Washington, Jan 9 (IANS): Researchers from the University of Missouri (MU) have found that separation from cell phone can have serious psychological and physiological effects on iPhone users, including poor performance on cognitive tests.

"Our findings suggest that iPhone separation can negatively impact performance on mental tasks," said Russell Clayton, doctoral candidate at the MU's school of journalism and lead author of the study.

Additionally, iPhones are capable of becoming an extension of ourselves such that when separated, we experience a lessening of "self" and a negative physiological state, Clayton added.

For the study, researchers asked iPhone users to sit at a computer cubicle in a media psychology lab.

The researchers told the participants that the purpose of the experiment was to test the reliability of a new wireless blood pressure cuff.

Participants completed the first word search puzzle with their iPhone in their possession and the second word search word puzzle without their iPhone in their possession or vice versa while the researchers monitored their heart rates and blood pressure levels.

While working on the puzzle, the researchers called the participants' iPhones.

After the phones finished ringing, researchers collected blood pressure and heart rate responses.

Clayton, along with Glenn Leshner, former MU professor and Anthony Almond, doctoral student at Indiana University-Bloomington, found a significant increase in anxiety, heart rate and blood pressure levels in participants who were separated from their iPhones.

Also, performance decreased as compared to when iPhone users completed similar word search puzzles while in possession of their iPhones.

"iPhone users should avoid parting with their phones during daily situations that involve a great deal of attention such as taking tests, sitting in conferences or meetings or completing important work assignments," the authors said.