Use of Task-Relevant Spoken Word Stimuli in an Auditory Brain-Computer Interface

Auditory brain-computer interfaces (aBCI) may be an effective solution for communication in cases of severely locked-in, late stage ALS (Lou Gehrig’s disease) and upper spinal cord injury patients who are otherwise not candidates for implanted electrodes. Feasibility of auditory BCI has been shown for both healthy participants, (Hill et al., 2004), and impaired populations (Sellers and Donchin, 2006). (Hill et al., 2014) found similar BCI performance in healthy participants and those with locked-in syndrome in a paradigm comparing words to pure tone stimuli. Additional BCI research has explored variations to augment P300 signals for use in speller paradigms, including more meaningful auditory stimuli (Klobassa et al., 2009; Furdea et al., 2009; Simon et al., 2014). It has been recognized in these studies that end users would much prefer natural sounds over a repeated tone stimulus. All of these systems required an association of sound with target stimuli, typically enforced by a visual support matrix. These systems would not be usable by the target end users of an auditory BCI. At- tempts to remove the need for visual referencing by investigating a BCI system with serial presentation of spoken letter streams as stimuli (Hoehne and Tangermann, 2014) or spoken words (Ferracuti et al., 2013) has met with limited success but presents a potential high speed communication solutions. The present study highlights a method of using BCI task relevant spoken word stimuli to eliminate visually presented references. By utilizing spoken word stimuli, a BCI system could utilize a range of stimuli equivalent to the size of the users vocabulary and provide faster communication out- put than spelling systems. As a control, spoken word stimuli that have no task specific relevance are also tested. Stimuli audio-spatial cues have shown significant improvements in aBCI performance (Käthner et al., 2013; Schreuder et al., 2011). The present study specifically evaluates the potential improvements to BCI performance of semantic and audio-spatial relevance by eliciting auditory oddball P300 responses to task relevant directional stimuli (spoken words: ‘front’, ‘back’, ‘left’, ‘right’). Participants completed several trials of a motivational game with directionally relevant targets over two experimental sessions. Offline analysis of training data was accomplished to evaluate the impact of stimulus characteristics on BCI performance. Questionnaire results on workload, motivation and system usability accurately reflected participant’s BCI performance. A behavioral button press study was utilized to further investigate the influence of spatial cues used in the paradigm, but also highlighted differences in the semantic relevance of the stimuli. Behavioral results correlated with BCI performance. The results of this study indicate task relevant stimuli are a viable option for eliminating artificial and visual stimulus references. This study’s results highlight several considerations for future auditory BCI studies, including: classifier selection, hearing threshold importance, aid of behavioral correlates to BCI performance and use of spatially separated spoken word stimuli

A Noninvasive Brain-Computer Interface for Real-Time Speech Synthesis: The Importance of Multimodal Feedback.

We conducted a study of a motor imagery brain-computer interface (BCI) using electroencephalography to continuously control a formant frequency speech synthesizer with instantaneous auditory and visual feedback. Over a three-session training period, sixteen participants learned to control the BCI for production of three vowel sounds (/ textipa i/ [heed], / textipa A/ [hot], and / textipa u/ [who'd]) and were split into three groups: those receiving unimodal auditory feedback of synthesized speech, those receiving unimodal visual feedback of formant frequencies, and those receiving multimodal, audio-visual (AV) feedback. Audio feedback was provided by a formant frequency artificial speech synthesizer, and visual feedback was given as a 2-D cursor on a graphical representation of the plane defined by the first two formant frequencies. We found that combined AV feedback led to the greatest performance in terms of percent accuracy, distance to target, and movement time to target compared with either unimodal feedback of auditory or visual information. These results indicate that performance is enhanced when multimodal feedback is meaningful for the BCI task goals, rather than as a generic biofeedback signal of BCI progress

Interdisciplinary views of fNIRS: Current advancements, equity challenges, and an agenda for future needs of a diverse fNIRS research community

Functional Near-Infrared Spectroscopy (fNIRS) is an innovative and promising neuroimaging modality for studying brain activity in real-world environments. While fNIRS has seen rapid advancements in hardware, software, and research applications since its emergence nearly 30 years ago, limitations still exist regarding all three areas, where existing practices contribute to greater bias within the neuroscience research community. We spotlight fNIRS through the lens of different end-application users, including the unique perspective of a fNIRS manufacturer, and report the challenges of using this technology across several research disciplines and populations. Through the review of different research domains where fNIRS is utilized, we identify and address the presence of bias, specifically due to the restraints of current fNIRS technology, limited diversity among sample populations, and the societal prejudice that infiltrates today's research. Finally, we provide resources for minimizing bias in neuroscience research and an application agenda for the future use of fNIRS that is equitable, diverse, and inclusive

Behind the Scenes of Noninvasive Brain– Computer Interfaces: A Review of Electroencephalography Signals, How They Are Recorded, and Why They Matter

Purpose: Brain–computer interface (BCI) techniques may provide computer access for individuals with severe physical impairments. However, the relatively hidden nature of BCI control obscures how BCI systems work behind the scenes, making it difficult to understand “how” electroencephalography (EEG) records the BCIrelated brain signals, “what” brain signals are recorded by EEG, and “why” these signals are targeted for BCI control. Furthermore, in the field of speech-languagehearing, signals targeted for BCI application have been of primary interest to clinicians and researchers in the area of augmentative and alternative communication (AAC). However, signals utilized for BCI control reflect sensory, cognitive, and motor processes, which are of interest to a range of related disciplines, including speech science. Method: This tutorial was developed by a multidisciplinary team emphasizing primary and secondary BCI-AAC–related signals of interest to speech-language-hearing. Results: An overview of BCI-AAC–related signals are provided discussing (a) “how” BCI signals are recorded via EEG; (b) “what” signals are targeted for noninvasive BCI control, including the P300, sensorimotor rhythms, steady-state evoked potentials, contingent negative variation, and the N400; and (c) “why” these signals are targeted. During tutorial creation, attention was given to help support EEG and BCI understanding for those without an engineering background. Conclusion: Tutorials highlighting how BCI-AAC signals are elicited and recorded can help increase interest and familiarity with EEG and BCI techniques and provide a framework for understanding key principles behind BCIAAC design and implementation

Using Motor Imagery to Control Brain-Computer Interfaces for Communication

Brain-computer interfaces (BCI) as assistive devices are designed to provide access to communication, navigation, locomotion and environmental interaction to individuals with severe motor impairment. In the present paper, we discuss two approaches to communication using a non-invasive BCI via recording of neurological activity related to motor imagery. The first approach uses modulations of the sensorimotor rhythm related to limb movement imagery to continuously modify the output of an artificial speech synthesizer. The second approach detects event-related changes to neurological activity during single trial motor imagery attempts to control a commercial augmentative and alternative communication device. These two approaches represent two extremes for BCI-based communication ranging from simple, “button-click” operation of a speech generating communication device to continuous modulation of an acoustic output speech synthesizer. The goal of developing along a continuum is to facilitate adoption and use of communication BCIs to a heterogeneous target user population

Gestión del compromiso institucional y el desempeño docente del profesorado de la Universidad Peruana Los Andes.

TesisLa presente tesis investigó la relación existente entre el compromiso organizacional y el desempeño docente en la Universidad Peruana Los Andes (UPLA) durante el semestre 2015-I . Se seleccionó como unidad de análisis a los estudiantes universitarios y como población al estudiantado del régimen presencial y semipresencial de la Facultad de Educación y Ciencias Humanas de dicha Universidad (N= 493), de la cual se extrajo la muestra, cuyo tamaño final quedó conformado por 200 estudiantes. La selección de éstos se hizo con la tabla de números aleatorios random. La investigación tuvo un enfoque cuantitativo, siendo de tipo correlacional, con un diseño de corte transversal. Los instrumentos de colecta de datos fueron el Cuestionario de Compromiso Organizacional y la Escala de Evaluación del Desempeño Docente. Ambos fueron replicados en la validez de contenido y confiabilidad de los mismos antes de ser administrados en el trabajo de campo. Los índices respectivos de la V de Aiken y el alfa de Cronbach reportaron alta validez de contenido y alta confiablidad en los dos instrumentos. La categorización de cada variable de la investigación así como de sus respectivas dimensiones se hizo con la técnica estadística escala de Stanones. Se utilizó la prueba paramétrica coeficiente de correlación de Pearson para medir las relaciones y efectuar la contrastación de hipótesis. Los resultados obtenidos sugieren que hay suficiente evidencia empírica para afirmar la· existencia de una correlación directa y significativa entre el compromiso organizacional y el desempeño docente, así como para apuntalar las correlaciones positivas y significativas entre las dimensiones del compromiso organizacional (afectivo, normativo y continuidad) y el desempeño docente. Las correlaciones general y específicas fueron estadísticamente significativos con un nivel de probabilidad de 0,5

Behind the Scenes of Noninvasive Brain– Computer Interfaces: A Review of Electroencephalography Signals, How They Are Recorded, and Why They Matter

Purpose: Brain–computer interface (BCI) techniques may provide computer access for individuals with severe physical impairments. However, the relatively hidden nature of BCI control obscures how BCI systems work behind the scenes, making it difficult to understand “how” electroencephalography (EEG) records the BCIrelated brain signals, “what” brain signals are recorded by EEG, and “why” these signals are targeted for BCI control. Furthermore, in the field of speech-languagehearing, signals targeted for BCI application have been of primary interest to clinicians and researchers in the area of augmentative and alternative communication (AAC). However, signals utilized for BCI control reflect sensory, cognitive, and motor processes, which are of interest to a range of related disciplines, including speech science. Method: This tutorial was developed by a multidisciplinary team emphasizing primary and secondary BCI-AAC–related signals of interest to speech-language-hearing. Results: An overview of BCI-AAC–related signals are provided discussing (a) “how” BCI signals are recorded via EEG; (b) “what” signals are targeted for noninvasive BCI control, including the P300, sensorimotor rhythms, steady-state evoked potentials, contingent negative variation, and the N400; and (c) “why” these signals are targeted. During tutorial creation, attention was given to help support EEG and BCI understanding for those without an engineering background. Conclusion: Tutorials highlighting how BCI-AAC signals are elicited and recorded can help increase interest and familiarity with EEG and BCI techniques and provide a framework for understanding key principles behind BCIAAC design and implementation