Strategic Resource Allocation in the Human Brain Supports Cognitive Coordination of Object and Spatial Working Memory

The ability to integrate different types of information (e.g., object identity and spatial orientation) and maintain or manipulate them concurrently in working memory (WM) facilitates the flow of ongoing tasks and is essential for normal human cognition. Research shows that object and spatial information is maintained and manipulated in WM via separate pathways in the brain (object/ventral versus spatial/dorsal). How does the human brain coordinate the activity of different specialized systems to conjoin different types of information? Here we used functional magnetic resonance imaging to investigate conjunction- versus single-task manipulation of object (compute average color blend) and spatial (compute intermediate angle) information in WM. Object WM was associated with ventral (inferior frontal gyrus, occipital cortex), and spatial WM with dorsal (parietal cortex, superior frontal, and temporal sulci) regions. Conjoined object/spatial WM resulted in intermediate activity in these specialized areas, but greater activity in different prefrontal and parietal areas. Unique to our study, we found lower temporo-occipital activity and greater deactivation in temporal and medial prefrontal cortices for conjunction- versus single-tasks. Using structural equation modeling, we derived a conjunction-task connectivity model that comprises a frontoparietal network with a bidirectional DLPFC-VLPFC connection, and a direct parietal-extrastriate pathway. We suggest that these activation/deactivation patterns reflect efficient resource allocation throughout the brain and propose a new extended version of the biased competition model of WM. Hum Brain Mapp, 2011. © 2010 Wiley-Liss, Inc

Mid-infrared GaSb-based resonant tunneling diode photodetectors for gas sensing applications

The authors are grateful for financial support by the BMBF via the national project HIRT (FKZ:13XP5003A).We present resonant tunneling diode-photodetectors (RTD-PDs) with GaAs0.15Sb0.85/AlAs0.1Sb0.9 double barrier structures combined with an additional quaternary Ga0.64In0.36As0.33Sb0.67 absorption layer covering the fingerprint absorption lines of various gases in the mid-infrared wavelength spectral region. The absorption layer cut-off wavelength is determined to be 3.5 µm and the RTD-PDs show peak-to-valley current ratios up to 4.3 with peak current densities of 12 A/cm-2.The incorporation of the quaternary absorption layer enables the RTD-PD to be sensitive to illumination with light up to the absorption lines of HCl at 3395 nm. At this wavelength, the detector shows a responsivity of 6.3 mA/W. At the absorption lines of CO2 and CO at 2004 nm and 2330 nm respectively, the RTD-PD reaches responsivities up to 0.97 A/W. Thus RTD-PDs pave the way towards high sensitive mid-infrared detectors that can be utilized in tunable laser absorption spectroscopy.PostprintPeer reviewe

Regulating Assisted Reproduction in Canada, Switzerland, and the USA: Comparing the Judicialization of Policy-making

This article analyses the extent to which courts shape policies for assisted reproduction. While the USA is considered to be the most litigious country, Canada has observed a growing involvement of the courts from the 1980’s onward, and Switzerland is characterized by a modest degree of judicialization. Based on national patterns, we would expect litigation and court impact to vary across these three countries. As this paper demonstrates, policy-process specific variables such as the structure of policy conflicts, the novelty of regulation, self-regulation by key stakeholders, and the policies in place better explain the variation in the judicialization of policy-making

The special case of self-perspective inhibition in mental, but not non-mental, representation

The ventrolateral prefrontal cortex (vlPFC) has been implicated in studies of both executive and social functions. Recent meta-analyses suggest that vlPFC plays an important but little understood role in Theory of Mind (ToM). Converging neuropsychological and functional Magnetic Resonance Imaging (fMRI) evidence suggests that this may reflect inhibition of self-perspective. The present study adapted an extensively published ToM localizer to evaluate the role of vlPFC in inhibition of self-perspective. The classic false belief, false photograph vignettes that comprise the localizer were modified to generate high and low salience of self-perspective. Using a factorial design, the present study identified a behavioural and neural cost associated with having a highly salient self-perspective that was incongruent with the representational content. Importantly, vlPFC only differentiated between high versus low salience of self-perspective when representing mental state content. No difference was identified for non-mental representation. This result suggests that different control processes are required to represent competing mental and non-mental content

The Neuronal Correlates of Digits Backward Are Revealed by Voxel-Based Morphometry and Resting-State Functional Connectivity Analyses

Digits backward (DB) is a widely used neuropsychological measure that is believed to be a simple and effective index of the capacity of the verbal working memory. However, its neural correlates remain elusive. The aim of this study is to investigate the neural correlates of DB in 299 healthy young adults by combining voxel-based morphometry (VBM) and resting-state functional connectivity (rsFC) analyses. The VBM analysis showed positive correlations between the DB scores and the gray matter volumes in the right anterior superior temporal gyrus (STG), the right posterior STG, the left inferior frontal gyrus and the left Rolandic operculum, which are four critical areas in the auditory phonological loop of the verbal working memory. Voxel-based correlation analysis was then performed between the positive rsFCs of these four clusters and the DB scores. We found that the DB scores were positively correlated with the rsFCs within the salience network (SN), that is, between the right anterior STG, the dorsal anterior cingulate cortex and the right fronto-insular cortex. We also found that the DB scores were negatively correlated with the rsFC within an anti-correlation network of the SN, between the right posterior STG and the left posterior insula. Our findings suggest that DB performance is related to the structural and functional organizations of the brain areas that are involved in the auditory phonological loop and the SN

Consensus Paper: Cerebellum and Social Cognition.

The traditional view on the cerebellum is that it controls motor behavior. Although recent work has revealed that the cerebellum supports also nonmotor functions such as cognition and affect, only during the last 5 years it has become evident that the cerebellum also plays an important social role. This role is evident in social cognition based on interpreting goal-directed actions through the movements of individuals (social "mirroring") which is very close to its original role in motor learning, as well as in social understanding of other individuals' mental state, such as their intentions, beliefs, past behaviors, future aspirations, and personality traits (social "mentalizing"). Most of this mentalizing role is supported by the posterior cerebellum (e.g., Crus I and II). The most dominant hypothesis is that the cerebellum assists in learning and understanding social action sequences, and so facilitates social cognition by supporting optimal predictions about imminent or future social interaction and cooperation. This consensus paper brings together experts from different fields to discuss recent efforts in understanding the role of the cerebellum in social cognition, and the understanding of social behaviors and mental states by others, its effect on clinical impairments such as cerebellar ataxia and autism spectrum disorder, and how the cerebellum can become a potential target for noninvasive brain stimulation as a therapeutic intervention. We report on the most recent empirical findings and techniques for understanding and manipulating cerebellar circuits in humans. Cerebellar circuitry appears now as a key structure to elucidate social interactions

When doctors shape policy: The impact of self-regulation on governing human biotechnology

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.This paper investigates the development and adoption of governance modes in the field of human biotechnology. As the field of human biotechnology is relatively new, voluntary professional self-regulation constituted the initial governing mode. In the meantime, with the exception of Ireland, all Western European countries have moved toward greater state intervention. Nevertheless, they have done so in contrasting ways and the resulting governance modes for assisted reproductive technology and embryonic stem-cell research vary greatly. Instead of imposing their steering capacity in a “top-down” fashion, governments have taken pre-existing self-regulatory arrangements in the field into account and built up governance mechanisms in conjunction with private actors and pre-existing modes of private governance. Our analysis demonstrates that the form and content of the initial self-regulation explain why the self-steering capacity of the medical profession was largely or at least partially preserved through hybrid governance systems in Britain and Germany, while in France the self-regulation was entirely replaced by governmental intervention

Institutional vulnerability to social constructions - Federalism, target populations, and policy designs for assisted reproductive technology in six democracies

This article contributes to efforts to integrate power-based, institutionalist, and constructivist perspectives on policy making. Using an analysis of policy designs for assisted reproductive technology, the authors argue that jurisdictional federations are more vulnerable to social constructions based on widely held perceptions of social groups than functional federations and, to a lesser extent, unitary states. In fact, policy makers in jurisdictional federations tend to rely on communicative discourses aimed at convincing a wide public, whereas those in functional federations need coordinative discourses to obtain the support of actors who play key roles in decision making. Where coordinative discourses prevail over communicative discourses, policy makers will more likely target advantaged groups with restrictive policies