Neuro-cortical signatures of attention in uni- and multi-sensory audio-visual processing in children.

The ability of the brain to integrate information from multiple sensory modalities is essential for forming coherent perceptions of the environment. Attention plays a critical role in binding or segregating neural activity to generate unified perceptual experiences. However, the mechanisms by which attention modulates sensory responses remain unclear. We hypothesized that children with low attention would exhibit reduced amplitude and delayed latency in sensory processing regions across modalities. Data were analyzed from 72 typically developing children (ages 9-14), grouped into high-attention (N = 33) and low-attention (N = 39) groups using Conners 3-P inattention scores. Participants performed an audio-visual multisensory task while MEG data were recorded using a 306-channel MEGIN Neuromag system. Preprocessing and source analysis were conducted in Brainstorm. Task-evoked source activity was quantified by analyzing amplitude and latency in predefined cortical regions and time windows (P1: 100-240 ms; P2: 240-400 ms) using multivariate analysis. High-attention participants showed significantly (p < 0.05) greater amplitude in visual cortex across P1 and P2 time windows. The low-attention group showed delayed latency in visual cortex (P2) and auditory cortex (P1). Significant three-way interactions (attention, hemisphere, sensory condition) were found in visual-cortex amplitude and auditory-cortex latency at P1, where low-attention group showed reduced amplitude and delayed latency, respectively. Inferior parietal cortex showed a significant two-way interaction (attention, condition) in response latency at P2, with post hoc tests confirming low-attention group showed delayed latency during multisensory responses. Attention significantly influences sensory processing, affecting both response strength and timing, with implications for interventions targeting attention-related sensory difficulties.