Evolutionary psychologists believe that dreams serve some adaptive function for survival. Deirdre Barrett describes dreaming as simply "thinking in different biochemical state" and believes people continue to work on all the same problems—personal and objective—in that state. Her research finds that anything—math, musical composition, business dilemmas—may get solved during dreaming, but the two areas especially likely to help are 1) anything where vivid visualization contributes to the solution, whether in artistic design or invention of 3-D technological devices and 2) problem where the solution lies in "thinking outside the box"—i.e. the person is stuck because conventional wisdom on how to approach the problem is wrong. In a related theory, which Mark Blechner terms "Oneiric Darwinism," dreams are seen as creating new ideas through the generation of random thought mutations. Some of these may be rejected by the mind as useless, while others may be seen as valuable and retained. Finnish psychologist Antti Revonsuo posits that dreams have evolved for "threat simulation" exclusively.