  Electroencephalography (EEG) is a popular and effective tool for emotion
recognition. However, the propagation mechanisms of EEG in the human brain and
its intrinsic correlation with emotions are still obscure to researchers. This
work proposes four variant transformer frameworks~(spatial attention, temporal
attention, sequential spatial-temporal attention and simultaneous
spatial-temporal attention) for EEG emotion recognition to explore the
relationship between emotion and spatial-temporal EEG features. Specifically,
spatial attention and temporal attention are to learn the topological structure
information and time-varying EEG characteristics for emotion recognition
respectively. Sequential spatial-temporal attention does the spatial attention
within a one-second segment and temporal attention within one sample
sequentially to explore the influence degree of emotional stimulation on EEG
signals of diverse EEG electrodes in the same temporal segment. The
simultaneous spatial-temporal attention, whose spatial and temporal attention
are performed simultaneously, is used to model the relationship between
different spatial features in different time segments. The experimental results
demonstrate that simultaneous spatial-temporal attention leads to the best
emotion recognition accuracy among the design choices, indicating modeling the
correlation of spatial and temporal features of EEG signals is significant to
emotion recognition.
