The Hodgkin-Huxley is an observation on cellular processes. It cannot embrace structures of just a few neurons, as a neural schema. For action potentials, we could say they are all-or-none options. Singular potentials yet are ignored by the nervous system by biological default, and we cannot discard the role of graded potentials, in the work of the system.
Of the Hodgkin-Huxley, it is the hypothesis that cell membranes had ion channels to remain valid and affirmed (Erwin Neher, Bert Sakmann, and Roderick MacKinnon). However, singular cell incitation may test inconclusive (Vander et al., 1985), therefore mathematical models have been mostly abandoned, for life sciences.
Mathematical calculation on the human mind is not considered likely either, see Damasio, A. 2000. The Feeling of What Happens: Body, Emotion and the Making of Consciousness. MIT Press.
There are no equations in psychology, unless you take an equation for a figure of speech. :)
"Mathematical psychology" or psychometrics would reflect on data, and data presentations may be affected by the way measurements are gathered and analyzed.
Ability to sum up, make an integer, or a differential equation on machine output does not mean capableness to perceive a human being mathematically. (Further, I really do not know why try to picture humans as sets of mathematical figures.)
"Mathematical predictability" about a person could be only a manipulated result, via incentives or stimuli. Obviously, such manipulation would be ethically disagreeable as well as scientifically useless.
Update, June 5 2016: Artem Kaznatcheev's marking the question as answered with artificial network and hologram semantics theory is a misunderstanding. This question is about psychology as concerned with emotions, social psychology, or cognitive psychology:
"I mean (...) research (like in emotions or social psychology, or cognitive psychology)", is the wording.
For example, the holoword theory as indicated among the "answers" cannot apply to natural information processing:
A major stumbling block on the road to a unified account of lexical processing has been the lack of a unified representation for words that incorporates information about orthography, phonology, semantics, and syntax.
No such unified account is likely about humans. Human information processing is feedback-oriented. The observation does not encourage pursuits for a uniform neural model for language. Human speech and language are a natural faculty by a human person.
Personality factors matter already with language cerebral patterns. The patterns and their networks are not innate. They are biological connections everyone needs to make on his or her own. In consequence, there cannot be a universal (unified, uniform) neural format for language.
Likewise, "mind modularity”, “language universals”, or “notional matrices” cannot explain the language information pool phenomena of the Warrens experiment. The fact does not make room for mathematics or physics. Not only with generative phonology, mathematical values or symbolics that pertain with physics would be an arbitrary ascription, to think about live human brain tissue.
The question wording also is,
"I am wondering (and searching with no success)"
This is because there are no such equations. I'm fine with that, and now I've done all I could to explain: if you make a computer, you naturally mind this is a computer you make, not a human brain. Here's the bibliography :)