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  <front>
    <journal-meta>
      <issn pub-type="ppub">1613-0073</issn>
    </journal-meta>
    <article-meta>
      <title-group>
        <article-title>Development of a Prototype AI System for Real-time Emotion Prediction and Mental State Adjustment</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Akihiro Sasaki</string-name>
          <email>xakh-sasaki@kddi.com</email>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Eriko Sugisaki</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Roberto Legaspi</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Yasushi Naruse</string-name>
          <xref ref-type="aff" rid="aff1">1</xref>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Nao Kobayashi</string-name>
          <email>no-kobayashi@kddi.com</email>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Japan</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
          <xref ref-type="aff" rid="aff3">3</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Workshop</string-name>
          <xref ref-type="aff" rid="aff2">2</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>AI Division, KDDI Research, Inc.</institution>
          ,
          <addr-line>Fujimino</addr-line>
          ,
          <country country="JP">Japan</country>
        </aff>
        <aff id="aff1">
          <label>1</label>
          <institution>Center for Information and Neural Networks, National Institute of Information and Communications Technology</institution>
          ,
          <addr-line>Kobe</addr-line>
        </aff>
        <aff id="aff2">
          <label>2</label>
          <institution>Conference on Persuasive Technology</institution>
        </aff>
        <aff id="aff3">
          <label>3</label>
          <institution>Healthcare Medical Group, Life Science Laboratories</institution>
        </aff>
      </contrib-group>
      <abstract>
        <p>Our emotional state influences our daily performance. Recent reports have highlighted a hormetic relationship between stress and cognitive performance [1, 2], suggesting that understanding the optimal balance of emotional states, rather than adopting a simple negativepositive emotion perspective, could potentially enhance the optimization of behavioral performance. Our ultimate goal is to construct a system that discerns individual emotional states from physiological information, and generates music, visuals, or conversations as means to facilitate the individual's transition toward their desired emotional state. To achieve this, it is essential to evaluate complex emotional states on different emotional axes and assess possibly continuously fluctuating emotional states in real-time as possible.</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
    </sec>
    <sec id="sec-2">
      <title>3. Emotion Estimation System During Music Listening</title>
      <p>
        Here, we present an emotion estimation system that provides predicted emotional values on six
emotional axes, similar to Ishikawa et al. [
        <xref ref-type="bibr" rid="ref6">6</xref>
        ]. In our system, notably, we have incorporated the
real-time prediction capability, allowing us to update the predicted values every 0.5 seconds.
Model construction: We trained our model on 2,322 instances from 54 participants, each giving
physiological (EEG and ECG) and emotional rating data. Participants listened to music for a
minute while recording EEG and ECG, then rated their emotion on a 15-point scale for six
emotional axes. Explanatory variables were taken from the 10 seconds of EEG and ECG data
immediately preceding the emotion rating, and the emotion ratings served as the objective
variables. The model was trained using XGboost due to its computational efficiency, smaller
resource requirement, and faster training speed, enabling real-time estimation.
Implementation of emotion estimation: Users wear EEG and ECG devices and transmit the
measured data to a computer via a smartphone using Bluetooth. Once the computer accumulates
10 seconds of data, it begins estimating the emotional state. The emotional state estimate is then
      </p>
      <p>2024 Copyright for this paper by its authors.
CEUR</p>
      <p>ceur-ws.org
updated every 0.5 seconds based on the preceding 10 seconds of data. This system, as shown in
Figure 1, enables the real-time estimation of emotional state transitions during music or visual
content consumption.</p>
    </sec>
    <sec id="sec-3">
      <title>4. Prospects and potential applications</title>
      <p>In the future, we plan a comprehensive evaluation of our models' accuracy using metrics, such as
MAPE and other relevant measures, aiming for less than 20% error in both training and
realworld application. Future developments will merge AI to generate music or visuals, guiding users
to their desired emotional states, potentially enhancing presentations, work efficiency, and
mental health.</p>
    </sec>
    <sec id="sec-4">
      <title>Acknowledgements References</title>
      <p>This work was partially supported by Innovative Science and Technology Initiative for Security
(JPJ004596), Acquisition, Technology, and Logistics Agency, Japan.</p>
    </sec>
  </body>
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