Facial Expression–Based Evaluation of the Emotion Estimation Software Kokoro Sensor in Healthy Individuals: Validation and Reliability Pilot Study

Our findings suggest that the Kokoro Sensor may be useful for identifying positive affect, given its acceptable concurrent validity for overall valence estimation and its high agreement for distinguishing positive from neutral expressions. However, concurrent validity for negative expressions did not meet the prespecified benchmark based on the researcher's ratings, and agreement for distinguishing negative from neutral expressions was limited, which may constrain clinical utility for detecting negative affect. Therefore, in clinical settings, the Kokoro Sensor should be used as an assistive tool rather than a stand-alone method.