Comparing brain-computer interfaces across varying technology access levels

Loading...
Thumbnail Image
Date
2014
Authors
Dollman, Gavin John
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Free State
Abstract
English: A brain-computer interface (BCI) is a device that uses neurophysiological signals measured from the brain to activate external machinery. BCIs have traditionally been used to enhance the standard of living for severely disabled patients. This has resulted in a shortage of data on how BCIs perform with able-bodied individuals. There has recently (2012) been a trend towards BCI research involving able users but these studies are still too few to make a substantial impact. Additionally, traditional input methods are being replaced or supplemented by alternative natural modes of interaction and these natural interactions have become known as NUIs. To investigate the suitability of a BCI as a NUI, this study used the Emotiv headset to provide direct measurement of a participant’s performance while performing tasks similar to wheelchair manipulation in order to determine whether a participant’s access to traditional input methods influences their performance. Thus, the main aim of this study was to investigate the usability of an Emotiv for robot navigation. Additionally, the study aimed to discover whether a user’s performance differed when using a keyboard compared to the Emotiv as well as investigating whether there was improvement of performance in the short term for a user through repetitive use of the Emotiv. In order to compare the usability of the Emotiv to a keyboard the participants were placed into groups based on their exposure to traditional input methods. This was verified based on their individual expertise rating, which was a measure of frequency and length of use. The test instrument used consisted of a written program that navigated a pair of Mindstorm NXT robots across a custom designed test course. Data was collected via usability testing which measured learnability, efficiency and effectiveness. Efficiency was measured as the time taken to complete a task while effectiveness was a measure of the errors made by a participant when completing a task. Results indicated that there was no significant difference between the groups’ efficiency and effectiveness when using the Emotiv to complete a task. Thus, a user’s previous experience with a traditional input method does not influence a user’s performance with an Emotiv when navigating a robot. This result indicates that the interface is intuitive to use and, therefore the Emotiv could be suitable as a NUI. The results for the usability metrics efficiency and effectiveness indicated that there was a significant difference between the performances with the Emotiv and a keyboard. The results show that, with the Emotiv, participants took more time to complete a task and made more errors when compared to a keyboard. This discrepancy was attributed to cognitive theory as it is believed that the participants violated their preformed schema which affected their performance. However, the participants quickly became comfortable with the Emotiv which supports the evidence that the interface is intuitive to use. For neither the usability metrics efficiency nor effectiveness was a significant improvement detected with repetitive use of the Emotiv. Thus, repetitive use of the Emotiv to navigate a robot does not improve a user’s performance over a short period of time. These results indicate that in terms of efficiency and effectiveness the keyboard is the superior interface. The results also revealed that a participant’s performance is not affected by their exposure to traditional input methods when utilising a BCI. Thus, the Emotiv is intuitive to use and appears suitable for use as a NUI. This study proved that the Emotiv is an intuitive interface and can be used with little to no previous experience.
Afrikaans: 'n Brein-rekenaar-koppelvlak (BCI) is 'n toestel wat gebruik maak van neurofisiologiese seine gemeet van die brein om eksterne masjinerie te aktiveer. BCIs is tradisioneel gebruik om die lewenskwaliteit van erg gestremde pasiënte te verbeter. Dit het tot 'n tekort aan data gelei oor hoe BCIs met nie-gestremde individue vaar. Daar is onlangs (2012 ) 'n tendens, in die BCI navorsingsrigting, met die gebruik van nie-gestremde gebruikers maar hierdie studies is nie genoeg om 'n beduidende impak te hê nie. Daarbenewens is die tradisionele invoer metodes vervang of aangevul deur alternatiewe, natuurlike maniere van interaksie. Die natuurlike interaksies staan bekend as NUIs. So, die belangrikste doel van hierdie studie was om die bruikbaarheid van 'n Emotiv vir robot navigasie te ondersoek. Verder het die studie gepoog om vas te stel of 'n gebruiker se prestasie verskil wanneer die gebruik van 'n sleutelbord in vergelyking met die Emotiv sowel as die ondersoek of daar ' n verbetering van die prestasie in die kort termyn vir 'n gebruiker deur middel van herhaalde gebruik van die Emotiv. Ten einde die bruikbaarheid van die Emotiv na 'n sleutelbord te vergelyk die deelnemers in groepe op grond van hul blootstelling aan tradisionele insette metodes geplaas . Dit is bevestig op grond van hul individuele kundigheid gradering , wat 'n mate van frekwensie en lengte van gebruik. Die toets instrument gebruik het bestaan uit 'n skriftelike program wat navigator 'n paar van Mindstorm NXT robots in 'n persoonlike ontwerp toets kursus. Data is ingesamel deur middel van gebruikers toets wat gemeet leerbaarheid , doeltreffendheid en effektiwiteit. Doeltreffendheid is gemeet as die tyd wat dit neem om 'n taak te voltooi , terwyl doeltreffendheid was 'n mate van die foute wat gemaak word deur 'n deelnemer tydens die voltooiing van 'n taak. Resultate het aangedui dat daar geen beduidende verskil tussen die groepe se effektiwiteit en doeltreffendheid by die gebruik van die Emotiv 'n taak te voltooi. Dus, 'n gebruiker se vorige ondervinding met 'n tradisionele invoer metode nie 'n gebruiker se prestasie beïnvloed met 'n Emotiv toe opgevolg 'n robot. Hierdie resultaat dui daarop dat die koppelvlak is intuïtief te gebruik en dus die Emotiv geskik as 'n NUI kan wees . Die resultate vir die bruikbaarheid statistieke doeltreffendheid en het aangedui dat daar 'n beduidende verskil tussen die optredes saam met die Emotiv en 'n klawerbord . Die resultate dui daaropdat , met die Emotiv , deelnemers het meer tyd om 'n taak te voltooi en het meer foute in vergelyking met 'n klavier. Dit verskil is toegeskryf aan kognitiewe teorie as dit word geglo dat die deelnemers geskend hul gevormde skema wat hul prestasie beïnvloed . Die deelnemers het egter vinnig gemaklik met die Emotiv wat ondersteun die bewyse dat die koppelvlak is intuïtief te gebruik geword het. Want ook die bruikbaarheid statistieke doeltreffendheid of effektiwiteit was 'n aansienlike verbetering bespeur met herhalende gebruik van die Emotiv . So , herhalende gebruik van die Emotiv 'n robot om te navigeer nie 'n gebruiker se prestasie oor 'n kort tydperk van die tyd te verbeter. Hierdie resultate dui daarop dat in terme van doeltreffendheid en effektiwiteit van die sleutelbord is die beter koppelvlak. Die resultate het ook getoon dat 'n deelnemer se prestasie is nie geraak deur hul blootstelling aan tradisionele insette metodes toe behulp van 'n indeks . Dus, die Emotiv is intuïtief te gebruik en geskik vir gebruik as 'n NUI verskyn. Hierdie studie bewys dat die Emotiv is 'n intuïtiewe koppelvlak en kan gebruik word met min of geen vorige ondervinding.
Description
Keywords
Pattern recognition systems, Signal processing -- Digital techniques, Brain-computer interfaces, Data transmission systems, Dissertation (M.Sc. (Computer Science and Informatics))--University of the Free State, 2014
Citation