This study aims to investigate whether amusement and negativity counteract each other or are jointly intensified during the online processing of negative keywords in pun-humor sentences, and how mixed feelings blending these two emotional states are dynamically experienced over time. Participants read three types of sentences that included the same negative words as keywords: pun-humor (negative words can generate humorous effects by resonating with the context), non-humor (negative words seamlessly align with the context), and nonsensical (negative words cannot be integrated with the context) sentences. The behavioral ratings revealed that compared with non-humor and nonsensical sentences, pun-humor sentences evoked stronger amusement and intensified negative feelings, indicating that pun-humor sentences containing negative keywords can effectively elicit mixed feelings that encompass conflicting emotional states. The ERP results showed that the N400 (300-500 ms) elicited by negative words in pun-humor sentences was comparable to that in non-humor sentences, suggesting that negative words were connected contextually in both sentence types. Besides, negative words elicited greater LPC (600-800 ms) in pun-humor sentences than in non-humor and nonsensical sentences, suggesting that pun-humor sentences require additional semantic processing and more elaborate emotional processing. Moreover, the representational similarity analysis (RSA) results revealed that in pun-humor sentences, the representation of negativity persisted for a longer duration, and it occurred and peaked earlier than that of amusement. This implies that within the dynamic representation of mixed feelings, negativity was experienced first, whereas amusement was subsequently felt within a brief period, during which negativity was not offset but rather continued to be represented over a longer time span, resulting in the simultaneous presence of both amused and negative feelings. Taken together, these findings show that mixed feelings elicited during the online processing of negative keywords in pun-humor sentences can be dynamically experienced in a way that aligns with the highly simultaneous pattern and that negativity can be experienced before amusement during the dynamic representation of mixed feelings.
