Reliable applications of affective brain-computer interfaces (aBCI) in realistic, multi-modal env... more Reliable applications of affective brain-computer interfaces (aBCI) in realistic, multi-modal environments require a detailed understanding of the processes involved in emotions. To explore the modalityspecific nature of affective responses, we studied neurophysiological responses (i.e., EEG) of 24 participants during visual, auditory, and audiovisual affect stimulation. The affect induction protocols were validated by participants' subjective ratings and physiological responses (i.e., ECG). Coherent with literature, we found modality-specific responses in the EEG: posterior alpha power decreases during visual stimulation and increases during auditory stimulation, anterior alpha power tends to decrease during auditory stimulation and to increase during visual stimulation. We discuss the implications of these results for multi-modal aBCI.
Reliable applications of multimodal affective brain-computer interfaces (aBCI) require a detailed... more Reliable applications of multimodal affective brain-computer interfaces (aBCI) require a detailed understanding of the processes involved in emotions. To explore the modality-specific nature of affective responses, we studied neurophysiological responses of 24 subjects during visual, auditory, and audiovisual affect stimulation and obtained their subjective ratings. Coherent with literature, we found modality-specific responses in the EEG: parietal alpha power decreases during
This study was designed to develop and test an auditory event-related potential (ERP) based spell... more This study was designed to develop and test an auditory event-related potential (ERP) based spelling system for a brain-computer interface (BCI) and to compare user's performance between the auditory and visual modality. The spelling system, where letters in a matrix were coded with acoustically presented numbers, was tested on a group of healthy volunteers. The results were compared with a visual spelling system. Nine of the 13 participants presented with the auditory ERP spelling system scored above a predefined criterion level control for communication. Compared to the visual spelling system, users' performance was lower and the peak latencies of the auditorily evoked ERPs were delayed. It was concluded that auditorily evoked ERPs from the majority of the users could be reliably classified. High accuracies were achieved in these users, rendering item selection with a BCI based on auditory stimulation feasible for communication.
Generally brain-computer interface (BCI) systems are evaluated based on the assumption that the u... more Generally brain-computer interface (BCI) systems are evaluated based on the assumption that the user is trying to perform a specific task in the most efficient way. BCI for entertainment yields interesting applications for both patients and healthy users. Then the purpose is to create positive experiences that enrich our lives. To evaluate such systems, the user experience needs to be taken into account to understand how a system can satisfy these needs. This paper points at the gap in user experience evaluation currently in BCI research, and shows how user experience evaluation could benefit BCI, through increased user acceptance, enjoyment, BCI task performance, enhanced human-computer interaction, and improved selection of suitable mental tasks in a given context.
While there is a gap between user-centered human-computer interaction (HCI) research and the more... more While there is a gap between user-centered human-computer interaction (HCI) research and the more technology driven brain-computer interface (BCI) research, there are numerous possibilities and advantages for the two fields to help each other. Methods to evaluate the user experience of BCI systems include: 1) involvement of users in the design process, 2) administration of standardized questionnaires, 3) assessment of cognitive and physiological state.
While there is a gap between user-centered human-computer interaction (HCI) research and the more... more While there is a gap between user-centered human-computer interaction (HCI) research and the more technology driven brain-computer interface (BCI) research, there are numerous possibilities and advantages for the two fields to help each other. Methods to evaluate the user experience of BCI systems include: 1) involvement of users in the design process, 2) administration of standardized questionnaires, 3) assessment of cognitive and physiological state.
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2006
We summarize results from a series of related studies that aim to develop a motor-imagery-based b... more We summarize results from a series of related studies that aim to develop a motor-imagery-based brain-computer interface using a single recording session of EEG or ECoG signals for each subject. We apply the same experimental and analytical methods to 11 non-paralysed subjects (8 EEG, 3 ECoG), and to 5 paralysed subjects (4 EEG, 1 ECoG) who had been unable to communicate for some time. While it was relatively easy to obtain classifiable signals quickly from most of the non-paralysed subjects, it proved impossible to classify the signals obtained from the paralysed patients by the same methods. This highlights the fact that though certain BCI paradigms may work well with healthy subjects, this does not necessarily indicate success with the target user group. We outline possible reasons for this failure to transfer.
Affective Brain-Computer Interfaces (BCI) are systems that measure signals from the peripheral an... more Affective Brain-Computer Interfaces (BCI) are systems that measure signals from the peripheral and central nervous system, extract features related to affective states of the user, and use these features to adapt human-computer interaction (HCI). Affective BCIs provide new perspectives on the applicability of BCIs. Affective BCIs may serve as assessment tools and adaptive systems for HCI for the general population and may prove to be especially interesting for people with severe motor impairment. In this context, affective BCIs will enable simultaneous expression of affect and content, thus providing more quality of life for the patient and the caregiver. In the present paper, we will present psychophysiological markers for affective BCIs, and discuss their usability in the day to day life of patients with amyotrophic lateral sclerosis (ALS).
This represents the first documentation of transition of a patient with ALS from the Locked In St... more This represents the first documentation of transition of a patient with ALS from the Locked In State the to Completely Locked In State, and the first EMG documentation of loss of all muscle activities, including sphincter function, but with retained cognition as measured with ERPs. In this patient, any stimulation, communication or learning using visual and tactile stimuli was lost. Visual BCI was useless. The findings suggest ALS as a multisystem disorder, even affecting afferent sensory pathways.
The steadily growing field of brain-computer interfacing (BCI) may develop useful technologies, w... more The steadily growing field of brain-computer interfacing (BCI) may develop useful technologies, with a potential impact not only on individuals, but also on society as a whole. At the same time, the development of BCI presents significant ethical and legal challenges. In a workshop during the 4th International BCI meeting (Asilomar, California, 2010), six panel members from various BCI laboratories and companies set out to identify and disentangle ethical issues related to BCI use in four case scenarios, which were inspired by current experiences in BCI laboratories. Results of the discussion are reported in this article, touching on topics such as the representation of persons with communication impairments, dealing with technological complexity and moral responsibility in multidisciplinary teams, and managing expectations, ranging from an individual user to the general public. Furthermore, we illustrate that where treatment and research interests conflict, ethical concerns arise. On the basis of the four case scenarios, we discuss salient, practical ethical issues that may confront any member of a typical multidisciplinary BCI team. We encourage the BCI and rehabilitation communities to engage in a dialogue, and to further identify and address pressing ethical issues as they occur in the practice of BCI research and its commercial applications.
Objective: Brain-computer interfaces (BCIs) provide non-muscular communication for individuals di... more Objective: Brain-computer interfaces (BCIs) provide non-muscular communication for individuals diagnosed with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS)). In the final stages of the disease, a BCI cannot rely on the visual modality. This study examined a method to achieve high accuracies using auditory stimuli only. Methods: We propose an auditory BCI based on a three-stimulus paradigm. This paradigm is similar to the standard oddball but includes an additional target (i.e. two target stimuli, one frequent stimulus). Three versions of the task were evaluated in which the target stimuli differed in loudness, pitch or direction. Results: Twenty healthy participants achieved an average information transfer rate (ITR) of up to 2.46 bits/min and accuracies of 78.5%. Most subjects (14 of 20) achieved their best performance with targets differing in pitch. Conclusions: With this study, the viability of the paradigm was shown for healthy participants and will next be evaluated with individuals diagnosed with ALS or locked-in syndrome (LIS) after stroke. Significance: The here presented BCI offers communication with binary choices (yes/no) independent of vision. As it requires only little time per selection, it may constitute a reliable means of communication for patients who lost all motor function and have a short attention span.
Brain-Computer Interface (BCI) research and (future) applications raise important ethical issues ... more Brain-Computer Interface (BCI) research and (future) applications raise important ethical issues that need to be addressed to promote societal acceptance and adequate policies. Here we report on a survey we conducted among 145 BCI researchers at the 4th International BCI conference, which took place in May–June 2010 in Asilomar, California. We assessed respondents’ opinions about a number of topics. First, we investigated preferences for terminology and definitions relating to BCIs. Second, we assessed respondents’ expectations on the marketability of different BCI applications (BCIs for healthy people, BCIs for assistive technology, BCIs-controlled neuroprostheses and BCIs as therapy tools). Third, we investigated opinions about ethical issues related to BCI research for the development of assistive technology: informed consent process with locked-in patients, risk-benefit analyses, team responsibility, consequences of BCI on patients’ and families’ lives, liability and personal identity and interaction with the media. Finally, we asked respondents which issues are urgent in BCI research.
The current study investigated the effects of psychological well-being measured as quality of lif... more The current study investigated the effects of psychological well-being measured as quality of life (QoL), depression, current mood and motivation on brain-computer interface (BCI) performance in amyotrophic lateral sclerosis (ALS). Six participants with most advanced ALS were trained either for a block of 20 sessions with a BCI based on sensorimotor rhythms (SMR) or a block of 10 sessions with a BCI based on event-related potentials, or both. Questionnaires assessed QoL and severity of depressive symptoms before each training block and mood and motivation before each training session. The SMR-BCI required more training than the P300-BCI. The information transfer rate was higher with the P300-BCI (3.25 bits/min) than with the SMR-BCI (1.16 bits/ min). Mood and motivation were related to the number of BCI sessions. Motivational factors, specifically challenge and mastery confidence, were positively related to BCI performance (controlled for the number of sessions) in tow participants, while incompetence fear was negatively related with performance in one participant. BCI performance was not related to motivational factors in three other participants nor to mood in any of the six participants. We conclude that motivational factors may be related to BCI performance in individual subjects and suggest that motivational factors and well-being should be assessed in standard BCI protocols. We also recommend using P300-based BCI as first choice in severely paralyzed patients who present with a P300 evoked potential.
3 Bram van de Laar, Hayrettin Gürkök, Danny Plass-Oude Bos, 4 Femke Nijboer, and Anton Nijholt 5 ... more 3 Bram van de Laar, Hayrettin Gürkök, Danny Plass-Oude Bos, 4 Femke Nijboer, and Anton Nijholt 5 AQ1 11.1 Introduction 6
Objective: This study examined the effect of motivation as a possible psychological influencing v... more Objective: This study examined the effect of motivation as a possible psychological influencing variable on P300 amplitude and performance in a brain-computer interface (BCI) controlled by event-related potentials (ERP). Methods: Participants were instructed to copy spell a sentence by attending to cells of a randomly flashing 7 Ã 7 matrix. Motivation was manipulated by monetary reward. In two experimental groups participants received 25 (N = 11) or 50 (N = 11) Euro cent for each correctly selected character; the control group (N = 11) was not rewarded. BCI performance was defined as the overall percentage of correctly selected characters (correct response rate = CRR). Results: Participants performed at an average of 99%. At electrode location Cz the P300 amplitude was positively correlated to self-rated motivation. The P300 amplitude of the most motivated participants was significantly higher than that of the least motivated participants. Highly motivated participants were able to communicate correctly faster with the ERP-BCI than less motivated participants. Conclusions: Motivation modulates the P300 amplitude in an ERP-BCI. Significance: Motivation may contribute to variance in BCI performance and should be monitored in BCI settings.
Most Brain–Computer Interface (BCI) research aims at helping people who are severely paralyzed to... more Most Brain–Computer Interface (BCI) research aims at helping people who are severely paralyzed to regain control over their environment and to communicate with their social environment. There has been a tremendous increase in BCI research the last years, which might lead to the belief that we are close to a commercially available BCI applications to patients. However, studies with users from the future target group (those who are indeed paralyzed) are still outnumbered by studies on technical aspects of BCI applications and studies with healthy young participants. This might explain why the number of patients who use a BCI in daily life, without experts from a BCI group being present, can be counted on one hand.
Objective: The current study evaluates the efficacy of a P300-based brain-computer interface (BCI... more Objective: The current study evaluates the efficacy of a P300-based brain-computer interface (BCI) communication device for individuals with advanced ALS. Methods: Participants attended to one cell of a N Â N matrix while the N rows and N columns flashed randomly. Each cell of the matrix contained one character. Every flash of an attended character served as a rare event in an oddball sequence and elicited a P300 response. Classification coefficients derived using a stepwise linear discriminant function were applied to the data after each set of flashes. The character receiving the highest discriminant score was presented as feedback.
BCI research and (future) applications raise ethical questions. A websurvey among 144 BCI researc... more BCI research and (future) applications raise ethical questions. A websurvey among 144 BCI researchers identified disseminating BCI research to the public media as a central topic. Most researchers felt that BCI scientists must responsibly communicate with the media and that general ethical guidelines on BCI research and application are needed within the next 5 years. We recommend further debate on ethical aspects related to BCI and the development of guidelines.
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2006
This paper describes the highlights of presentations and discussions during the Third Internation... more This paper describes the highlights of presentations and discussions during the Third International BCI Meeting in a workshop that evaluated potential brain-computer interface (BCI) signals and currently available recording methods. It defined the main potential user populations and their needs, addressed the relative advantages and disadvantages of noninvasive and implanted (i.e., invasive) methodologies, considered ethical issues, and focused on the challenges involved in translating BCI systems from the laboratory to widespread clinical use. The workshop stressed the critical importance of developing useful applications that establish the practical value of BCI technology.
Reliable applications of affective brain-computer interfaces (aBCI) in realistic, multi-modal env... more Reliable applications of affective brain-computer interfaces (aBCI) in realistic, multi-modal environments require a detailed understanding of the processes involved in emotions. To explore the modalityspecific nature of affective responses, we studied neurophysiological responses (i.e., EEG) of 24 participants during visual, auditory, and audiovisual affect stimulation. The affect induction protocols were validated by participants' subjective ratings and physiological responses (i.e., ECG). Coherent with literature, we found modality-specific responses in the EEG: posterior alpha power decreases during visual stimulation and increases during auditory stimulation, anterior alpha power tends to decrease during auditory stimulation and to increase during visual stimulation. We discuss the implications of these results for multi-modal aBCI.
Reliable applications of multimodal affective brain-computer interfaces (aBCI) require a detailed... more Reliable applications of multimodal affective brain-computer interfaces (aBCI) require a detailed understanding of the processes involved in emotions. To explore the modality-specific nature of affective responses, we studied neurophysiological responses of 24 subjects during visual, auditory, and audiovisual affect stimulation and obtained their subjective ratings. Coherent with literature, we found modality-specific responses in the EEG: parietal alpha power decreases during
This study was designed to develop and test an auditory event-related potential (ERP) based spell... more This study was designed to develop and test an auditory event-related potential (ERP) based spelling system for a brain-computer interface (BCI) and to compare user's performance between the auditory and visual modality. The spelling system, where letters in a matrix were coded with acoustically presented numbers, was tested on a group of healthy volunteers. The results were compared with a visual spelling system. Nine of the 13 participants presented with the auditory ERP spelling system scored above a predefined criterion level control for communication. Compared to the visual spelling system, users' performance was lower and the peak latencies of the auditorily evoked ERPs were delayed. It was concluded that auditorily evoked ERPs from the majority of the users could be reliably classified. High accuracies were achieved in these users, rendering item selection with a BCI based on auditory stimulation feasible for communication.
Generally brain-computer interface (BCI) systems are evaluated based on the assumption that the u... more Generally brain-computer interface (BCI) systems are evaluated based on the assumption that the user is trying to perform a specific task in the most efficient way. BCI for entertainment yields interesting applications for both patients and healthy users. Then the purpose is to create positive experiences that enrich our lives. To evaluate such systems, the user experience needs to be taken into account to understand how a system can satisfy these needs. This paper points at the gap in user experience evaluation currently in BCI research, and shows how user experience evaluation could benefit BCI, through increased user acceptance, enjoyment, BCI task performance, enhanced human-computer interaction, and improved selection of suitable mental tasks in a given context.
While there is a gap between user-centered human-computer interaction (HCI) research and the more... more While there is a gap between user-centered human-computer interaction (HCI) research and the more technology driven brain-computer interface (BCI) research, there are numerous possibilities and advantages for the two fields to help each other. Methods to evaluate the user experience of BCI systems include: 1) involvement of users in the design process, 2) administration of standardized questionnaires, 3) assessment of cognitive and physiological state.
While there is a gap between user-centered human-computer interaction (HCI) research and the more... more While there is a gap between user-centered human-computer interaction (HCI) research and the more technology driven brain-computer interface (BCI) research, there are numerous possibilities and advantages for the two fields to help each other. Methods to evaluate the user experience of BCI systems include: 1) involvement of users in the design process, 2) administration of standardized questionnaires, 3) assessment of cognitive and physiological state.
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2006
We summarize results from a series of related studies that aim to develop a motor-imagery-based b... more We summarize results from a series of related studies that aim to develop a motor-imagery-based brain-computer interface using a single recording session of EEG or ECoG signals for each subject. We apply the same experimental and analytical methods to 11 non-paralysed subjects (8 EEG, 3 ECoG), and to 5 paralysed subjects (4 EEG, 1 ECoG) who had been unable to communicate for some time. While it was relatively easy to obtain classifiable signals quickly from most of the non-paralysed subjects, it proved impossible to classify the signals obtained from the paralysed patients by the same methods. This highlights the fact that though certain BCI paradigms may work well with healthy subjects, this does not necessarily indicate success with the target user group. We outline possible reasons for this failure to transfer.
Affective Brain-Computer Interfaces (BCI) are systems that measure signals from the peripheral an... more Affective Brain-Computer Interfaces (BCI) are systems that measure signals from the peripheral and central nervous system, extract features related to affective states of the user, and use these features to adapt human-computer interaction (HCI). Affective BCIs provide new perspectives on the applicability of BCIs. Affective BCIs may serve as assessment tools and adaptive systems for HCI for the general population and may prove to be especially interesting for people with severe motor impairment. In this context, affective BCIs will enable simultaneous expression of affect and content, thus providing more quality of life for the patient and the caregiver. In the present paper, we will present psychophysiological markers for affective BCIs, and discuss their usability in the day to day life of patients with amyotrophic lateral sclerosis (ALS).
This represents the first documentation of transition of a patient with ALS from the Locked In St... more This represents the first documentation of transition of a patient with ALS from the Locked In State the to Completely Locked In State, and the first EMG documentation of loss of all muscle activities, including sphincter function, but with retained cognition as measured with ERPs. In this patient, any stimulation, communication or learning using visual and tactile stimuli was lost. Visual BCI was useless. The findings suggest ALS as a multisystem disorder, even affecting afferent sensory pathways.
The steadily growing field of brain-computer interfacing (BCI) may develop useful technologies, w... more The steadily growing field of brain-computer interfacing (BCI) may develop useful technologies, with a potential impact not only on individuals, but also on society as a whole. At the same time, the development of BCI presents significant ethical and legal challenges. In a workshop during the 4th International BCI meeting (Asilomar, California, 2010), six panel members from various BCI laboratories and companies set out to identify and disentangle ethical issues related to BCI use in four case scenarios, which were inspired by current experiences in BCI laboratories. Results of the discussion are reported in this article, touching on topics such as the representation of persons with communication impairments, dealing with technological complexity and moral responsibility in multidisciplinary teams, and managing expectations, ranging from an individual user to the general public. Furthermore, we illustrate that where treatment and research interests conflict, ethical concerns arise. On the basis of the four case scenarios, we discuss salient, practical ethical issues that may confront any member of a typical multidisciplinary BCI team. We encourage the BCI and rehabilitation communities to engage in a dialogue, and to further identify and address pressing ethical issues as they occur in the practice of BCI research and its commercial applications.
Objective: Brain-computer interfaces (BCIs) provide non-muscular communication for individuals di... more Objective: Brain-computer interfaces (BCIs) provide non-muscular communication for individuals diagnosed with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS)). In the final stages of the disease, a BCI cannot rely on the visual modality. This study examined a method to achieve high accuracies using auditory stimuli only. Methods: We propose an auditory BCI based on a three-stimulus paradigm. This paradigm is similar to the standard oddball but includes an additional target (i.e. two target stimuli, one frequent stimulus). Three versions of the task were evaluated in which the target stimuli differed in loudness, pitch or direction. Results: Twenty healthy participants achieved an average information transfer rate (ITR) of up to 2.46 bits/min and accuracies of 78.5%. Most subjects (14 of 20) achieved their best performance with targets differing in pitch. Conclusions: With this study, the viability of the paradigm was shown for healthy participants and will next be evaluated with individuals diagnosed with ALS or locked-in syndrome (LIS) after stroke. Significance: The here presented BCI offers communication with binary choices (yes/no) independent of vision. As it requires only little time per selection, it may constitute a reliable means of communication for patients who lost all motor function and have a short attention span.
Brain-Computer Interface (BCI) research and (future) applications raise important ethical issues ... more Brain-Computer Interface (BCI) research and (future) applications raise important ethical issues that need to be addressed to promote societal acceptance and adequate policies. Here we report on a survey we conducted among 145 BCI researchers at the 4th International BCI conference, which took place in May–June 2010 in Asilomar, California. We assessed respondents’ opinions about a number of topics. First, we investigated preferences for terminology and definitions relating to BCIs. Second, we assessed respondents’ expectations on the marketability of different BCI applications (BCIs for healthy people, BCIs for assistive technology, BCIs-controlled neuroprostheses and BCIs as therapy tools). Third, we investigated opinions about ethical issues related to BCI research for the development of assistive technology: informed consent process with locked-in patients, risk-benefit analyses, team responsibility, consequences of BCI on patients’ and families’ lives, liability and personal identity and interaction with the media. Finally, we asked respondents which issues are urgent in BCI research.
The current study investigated the effects of psychological well-being measured as quality of lif... more The current study investigated the effects of psychological well-being measured as quality of life (QoL), depression, current mood and motivation on brain-computer interface (BCI) performance in amyotrophic lateral sclerosis (ALS). Six participants with most advanced ALS were trained either for a block of 20 sessions with a BCI based on sensorimotor rhythms (SMR) or a block of 10 sessions with a BCI based on event-related potentials, or both. Questionnaires assessed QoL and severity of depressive symptoms before each training block and mood and motivation before each training session. The SMR-BCI required more training than the P300-BCI. The information transfer rate was higher with the P300-BCI (3.25 bits/min) than with the SMR-BCI (1.16 bits/ min). Mood and motivation were related to the number of BCI sessions. Motivational factors, specifically challenge and mastery confidence, were positively related to BCI performance (controlled for the number of sessions) in tow participants, while incompetence fear was negatively related with performance in one participant. BCI performance was not related to motivational factors in three other participants nor to mood in any of the six participants. We conclude that motivational factors may be related to BCI performance in individual subjects and suggest that motivational factors and well-being should be assessed in standard BCI protocols. We also recommend using P300-based BCI as first choice in severely paralyzed patients who present with a P300 evoked potential.
3 Bram van de Laar, Hayrettin Gürkök, Danny Plass-Oude Bos, 4 Femke Nijboer, and Anton Nijholt 5 ... more 3 Bram van de Laar, Hayrettin Gürkök, Danny Plass-Oude Bos, 4 Femke Nijboer, and Anton Nijholt 5 AQ1 11.1 Introduction 6
Objective: This study examined the effect of motivation as a possible psychological influencing v... more Objective: This study examined the effect of motivation as a possible psychological influencing variable on P300 amplitude and performance in a brain-computer interface (BCI) controlled by event-related potentials (ERP). Methods: Participants were instructed to copy spell a sentence by attending to cells of a randomly flashing 7 Ã 7 matrix. Motivation was manipulated by monetary reward. In two experimental groups participants received 25 (N = 11) or 50 (N = 11) Euro cent for each correctly selected character; the control group (N = 11) was not rewarded. BCI performance was defined as the overall percentage of correctly selected characters (correct response rate = CRR). Results: Participants performed at an average of 99%. At electrode location Cz the P300 amplitude was positively correlated to self-rated motivation. The P300 amplitude of the most motivated participants was significantly higher than that of the least motivated participants. Highly motivated participants were able to communicate correctly faster with the ERP-BCI than less motivated participants. Conclusions: Motivation modulates the P300 amplitude in an ERP-BCI. Significance: Motivation may contribute to variance in BCI performance and should be monitored in BCI settings.
Most Brain–Computer Interface (BCI) research aims at helping people who are severely paralyzed to... more Most Brain–Computer Interface (BCI) research aims at helping people who are severely paralyzed to regain control over their environment and to communicate with their social environment. There has been a tremendous increase in BCI research the last years, which might lead to the belief that we are close to a commercially available BCI applications to patients. However, studies with users from the future target group (those who are indeed paralyzed) are still outnumbered by studies on technical aspects of BCI applications and studies with healthy young participants. This might explain why the number of patients who use a BCI in daily life, without experts from a BCI group being present, can be counted on one hand.
Objective: The current study evaluates the efficacy of a P300-based brain-computer interface (BCI... more Objective: The current study evaluates the efficacy of a P300-based brain-computer interface (BCI) communication device for individuals with advanced ALS. Methods: Participants attended to one cell of a N Â N matrix while the N rows and N columns flashed randomly. Each cell of the matrix contained one character. Every flash of an attended character served as a rare event in an oddball sequence and elicited a P300 response. Classification coefficients derived using a stepwise linear discriminant function were applied to the data after each set of flashes. The character receiving the highest discriminant score was presented as feedback.
BCI research and (future) applications raise ethical questions. A websurvey among 144 BCI researc... more BCI research and (future) applications raise ethical questions. A websurvey among 144 BCI researchers identified disseminating BCI research to the public media as a central topic. Most researchers felt that BCI scientists must responsibly communicate with the media and that general ethical guidelines on BCI research and application are needed within the next 5 years. We recommend further debate on ethical aspects related to BCI and the development of guidelines.
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2006
This paper describes the highlights of presentations and discussions during the Third Internation... more This paper describes the highlights of presentations and discussions during the Third International BCI Meeting in a workshop that evaluated potential brain-computer interface (BCI) signals and currently available recording methods. It defined the main potential user populations and their needs, addressed the relative advantages and disadvantages of noninvasive and implanted (i.e., invasive) methodologies, considered ethical issues, and focused on the challenges involved in translating BCI systems from the laboratory to widespread clinical use. The workshop stressed the critical importance of developing useful applications that establish the practical value of BCI technology.
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