We do spend a lot of time with our devices, and some studies have suggested that excessive dependence on cellphones and the Internet is akin to an addiction. Web sites like NetAddiction.com offer self-assessment tests to determine if technology has become a drug. Among the questions used to identify those at risk: Do you neglect housework to spend more time online? Are you frequently checking your e-mail? Do you often lose sleep because you log in late at night? If you answered “often” or “always,” technology may be taking a toll on you.

In a study to be published in the journal Cyberpsychology, Behavior and Social Networking, researchers from the University of Melbourne in Australia subjected 173 college students to tests measuring risk for problematic Internet and gambling behaviors. About 5 percent of the students showed signs of gambling problems, but 10 percent of the students posted scores high enough to put them in the at-risk category for Internet “addiction.”

Technology use was clearly interfering with the students’ daily lives, but it may be going too far to call it an addiction, says Nicki Dowling, a clinical psychologist who led the study. Ms. Dowling prefers to call it “Internet dependence.”

Typically, the concern about our dependence on technology is that it detracts from our time with family and friends in the real world. But psychologists have become intrigued by a more subtle and insidious effect of our online interactions. It may be that the immediacy of the Internet, the efficiency of the iPhone and the anonymity of the chat room change the core of who we are, issues that Dr. Aboujaoude explores in a book, “Virtually You: The Internet and the Fracturing of the Self,” to be released next year.

Dr. Aboujaoude also asks whether the vast storage available in e-mail and on the Internet is preventing many of us from letting go, causing us to retain many old and unnecessary memories at the expense of making new ones. Everything is saved these days, he notes, from the meaningless e-mail sent after a work lunch to the angry online exchange with a spouse.