Neurophysiological foundations of loss and failure sadness differently modulate emotional conceptual processing.

Sadness is divided into two subtypes, namely loss and failure sadness, which are encoded by different concepts of one's mind. However, it is unclear how such a conceptual difference is supported by neurophysiological foundations. In the present study, we conducted an electroencephalogram experiment for processing congruency between loss- and failure-sadness contexts and emotional words. Electroencephalogram recordings were performed for 23 participants, using a picture-word priming paradigm without explicit congruency judgment. One of the three types of emotional pictures (loss, failure, or neutral picture as the baseline) preceded emotional target words with high, middle, or low fitting properties for sadness contexts in each trial. No significant word-onset event-related potential effects were observed. Upon word-offset event-related potential effects, middle-phase negative potentials around 400 ms for high-fitting words, increased in the failure prime-target context but not in the loss context, compared to the neutral context. Additionally, the negative potentials increased as the failure-sadness intensity decreased, which indicated contextual conflict between prime pictures and target words. In contrast, the corresponding negative potentials for the loss context increased as the loss-sadness intensity increased, which indicated congruency effects under sadness bias. In later latency, after around 400 ms, the slow negative event-related potential effects appeared similar for both the loss and failure contexts. These results suggest that loss and failure sadness are differently represented in the mind, and are founded on the middle-phase neurophysiological processing.