This is a model of language learning first proposed by Barry McLaughlin in 1983. It argues that learning an L2 involves moving from controlled to automatic processing via practice.
Second language learning is viewed as the acquisition of a complex cognitive skill. To learn a second language is to learn a skill because various aspects of the task must be practised and integrated into fluent performance. This requires the automatization of component sub-skills…As performance improves, there is a constant restructuring as learners simplify, unify and gain increasing control over their internal representations. These two notions – automatization and restructuring – are central to cognitive theory.
McLaughlin 1987: 133-134
Conscious – or ‘controlled’ – processing puts lots of demands on the learner’s cognitive skills and short term memory. Indeed, the limitations of short-term memory limit what can be consciously learned. Even a simple sentence like ‘Hello, my name is Mary’ requires a lot of controlled processing by the early learner (as anyone who has tried to learn an L2 will understand).
But eventually, such a simple sentence can be said and written automatically, without any conscious thought or effort…making room for new structures to be produced consciously. These automatic processes are stored in long-term memory, meaning they can be accessed very rapidly when needed.
This means that a learner’s interlanguage is being restructured as language items move from short term memory to long term memory, a restructuring that may destabilize some existing components of interlanguage, sometimes causing the re-emergence of errors (U shaped development). Incorrect items can become automatic, which may be a cause of fossilization of an L2.
The implication for teaching is that the learner cannot handle too many new structures that require conscious thought. The short term memory just cannot handle it. So we must wait for the learner to automatize a structure before giving them new structures to master.
A good example of when we use information processing is when we learn to drive a car. First of all, skills like changing gear or making the car go faster require conscious thought and attention, but eventually these become automatic, requiring no thought at all.
McLaughlin (1990), Restructuring. Applied Linguistics 11:113-128