There are numerous studies that reveal contradictory data about face-to-face in autism. Continues the research paradigm that contrasts faces and objects. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2174902/
I think the best text I've found to get started is: this:https://psych.nyu.edu/pelli/pubs/watson1983quest.pdf
Software: http://www.mas.ncl.ac.uk/~ndjw1/bookmarks/Stats/Software-Statistical_computing/Bayesian_software/index.html (Some links do not work but you can find the programsthis software by google)
Differing sources indicate that differences or difficulties in looking at the face in autism are to a greater extent related to communication processes.
Frith, Uta. (1989). Autism: Explaining the enigma. New York: Blackwell. Page 199 et seq.
(Very interestingEssential book which I recommend starting a task about autism.)
This can constitute a powerful critic to this type of investigations today.
In relation to the above it is considered that the investigation of these factors should be considered in a communication context that on the other hand is not incompatible with research on basic processes.