Emotional Content Enhances Neural Tracking of Conversations

Engagement in interaction arises through the continuous monitoring of conversation content, allowing individuals to detect and act upon information that is personally relevant or socially significant. Emotional salience of speech content is a key factor in guiding this attentional engagement. By combining an audiovisual "Cocktail-party" paradigm with source-localized magnetoencephalography and encoding-decoding models, we examined whether emotionally salient content continuously enhances attentional tracking of conversations. Decoding analyses showed that emotional salience strengthened neural speech tracking across the conversational arc, but only when dialogue was attended to. The emotional enhancement was also sensitive to the dialogues semantic structure, peaking earlier in semantically coherent than incoherent conversations. Encoding analyses revealed latency-specific effects across temporal, parietal and frontal regions. Emotional salience and semantic structure co-modulated mid-latency sensory encoding, whereas later semantic integration was driven by emotionality alone. The observed results support the notion of adaptive tuning of auditory-language networks to socially and motivationally significant semantic cues. Rather than acting as a simple amplifier of semantic processing, emotional salience of dialogue topics shapes neural speech processing at multiple stages. The exact modulations depend on the semantic structure of the dialogue, balancing the needs between efficiency and adaptability that together support the ability to engage optimally in real-world interactions. Significance statementThe emotionality of a conversation is a key factor in how people allocate attention during interaction. Using a multi-speaker "cocktail-party" paradigm with magnetoencephalography, we show that emotionally salient content and semantic coherence influence the brains tracking of continuous dialogues in the presence of competing speech. Emotionally salient content enhances neural tracking only for attended speech, and this enhancement appears earlier when the conversation consists of semantically interrelated turns and is easier to follow. This is supported by modulations in neural activity at distinct processing stages across a distributed cortical network. These findings indicate that emotionality functions as a relevance signal, sustaining attentional engagement in conversation by affecting predictive processing and modulating activations in a large-scale cortical system linked to speech comprehension.