Which ERP components are involved in naïve-scientific concept tasks? Evidence for N400 effects and a reconsideration...

Previous event-related potential (ERP) studies investigating the neural processing of scientific and naïve concepts have suggested that the conflict between these two types of concepts is reflected in a negative-going N2 component. However, the evidence from those studies remains inconclusive. The present study examined which ERP components reflect concept-based processing.

We used word stimuli in a living-nonliving categorization task, a representative task involving conflict between naïve and scientific concepts. ERPs were recorded from undergraduate and graduate students (n = 22) while they performed the task.

Differences in ERP waveforms between conditions emerged in the N400 component approximately 250-420 ms after stimulus onset. In the 250-350 ms latency window (early N400), non-moving objects elicited significantly greater negativity than animals, plants, and moving objects. In the 350-420 ms latency window (late N400), both non-moving and moving objects elicited significantly greater negativity than animals and plants.

The difference in N400 latency patterns between moving and non-moving objects suggests that judgments in the earlier time window may have been guided primarily by a naïve mobility-based heuristic. Unexpectedly, no enhanced negative component was observed for plants, for which conflict between naïve and scientific concepts would typically be expected. These findings suggest that participants' level of expertise and task difficulty may modulate the time window during which naïve and scientific concepts are processed. Overall, the present findings indicate that the ERP component reported in previous studies is not the only critical component involved in naïve-versus-scientific concept conflict tasks.