Automatic subject-specific spatiotemporal feature selection for subject-independent affective BCI

PLoS One. 2021 Aug 26;16(8):e0253383. doi: 10.1371/journal.pone.0253383. eCollection 2021.

Abstract

The dimensionality of the spatially distributed channels and the temporal resolution of electroencephalogram (EEG) based brain-computer interfaces (BCI) undermine emotion recognition models. Thus, prior to modeling such data, as the final stage of the learning pipeline, adequate preprocessing, transforming, and extracting temporal (i.e., time-series signals) and spatial (i.e., electrode channels) features are essential phases to recognize underlying human emotions. Conventionally, inter-subject variations are dealt with by avoiding the sources of variation (e.g., outliers) or turning the problem into a subject-deponent. We address this issue by preserving and learning from individual particularities in response to affective stimuli. This paper investigates and proposes a subject-independent emotion recognition framework that mitigates the subject-to-subject variability in such systems. Using an unsupervised feature selection algorithm, we reduce the feature space that is extracted from time-series signals. For the spatial features, we propose a subject-specific unsupervised learning algorithm that learns from inter-channel co-activation online. We tested this framework on real EEG benchmarks, namely DEAP, MAHNOB-HCI, and DREAMER. We train and test the selection outcomes using nested cross-validation and a support vector machine (SVM). We compared our results with the state-of-the-art subject-independent algorithms. Our results show an enhanced performance by accurately classifying human affection (i.e., based on valence and arousal) by 16%-27% compared to other studies. This work not only outperforms other subject-independent studies reported in the literature but also proposes an online analysis solution to affection recognition.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Algorithms
  • Brain-Computer Interfaces*
  • Electrodes
  • Electroencephalography / methods*
  • Emotions*
  • Humans
  • Support Vector Machine

Grants and funding

B.A. acknowledges the financial support of the Deanship of Scientific Research at King Faisal University under the Nasher Track No. 206136. This work has been supported in part by the NSF Grants 1743418 and 1843025 to S.R. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.