Modern NLP workflows (e.g., RAG systems) require different models for generation and embedding tasks, where bidirectional pre-trained encoders and decoder-only Large Language Models (LLMs) dominate respective tasks. Structural differences between models result in extra development costs and limit knowledge sharing between tasks. In this work, we present UniMAE, a novel unsupervised training method that transforms an Decoder-Only LLM into a Uni-Directional Masked Auto-Encoder. UniMAE compresses high-quality semantic information into the [EOS] embedding while preserving the generation capabilities of LLMs. Comprehensive evaluations across 56 MTEB datasets demonstrate that UniMAE can achieve state-of-the-art results under unsupervised settings with merely 100 training steps, establishing the first effective approach to unifying generation and representation learning in decoder-only architectures.

Using large language models (LLMs) to assist psychological counseling is a significant but challenging task at present. Attempts have been made on improving empathetic conversations or acting as effective assistants in the treatment with LLMs. However, the existing datasets lack consulting knowledge, resulting in LLMs lacking professional consulting competence. Moreover, how to automatically evaluate multi-turn dialogues within the counseling process remains an understudied area. To bridge the gap, we propose CPsyCoun, a report-based multi-turn dialogue reconstruction and evaluation framework for Chinese psychological counseling. To fully exploit psychological counseling reports, a two-phase approach is devised to construct high-quality dialogues while a comprehensive evaluation benchmark is developed for the effective automatic evaluation of multi-turn psychological consultations. Competitive experimental results demonstrate the effectiveness of our proposed framework in psychological counseling. We open-source the datasets and model for future research.