Effect of Distracting Background Speech in an Auditory Brain–Computer Interface

Studies so far have analyzed the effect of distractor stimuli in different types of brain–computer interface (BCI). However, the effect of a background speech has not been studied using an auditory event-related potential (ERP-BCI), a convenient option when the visual path cannot be adopted by users. Thus, the aim of the present work is to examine the impact of a background speech on selection performance and user workload in auditory BCI systems. Eleven participants tested three conditions: (i) auditory BCI control condition, (ii) auditory BCI with a background speech to ignore (non-attentional condition), and (iii) auditory BCI while the user has to pay attention to the background speech (attentional condition). The results demonstrated that, despite no significant differences in performance, shared attention to auditory BCI and background speech required a higher cognitive workload. In addition, the P300 target stimuli in the non-attentional condition were significantly higher than those in the attentional condition for several channels. The non-attentional condition was the only condition that showed significant differences in the amplitude of the P300 between target and non-target stimuli. The present study indicates that background speech, especially when it is attended to, is an important interference that should be avoided while using an auditory BCI.

The Differential Effect of Attentional Condition on Subsequent Vocabulary Development

<p>This study addressed the potential methodological issues effect of attentional condition on subsequent vocabulary development from a different perspective, which addressed several potential methodological issues of previous research that have been based on psycholinguistic notion of second language learner as a limited capacity processor. The issue of whether learners paying attention to the processing of input for meaning can simultaneously pay attention to process form remains methodologically unclear issue in the area of reactivity. A qualitative study was conducted on six intermediate English as a foreign language learners. Participants were assigned to one of the three types of reading comprehension tasks. Concurrent data of think aloud was employed to establish learners’ attention. Results showed that attending learners’ attention to processing of lexical forms while reading for meaning has an effect to induce the issue of reactivity effect on subsequent vocabulary development.</p>

Fronto-limbic-striatal dysfunction in pediatric and adult patients with bipolar disorder: impact of face emotion and attentional demands

BackgroundResearch in bipolar disorder (BD) implicates fronto-limbic-striatal dysfunction during face emotion processing but it is unknown how such dysfunction varies by task demands, face emotion and patient age.MethodDuring functional magnetic resonance imaging (fMRI), 181 participants, including 62 BD (36 children and 26 adults) and 119 healthy comparison (HC) subjects (57 children and 62 adults), engaged in constrained and unconstrained processing of emotional (angry, fearful, happy) and non-emotional (neutral) faces. During constrained processing, subjects answered questions focusing their attention on the face; this was processed either implicitly (nose width rating) or explicitly (hostility; subjective fear ratings). Unconstrained processing consisted of passive viewing.ResultsPediatric BD rated neutral faces as more hostile than did other groups. In BD patients, family-wise error (FWE)-corrected region of interest (ROI) analyses revealed dysfunction in the amygdala, inferior frontal gyrus (IFG), anterior cingulate cortex (ACC) and putamen. Patients with BD showed amygdala hyperactivation during explicit processing (hostility ratings) of fearful faces and passive viewing of angry and neutral faces but IFG hypoactivation during implicit processing of neutral and happy faces. In the ACC and striatum, the direction of dysfunction varied by task demand: BD demonstrated hyperactivation during unconstrained processing of angry or neutral faces but hypoactivation during constrained processing (implicit or explicit) of angry, neutral or happy faces.ConclusionsFindings suggest amygdala hyperactivation in BD while processing negatively valenced and neutral faces, regardless of attentional condition, and BD IFG hypoactivation during implicit processing. In the cognitive control circuit involving the ACC and putamen, BD neural dysfunction was sensitive to task demands.

A Framework to Identify Task-Phase and Attentional-Condition for Supporting Complicated Dual-Arm Operations

The state identification framework we propose supports complex construction machinery operations using a dual arm. Such support requires compatibility with different types of support and commonality among various operator skill levels. Our framework is organized into (i) real-time task phase identification defined using joint load applied based on environment constraints and (ii) time-series attentional condition identification defined as an internal work-state condition classified by the operational support necessity level and dependent on the vectorial or time-series data selected by the identified task phase. Experiments are conducted using the instrumented hydraulic dual arm system for transport and removal tasks, including complex dual-arm operations. Results show that the number of erroneous contacts, internal force applied, and mental workload decreased without any increase in time, confirming that operational support based on our framework greatly improves individual operator work performance.

Reaction Time as a Measure of the Effect of Selective Attention

In a dichotic-listening paradigm, reaction time was used to monitor the effect of selective attention for 8 Ss. Reaction times were longer for targets in the non-attended channel, but there was no difference between the performance in the attended channel and a divided attention condition which may be interpreted as evidence for attenuation of the unattended channel. For all conditions the reaction time for semantic stimuli is longer than that for tonal stimuli, and there is an interaction between stimulus type and attentional condition which may indicate a stimulus-processing component in selective attention.