There is a body of research reporting an increase in N400 amplitude while processing semantically incongruent verbal stimuli.
However, there is no evidence to suggest that ERPs during semantic incongruence might be associated with certain psychological
parameters, such as IQ. We tested whether ERPs during responses to perceptions of verbal antilogies differed in participants with
various IQ levels. We expected to find differences in the N400 and P600 components.
Method
We assessed the participants’ (N=155) IQ with Raven’s "Standard Progressive Matrices" and ranked them according to the scores they
achieved. Out of the initial pool of participants, we composed 3 groups (N=15 each): HighIQ (120–130 scores), ModerateIQ (102–116
scores), LowIQ (83–100 scores). The groups were presented with 3 types of visual stimuli: verbal antilogies (to bereave generously),
normal (to gift generously) and meaningless (to sink generously) phrases while ERPs were recorded.
Results
Differences in ERPs during responses for the 3 types of stimuli were found between the groups. HighIQ: N400 was more pronounced
in response to antilogies and meaningless phrases vs. normal phrases; P600 was more pronounced in response to antilogies and
normal phrases vs. meaningless phrases. ModerateIQ: N400 was more pronounced in response to normal phrases vs. antilogies and
meaningless phrases; differences in P600 were the same as HighIQ. LowIQ: N400 was more pronounced in response to meaningless
phrases vs. antilogies and normal phrases; no differences in P600 were found between the 3 types of stimuli.
Conclusions
We interpret these findings as support for the idea that participants with higher IQ (unlike those with low or moderate IQ) use more
sufficient cognitive schemes for processing semantic incongruence, which allow them to take antilogies as similar to normal phrases
and opposite to meaningless ones.
Supported by the President of the Russian Federation grant № МК-7507.2016.6.