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Developing an EEG-based on-line closed-loop lapse detection and mitigation system.

Wang YT, Huang KC, Wei CS, Huang TY, Ko LW, Lin CT, Cheng CK, Jung TP - Front Neurosci (2014)

Bottom Line: However, the arousing auditory signals were not always effective.The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals.The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer Science and Engineering, Jacobs School of Engineering, University of California San Diego La Jolla, CA, USA ; Swartz Center for Computational Neuroscience, Institute for Neural Computation, University of California San Diego La Jolla, CA, USA.

ABSTRACT
In America, 60% of adults reported that they have driven a motor vehicle while feeling drowsy, and at least 15-20% of fatal car accidents are fatigue-related. This study translates previous laboratory-oriented neurophysiological research to design, develop, and test an On-line Closed-loop Lapse Detection and Mitigation (OCLDM) System featuring a mobile wireless dry-sensor EEG headgear and a cell-phone based real-time EEG processing platform. Eleven subjects participated in an event-related lane-keeping task, in which they were instructed to manipulate a randomly deviated, fixed-speed cruising car on a 4-lane highway. This was simulated in a 1st person view with an 8-screen and 8-projector immersive virtual-reality environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory warning was delivered to rectify the performance decrements. However, the arousing auditory signals were not always effective. The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals. In this on-line pilot study, the proposed OCLDM System was able to continuously detect EEG signatures of fatigue, deliver arousing warning to subjects suffering momentary cognitive lapses, and assess the efficacy of the warning in near real-time to rectify cognitive lapses. The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events. This study may lead to a practical on-line lapse detection and mitigation system in real-world environments.

No MeSH data available.


Related in: MedlinePlus

Experiment results. (A) The boxplot for the RT distribution of trials with effective warning, ineffective warning, and without warning among CTs and CTs + 1. Note that middle horizontal line is the median of the distribution, and the top and bottom of the rectangle are the third and first quartile, and the dash line ends are the maximum and minimum after outlier removal. (B) The component spectra of the alert CTs (black curve), with an effective warning (red curve), with an ineffective warning (light blue curve) and without warning (dark blue curve). The red, light blue and blue horizontal lines mark the spectral differences between the alert trials and trials with an effective warning, with an ineffective warning, and without warning, respectively. All the spectral plots were calculated from the activity of the bilateral occipital components separated by ICA.
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Figure 2: Experiment results. (A) The boxplot for the RT distribution of trials with effective warning, ineffective warning, and without warning among CTs and CTs + 1. Note that middle horizontal line is the median of the distribution, and the top and bottom of the rectangle are the third and first quartile, and the dash line ends are the maximum and minimum after outlier removal. (B) The component spectra of the alert CTs (black curve), with an effective warning (red curve), with an ineffective warning (light blue curve) and without warning (dark blue curve). The red, light blue and blue horizontal lines mark the spectral differences between the alert trials and trials with an effective warning, with an ineffective warning, and without warning, respectively. All the spectral plots were calculated from the activity of the bilateral occipital components separated by ICA.

Mentions: This study first explored the efficacy of the delivery of arousing auditory signals by measuring the change in subjects' reaction time. Figure 2A shows the boxplots of RTs of three trial groups: Alertness, CT, and CT + 1 (left to right). The averaged aRT of trials within the Alertness group across 11 subjects was ~676 ms. The RTs of the CT group with arousing warning (red and light blue) were statistically significantly shorter than those of trials without receiving arousing warning (dark blue). The RTs of the CT + 1 group with effective vs. ineffective warning differed while the RTs of the preceding group (CT) were comparable. Even though the subjects responded to the arousing warning by immediately steering the simulated car back to the cruising position, they could well be totally non-responsive to the very next lane-departure event (~10 s later). In other words, the arousing signals reliably rectified human behavioral lapses, but did not guarantee that subjects were fully awake, alert, or attentive. This suggests an analogous regime of snooze after an alarm is turned off.


Developing an EEG-based on-line closed-loop lapse detection and mitigation system.

Wang YT, Huang KC, Wei CS, Huang TY, Ko LW, Lin CT, Cheng CK, Jung TP - Front Neurosci (2014)

Experiment results. (A) The boxplot for the RT distribution of trials with effective warning, ineffective warning, and without warning among CTs and CTs + 1. Note that middle horizontal line is the median of the distribution, and the top and bottom of the rectangle are the third and first quartile, and the dash line ends are the maximum and minimum after outlier removal. (B) The component spectra of the alert CTs (black curve), with an effective warning (red curve), with an ineffective warning (light blue curve) and without warning (dark blue curve). The red, light blue and blue horizontal lines mark the spectral differences between the alert trials and trials with an effective warning, with an ineffective warning, and without warning, respectively. All the spectral plots were calculated from the activity of the bilateral occipital components separated by ICA.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4195274&req=5

Figure 2: Experiment results. (A) The boxplot for the RT distribution of trials with effective warning, ineffective warning, and without warning among CTs and CTs + 1. Note that middle horizontal line is the median of the distribution, and the top and bottom of the rectangle are the third and first quartile, and the dash line ends are the maximum and minimum after outlier removal. (B) The component spectra of the alert CTs (black curve), with an effective warning (red curve), with an ineffective warning (light blue curve) and without warning (dark blue curve). The red, light blue and blue horizontal lines mark the spectral differences between the alert trials and trials with an effective warning, with an ineffective warning, and without warning, respectively. All the spectral plots were calculated from the activity of the bilateral occipital components separated by ICA.
Mentions: This study first explored the efficacy of the delivery of arousing auditory signals by measuring the change in subjects' reaction time. Figure 2A shows the boxplots of RTs of three trial groups: Alertness, CT, and CT + 1 (left to right). The averaged aRT of trials within the Alertness group across 11 subjects was ~676 ms. The RTs of the CT group with arousing warning (red and light blue) were statistically significantly shorter than those of trials without receiving arousing warning (dark blue). The RTs of the CT + 1 group with effective vs. ineffective warning differed while the RTs of the preceding group (CT) were comparable. Even though the subjects responded to the arousing warning by immediately steering the simulated car back to the cruising position, they could well be totally non-responsive to the very next lane-departure event (~10 s later). In other words, the arousing signals reliably rectified human behavioral lapses, but did not guarantee that subjects were fully awake, alert, or attentive. This suggests an analogous regime of snooze after an alarm is turned off.

Bottom Line: However, the arousing auditory signals were not always effective.The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals.The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events.

View Article: PubMed Central - PubMed

Affiliation: Department of Computer Science and Engineering, Jacobs School of Engineering, University of California San Diego La Jolla, CA, USA ; Swartz Center for Computational Neuroscience, Institute for Neural Computation, University of California San Diego La Jolla, CA, USA.

ABSTRACT
In America, 60% of adults reported that they have driven a motor vehicle while feeling drowsy, and at least 15-20% of fatal car accidents are fatigue-related. This study translates previous laboratory-oriented neurophysiological research to design, develop, and test an On-line Closed-loop Lapse Detection and Mitigation (OCLDM) System featuring a mobile wireless dry-sensor EEG headgear and a cell-phone based real-time EEG processing platform. Eleven subjects participated in an event-related lane-keeping task, in which they were instructed to manipulate a randomly deviated, fixed-speed cruising car on a 4-lane highway. This was simulated in a 1st person view with an 8-screen and 8-projector immersive virtual-reality environment. When the subjects experienced lapses or failed to respond to events during the experiment, auditory warning was delivered to rectify the performance decrements. However, the arousing auditory signals were not always effective. The EEG spectra exhibited statistically significant differences between effective and ineffective arousing signals, suggesting that EEG spectra could be used as a countermeasure of the efficacy of arousing signals. In this on-line pilot study, the proposed OCLDM System was able to continuously detect EEG signatures of fatigue, deliver arousing warning to subjects suffering momentary cognitive lapses, and assess the efficacy of the warning in near real-time to rectify cognitive lapses. The on-line testing results of the OCLDM System validated the efficacy of the arousing signals in improving subjects' response times to the subsequent lane-departure events. This study may lead to a practical on-line lapse detection and mitigation system in real-world environments.

No MeSH data available.


Related in: MedlinePlus