The right hemisphere maintains solution-related activation for yet-to-be-solved problems

In five experiments, we examined the time course of hemispheric differences in solution activation for insight-like problems. We propose that solving insight problems requires retrieval of unusual interpretations of problem e lements, and that right-hemisphere (RH) coarse semantic coding is more like ly than left-hemisphere (LH) fine semantic coding to maintain semantic acti vation of such interpretations. In four experiments, participants attempted word problems for 7 sec (Experiments 1A and 1B) or 2 sec (Experiments 2A a nd 2B), and 750 msec later responded to lateralized target words. After 7 s ec of solving effort, Experiment 1A participants showed greater solution-re lated priming (i.e., they named solutions faster than unrelated words) for left visual field-RH (lvf-RH) targets than for right visual field-LH (rvf-L H) targets, and Experiment 1B participants made faster solution decisions o n target words presented to the RH, as previously demonstrated following 15 sec of effort. After 2 sec of solving effort in Experiment 2A, women showe d symmetric solution-related priming, although men showed a slight Ivf-RH a dvantage in priming; and in Experiment 2B participants made equally quick s olution decisions for targets presented to the LH and to the RH. In Experim ent 3, participants viewed the problems for 1,250 msec then named lateraliz ed target words; they showed symmetric solution-related priming. These expe riments demonstrate solution activation initially in both hemispheres, but maintained solution activation only in the RH.