87,677 research outputs found
Practical Brain Computer Interfacing
A brain-computer interface (BCI) is a communication system that enables users to voluntary send messages or commands without movement. The classical goal of BCI research is to support communication and control for users with impaired communication due to illness or injury. Typical BCI applications are the operation of computer cursors, spelling programs or external devices, such as wheelchairs, robots and neural prostheses. The user sends modulated information to the BCI by engaging in mental tasks that produce distinct brain patterns. The BCI acquires signals from the user's brain and translates them into suitable communication. This dissertation aims to develop faster and more reliable non-invasive BCI communication based on the study of users learning process and their interaction with the BCI transducer. To date, BCI research has focused on the development of advanced pattern recognition and classification algorithms to improve accuracy and reliability of the classified patterns. However, even with optimal detection methods, successful BCI operation depends on the degree to which the users can voluntary modulate their brain signals. Therefore, learning to operate a BCI requires repeated practice with feedback that engages learning mechanisms in the brain. In this work, several aspects including signal processing techniques, feedback methods, experimental and training protocols, demographics, and applications were explored and investigated. Research was focused on two BCI paradigms, steady-state visual evoked potentials (SSVEP) and event-related (de-)synchronization (ERD/ERS). Signal processing algorithms for the detection of both brain patterns were applied and evaluated. A general application interface for BCI feedback tasks was developed to evaluate the practicability, reliability and acceptance of new feedback methods. The role of feedback and training was fully investigated on studies conducted with healthy subjects. The influence of demographics on BCIs was explored in two field studies with a large number of subjects. Results were supported through advanced statistical analysis. Furthermore, the BCI control was evaluated in a spelling application and a service robotic application. This dissertation demonstrates that BCIs can provide effective communication for most subjects. Presented results showed that improvements in the BCI transducer, training protocols, and feedback methods constituted the basis to achieve faster and more reliable BCI communication. Nevertheless, expert assistance is necessary for both initial configuration and daily operation, which reduces the practicability of BCIs for people who really need them
A Comparison of a Brain-Computer Interface and an Eye Tracker: Is There a More Appropriate Technology for Controlling a Virtual Keyboard in an ALS Patient?
The ability of people affected by amyotrophic lateral sclerosis (ALS), muscular dystrophy or spinal cord injuries to physically interact with the environment, is usually reduced. In some cases, these patients suffer from a syndrome known as locked-in syndrome (LIS), defined by the patientâs inability to make any move-ment but blinks and eye movements. Tech communication systems available for people in LIS are very limited, being those based on eye-tracking and brain-computer interface (BCI) the most useful for these patients. A comparative study between both technologies in an ALS patient is carried out: an eye tracker and a visual P300-based BCI. The purpose of the study presented in this paper is to show that the choice of the technology could depend on userÂŽs preference. The evaluation of performance, workload and other subjective measures will allow us to determine the usability of the systems. The obtained results suggest that, even if for this patient the BCI technology is more appropriate, the technology should be always tested and adapted for each user.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Inter-stimulus Interval Study for the Tactile Point-pressure Brain-computer Interface
The paper presents a study of an inter-stimulus interval (ISI) influence on a
tactile point-pressure stimulus-based brain-computer interface's (tpBCI)
classification accuracy. A novel tactile pressure generating tpBCI stimulator
is also discussed, which is based on a three-by-three pins' matrix prototype.
The six pin-linear patterns are presented to the user's palm during the online
tpBCI experiments in an oddball style paradigm allowing for "the aha-responses"
elucidation, within the event related potential (ERP). A subsequent
classification accuracies' comparison is discussed based on two ISI settings in
an online tpBCI application. A research hypothesis of classification
accuracies' non-significant differences with various ISIs is confirmed based on
the two settings of 120 ms and 300 ms, as well as with various numbers of ERP
response averaging scenarios.Comment: 4 pages, 5 figures, accepted for EMBC 2015, IEEE copyrigh
Student Teaching and Research Laboratory Focusing on Brain-computer Interface Paradigms - A Creative Environment for Computer Science Students -
This paper presents an applied concept of a brain-computer interface (BCI)
student research laboratory (BCI-LAB) at the Life Science Center of TARA,
University of Tsukuba, Japan. Several successful case studies of the student
projects are reviewed together with the BCI Research Award 2014 winner case.
The BCI-LAB design and project-based teaching philosophy is also explained.
Future teaching and research directions summarize the review.Comment: 4 pages, 4 figures, accepted for EMBC 2015, IEEE copyrigh
Electroencephalography (EEG)-Derived Markers to Measure Components of Attention Processing
Although extensively studied for decades,
attention system remains an interesting challenge in
neuroscience field. The Attention Network Task (ANT)
has been developed to provide a measure of the
efficiency for the three attention components identified
in the Posnerâs theoretical model: alerting, orienting and
executive control. Here we propose a study on 15 healthy
subjects who performed the ANT. We combined
advanced methods for connectivity estimation on
electroencephalographic (EEG) signals and graph theory
with the aim to identify neuro-physiological indices
describing the most important features of the three
networks correlated with behavioral performances. Our
results provided a set of band-specific connectivity
indices able to follow the behavioral task performances
among subjects for each attention component as defined
in the ANT paradigm. Extracted EEG-based indices
could be employed in future clinical applications to
support the behavioral assessment or to evaluate the
influence of specific attention deficits on Brain Computer
Interface (BCI) performance and/or the effects of BCI
training in cognitive rehabilitation applications
Neuro-electronic technology in medicine and beyond
This dissertation looks at the technology and social issues involved with interfacing electronics directly to the human nervous system, in particular the methods for both reading and stimulating nerves. The development and use of cochlea implants is discussed, and is compared with recent developments in artificial vision. The final sections consider a future for non-medicinal applications of neuro-electronic technology. Social attitudes towards use for both medicinal and non-medicinal purposes are discussed, and the viability of use in the latter case assessed
Teegi: Tangible EEG Interface
We introduce Teegi, a Tangible ElectroEncephaloGraphy (EEG) Interface that
enables novice users to get to know more about something as complex as brain
signals, in an easy, en- gaging and informative way. To this end, we have
designed a new system based on a unique combination of spatial aug- mented
reality, tangible interaction and real-time neurotech- nologies. With Teegi, a
user can visualize and analyze his or her own brain activity in real-time, on a
tangible character that can be easily manipulated, and with which it is
possible to interact. An exploration study has shown that interacting with
Teegi seems to be easy, motivating, reliable and infor- mative. Overall, this
suggests that Teegi is a promising and relevant training and mediation tool for
the general public.Comment: to appear in UIST-ACM User Interface Software and Technology
Symposium, Oct 2014, Honolulu, United State
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