Spatial contextual statistical learning throughout the ventral visual stream

Both spatial and temporal context play an important role in visual perception and behavior. Humans can extract statistical regularities from these contexts to help processing the present and to construct expectations about the future. Numerous studies have found reduced neural responses to expected stimuli compared to unexpected stimuli. However, most of these results concern expectations derived from temporal (sequential) regularities. Thus, little is known about the neural consequences of statistical learning of spatial regularities. In the current fMRI study, thirty-three human volunteers were exposed to object stimuli that could be expected or surprising in terms of their spatial and temporal context. We found a reliable modulation of neural responses by both, spatial and temporal context. Specifically, neural responses to stimuli in expected compared to unexpected contexts were suppressed throughout the ventral visual stream. Interestingly, the modulation by spatial context was stronger in magnitude and more reliable than modulations by temporal context. These results suggest that while both, spatial and temporal context priors modulate sensory processing in a similar fashion, predictions of spatial context may be a more powerful modulator in the visual system.