EEG classification for the detection of mental states

Published in Journal Articles

Abstract

The objective of the present work is to develop a method that is able to automatically determine mental states of vigilance; i.e., a person's state of alertness. Such a task is relevant to diverse domains, where a person is expected or required to be in a particular state of mind. For instance, pilots and medical staff are expected to be in a highly alert state and the proposed method could help to detect possible deviations from this expected state. This work poses a binary classification problem where the goal is to distinguish between a "relaxed" state and a baseline state ("normal") from the study of electroencephalographic signals (EEG) collected with a small number of electrodes. The EEG of 58 subjects in the two alertness states (116 records) were collected via a cap with 58 electrodes. After a data validation step, 19 subjects were retained for further analysis. A genetic algorithm was used to select a subset of electrodes. Common spatial pattern (CSP) coupled to linear discriminant analysis (LDA) was used to build a decision rule and thus predict the alertness of the subjects. Different subset sizes were investigated and the best compromise between the number of selected electrodes and the quality of the solution was obtained by considering 9 electrodes. Even if the present approach is costly in computation time (GA search), it allows to construct a decision rule that provides an accurate and fast prediction of the alertness state of an unseen individual.

  1. Laurent Vézard, Pierrick Legrand, Marie Chavent, Frédérique Faïta-Aïnseba and Leonardo Trujillo. EEG Classification for the Detection of Mental States. Appl. Soft Comput. 32(C):113–131, 2015. URL, DOI BibTeX

    @article{,
    	author = {V\'{e}zard, Laurent and Legrand, Pierrick and Chavent, Marie and Fa\"{i}ta-A\"{i}nseba, Fr\'{e}d\'{e}rique and Trujillo, Leonardo},
    	title = "EEG Classification for the Detection of Mental States",
    	journal = "Appl. Soft Comput.",
    	issue_date = "July 2015",
    	volume = 32,
    	number = "C",
    	month = "",
    	year = 2015,
    	issn = "1568-4946",
    	pages = "113--131",
    	numpages = 19,
    	url = "http://dx.doi.org/10.1016/j.asoc.2015.03.028",
    	doi = "10.1016/j.asoc.2015.03.028",
    	acmid = 2778066,
    	publisher = "Elsevier Science Publishers B. V.",
    	address = "Amsterdam, The Netherlands, The Netherlands",
    	keywords = "Alertness, Common spatial pattern, Electroencephalographic signals, Genetic algorithm, Variable selection"
    }
    
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Multiple Objective Genetic Algorithms for Path-planning Optimization in Autonomous Mobile Robots

Published in Journal Articles

Abstract

This paper describes the use of a genetic algorithm (GA) for the problem of offline point-to-point autonomous mobile robot path planning. The problem consists of generating “valid” paths or trajectories, for an Holonomic Robot to use to move from a starting position to a destination across a flat map of a terrain, represented by a two-dimensional grid, with obstacles and dangerous ground that the Robot must evade. This means that the GA optimizes possible paths based on two criteria: length and difficulty. First, we decided to use a conventional GA to evaluate its ability to solve this problem (using only one criteria for optimization). Due to the fact that we also wanted to optimize paths under two criteria or objectives, then we extended the conventional GA to implement the ideas of Pareto optimality, making it a multi-objective genetic algorithm (MOGA). We describe useful performance measures and simulation results of the conventional GA and of the MOGA that show that both types of GAs are effective tools for solving the point-to-point path-planning problem.

  1. Oscar Castillo, Leonardo Trujillo and Patricia Melin. Multiple Objective Genetic Algorithms for Path-planning Optimization in Autonomous Mobile Robots. Soft Comput. 11(3):269–279, 2006. URL, DOI BibTeX

    @article{Castillo:2006:MOG:1178398.1178406,
    	author = "Castillo, Oscar and Trujillo, Leonardo and Melin, Patricia",
    	title = "Multiple Objective Genetic Algorithms for Path-planning Optimization in Autonomous Mobile Robots",
    	journal = "Soft Comput.",
    	issue_date = "October 2006",
    	volume = 11,
    	number = 3,
    	month = "",
    	year = 2006,
    	issn = "1432-7643",
    	pages = "269--279",
    	numpages = 11,
    	url = "http://dx.doi.org/10.1007/s00500-006-0068-4",
    	doi = "10.1007/s00500-006-0068-4",
    	acmid = 1178406,
    	publisher = "Springer-Verlag",
    	address = "Berlin, Heidelberg",
    	keywords = "Autonomous robots, Genetic algorithms, Multiple objective optimization, Path planning"
    }
    

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