Intuitionistic Epistemic Logic,Kripke Models and Fitch’s Paradox

The present work is motivated by two questions. (1) What should an intuitionistic epistemic logic look like? (2) How should one interpret the knowledge operator in a Kripke-model for it? In what follows we outline an answer to (2) and give a model-theoretic definition of the operator K. This will shed some light also on (1), since it turns out that K, defined as we do, fulfills the properties of a necessity operator for a normal modal logic. The interest of our construction also lies in a better insight into the intuitionistic solution to Fitch’s paradox, which is discussed in the third section. In particular we examine, in the light of our definition, DeVidi and Solomon’s proposal of formulating the verification thesis as \(\phi \rightarrow \neg \neg K\phi\). We show, as our main result, that this definition excapes the paradox, though it is validated only under restrictive conditions on the models.     

Priming the mental time line

Growing experimental evidence suggests that temporal events are represented on a mental time line, spatially oriented from left to right. Support for the spatial representation of time comes mostly from studies that have used spatially organized responses. Moreover, many of these studies did not avoid possible confounds attributable to target stimuli that simultaneously convey both spatial and temporal dimensions. Here we show that task-irrelevant, lateralized visuospatial primes affect auditory duration judgments. Responses to short durations were faster when the auditory target was paired with left- than with right-sided primes, whereas responses to long durations were faster when paired with right- than with left-sided primes. Thus, when the representations of physical space and time are concurrently activated, physical space may influence time even when a lateralized, spatially encoded response is not required by the task. The time-space interaction reported here cannot be ascribed to any Spatial-Temporal Association of Response Codes effect. It supports the hypothesis that the representation of time is spatially organized, with short durations represented on the left space and longer ones on the right.     

Attention allocation modulates the processing of hierarchical visual patterns: a comparative analysis of capuchin monkeys (Cebus apella) and humans

Humans show a global advantage when processing hierarchical visual patterns, and they detect the global level of stimulus structure more accurately and faster than the local level in several stimulus contexts. By contrast, capuchins (Cebus apella) and other monkey species show a strong local advantage. A key factor which, if manipulated, could cause an inversion of this effect in monkeys is still to be found. In this study, we examined whether it was possible to induce attention allocation to global and local levels of perceptual analysis in capuchin monkeys and if by doing so, their local dominance could be reversed. We manipulated attentional bias using a matching-to-sample (MTS) task where the proportion of trials requiring global and local processing varied between conditions. The monkeys were compared with humans tested with the same paradigm. Monkeys showed a local advantage in the local bias condition but a global advantage in the global bias condition. The role of attention in processing was confined to the local trials in a first phase of testing but extended to both local and global trials in the course of task practice. Humans exhibited an overall global dominance and an effect of attentional bias on the speed of processing of the global and local level of the stimuli. These results indicate a role for attention in the processing of hierarchical stimuli in monkeys and are discussed in relation to the extent to which they can explain the differences between capuchin monkeys and humans observed in this and other studies.     

Effects of verbal ability and fluid intelligence on children's emotion understanding

This study investigated the role of verbal ability and fluid intelligence on children's emotion understanding, testing the hypothesis that fluid intelligence predicts the development of emotion comprehension over and above age and verbal ability. One hundred and two children (48 girls) aged 3.6–6 years completed the Test of Emotion Comprehension (TEC) that comprised external and mental components, the Coloured Progressive Matrices and the Test for Reception of Grammar. Regression analysis showed that fluid intelligence was not equally related to the external and mental components of the TEC (Pons & Harris, 2000). Specifically, the results indicated that the external component was related to age and verbal ability only, whereas recognition of mental emotional patterns required abstract reasoning skills more than age and verbal ability. It is concluded that the development of fluid intelligence has a significant role in the development of mental component of emotion comprehension.     

Disagreement behind the veil of ignorance

In this paper we argue that there is a kind of moral disagreement that survives the Rawlsian veil of ignorance. While a veil of ignorance eliminates sources of disagreement stemming from self-interest, it does not do anything to eliminate deeper sources of disagreement. These disagreements not only persist, but transform their structure once behind the veil of ignorance. We consider formal frameworks for exploring these differences in structure between interested and disinterested disagreement, and argue that consensus models offer us a solution concept for disagreements behind the veil of ignorance.     

Experts in science: a view from the trenches

In this paper I analyze four so-called “principles of expertise”; that is, good epistemic practices that are normatively motivated by the epistemological literature on expert judgment. I highlight some of the problems that the four principles of expertise run into, when we try to implement them in concrete contexts of application (e.g. in science committees). I suggest some possible alternatives and adjustments to the principles, arguing in general that the epistemology of expertise should be informed both by case studies and by the literature on the use of experts in science practice.     

BDNF serum levels in subjects developing or not post-traumatic stress disorder after trauma exposure

Post-traumatic stress disorder (PTSD) is a syndrome resulting from exposure to a severe traumatic event that poses threatened death or injury and produces intense fear and helplessness. The neural structures implicated in PTSD development belong to the limbic system, an important region for emotional processing. Brain-derived neurotrophic factor (BDNF) is a neurotrophin that serves as survival factor for selected populations of central nervous system (CNS) neurons and plays a role in the limbic system by regulating synaptic plasticity, memory processes and behavior. Impaired BDNF production in the brain can lead to a variety of CNS dysfunctions including symptoms associated with PTSD. However, so far fewer studies have investigated this neurotrophin in patients with PTSD. Furthermore, given the multiple role of BDNF in various CNS disorders, it cannot be excluded that traumatic events per se may influence neurotrophin levels, without a direct association to the PTSD syndrome.     

Validation and Standardization of the Dutch Trauma Symptom Checklist for Young Children in a Normative and Clinical Sample

The study aimed to describe the psychometric properties of the Dutch version of the Trauma Symptom Checklist for Young Children (TSCYC) in normative and clinical populations in the Netherlands. Caregivers’ ratings on the TSCYC were obtained for 1,802 children from the normal population, and for 515 children from a clinical population of traumatized children. In the clinical sample, additional measures were taken. The internal consistency and test-retest reliability of TSCYC scales were adequate. Confirmatory factor analysis showed acceptable fit on the putative scale structure. Regarding criterion validity, the clinical sample scored significantly higher on all clinical scales when compared to the normal population sample. Within the clinical sample, significant associations were found between TSCYC scales and convergent scales of other instruments. The Posttraumatic Stress-Total subscale demonstrated excellent discriminative ability between traumatized children and children from the normal population. The Dutch version of the TSCYC proved a valid and reliable instrument to measure trauma symptoms in young children through caregiver report, similar to the original American version. Further comparisons with diagnostic interviews are warranted.     

Principles for Object-Linguistic Consequence: from Logical to Irreflexive

We discuss the principles for a primitive, object-linguistic notion of consequence proposed by (Beall and Murzi, Journal of Philosophy, 3 pp. 143–65 (2013)) that yield a version of Curry’s paradox. We propose and study several strategies to weaken these principles and overcome paradox: all these strategies are based on the intuition that the object-linguistic consequence predicate internalizes whichever meta-linguistic notion of consequence we accept in the first place. To these solutions will correspond different conceptions of consequence. In one possible reading of these principles, they give rise to a notion of logical consequence: we study the corresponding theory of validity (and some of its variants) by showing that it is conservative over a wide range of base theories: this result is achieved via a well-behaved form of local reduction. The theory of logical consequence is based on a restriction of the introduction rule for the consequence predicate. To unrestrictedly maintain this principle, we develop a conception of object-linguistic consequence, which we call grounded consequence, that displays a restriction of the structural rule of reflexivity. This construction is obtained by generalizing Saul Kripke’s inductive theory of truth (strong Kleene version). Grounded validity will be shown to satisfy several desirable principles for a naïve, self-applicable notion of consequence.