The difference is that humans are not like control systems, they are control systems, and are not and cannot be modelled as sets of "if-then" loops, whatever those are supposed to be.
Humans consist of atoms. The statement was obviously about humans being modelable as physical/[digital computation] processes, forgetting all the stuff about intelligence and control.
Transhumanists have high hopes for enhancing human cognitive abilities in the future. But what realistic steps can we take to enhance them now? On the one hand Flynn effect suggests IQ (which is a major factor in human cognition) can be increased a lot with current technology, on the other hand review of existing drugs seems rather pessimistic - they seem to have minor positive effect on low performers, and very little effect on high performers, what means they're mostly of therapeutic not enhancing use.
So, fellow rationalists, how can we enhance our cognition now? Solid research especially welcome, but consistent anecdotal evidence is also welcome.