Fixation-related Brain Potentials during Semantic Integration of Object-Scene Information

Area of Science:

• Vision science
• Cognitive neuroscience
• Perceptual psychology

Background:

• The availability of semantic information from objects in peripheral vision is a debated topic in vision science.
• Understanding how the brain integrates object and scene information during natural viewing is crucial.

Purpose of the Study:

• To investigate the speed and mechanisms of semantic information access in extrafoveal vision.
• To examine how object-scene consistency influences visual attention and processing during natural scene viewing.
• To explore the neural correlates of semantic processing using electroencephalography (EEG) and eye-tracking.

Main Methods:

• Coregistration of eye movements and EEG during the viewing of indoor scenes with consistent or inconsistent target objects.
• Analysis of event-related potentials (ERPs) to scene onset and fixation-related potentials (FRPs) using linear deconvolution modeling.
• Behavioral analysis of fixation patterns and ERP/FRP modulations based on object-scene consistency.

Main Results:

• Object-scene consistency did not affect initial scene processing (ERPs to scene onset).
• Inconsistent objects were prioritized in extrafoveal vision (attended earlier) and required more processing in foveal vision (attended longer).
• A fixation-related N300/N400 effect showed greater negativity for inconsistent objects, evident even before foveal fixation, indicating early semantic processing.

Conclusions:

• Semantic extraction of object information can begin in extrafoveal vision, challenging previous assumptions about immediate semantic access.
• Combined EEG and eye-tracking are valuable tools for elucidating the mechanisms of object-scene integration during natural viewing.
• The findings highlight the dynamic interplay between attention, semantics, and visual processing during scene exploration.