Differences in the processing of anaphoric reference between closely related languages: neurophysiological evidence

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Internal and external information in error processing

<p>Abstract</p> <p>Background</p> <p>The use of self-generated and externally provided information in performance monitoring is reflected by the appearance of error-related and feedback-related negativities (ERN and FRN), respectively. Several authors proposed that ERN and FRN are supported by similar neural mechanisms residing in the anterior cingulate cortex (ACC) and the mesolimbic dopaminergic system. The present study is aimed to test the functional relationship between ERN and FRN. Using an Eriksen-Flanker task with a moving response deadline we tested 17 young healthy subjects. Subjects received feedback with respect to their response accuracy and response speed. To fulfill both requirements of the task, they had to press the correct button and had to respond in time to give a valid response.</p> <p>Results</p> <p>When performance monitoring based on self-generated information was sufficient to detect a criterion violation an ERN was released, while the subsequent feedback became redundant and therefore failed to trigger an FRN. In contrast, an FRN was released if the feedback contained information which was not available before and action monitoring processes based on self-generated information failed to detect an error.</p> <p>Conclusion</p> <p>The described pattern of results indicates a functional interrelationship of response and feedback related negativities in performance monitoring.</p

ISLES 2015 - A public evaluation benchmark for ischemic stroke lesion segmentation from multispectral MRI

Ischemic stroke is the most common cerebrovascular disease, and its diagnosis, treatment, and study relies on non-invasive imaging. Algorithms for stroke lesion segmentation from magnetic resonance imaging (MRI) volumes are intensely researched, but the reported results are largely incomparable due to different datasets and evaluation schemes. We approached this urgent problem of comparability with the Ischemic Stroke Lesion Segmentation (ISLES) challenge organized in conjunction with the MICCAI 2015 conference. In this paper we propose a common evaluation framework, describe the publicly available datasets, and present the results of the two sub-challenges: Sub-Acute Stroke Lesion Segmentation (SISS) and Stroke Perfusion Estimation (SPES). A total of 16 research groups participated with a wide range of state-of-the-art automatic segmentation algorithms. A thorough analysis of the obtained data enables a critical evaluation of the current state-of-the-art, recommendations for further developments, and the identification of remaining challenges. The segmentation of acute perfusion lesions addressed in SPES was found to be feasible. However, algorithms applied to sub-acute lesion segmentation in SISS still lack accuracy. Overall, no algorithmic characteristic of any method was found to perform superior to the others. Instead, the characteristics of stroke lesion appearances, their evolution, and the observed challenges should be studied in detail. The annotated ISLES image datasets continue to be publicly available through an online evaluation system to serve as an ongoing benchmarking resource (www.isles-challenge.org).Peer reviewe

Deep Brain Stimulation of Nucleus Accumbens Region in Alcoholism Affects Reward Processing

The influence of bilateral deep brain stimulation (DBS) of the nucleus nucleus (NAcc) on the processing of reward in a gambling paradigm was investigated using H2[15O]-PET (positron emission tomography) in a 38-year-old man treated for severe alcohol addiction. Behavioral data analysis revealed a less risky, more careful choice behavior under active DBS compared to DBS switched off. PET showed win- and loss-related activations in the paracingulate cortex, temporal poles, precuneus and hippocampus under active DBS, brain areas that have been implicated in action monitoring and behavioral control. Except for the temporal pole these activations were not seen when DBS was deactivated. These findings suggest that DBS of the NAcc may act partially by improving behavioral control

The Role of the Subthalamic Nucleus in Sequential Working Memory in De Novo Parkinson's Disease

Background Deficits in maintaining and manipulating sequential information online can occur even in patients with mild Parkinson&#39;s disease. The subthalamic nucleus may play a modulatory role in the neural system for sequential working memory, which also includes the lateral prefrontal cortex. Objectives The objective of this study was to investigate neural markers of sequential working memory deficits in patients with de novo Parkinson&#39;s disease. Methods A total of 50 patients with de novo Parkinson&#39;s disease and 50 healthy controls completed a digit ordering task during functional magnetic resonance imaging scanning. The task separated the maintenance (&quot;pure recall&quot;) and manipulation of sequences (&quot;reorder &amp; recall&quot; vs. &quot;pure recall&quot;). Results In healthy controls, individual participants&#39; task accuracy was predicted by the regional activation and functional connectivity of the subthalamic nucleus. Healthy participants who showed lower subthalamic nucleus activation and stronger subthalamic nucleus connectivity with the putamen performed more accurately in maintaining sequences (&quot;pure recall&quot;). Healthy participants who showed greater ordering-related subthalamic nucleus activation change exhibited smaller accuracy costs in manipulating sequences (&quot;reorder &amp; recall&quot; vs. &quot;pure recall&quot;). Patients performed less accurately than healthy controls, especially in &quot;reorder &amp; recall&quot; trials, accompanied by an overactivation in the subthalamic nucleus and a loss of synchrony between the subthalamic nucleus and putamen. Individual patients&#39; task accuracy was predicted only by the subthalamic nucleus connectivity. The contribution of the subthalamic nucleus activation or activation change was absent. We observed no change in the lateral prefrontal cortex. Conclusions The overactivation and weakened functional connectivity of the subthalamic nucleus are the neural markers of sequential working memory deficits in de novo Parkinson&#39;s disease. (c) 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC. on behalf of International Parkinson and Movement Disorder Society</p

Substantia Nigra Integrity Correlates with Sequential Working Memory in Parkinson's Disease

Maintaining and manipulating sequences online is essential for daily activities such as scheduling a day. In Parkinson's disease (PD), sequential working memory deficits have been associated with altered regional activation and functional connectivity in the basal ganglia. This study demonstrates that the substantia nigra (SN) integrity correlated with basal ganglia function and sequencing perform-ance in 29 patients with PD (17 women) and 29 healthy controls (HCs; 18 women). In neuromelanin-sensitive structural magnetic resonance imaging (MRI), PD patients showed smaller SNs than HCs. In a digitordering task with functional MRI (fMRI), partici-pants either recalled sequential digits in the original order (pure recall) or rearranged the digits and recalled the new sequence (reorder and recall). PD patients performed less accurately than HCs, accompanied by the caudate and pallidal hypoactivation, subthalamic hyperactivation, and weakened functional connectivity between the bilateral SN and all three basal ganglia regions. PD patients with larger SNs tended to exhibit smaller ordering-related accuracy costs (reorder and recall vs pure recall). This effect was fully mediated by the ordering-related caudate activation. Unlike HCs, the ordering-related accuracy cost correlated with the ordering-related caudate activation but not subthalamic activation in PD patients. Moreover, the ordering-related caudate activation correlated with the SN area but not with the daily dose of D-2/3 receptor agonists. In PD patients, the daily dose of D-2/3 receptor agonists correlated with the ordering-related subthalamic activation, which was not related to the accuracy cost. The findings suggest that damage to the SN may lead to sequential working memory deficits in PD patients, mediated by basal ganglia dysfunction