Multimodal general expectancy effects elicited without influencing sensory representations

Predictive coding theories posit a reduction in error-signalling neural activity when incoming sensory input matches existing expectations – a phenomenon termedexpectation suppression. While human neuroimaging studies have consistently reported reduced neural activity for expected events, it is uncertain whether this reduction arises from thesharpeningordampeningof neurons selective for expected features. A further aspect of predictive coding that remains untested is how predictions are integrated across sensorimotor domains. To investigate these two questions, we employed a novel cross-domain probabilistic cueing paradigm, where participants were presented with both visual and motor cues within a single trial. These cues manipulated the orientation and temporal expectancy of target stimuli with 75% validity. Participants completed a reproduction task where they rotated a bar to match the orientation of the target stimulus while their neural and pupil responses were respectively measured via electroencephalography and eye tracking. Our results showed an effect of expectancy in the motor condition across multiple measures, while evidence in the visual condition was inconsistent. However, no differences in orientation fidelity were found in sensory representations between expected and violation trials for either domain. These findings show that violations of temporal expectancy produce prediction error signals that do not influence sensory representations. Further, the findings add to a growing body of work casting doubt on the effectiveness of probabilistic cueing paradigms for eliciting prediction errors. Due to null findings in the visual and representational analyses, we did not further investigate cross-domain prediction integration.