Sometimes, a familiar face is the last thing you need to see. Reminders of home can disrupt your ability to process a foreign language, a new study says.

The findings help us understand why cultural immersion is the most effective way to learn a new language, and how immigrants and expats can gain fluency in non-native tongues.

Previous studies have found that culturally evocative stimuli from your homeland -- like celebrities or a landmark -- can subconsciously trigger native cognitive patterns.

Shu Zhang from Columbia University and colleagues investigated whether visual cues also trigger the use of your native language, and thus interfere with processing an adopted language. ScienceNOW explains:

They recruited Chinese students who had lived in the U.S. for less than a year and had them converse with a computer screen displaying the face of a Chinese male called Michael Lee, who spoke to them in English with an American accent about campus life. Then the team compared the fluency of their speech when they spoke to a Caucasian version of Lee.

They found that for Chinese immigrants, addressing a Chinese face increased social comfort but reduced English fluency. "It's ironic" that the more comfortable volunteers were with their conversational partner, the less fluent they became, Zhang says.

When chatting with the Chinese version of Lee, the volunteers produced 11 percent fewer words per minute on average.

Viewing iconic images of Chinese culture (such as the Great Wall) also interfered with their English fluency, causing a 16 percent drop in words produced per minute.

This “cultural priming” also made the volunteers 85 percent more likely to name objects with literal translations from Chinese -- such as calling pistachios, “happy nuts.”

Understanding how subtle cultural cues affect fluency could also help employers design better job interviews. For example, says study coauthor Michael Morris of Columbia, taking a Japanese job candidate out for sushi, although a well-meaning gesture, might not be the best way to help them shine.

The work was published in Proceedings of the National Academy of Sciences last week.

[Via ScienceNOW]

Image: Michael Morris & Shu Zhang, pistachio nut by Dmitry Rukhlenko/iStockphoto.com

This post was originally published on Smartplanet.com