Mechanisms responsible for the integration of perceptual events and appropriate actions (sensorimotor processes) have been subject to intense research. Different theoretical frameworks have been put forward with the "Theory of Event Coding (TEC)" being one of the most influential. In the current study, we focus on the concept of 'event files' within TEC and examine what sub-processes being dissociable by means of cognitive-neurophysiological methods are involved in voluntary event coding. This was combined with EEG source localization. We also introduce reward manipulations to delineate the neurophysiological sub-processes most relevant for performance variations during event coding. The results show that processes involved in voluntary event coding included predominantly stimulus categorization, feature unbinding and response selection, which were reflected by distinct neurophysiological processes (the P1, N2 and P3 ERPs). On a system's neurophysiological level, voluntary event-file coding is thus related to widely distributed parietal-medial frontal networks. Attentional selection processes (N1 ERP) turned out to be less important. Reward modulated stimulus categorization in parietal regions likely reflecting aspects of perceptual decision making but not in other processes. The perceptual categorization stage appears central for voluntary event-file coding.

• MeSH
• Adult MeSH
• Cognition physiology   MeSH
• Humans MeSH
• Models, Neurological * MeSH
• Reward * MeSH
• Task Performance and Analysis * MeSH
• Computer Simulation MeSH
• Somatosensory Cortex physiology   MeSH
• Information Storage and Retrieval methods   MeSH
• Volition physiology   MeSH
• Visual Perception physiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Psycholinguistics MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Lingvistika. Jazyky
• NML Fields
• psychologie, klinická psychologie
• lingvistika, lékařská terminologie

• MeSH
• Qualitative Research MeSH
• Research MeSH

• Conspectus
• Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce
• NML Fields
• věda a výzkum
• NML Publication type
• kolektivní monografie

The nature of neural codes is central to neuroscience. Do neurons encode information through relatively slow changes in the firing rates of individual spikes (rate code) or by the precise timing of every spike (temporal code)? Here we compare the loss of information due to correlations for these two possible neural codes. The essence of Shannon's definition of information is to combine information with uncertainty: the higher the uncertainty of a given event, the more information is conveyed by that event. Correlations can reduce uncertainty or the amount of information, but by how much? In this paper we address this question by a direct comparison of the information per symbol conveyed by the words coming from a binary Markov source (temporal code) with the information per symbol coming from the corresponding Bernoulli source (uncorrelated, rate code). In a previous paper we found that a crucial role in the relation between information transmission rates (ITRs) and firing rates is played by a parameter s, which is the sum of transition probabilities from the no-spike state to the spike state and vice versa. We found that in this case too a crucial role is played by the same parameter s. We calculated the maximal and minimal bounds of the quotient of ITRs for these sources. Next, making use of the entropy grouping axiom, we determined the loss of information in a Markov source compared with the information in the corresponding Bernoulli source for a given word length. Our results show that in the case of correlated signals the loss of information is relatively small, and thus temporal codes, which are more energetically efficient, can replace rate codes effectively. These results were confirmed by experiments.

• MeSH
• Action Potentials * MeSH
• Information Theory * MeSH
• Markov Chains * MeSH
• Models, Neurological * MeSH
• Uncertainty * MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH

• MeSH
• Nursing MeSH
• Research MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• ošetřovatelství

OBJECTIVE: One of the primary goals of neuroscience is to understand how neurons encode and process information about their environment. The problem is often approached indirectly by examining the degree to which the neuronal response reflects the stimulus feature of interest. APPROACH: In this context, the methods of signal estimation and detection theory provide the theoretical limits on the decoding accuracy with which the stimulus can be identified. The Cramér-Rao lower bound on the decoding precision is widely used, since it can be evaluated easily once the mathematical model of the stimulus-response relationship is determined. However, little is known about the behavior of different decoding schemes with respect to the bound if the neuronal population size is limited. MAIN RESULTS: We show that under broad conditions the optimal decoding displays a threshold-like shift in performance in dependence on the population size. The onset of the threshold determines a critical range where a small increment in size, signal-to-noise ratio or observation time yields a dramatic gain in the decoding precision. SIGNIFICANCE: We demonstrate the existence of such threshold regions in early auditory and olfactory information coding. We discuss the origin of the threshold effect and its impact on the design of effective coding approaches in terms of relevant population size.

• MeSH
• Action Potentials physiology   MeSH
• Algorithms * MeSH
• Evoked Potentials physiology   MeSH
• Humans MeSH
• Models, Neurological * MeSH
• Neurons physiology   MeSH
• Perception physiology   MeSH
• Computer Simulation MeSH
• Reproducibility of Results MeSH
• Sensitivity and Specificity MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Evaluation Study MeSH
• Research Support, Non-U.S. Gov't MeSH

Background: Medical informatics is regarded as a scientific discipline dealing with theory and practice of information processes in medicine, comprising data communication by information and communication technologies (ICT), with computers as an especially important ICT. It means Medical informatics history can be stated connected with the beginnings of computer usage in medicine. Objective: The aim of this reviewe was to describe most important facts about historical backgrounds of development of Health/ Medical/Biomedical informatics based on facts searched through systematic scientific literature. Methods: Author used descriptive method for explanation history of medical informatics based on published facts in the scientific literature deposited in online databases. Results and discussion: The development of medical informatics began in the 1950’s of 20th century, when the earliest reference to applications of electronic digital computers in medicine appeared. Historical facts in this article reflect on the development of the discipline of Medical informatics that is now part of all medical disciplines of all health professionals. Applications of computer and information technologies in all segments of society and knowledge of information technology is now part of general literacy. The classical way to present a “history” is to list major events in chronological order, with more or less detailed comments about the persons, ideas or events. A distinction between periods brings a systematization flavor, easing the comments. Conclusion: During last 70 years Biomedical informatics became one of the most prominent biomedical disciplines included in almost all other academic and scientific medical disciplines.

• Keywords
• IMIA,
• MeSH
• Electronic Data Processing methods   MeSH
• History, 20th Century MeSH
• Information Technology MeSH
• Medical Informatics * history   MeSH
• Medical Informatics Applications MeSH
• Education, Professional MeSH
• Check Tag
• History, 20th Century MeSH

• MeSH
• Genetics MeSH

• Conspectus
• Obecná genetika. Obecná cytogenetika. Evoluce
• NML Fields
• genetika, lékařská genetika

• MeSH
• Electrodiagnosis methods   MeSH
• Electromyography MeSH
• Spinal Cord Diseases diagnosis   MeSH
• Neural Conduction physiology   MeSH
• Synaptic Transmission physiology   MeSH
• Neuromuscular Diseases diagnosis   MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• neurologie
• diagnostika
• NML Publication type
• kolektivní monografie

BACKGROUND AND AIMS: The centromere drive theory explains diversity of eukaryotic centromeres as a consequence of the recurrent conflict between centromeric repeats and centromeric histone H3 (CenH3), in which selfish centromeres exploit meiotic asymmetry and CenH3 evolves adaptively to counterbalance deleterious consequences of driving centromeres. Accordingly, adaptively evolving CenH3 has so far been observed only in eukaryotes with asymmetric meiosis. However, if such evolution is a consequence of centromere drive, it should depend not only on meiotic asymmetry but also on monocentric or holokinetic chromosomal structure. Selective pressures acting on CenH3 have never been investigated in organisms with holokinetic meiosis despite the fact that holokinetic chromosomes have been hypothesized to suppress centromere drive. Therefore, the present study evaluates selective pressures acting on the CenH3 gene in holokinetic organisms for the first time, specifically in the representatives of the plant genus Luzula (Juncaceae), in which the kinetochore formation is not co-localized with any type of centromeric repeat. METHODS: PCR, cloning and sequencing, and database searches were used to obtain coding CenH3 sequences from Luzula species. Codon substitution models were employed to infer selective regimes acting on CenH3 in Luzula KEY RESULTS: In addition to the two previously published CenH3 sequences from L. nivea, 16 new CenH3 sequences have been isolated from 12 Luzula species. Two CenH3 isoforms in Luzula that originated by a duplication event prior to the divergence of analysed species were found. No signs of positive selection acting on CenH3 in Luzula were detected. Instead, evidence was found that selection on CenH3 of Luzula might have been relaxed. CONCLUSIONS: The results indicate that holokinetism itself may suppress centromere drive and, therefore, holokinetic chromosomes might have evolved as a defence against centromere drive.

• MeSH
• Centromere genetics   MeSH
• Chromosomes, Plant genetics   MeSH
• Phylogeny MeSH
• Genome, Plant genetics   MeSH
• Histones genetics   MeSH
• Magnoliopsida genetics   MeSH
• Meiosis genetics   MeSH
• Sequence Analysis, DNA MeSH
• Sequence Alignment MeSH
• Selection, Genetic genetics   MeSH
• Publication type
• Journal Article MeSH