Equation 3 should be: $$\begin{eqnarray} s^a & = & softmax \left( (x^aW^Q)(x^aW^K)^T / \sqrt(d_k) \right)(x^aW^V) \\ s^l & = & softmax \left( (x^lW^Q)(x^lW^K)^T / \sqrt(d_k) \right)(x^lW^V) \end{eqnarray}$$
Text after Equation 4 should be: \(c^a \in R^{(t × d)}\) integrates emotional information from \(s^a\) to \(s^l\), and \(c^l \in R^{(t × d)}\) integrates emotional information from \(s^l\) to \(s^a\).