On the relation between mental ability and speed of information processing in the Hick task: An analysis of behavioral and electrophysiological speed measures

Inspired by Robert Stelmack's research on the electrophysiological foundation ofmental ability (MA), the present study investigated whether the well-established negative relation between reaction times (RTs) and MA in four conditions of the Hick task can be explained by faster stimulus classification and consolidation in workingmemory asmeasured by the P300 latency in the event-related potential. RTs of 113 female participants aged from 17 to 38 years increased with increasing number of response alternatives in the Hick task. Except for one condition, RTs were negatively and significantly related to MA but this relationship did not increase with task complexity. This pattern of results suggests that speed of response selection does not account for shorter RTs in individuals with higher than lower MA. Against our expectations, however, in none of the four conditions, P300 latency was related to MA. Thus, the negative association between RTs and MA cannot be explained in terms of faster stimulus evaluation and consolidation in working memory. As a tentative explanation of this lack of association, even themost complex condition was not demanding enough to require the inhibitory processes underlying the P300 component in a sufficient extent to reveal MA-related individual differences in P300 latency