Behavioural and neuronal insights into multisensory combination of unpracticed cues.

Effective decision-making requires integrating multiple information sources, weighted by their reliability and context. While classic studies show near-optimal cue combination in extensively controlled laboratory settings and lengthy inperson experiments, everyday choices often occur in less controlled environments. We examined cue combination under these conditions using an online perceptual estimation task in large and diverse participant cohorts. Participants combined cues, including visual motion direction, spatial visual information, and sound. We investigated cue combination with and without cue conflict. Performance varied with age and self-reported ADHD or Autism. Visual cues were combined more optimally than audio-visual combinations. We observed qualitative similarities in an analagous task with non-human primates. We used electrical microstimulation in non-human primates, targeting unimodal or cross-modal association areas. Stimulation of visual cortex was integrated with sensory motion cues, while stimulation of prefrontal cortex promoted winner-take-all choices. These findings suggest distinctions between within- and across-modality integration, with deviations potentially informative of age or neurodiversity.