Limited Impact of Object Attributes on Event-related Potentials During an Implicit Word Reading Task.

Background: Previous research in cognitive science has focused on the encoding and activation of sensory-based object knowledge in the brain during language comprehension, including aspects such as appearance, movement, and taste.

Objective: To investigate how different object-related attributes affect event-related potentials (ERPs), specifically the N400 component, during word processing in an implicit task setting.

Method: We embedded a set of 420 critical nouns within a list of 2,745 total words and asked 240 participants to read each one, but to respond only to words denoting colors. We categorized each noun by attributes such as familiarity, smell, pain, taste, sound, graspability, and motion. We focused primarily on changes in the N400 component, indicative of semantic processing, across nouns with different attributes.

Results: The least familiar stimuli elicited the strongest N400 response, indicating significant ERP variability across familiarity levels with more positive amplitudes for highly familiar stimuli. Among the attributes examined, only the attribute of smell demonstrated a notable, though isolated, increase in N400 amplitude. Other attributes, including pain, taste, sound, graspability, and visual motion showed no significant differences in N400 responses, suggesting a minimal influence on semantic processing in this context.

Conclusion: These results suggest that the specific sensory attributes of objects have limited influence on the N400 component of ERPs in implicit reading tasks, highlighting the complexity of semantic networks in cognitive processing. The subtlety of ERP modulations driven by object-related attributes points to the need for further exploration into how these attributes interact within semantic networks during cognitive tasks.