Cross-modal cueing effects of visuospatial attention on conscious somatosensory perception

A Trained Humanoid Robot can Perform Human-Like Crossmodal Social Attention and Conflict Resolution

To enhance human-robot social interaction, it is essential for robots to process multiple social cues in a complex real-world environment. However, incongruency of input information across modalities is inevitable and could be challenging for robots to process. To tackle this challenge, our study adopted the neurorobotic paradigm of crossmodal conflict resolution to make a robot express human-like social attention. A behavioural experiment was conducted on 37 participants for the human study. We designed a round-table meeting scenario with three animated avatars to improve ecological validity. Each avatar wore a medical mask to obscure the facial cues of the nose, mouth, and jaw. The central avatar shifted its eye gaze while the peripheral avatars generated sound. Gaze direction and sound locations were either spatially congruent or incongruent. We observed that the central avatar's dynamic gaze could trigger crossmodal social attention responses. In particular, human performance was better under the congruent audio-visual condition than the incongruent condition. Our saliency prediction model was trained to detect social cues, predict audio-visual saliency, and attend selectively for the robot study. After mounting the trained model on the iCub, the robot was exposed to laboratory conditions similar to the human experiment. While the human performance was overall superior, our trained model demonstrated that it could replicate attention responses similar to humans.

Cross-modal social attention triggered by biological motion cues

Previous research has demonstrated that biological motion (BM) cues can induce reflexive attentional orienting. This BM-triggered social attention has hitherto only been investigated within visual modality. It remains unknown whether and to what extent social attention induced by BM cues can occur across different sensory modalities. By introducing auditory stimuli to a modified central cueing paradigm, we showed that observers responded significantly faster to auditory targets presented in the walking direction of BM than in the opposite direction, reflecting the notion that BM cues can trigger cross-modal social attention. This effect was not due to the viewpoint effect of the global configuration and could be extended to local BM cues without any global configuration. Critically, such cross-modal social attention was sensitive to the orientation of BM cues and completely disappeared when critical biological characteristics were removed. Our findings, taken together, support the existence of a special multimodal attention mechanism tuned to life motion signals and shed new light on the unique and cross-modal nature of social attention.