EEG signal processing methods for BCI applications

Abstract Brain-computer interface (BCI) is a communication system that translates brain activity into commands for a computer or other digital device. The majority of BCI systems work by reading and interpreting cortically-evoked electro-potentials ("brain waves") via an electroencephalogram (EEG) data. The EEG data is inherently complex. The signals are non-linear, non-stationary and therefore difficult to analyze. After acquisition, pre-processing, feature extraction and dimensionality reduction is performed, after witch machine learning algorithms can be applied to classify the signals into classes, where each class corresponds to a specific intention of the user. BCI systems require correct classification of signals interpreted from the brain for useful operation. This paper reviews our proposed methods for EEG signal processing and classification, which include Wave Atom transform, use of nonlinear operators, class-adaptive denoising using Shrinkage Functions and real time training of Voted Perceptron artificial neural networks

EEG signal processing methods for BCI applications

Abstract Brain-computer interface (BCI) is a communication system that translates brain activity into commands for a computer or other digital device. The majority of BCI systems work by reading and interpreting cortically-evoked electro-potentials ("brain waves") via an electroencephalogram (EEG) data. The EEG data is inherently complex. The signals are non-linear, non-stationary and therefore difficult to analyze. After acquisition, pre-processing, feature extraction and dimensionality reduction is performed, after witch machine learning algorithms can be applied to classify the signals into classes, where each class corresponds to a specific intention of the user. BCI systems require correct classification of signals interpreted from the brain for useful operation. This paper reviews our proposed methods for EEG signal processing and classification, which include Wave Atom transform, use of nonlinear operators, class-adaptive denoising using Shrinkage Functions and real time training of Voted Perceptron artificial neural networks

Controlled experiments in lithic technology and function

From the earliest manifestations of tool production, technologies have played a fundamental role in the acquisition of different resources and are representative of daily activities in the lives of ancient humans, such as hunting (stone-tipped spears) and meat processing (chipped stone tools) (Lombard 2005; McPherron et al. 2010; Lombard and Phillipson 2010; Brown et al. 2012; Wilkins et al. 2012; Sahle et al. 2013; Joordens et al. 2015; Ambrose 2001; Stout 2001). Yet many questions remain, such as how and why technological changes took place in earlier populations, and how technological traditions, innovations, and novelties enabled hominins to survive and disperse across the globe (Klein 2000; McBrearty and Brooks 2000; Henshilwood et al. 2001; Marean et al. 2007; Brown et al. 2012; Režek et al. 2018).Projekt DEALinfo:eu-repo/semantics/publishedVersio

Identifying the unidentified fauna enhances insights into hominin subsistence strategies during the Middle to Upper Palaeolithic transition

Understanding Palaeolithic hominin subsistence strategies requires the comprehensive taxonomic identification of faunal remains. The high fragmentation of Late Pleistocene faunal assemblages often prevents proper taxonomic identification based on bone morphology. It has been assumed that the morphologically unidentifiable component of the faunal assemblage would reflect the taxonomic abundances of the morphologically identified portion. In this study, we analyse three faunal datasets covering the Middle to Upper Palaeolithic transition (MUPT) at Bacho Kiro Cave (Bulgaria) and Les Cottés and La Ferrassie (France) with the application of collagen type I peptide mass fingerprinting (ZooMS). Our results emphasise that the fragmented component of Palaeolithic bone assemblages can differ significantly from the morphologically identifiable component. We obtain contrasting identification rates between taxa resulting in an overrepresentation of morphologically identified reindeer (Rangifer tarandus) and an underrepresentation of aurochs/bison (Bos/Bison) and horse/European ass (Equus) at Les Cottés and La Ferrassie. Together with an increase in the relative diversity of the faunal composition, these results have implications for the interpretation of subsistence strategies during a period of possible interaction between Neanderthals and Homo sapiens in Europe. Furthermore, shifts in faunal community composition and in carnivore activity suggest a change in the interaction between humans and carnivores across the MUPT and indicate a possible difference in site use between Neanderthals and Homo sapiens. The combined use of traditional and biomolecular methods allows (zoo)archaeologists to tackle some of the methodological limits commonly faced during the morphological assessment of Palaeolithic bone assemblages

Rethinking use-wear analysis and experimentation as applied to the study of past hominin tool use

In prehistoric human populations, technologies played a fundamental role in the acquisition of different resources and are represented in the main daily living activities, such as with bone, wooden, and stone-tipped spears for hunting, and chipped-stone tools for butchering. Considering that paleoanthropologists and archeologists are focused on the study of different processes involved in the evolution of human behavior, investigating how hominins acted in the past through the study of evidence on archeological artifacts is crucial. Thus, investigat ing tool use is of major importance for a comprehensive understanding of all processes that characterize human choices of raw materials, techniques, and tool types. Many functional assumptions of tool use have been based on tool design and morphology according to archeologists’ interpretations and ethnographic observations. Such assumptions are used as baselines when inferring human behavior and have driven an improvement in the methods and techniques employed in functional studies over the past few decades. Here, while arguing that use-wear analysis is a key discipline to assess past hominin tool use and to interpret the organization and variability of artifact types in the archeological record, we aim to review and discuss the current state-of-the-art methods, protocols, and their limitations. In doing so, our discussion focuses on three main topics: (1) the need for fundamental improvements by adopting established methods and techniques from similar research fields, (2) the need to implement and combine different levels of experimentation, and (3) the crucial need to establish standards and protocols in order to improve data quality, standard ization, repeatability, and reproducibility. By adopting this perspective, we believe that studies will increase the reliability and applicability of use-wear methods on tool function. The need for a holistic approach that combines not only use-wear traces but also tool technology, design, curation, durability, and efficiency is also debated and revised. Such a revision is a crucial step if archeologists want to build major inferences on human decision making behavior and biocultural evolution processes.info:eu-repo/semantics/publishedVersio