastar estos contratos laborales con la política migratoria colombiana y con la responsabilidad pedagógica cívica que se le imponía a la actividad musical académica, se plantean algunas preguntas para debatir acerca de la narrativa oficial que presenta a estos músicos como agentes de modernidad importados e integrados a un proceso de modernización cuya representación se ha caracterizado por la ausencia de conflicto. (shrink)

ABSTRACT In this article, we propose strategies for capturing polemical regions in a corpus of posts from Twitter, setting out from a theoretical framework that emphasises a dialogic perspective. Based on these strategies, we provide entry points for analysing the materiality of the techno-discursive universe that circulates in digital environments. By producing this research corpus, we acquired a clearer understanding of elements that compose discursive images surrounding Diego Maradona in circulation on Twitter following the player’s death. Towards this aim, we (...) formulated and critically considered techniques for extracting and producing a digital research corpus by delimiting a discursive space on Twitter surrounding Maradona’s death. The results obtained pertain to the conditions for use of these platforms by discourse analysts, the cartography of the regions configured in this space and the clashes that become consolidated within them. RESUMO Neste artigo, propomos estratégias de captação de regiões polêmicas em corpus produzido a partir de publicações do Twitter, partindo de quadro teórico que enfatiza a perspectiva dialógica. Com base nessas estratégias, fornecemos entradas para a análise da materialidade oriunda do universo tecnodiscursivo em circulação em ambientes digitais. Em razão da produção do corpus da investigação, avançamos na compreensão de traços que compõem imagens discursivas em torno de Diego Maradona em circulação no Twitter por ocasião de seu falecimento. Para tanto, explicitamos e problematizamos técnicas de captação e produção de um corpus digital de pesquisa, através da delimitação de um espaço discursivo no Twitter que circundou a morte de Maradona. Os resultados obtidos se dirigem tanto às condições de utilização dessas plataformas por analistas do discurso, quanto à cartografia das regiões do dizer que se configuram nesse espaço e dos embates que nelas ganham consistência. (shrink)

The article is proposed as a reading of A Feminist Theory of Refusal (2021), by Bonnie Honig. Under the assumption that Honig has the merit of introducing into feminist political theory a thought of rejection patiently elaborated from a commentary on literary figures such as Antigone and Bartleby, the article interrogates the logic of resistance that these figurations of negativity advance. From the perspective of A Feminist Theory of Refusal, the names of Antigone and Bartleby are not only subjective indications (...) of the interruption of a domain, but above all they are agonistic figurations of a politics that has the dispute of meaning as one of its main axes. In other words, the politics of rejection that Honig proposes is at the same time an agonal politics that is organized around the meaning of words, of the narratives that structure the commonality of a social order. Following this line of reading, the essay sets out to interrogate the politics of rejection elaborated by Honig from the figurations that embody it. (shrink)

At Universitat Politècnica de València, Meridies, an internship programme that places engineering students in countries of Latin America, is one of the few opportunities the students have to explore the implications of being a professional in society in a different cultural and social context. This programme was analyzed using the capabilities approach as a frame of reference for examining the effects of the programme on eight student participants. The eight pro-public-good capabilities proposed by Melanie Walker were investigated through semi-structured interviews. (...) The internship is an environment in which students can put into practice the knowledge they have acquired in undergraduate studies and to find practical relevance in what they studied. Occasionally, this also entails a critical questioning of what they have learned, a greater awareness of the limits of the contents of their studies and of the way things were taught, and interest in less explored issues that are closely linked to social justice. However, tensions can arise between the pro-public-good oriented perspectives of this programme, and a more instrumental vision. One way to overcome these tensions is to foster consideration of reflexivity, that is, the dynamic relationship between technology and society. To do so, the programme must create space before and during the internship, and upon the return of the students, to discuss and collectively reflect upon their lived experience. Additionally, it ought to engage supervisors in this educational journey, both at the university and in the host institutions, and also involve socially committed organisations in this task. (shrink)

Perception of time is susceptible to distortions; among other factors, it has been suggested that the perceived duration of a stimulus is affected by the observer’s expectations. It has been hypothesized that the duration of an oddball stimulus is overestimated because it is unexpected, whereas repeated stimuli have a shorter perceived duration because they are expected. However, recent findings suggest instead that fulfilled expectations about a stimulus elicit an increase in perceived duration, and that the oddball effect occurs because the (...) oddball is a target stimulus, not because it is unexpected. Therefore, it has been suggested that top-down attention is sometimes sufficient to explain this effect, and sometimes only necessary, with an additional contribution from saliency. However, how the expectedness of a target stimulus and its salient features affect its perceived duration is still an open question. In the present study, participants’ expectations about and the saliency of target stimuli were orthogonally manipulated with stimuli presented on a short (Experiment 1) or long (Experiment 2) temporal scale. Four repetitive standard stimuli preceded each target stimulus in a task in which participants judged whether the target was longer or shorter in duration than the standards. Engagement of top-down attention to target stimuli increased their perceived duration to the same extent irrespective of their expectedness. A small but significant additional contribution to this effect from the saliency of target stimuli was dependent on the temporal scale of stimulus presentation. In Experiment 1, saliency only significantly increased perceived duration in the case of expected target stimuli. In contrast, in Experiment 2, saliency exerted a significant effect on the overestimation elicited by unexpected target stimuli, but the contribution of this variable was eliminated in the case of expected target stimuli. These findings point to top-down attention as the primary cognitive mechanism underlying the perceptual extraction and processing of task-relevant information, which may be strongly correlated with perceived duration. Furthermore, the scalar properties of timing were observed, favoring the pacemaker-accumulator model of timing as the underlying timing mechanism. (shrink)