Temporal context in speech processing and attentional stream selection: a behavioral and neural perspective

The human capacity for processing speech is remarkable, especially given that information in speech unfolds over multiple time scales concurrently. Similarly notable is our ability to filter out of extraneous sounds and focus our attention on one conversation, epitomized by the ‘Cocktail Party’ effect. Yet, the neural mechanisms underlying on-line speech decoding and attentional stream selection are not well understood. We review findings from behavioral and neurophysiological investigations that underscore the importance of the temporal structure of speech for achieving these perceptual feats. We discuss the hypothesis that entrainment of ambient neuronal oscillations to speech’s temporal structure, across multiple time-scales, serves to facilitate its decoding and underlies the selection of an attended speech stream over other competing input. In this regard, speech decoding and attentional stream selection are examples of ‘Active Sensing’, emphasizing an interaction between proactive and predictive top-down modulation of neuronal dynamics and bottom-up sensory input.     

Better not to deal with two tasks at the same time when stressed? Acute psychosocial stress reduces task shielding in dual-task performance

A major control demand in successful dual-task performance is the task-specific separation of task-goal representations and of the related stimulus-response translation processes. In the present study, we investigated how these cognitive control processes of task shielding are affected by acute psychosocial stress. Fifty-six healthy participants were exposed to either an acute psychosocial stressor (the Trier Social Stress Test) or a standardized control situation prior to a dual task. Task shielding was assessed by analyzing the interference of Task 2 processing on prioritized Task 1 performance. Following successful stress induction, as indicated by increases in salivary α-amylase (sAA) and cortisol that reflect increases in sympathetic nervous system and hypothalamus-pituitary-adrenal (HPA) axis activity, respectively, stressed individuals displayed reduced task shielding relative to controls. This result was further substantiated by a correlation between treatment-related increase in cortisol, but not sAA, and between-task interference, suggesting a potential role of the HPA stress response for the development of the observed effects. As an additional finding, when the volunteers were categorized with regard to their action-state orientation, their orientation did not interact with stress but did reveal generally increased between-task interference, and thus inferior task shielding, for state-oriented as compared to action-oriented individuals.     

The Performance of the AUDIT-C and the Examination of Risks Associated With Postdeployment Alcohol Misuse in Air Force Medical Service Personnel

This study assessed the performance of the Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) in diagnosing a postdeployment alcohol disorder in a cohort of Air Force Medical Services personnel (N = 13,353). The prevalence of alcohol disorders in this population of previously deployed military healthcare personnel was 1.26% based on medical record data. Assessing the AUDIT-C as a screening tool, the following characteristics were found: sensitivity was 23.81%, specificity was 91.48%, positive predictive value was 3.44%, and negative predictive value was 98.95%. The positive and negative likelihood ratios were 2.80 and 0.83, respectively. Classification accuracy of the AUDIT-C was improved by accounting for officer status and female gender. The area under the receiver operating characteristic curve was 0.69 for the multivariable model, indicating poor to fair classification accuracy. However, this model was significantly improved over the univariate model. Thus, taking rank and gender into account when conducting screening may improve the utility of the AUDIT-C.     

The Performance of the PHQ-2 and the Examination of Risks Associated With Postdeployment Depression in Air Force Medical Service Personnel

This study assessed the performance of the 2-item Patient Health Questionnaire (PHQ-2) in identifying postdeployment depressive disorders in a cohort of Air Force Medical Services personnel (N = 18,398). The prevalence of depressive disorders in the cohort was 9.00% based on medical record data. The area under the receiver operating characteristic curve was 0.56, indicating very poor classification accuracy. Sensitivity was 15.53%, specificity was 95.57%, positive predictive value was 25.75%, and negative predictive value was 91.97%. The positive and negative likelihood ratios were 3.51 and 0.88, respectively. Several risk factors associated with postdeployment depressive disorders were identified that could potentially improve screening in this population.     

The Crimes and Punishments of the ‘Enemies of the Church’ and the Nature of Russia’s Desecularising Regime1

Following a longstanding sociological tradition, this paper looks at reactions to nonconformity in order to understand the nature of social norms. In particular, it explores the patterns and scope of intolerance towards the perceived ‘enemies of the Church’ in order to understand social norms emerging in post-atheist Russia. Utilising the ‘social drama’ approach, the paper offers a comparative case study of increasingly repressive reactions by the Russian Orthodox Church (ROC) and state to two art exhibitions at the Sakharov Museum and anti-clerical publications by a blogger in Karelia, along with an in-depth analysis of the recent (2012) Pussy Riot action at Christ the Saviour Cathedral in Moscow and the resulting trial and punishment of three of the band’s members, as well as of a variety of events that have followed this initial action. We then utilise national and cross-national representative survey data to suggest that these repressive reactions were congruent with an intolerant public sentiment towards opponents of the ROC. Ultimately, we draw on Durkheim’s dialectic of norm and deviance, work on disciplinary modalities of power by Foucault and Agamben, desecularisation analysis and social identity theory to argue that the severe punishment of the perceived ‘enemies of the Church’ and the popular support for it reflect the crystallisation of a new normative system brought about by the desecularising regime in Russia, a regime which is characterised by a symbiosis of the ROC and the state.     

A stop-signal task for sheep: introduction and validation of a direct measure for the stop-signal reaction time

Huntington’s disease (HD) patients show reduced flexibility in inhibiting an already-started response. This can be quantified by the stop-signal task. The aim of this study was to develop and validate a sheep version of the stop-signal task that would be suitable for monitoring the progression of cognitive decline in a transgenic sheep model of HD. Using a semi-automated operant system, sheep were trained to perform in a two-choice discrimination task. In 22% of the trials, a stop-signal was presented. Upon the stop-signal presentation, the sheep had to inhibit their already-started response. The stopping behaviour was captured using an accelerometer mounted on the back of the sheep. This set-up provided a direct read-out of the individual stop-signal reaction time (SSRT). We also estimated the SSRT using the conventional approach of subtracting the stop-signal delay (i.e., time after which the stop-signal is presented) from the ranked reaction time during a trial without a stop-signal. We found that all sheep could inhibit an already-started response in 91% of the stop-trials. The directly measured SSRT (0.974 ± 0.04 s) was not significantly different from the estimated SSRT (0.938 ± 0.04 s). The sheep version of the stop-signal task adds to the repertoire of tests suitable for investigating both cognitive dysfunction and efficacy of therapeutic agents in sheep models of neurodegenerative disease such as HD, as well as neurological conditions such as attention deficit hyperactivity disorder.     

The goal of locomotion: Separating the fundamental task from the mechanisms that accomplish it

Human locomotion has been well described but is still not well understood. This is largely true because the observable aspects of locomotion—neuromuscular activity that generates forces and motions—relate to both the task solution and the problem being solved. Identifying the fundamental task achieved in locomotion makes it possible to critically evaluate the motor control strategy used to accomplish the task goal. We contend that the readily observed movements and activities of locomotion should be considered mechanism(s). Our proposal is that the fundamental task of walking and running is analogous to flight, and should be defined in terms of the interaction of the individual’s mass with the medium in which it moves: a low-density fluid for flight, or the supporting substrate for legged locomotion. A rigorous definition of the fundamental task can help identify the constraints and opportunities that influence its solution and guide the selection of appropriate mechanisms to accomplish the task effectively. The results from robotics-based modeling studies have demonstrated how the interaction of the mass and substrate can be optimized, making the goal of movement a defined trajectory of the individual’s mass. We assessed these concepts by evaluating the ground reaction forces generated by an optimization model that satisfies the task but uses none of the mechanisms that are available to the human leg. Then we compared this model to normal human walking. Although it is obvious that the specific task of locomotion changes with a variety of movement challenges, clearly identifying the fundamental task of locomotion puts all other features in an interpretable context.     

Supervenience arguments under relaxed assumptions

When it comes to evaluating reductive hypotheses in metaphysics, supervenience arguments are the tools of the trade. Jaegwon Kim and Frank Jackson have argued, respectively, that strong and global supervenience are sufficient for reduction, and others have argued that supervenience theses stand in need of the kind of explanation that reductive hypotheses are particularly suited to provide. Simon Blackburn’s arguments about what he claims are the specifically problematic features of the supervenience of the moral on the natural have also been influential. But most discussions of these arguments have proceeded under the strong and restrictive assumptions of the S5 modal logic. In this paper we aim to remedy that defect, by illustrating in an accessible way what happens to these arguments under relaxed assumptions and why. The occasion is recent work by Ralph Wedgwood, who seeks to defend non-reductive accounts of moral and mental properties together with strong supervenience, but to evade both the arguments of Kim and Jackson and the explanatory challenge by accepting only the weaker, B, modal logic. In addition to drawing general lessons about what happens to supervenience arguments under relaxed assumptions, our goal is therefore to shed some light on both the virtues and costs of Wedgwood’s proposal.