I am researching on the distinction between manner-in-verb languages (e.g., English and German) and path-in-verb languages (e.g., Spanish and Greek). This issue has been researched extensively, both theoretically -- esp. by Dan Slobin -- and empirically -- e.g. by Lera Boroditsky and Anna Papafragou, with diverging results.
In relation to other areas in the battlefield of linguistic relativity (e.g., colour or gender categorization), the topic of motion seems to be the hardest 'nut to crack,' with research shedding totally opposite results. Now, I can think of two reasons for that, namely
(1) it is still unclear what speakers really focus on in their general attention to the world, as biased by their language. That is, where most research seems to indicate that we'll focus on what's encoded in our own language, there are also indications of the opposite (i.e. Papafragou, Hulbert & Trueswell 2008: 'participants spontaneously studied those aspects of the scene that their language does not routinely encode in verbs').
and (2) so-called manner-in-verb languages actually tend to encode path information with great frequency and detail (albeit as a satellite to the verb, e.g. the leaf floated OUT OF THE CAVE AND RIGHT INTO THE HOLE ON THE DRIFTING LOG), such that the language-specific dichotomy is a little blurry.
I would highly appreciate any opinions on these issues. Also, would you please direct me towards any recent publications of relevance (other than Gumperz&Levinson 1999, Boroditsky and Papafragou)? Thank you so much.