Showing papers by "Gert Pfurtscheller published in 2013"

Brain-Computer Interfaces: Revolutionizing Human-Computer Interaction

Abstract: A brain-computer interface (BCI) establishes a direct output channel between the human brain and external devices. BCIs infer user intent via direct measures of brain activity and thus enable communication and control without movement. This book, authored by experts in the field, provides an accessible introduction to the neurophysiological and signal-processing background required for BCI, presents state-of-the-art non-invasive and invasive approaches, gives an overview of current hardware and software solutions, and reviews the most interesting as well as new, emerging BCI applications. The book is intended not only for students and young researchers, but also for newcomers and other readers from diverse backgrounds keen to learn about this vital scientific endeavour.

Thinking Penguin: Multimodal Brain–Computer Interface Control of a VR Game

Abstract: In this paper, we describe a multimodal brain-computer interface (BCI) experiment, situated in a highly immersive CAVE. A subject sitting in the virtual environment controls the main character of a virtual reality game: a penguin that slides down a snowy mountain slope. While the subject can trigger a jump action via the BCI, additional steering with a game controller as a secondary task was tested. Our experiment profits from the game as an attractive task where the subject is motivated to get a higher score with a better BCI performance. A BCI based on the so-called brain switch was applied, which allows discrete asynchronous actions. Fourteen subjects participated, of which 50% achieved the required performance to test the penguin game. Comparing the BCI performance during the training and the game showed that a transfer of skills is possible, in spite of the changes in visual complexity and task demand. Finally and most importantly, our results showed that the use of a secondary motor task, in our case the joystick control, did not deteriorate the BCI performance during the game. Through these findings, we conclude that our chosen approach is a suitable multimodal or hybrid BCI implementation, in which the user can even perform other tasks in parallel.

Brisk heart rate and EEG changes during execution and withholding of cue-paced foot motor imagery.

Abstract: Cue-paced motor imagery (MI) is a frequently used mental strategy to realize a Brain-Computer Interface (BCI) Recently it has been reported that two MI tasks can be separated with a high accuracy within the first second after cue presentation onset To investigate this phenomenon in detail we studied the dynamics of motor cortex beta oscillations in EEG and the changes in heart rate (HR) during visual cue-paced foot MI using a go (execution of imagery) vs nogo (withholding of imagery) paradigm in 16 healthy subjects Both execution and withholding of MI resulted in a brisk centrally localized beta event-related desynchronization (ERD) with a maximum at ~400 ms and a concomitant HR deceleration We found that response patterns within the first second after stimulation differed between conditions The ERD was significantly larger in go as compared to nogo In contrast the HR deceleration was somewhat smaller and followed by an acceleration in go as compared to nogo These findings suggest that the early beta ERD reflects visually induced preparatory activity in motor cortex networks Both the early beta ERD and the HR deceleration are the result of automatic operating processes that are likely part of the orienting reflex (OR) Of interest, however, is that the preparatory cortical activity is strengthened and the HR modulated already within the first second after stimulation during the execution of MI The subtraction of the HR time course of the nogo from the go condition revealed a slight HR acceleration in the first seconds most likely due to the increased mental effort associated with the imagery process

Discussion of "time-frequency techniques in biomedical signal analysis: a tutorial review of similarities and differences".

Abstract: Discussion of “Time-frequency Techniques in Biomedical Signal Analysis: A Tutorial Review of Similarities and Differences” -