A new app in Apple’s iTunes App Store could help users determine what they want to dream and when.

The app, called Sigmund, contains lists of words that users pick before going to sleep, which the app then plays at key moments during the user’s sleep cycle in an attempt to influence what they dream about. As CNN reports, the sleep study that led to the creation of the app found success in 34 to 40 percent of participants who heard the words at specific times during their sleep cycles.

Sigmund is the work of Harvard Ph.D. student Daniel Nadler and two others, and it has been programmed to work in such a way that you won’t have to fall asleep listening to a female voice repeating inane words all night. Instead, you can program Sigmund by telling it when you’re going to sleep and when you intend to wake up. The app then figures out when you’re most likely to experience REM sleep, which is the time of most vivid dreaming, and starts playing the words then over headphones or the iPhone’s speakers.

How well the app actually works is still a matter of research, although CNN spoke to a few users who reported success with Sigmund. Nadler and his fellow researchers are hoping Sigmund and the research accompanying it will be the first step toward potentially leveraging dreams to help people learn, and the real purpose of Sigmund isn’t to make dreams more interesting or entertaining, but to help people with recurring nightmares. Nadler said the researchers had seen success with reprogramming dreams in people with nightmares, helping to stop the recurring dreams and replace them with more pleasant ones.

The Sigmund team says it has worked hard to keep words with negative connotations out of the lists of available words, although just what “negative connotations” might mean is the matter of some debate. Words mentioned in the CNN report range from “mountain” and “panda” to “army” and “battle,” with a few more provocative terms thrown in for users who hope to dream about a romantic encounter. Sigmund contains more than 1,000 words to choose from, broken down by category, but it limits your choices to five for each night.

In the iTunes App Store, reviews so far are generally favorable. Sigmund runs at $0.99, so even if it doesn’t work for everyone, the price of admission is pretty low.

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