Can self-relevant stimuli help assessing patients with disorders of consciousness?

Emotional and self-relevant stimuli are able to automatically attract attention and their use in patients suffering from disorders of consciousness (DOC) might help detecting otherwise hidden signs of cognition.We here recorded EEG in three Locked-in syndrome (LIS) and four Vegetative State/Unresponsive Wakefulness Syndrome (VS/UWS) patients while they listened to the voice of a family member or an unfamiliar voice during a passive. Data indicate that, in a passive listening condition, the familiar voice induces stronger alpha desynchronization than the unfamiliar one. In an active condition, the target evoked stronger alpha desynchronization in controls, two LIS patients and one VS/UWS patient. Results suggest that self-relevant familiar voice stimuli can engage additional attentional resources and might allow the detection of otherwise hidden signs of instruction-following and thus residual awareness. Further studies are necessary to find sensitive paradigms that are suited to find subtle signs of cognition and awareness in DOC patients.     

Animal model of posterior cingulate cortex hypometabolism implicated in amnestic MCI and AD

The posterior cingulate cortex (PCC) is the brain region displaying the earliest sign of energy hypometabolism in patients with amnestic mild cognitive impairment (MCI) who develop Alzheimer’s disease (AD). In particular, the activity of the mitochondrial respiratory enzyme cytochrome oxidase (C.O.) is selectively inhibited within the PCC in AD. The present study is the first experimental analysis designed to model in animals the localized cortical C.O. inhibition found as the earliest metabolic sign of early-stage AD in human neuroimaging studies. Rats were used to model local inhibition of C.O. by direct injection of the C.O. inhibitor sodium azide into the PCC. Learning and memory were examined in a spatial holeboard task and brains were analyzed using quantitative histochemical, morphological and biochemical techniques. Behavioral results showed that sodium azide-treated rats were impaired in their memory of the baited pattern in probe trials as compared to their training scores before treatment, without non-specific behavioral differences. Brain analyses showed that C.O. inhibition was specific to the PCC, and sodium azide increased lipid peroxidation, gliosis and neuron loss, and lead to a network functional disconnection between the PCC and interconnected hippocampal regions. It was concluded that impaired memory by local C.O. inhibition in the PCC may serve to model in animals a metabolic lesion similar to that found in patients with amnestic MCI and early-stage AD. This model may be useful as an in vivo testing platform to investigate neuroprotective strategies to prevent or reduce the amnestic effects produced by posterior cingulate energy hypometabolism.     

“A Father’s Touch:” Negotiating Masculinity and Sexual Subjectivity in Child Care

This essay explores changing attitudes towards male caregivers in postwar America to understand conceptions of prepubescent gender and sexuality. While the 1950s have been viewed as a period of rigid gender conventions, the demands of a baby boom generation allowed men unexpected roles as caregivers. In the 1960s and 1970s, challenges to the status quo along with fears of female-headed households encouraged men to move into the field of child care, but this was particularly short lived. Political backlash and a failing economy turned male daycare workers into suspects, revealing the ambiguity that so often distorts children’s interactions with men.

Basal ganglia, dopamine and temporal processing: performance on three timing tasks on and off medication in Parkinson's disease

A pervasive hypothesis in the timing literature is that temporal processing in the milliseconds and seconds range engages the basal ganglia and is modulated by dopamine. This hypothesis was investigated by testing 12 patients with Parkinson's disease (PD), both 'on' and 'off' dopaminergic medication, and 20 healthy controls on three timing tasks. In a seconds range (30-120 s) time production task, patients tested 'on' medication showed a significantly different accuracy profile compared to controls and when tested 'off' medication. However, no group or on vs off medication differences in accuracy were found on a time reproduction task and a warned reaction time task requiring temporal processing within the 250-2000 ms range. Variability was measured using the coefficient of variation, with the performance of the patient group on the time reproduction task violating the scalar property, suggesting atypical temporal processing mechanisms. The data suggest that the integrity of the basal ganglia is necessary for 'typical' time production in the seconds range as well as for time reproduction at shorter intervals. Exploratory factor analysis suggested that the time production task uses neural mechanisms distinct from those used in the other two timing tasks. The dissociation of the effects of dopaminergic medication and nature of task on performance in PD raises interesting questions about the pharmacological mediation and task-specificity of deficits in temporal processing.     

Stimulus timing by people with Parkinson's disease

Previous literature suggests that Parkinson’s disease is marked by deficits in timed behaviour. However, the majority of studies of central timing mechanisms in patients with Parkinson’s disease have used timing tasks with a motor component. Since the motor abnormalities are a defining feature of the condition, the status of timing in Parkinson’s disease remains uncertain. Data are reported from patients with mild to moderate Parkinson’s disease (both on and off medication) and age- and IQ-matched controls on a range of stimulus timing tasks without counting. Tasks used were temporal generalization, bisection, threshold determination, verbal estimation, and a memory for duration task. Performance of patients was generally “normal” on all tasks, but significant differences from performance of controls were found on the memory for duration task. Among the “normal” effects noted were arithmetic mean bisection, asymmetric temporal generalization gradients, and subjective shortening on the memory for duration task. The results suggest (a) that some previous reports of timing “deficits” in Parkinson’s patients were possibly due to the use of tasks requiring a timed manual response and (b) small differences between patients and controls may be found on tasks where two stimuli are presented on each trial, whether patients are on medication or off it.     

Eye-tracking the cancellation and focus model for preference judgments

By means of a relatively new eye-tracking method that allows for a test situation much closer to reality, we recorded and examined gaze time and fixation number within the cancellation and focus paradigm, a feature-matching model for preference judgments between two alternatives. In line with the cancellation and focus model we found that when subjects encountered the second option in each pair, shared features were canceled out and thus given less consideration whereas unique features were focused on more. We also investigated the role of feature attractiveness as a second important factor in preference judgments and found a U-shaped relationship between attractiveness and visual consideration intensity; that is, attractive and unattractive features received more attention than did those of intermediate attractiveness. Finally, we tested the ability of two models, Franklin’s rule and the WReSt (Weighted Recalled Stepwise Comparing) heuristic, to predict the preference ratings.     

Uniform Test Assembly

In educational practice, a test assembly problem is formulated as a system of inequalities induced by test specifications. Each solution to the system is a test, represented by a 0–1 vector, where each element corresponds to an item included (1) or not included (0) into the test. Therefore, the size of a 0–1 vector equals the number of items n in a given item pool. All solutions form a feasible set—a subset of 2 ⁿ vertices of the unit cube in an n-dimensional vector space. Test assembly is uniform if each test from the feasible set has an equal probability of being assembled. This paper demonstrates several important applications of uniform test assembly for educational practice. Based on Slepian’s inequality, a binary program was analytically studied as a candidate for uniform test assembly. The results of this study establish a connection between combinatorial optimization and probability inequalities. They identify combinatorial properties of the feasible set that control the uniformity of the binary programming test assembly. Computer experiments illustrating the concepts of this paper are presented.     

De Finetti’s No-Dutch-Book Criterion for Gödel logic

We extend de Finetti’s No-Dutch-Book Criterion to Gödel infinite-valued propositional logic.     

Suszko’s Thesis,Inferential Many-valuedness,and the Notion of a Logical System

According to Suszko’s Thesis, there are but two logical values, true and false. In this paper, R. Suszko’s, G. Malinowski’s, and M. Tsuji’s analyses of logical twovaluedness are critically discussed. Another analysis is presented, which favors a notion of a logical system as encompassing possibly more than one consequence relation.

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Presented by Jacek Malinowski     

The Humean problem of induction and Carroll’s Paradox

Hume argued that inductive inferences do not have rational justification. My aim is to reject Hume’s argument. The discussion is partly motivated by an analogy with Carroll’s Paradox, which concerns deductive inferences. A first radically externalist reply to Hume (defended by Dauer and Van Cleve) is that justified inductive inferences do not require the subject to know that nature is uniform, though the uniformity of nature is a necessary condition for having the justification. But then the subject does not have reasons for believing what she believes. I defend a moderate externalist account that seeks to partly accommodate that objection to the radical externalist proposal. It is based on an extension of Peacocke’s theory of concepts: possession conditions for predicative concepts standing for natural properties include (fallible) dispositions to project them to new cases in accordance with inductive inferential patterns.