Concatenation (in neurocognitive linguistics)

Concatenation (in neurocognitive linguistics) is when one line is activated after another line, in sequence, below an ordered AND node.

Types of Concatenation
A differentiation of concatenation into four separate cases was found by Reich (1968) to be useful in defining the performance characteristics of relational elements. The differentiation into four cases is based on the conditions under which the concatenation element can fail. Imagine an AND node with an incoming line A above it, and two outgoing lines, B and C, below it. Reich's notation for these types resembles that of a resistor in an electronic schematic: A short segment of the fallible line is made zig-zag.
 * 1) Infallible: The first possibility is simply that if incoming A is to be realized, the concatenation will never fail. This possibility is common in linguistic structure.
 * 2) B-fallible: The second type is where the outgoing B-line may succeed or fail, but the C-line will always succeed.
 * 3) C-fallible: A third possibility is that the concatenation may fail as a result of a condition on the C-line, but the B-line will always succeed. These are considerably rarer, but occasionally occur.
 * 4) B-or-C-fallible: A fourth possibility is that both conditions on the B-line and conditions on the C-line can independently cause the failure of the concatenation element. Reich had never come across an instance of this.