@ Pablo C De Juan Bernabéu : Thank you very much. I downloaded your attachment and I'm reading now

Parts of speech and syntactic position depend totally on the language or even dialect you're examining.  In some languages, verbs are always at the end of sentences. In others, at the start. The same differences occur with other parts of speech.

Hi Chang,

There have been a number of fMRI studies on parts of speech and syntax, including (but not limited to) canonical versus non canonical word order. Here are a few articles that might be useful:  Bornkessel et al. 2005, Be-Shachar and Grodzinsky 2004, Mack et al. 2013, and  Meltzer-Asscher et al. 2015

Here you have PubMed links to these publications:

http://www.ncbi.nlm.nih.gov/pubmed/?term=bornkessel+2005+who+did+what+to+whom

http://www.ncbi.nlm.nih.gov/pubmed/15050558

http://www.ncbi.nlm.nih.gov/pubmed/24961525

http://www.ncbi.nlm.nih.gov/pubmed/25658635

Best of luck!

Monika

For psycholinguistic proofs on part of speech and syntactic position, you can see

1. Cognitive bases of phono-grammar in Russian and Arabic

http://www.udla.edu.co/revistas/index.php/amazonia-investiga/article/viewFile/856/pdf

or

The three-level phono-grammar order and its derivational connecting link: the

elements of language system (on the material of Arabic)

Article The three-level phono-grammar order and its derivational con...

Abstract The paper deals with the progressive levels of phono-grammar and the role of word formation connecting different levels of the Arabic language. The clear selection of minimally significant language elements solves the problem of the linguistic science back-development and contributes to resolving the controversial issues while defining criteria for singling out parts of speech. The phonetic changes of basic elements at the word formation level provide the root with morphonological markers influencing the word declension; as a result the word formation serves as the link connecting all language levels. All these reveal the essence of the progressive inflected language categorization system – the phono-grammar. Key words: root, phono-grammar, elements of language system, parts of speech, morphonology, Arabic