New York, Feb 4 (IANS): You may not have full control over what you think as researchers have found that external environment influences our thoughts even against our own will.

"Our conscious thoughts seem protected from our surroundings, but we found that they are much more tightly linked to the external environment than we might realise," said co-author of the study Ezequiel Morsella, associate professor of psychology at the San Francisco State University.

"We have less control of what we will think of next," Morsella noted.

For the study, the researchers showed the study's participants 52 black-and-white images corresponding to familiar words of varying lengths -- basic drawings including a fox, heart and bicycle.

Participants were instructed not to subvocalise (speak in the mind) each word or how many letters the word had.

But the researchers found that on an average, 73 percent subvocalised a word, and 33 percent counted its letters.

This research has important implications for the study of psychopathological disorders that afflict people with uncontrollable repetitive thoughts or, more commonly, the inability to stifle an obsession, the authors noted.

The study appeared in the journal Consciousness and Cognition.