Abstract
Our every-day world is not random, but governed by rules regarding which objects can be found where. Imagine finding a bottle of milk in your bathroom. This would be quite surprising to us. But when during development are the semantic predictions implemented that would yield such a 'surprise effect'? Tracking kids' eye movements in a previous study (VSS 2016), we observed their gaze to be stuck on semantically inconsistent objects in scene photographs by the age of three, which we interpret as indication of their developed semantic expectations regarding object-scene relations. But besides behavioral evidence, semantic violations in scenes can also be tracked at the neural level as expressed by an N400 effect in adults. In an EEG-experiment with gaze-contingent scene presentation we tested seven 2-year olds and eleven adults. First, a scene preview was presented, without the critical object. Then, the children's gaze was attracted by an animated cue to the scene position where the critical object would occur. Upon cue fixation, the object, which could either be consistent or inconsistent with the scene context, would appear at the corresponding location. Using this paradigm, adults showed a reliable negativity to semantic violations with a central topography in the time range 300-500 ms. For the 2-year olds, we observed a trend for such an N400 effect (p = .07) indicating that semantic expectations in visual scenes might already be implemented earlier than by the age of three. First revealed in language development, future research could profit from directly comparing the developmental trajectories of this semantic processing between both, the scene and language domain to understand shared and distinct underlying mechanisms and their links to inter-individual differences in linguistic and cognitive abilities. This knowledge could eventually feed into earlier diagnosis and therapy of language disorders even at a preverbal stage.
Meeting abstract presented at VSS 2017