The first of them is Krashen’s Moni

The first of them is Krashen’s Monitor Theory (1981, 1982, 1985; Dulay, Burt,
and Krashen, 1982), which includes the Affective Filter Hypothesis, based on the
significance of emotional factors and motivation as key elements which control language
acquisition processes (Dulay, Burt, and Krashen, 1982: 4): "When a student is exposed to
a new language, the first internal hurdles are posed by the individual’s emotional state
and motivations ... filtering sources are the individual anxiety levels, peer identification,
and general motivation to learn a language. Together, they make up what we have called
the “Affective filter” or simply “Filter”. The Filter acts to control entry to further mental
processing".
Secondly, Carroll’s conscious reinforcement model (1981) uses reinforcement as
an efficient motivating resource which facilitates learning through successive habit
formation: "... reinforcement involves an increment to an individual’s perception of the
appropriateness of the behaviour to a specific context" (Gardner, 1985: 128).
Reinforcement has two consequences: on the one hand, it increases the probability
that the response be repeated in similar situations and become habitual, and, on the other,
it provides information on the suitability of the responses in the situations in which they
are used.