On Reverse Engineering in the Cognitive and Brain Sciences

Various research initiatives try to utilize the operational principles of organisms and brains to develop alternative, biologically inspired computing paradigms and artificial cognitive systems. This paper reviews key features of the standard method applied to complexity in the cognitive and brain sciences, i.e. decompositional analysis or reverse engineering. The indisputable complexity of brain and mind raise the issue of whether they can be understood by applying the standard method. Actually, recent findings in the experimental and theoretical fields, question central assumptions and hypotheses made for reverse engineering. Using the modeling relation as analyzed by Robert Rosen, the scientific analysis method itself is made a subject of discussion. It is concluded that the fundamental assumption of cognitive science, i.e. complex cognitive systems can be analyzed, understood and duplicated by reverse engineering, must be abandoned. Implications for investigations of organisms and behavior as well as for engineering artificial cognitive systems are discussed.Comment: 19 pages, 5 figure

Complex Neuro-Cognitive Systems

Cognitive functions such as a perception, thinking and acting are based on the working of the brain, one of the most complex systems we know. The traditional scientific methodology, however, has proved to be not sufficient to understand the relation between brain and cognition. The aim of this paper is to review an alternative methodology – nonlinear dynamical analysis – and to demonstrate its benefit\ud for cognitive neuroscience in cases when the usual reductionist method fails

Active percolation analysis of pyramidal neurons of somatosensory cortex: A comparison of wildtype and p21H-Ras<Sup>Val12 transgenic mice

This article describes the investigation of morphological variations among two sets of neuronal cells, namely a control group of wild type rat cells and a group of cells of a trangenic line. Special attention is given to singular points in the neuronal structure, namely the branching points and extremities of the dendritic processes. The characterization of the spatial distribution of such points is obtained by using a recently reported morphological technique based on forced percolation and window-size compensation, which is particularly suited to the analysis of scattered points, presenting several coexisting densities. Different dispersions were identified in our statistical analysis, suggesting that the transgenic line of neurons is characterized by a more pronounced morphological variation. A classification scheme based on a canonical discriminant function was also considered in order to identify the morphological differences

Serum levels of bone sialoprotein correlate with portal pressure in patients with liver cirrhosis

Liver cirrhosis represents the common end-stage of chronic liver diseases regardless of its etiology. Patients with compensated disease are mostly asymptomatic, however, progression to a decompensated disease stage is common. The available stratification strategies are often unsuitable to identify patients with a higher risk for disease progression and a limited prognosis. SIBLINGs, soluble glycophosphoproteins, are secreted into the blood by immune-cells. While osteopontin, the most prominent member of the SIBLINGs family, has been repeatedly associated with liver cirrhosis, data on the diagnostic and/or prognostic value of bone sialoprotein (BSP) are scarce and partly inconclusive. In this study, we analyzed the diagnostic and prognostic potential of circulating BSP in comparison to other standard laboratory markers in a large cohort of patients with liver cirrhosis receiving transjugular intrahepatic portosystemic shunt (TIPS). Serum levels of BSP were similar in patients with different disease stages and were not indicative for prognosis. Interestingly, BSP serum levels did correlate inversely with portal pressure, as well as its surrogates such as platelet count, the portal vein cross-sectional area and correlated positively with the portal venous velocity. In summary, our data highlight that BSP might represent a previously unrecognized marker for portal hypertension in patients with liver cirrhosis

The role of macrophage-inducible C-type lectin in different stages of chronic liver disease

The macrophage-inducible C-type lectin (mincle) is part of the innate immune system and acts as a pattern recognition receptor for pathogen-associated molecular patterns (PAMPS) and damage-associated molecular patterns (DAMPs). Ligand binding induces mincle activation which consequently interacts with the signaling adapter Fc receptor, SYK, and NF-kappa-B. There is also evidence that mincle expressed on macrophages promotes intestinal barrier integrity. However, little is known about the role of mincle in hepatic fibrosis, especially in more advanced disease stages. Mincle expression was measured in human liver samples from cirrhotic patients and donors collected at liver transplantation and in patients undergoing bariatric surgery. Human results were confirmed in rodent models of cirrhosis and acute-on-chronic liver failure (ACLF). In these models, the role of mincle was investigated in liver samples as well as in peripheral blood monocytes (PBMC), tissues from the kidney, spleen, small intestine, and heart. Additionally, mincle activation was stimulated in experimental non-alcoholic steatohepatitis (NASH) by treatment with mincle agonist trehalose-6,6-dibehenate (TDB). In human NASH, mincle is upregulated with increased collagen production. In ApoE deficient mice fed high-fat western diet (NASH model), mincle activation significantly increases hepatic collagen production. In human cirrhosis, mincle expression is also significantly upregulated. Furthermore, mincle expression is associated with the stage of chronic liver disease. This could be confirmed in rat models of cirrhosis and ACLF. ACLF was induced by LPS injection in cirrhotic rats. While mincle expression and downstream signaling via FC receptor gamma, SYK, and NF-kappa-B are upregulated in the liver, they are downregulated in PBMCs of these rats. Although mincle expressed on macrophages might be beneficial for intestinal barrier integrity, it seems to contribute to inflammation and fibrosis once the intestinal barrier becomes leaky in advanced stages of chronic liver disease

Blickkontrolle in neuraler Architektur für Aktive Sehsysteme

Im Unterschied zu traditionellen Methodologien in der Künstlichen Intelligenz wird das Sehen im Rahmen des neuen Paradigmas 'Aktives Sehen' im Verhaltenskontext des Systems untersucht. Aktive Sehsysteme (ASS) weisen Merkmale auf, die der Biologie entstammen (Binokularität, Foveae, Blickkontrolle mit hoher Geschwindigkeit). Dieser Bericht analysiert Berechnungsstrategien der visuomotorischen Kontrolle, die von biologischen Sehsystemen verwendet werden, um sie für künstliche ASS nutzbar zu machen. Neurale Karten, Populationskodierung und Informationsverarbeitung in geschichteten Strukturen werden als universelle Prinzipien analoger neuraler Berechnungen gekennzeichnet, die auch der Blickkontrolle zugrunde liegen. Auf der Basis dieser Prinzipien schlagen wir ein Modell vor, das kartierte neurale Felder verwendet, um die raum-zeitliche Dynamik in der Motorkarte des Colliculus superior der Säugetiere darzustellen, eines sensomotorischen Transformationszentrums im Mittelhirn, das entscheidend an der Blickkontrolle beteiligt ist

Blickkontrolle in neuraler Architektur für Aktive Sehsysteme

Im Unterschied zu traditionellen Methodologien in der Künstlichen Intelligenz wird das Sehen im Rahmen des neuen Paradigmas 'Aktives Sehen' im Verhaltenskontext des Systems untersucht. Aktive Sehsysteme (ASS) weisen Merkmale auf, die der Biologie entstammen (Binokularität, Foveae, Blickkontrolle mit hoher Geschwindigkeit). Dieser Bericht analysiert Berechnungsstrategien der visuomotorischen Kontrolle, die von biologischen Sehsystemen verwendet werden, um sie für künstliche ASS nutzbar zu machen. Neurale Karten, Populationskodierung und Informationsverarbeitung in geschichteten Strukturen werden als universelle Prinzipien analoger neuraler Berechnungen gekennzeichnet, die auch der Blickkontrolle zugrunde liegen. Auf der Basis dieser Prinzipien schlagen wir ein Modell vor, das kartierte neurale Felder verwendet, um die raum-zeitliche Dynamik in der Motorkarte des Colliculus superior der Säugetiere darzustellen, eines sensomotorischen Transformationszentrums im Mittelhirn, das entscheidend an der Blickkontrolle beteiligt ist