Cross-Modal Cloze Task: A New Task to Brain-to-Word Decoding

Shuxian Zou, Shaonan Wang, Jiajun Zhang, Chengqing Zong


Abstract
Decoding language from non-invasive brain activity has attracted increasing attention from both researchers in neuroscience and natural language processing. Due to the noisy nature of brain recordings, existing work has simplified brain-to-word decoding as a binary classification task which is to discriminate a brain signal between its corresponding word and a wrong one. This pairwise classification task, however, cannot promote the development of practical neural decoders for two reasons. First, it has to enumerate all pairwise combinations in the test set, so it is inefficient to predict a word in a large vocabulary. Second, a perfect pairwise decoder cannot guarantee the performance on direct classification. To overcome these and go a step further to a realistic neural decoder, we propose a novel Cross-Modal Cloze (CMC) task which is to predict the target word encoded in the neural image with a context as prompt. Furthermore, to address this task, we propose a general approach that leverages the pre-trained language model to predict the target word. To validate our method, we perform experiments on more than 20 participants from two brain imaging datasets. Our method achieves 28.91% top-1 accuracy and 54.19% top-5 accuracy on average across all participants, significantly outperforming several baselines. This result indicates that our model can serve as a state-of-the-art baseline for the CMC task. More importantly, it demonstrates that it is feasible to decode a certain word within a large vocabulary from its neural brain activity.
Anthology ID:
2022.findings-acl.54
Volume:
Findings of the Association for Computational Linguistics: ACL 2022
Month:
May
Year:
2022
Address:
Dublin, Ireland
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
648–657
Language:
URL:
https://aclanthology.org/2022.findings-acl.54
DOI:
10.18653/v1/2022.findings-acl.54
Bibkey:
Cite (ACL):
Shuxian Zou, Shaonan Wang, Jiajun Zhang, and Chengqing Zong. 2022. Cross-Modal Cloze Task: A New Task to Brain-to-Word Decoding. In Findings of the Association for Computational Linguistics: ACL 2022, pages 648–657, Dublin, Ireland. Association for Computational Linguistics.
Cite (Informal):
Cross-Modal Cloze Task: A New Task to Brain-to-Word Decoding (Zou et al., Findings 2022)
Copy Citation:
PDF:
https://aclanthology.org/2022.findings-acl.54.pdf
Code
 littletreezou/cross-modal-cloze-task