Complex sentence: In early January 1978 Genie's mother suddenly decided to prevent any further testing and scientific observations of Genie, and the very little available information on her ability to communicate since that time is exclusively from personal observations or secondary accounts of them.
Split into simpler sentences: In early January 1978, Genie's mother suddenly decided to prevent any further testing and scientific observations of Genie. There has been no direct scientific analysis of Genie since the end of 1977, and the very little available information on her ability to communicate since that time is exclusively from personal observations or secondary accounts of them.