Two accounts of insight problem solving dominate the current literature: the special-process theory (e.g., Bowden, Jung-Beeman, Fleck, & Kounios, 2005) which attributes insight to implicit processes of spreading activation that are localised in the right hemisphere, and the business-as-usual theory (e.g., MacGregor, Ormerod, & Chronicle, 2001), which proposes that both insight and non-insight problems draw on the same analytic mechanisms, which are verbally-based and left-hemisphere localised. We report an experiment in which participants tackled complex and simple insight tasks (Compound Remote Associates) whilst engaging in articulatory suppression (AS) or whilst thinking aloud (TA). Accuracy and latency data indicate that insight problem solving is hindered under AS requirements. Since AS should not affect implicit spreading activation this finding is difficult to reconcile with the special-process theory, although it would be predicted by the business-as-usual theory since AS would damage verbally-based problem analysis. The data also indicate that TA has a facilitatory effect on solving complex problems. Again, this seems explicable from the business-as-usual perspective since TA can enhance analytic processing, but is less easily accommodated by the special-process theory, which claims that verbalisation should overshadow insight.