Automatic binding of basic sensory features requires consciousness
Zhili Han, Hao Zhu, Qian Chu, Yuchunzi Wu, Xu Chen, Yuanqing Wang, Sixian Li, Xiangbin Teng, Patrick C. M. Wong, Chen Yao, Xing Tian
bioRxiv Preprint Server December 10, 2025 preprint DOI: 10.64898/2025.12.10.693567 via bioRxiv
Summary
Conscious awareness is needed for integrating basic sensory features into coherent percepts. Using intracranial recordings in awake and anesthetized states, the study found that in the awake state, the brain automatically encodes individual auditory features (loudness and tone) and binds them together without attention, within a localized sensory cortical network. In the anesthetized state, encoding of single attributes is preserved, but binding is abolished, and anesthesia mainly affects later cortical processes after stimulus offset. These results suggest the functional boundary of consciousness lies between encoding and manipulation of basic sensory features at local cortical circuits, rather than global computations.
Study at a glance
| Characteristics | Experimental study with intracranial stereo-electroencephalography (sEEG) recordings in awake and anesthetized states |
|---|---|
| Key finding | In the awake state, auditory feature binding occurs automatically without attention in a localized sensory cortical network, while in the anesthetized state, binding is abolished despite preserved single-attribute encoding. |
Abstract
Conscious awareness requires establishing coherent percepts. Yet, whether consciousness is necessary for initiating the integration of basic sensory features remains unclear. Competing theories implicate distinct functional regimes of consciousness in the process of feature binding and creating conscious percepts. We used a novel multi-feature oddball paradigm with intracranial stereo-electroencephalography (sEEG) recordings in awake and anesthetized states to investigate the functional boundary of consciousness. In the awake state, the auditory attributes of loudness and tone, as well as the binding of the two features, were automatically encoded without attention to the stimuli in a functionally localized sensory cortical network. In the anesthetized state, the cortical registration of single attributes was preserved, whereas the binding was abolished. Moreover, anesthesia mostly influenced later cortical processes after stimuli offset. These results reveal the borderline of exertion of consciousness between the encoding and manipulation of basic sensory features in local cortical circuits – the functional boundary of consciousness constrains the feedforward binding and recurrent process directly at local rather than global level computations.