S^2M-Former: Spiking Symmetric Mixing Branchformer for Brain Auditory Attention Detection - Wang, Jiaqi; Ma, Zhengyu; Shen, Xiongri; Zhou, Chenlin; Zhao, Leilei; Zhang, Han; Zhong, Yi; Cai, Siqi; Song, Zhenxi; Zhang, Zhiguo (Advances in Neural Information Processing Systems, 2025)