Edinburgh experts are attempting to find out whether being bilingual affects how people read in English.

Edinburgh University researchers are testing people who speak English and another language to find out exactly how they process English words.

It will see if people who learn English as a foreign language store words in their "mental dictionary" differently from native speakers of the language.

Native Arabic speakers are now being sought to volunteer for the study.

Tests have already been carried out with Japanese and Spanish speakers. Participants will be asked to complete a series of computer-based tasks which include listening, reading and judging the meanings of English words.

The team of psychologists and linguists are keen to interview Arabic speakers because Arabic has a different writing system and different speech sounds from English.

Researcher Sarah Haywood said: "Our theory is that even if a non-native speaker is extremely fluent in English, his or her memory code for some words will be quite different from the memory code of a native speaker.

"For example, a native speaker of Japanese may be more likely to confuse words like 'lock' and 'rock', because unlike English, Japanese does not make a distinction between the speech sounds 'l' and 'r'.

"Language is one of the most powerful human inventions, a skill that defines us as a species.

"Growing up in the UK, it's easy to forget that the majority of people around the world speak two or more languages.

"So understanding bilingualism is important in understanding how the brain learns and deals with language."

Volunteers will be required to attend the university for a testing session taking 60-90 minutes.

Volunteers need to have learned Arabic as their very first language as a child and should have lived in an English-speaking country for at least 12 months.