A multi-stage framework for emotionally intelligent dialogue systems using topological sentiment encoding and causal policy optimization

Emotionally intelligent dialogue systems should not only express sentence-level sentiment but also sense shifts in emotion from sentence to sentence, from speaker to speaker, and over time, and be interpretable down to the decision level. Existing approaches consider only sentiment as a single and static feature, and they either do not consider multi-turn context, temporal variation, speaker-specific trends, or the correlations between emotion and action. To fill these gaps, we introduce a unified 5-stage framework for systematically encoding, transforming, and operationalising emotion in multi-turn conversations. First, Context-Aware Multi-Level Sentiment Encoding (CMLSE) uses RoBERTa embeddings, self-attention, and Dynamic Time Warping (DTW), while preserving the speaker identity, turn order and sentiment continuity. Second, Emotion Clustering Topological Signal Mapping (ECTSM) uses an emotion vector sentiment and persistent homology to obtain robust emotion clusters based on topology and shape. Third, Emotion-Memory Reinforced Graph Aggregation Network (EMR-GAN) constructs a dynamic emotion graph and a long-term memory network, learning the best manner for optimizing emotional coherence through Reinforcement Learning (RL). The Adaptive Causal Decision-Graph Transformer (ACDGT) incorporates causal inference into graph attention to discover hidden emotion–behaviour causality and imitate counterfactual decisions. Finally, the Emotion-Driven Reinforcement Policy Synthesizer (EDRPS) combines emotional memory and causal representations with dual-reward Proximal Policy Optimization (PPO) to generate policies in real-time, emotion-aware mode. Our model shows an average accuracy of 78.8% (+6.4% above the best baseline) on MELD, 0.61 Adjusted Rand Index (ARI) for emotion clustering, and 92.5% accuracy in aligning the policy on DailyDialog. These assessments show scores of empathy, relevance, and naturalness to be higher, marking a new state-of-the-art for affective dialogue systems.