This study was intended to determine
whether or not the genre of text affects the incidental lexical gains of L2
learners while reading. As has been made clear by theoretical and empirical
observations in section 2, any incidental vocabulary acquisition from reading
is intricately interwoven with and related to text comprehension, and this has
been repeatedly pointed out in different studies (see Pulido, 2004). Therefore, it seems wise to
start our discussion from an understanding of overall text comprehension as
well as the mechanism involved in this process and then to use this
understanding as a basis in order to discuss the main dimensions of incidental
vocabulary acquisition from a genre analysis point of view.

4.6.1. Mental model of text
comprehension:

When readers set out to comprehend a
text, they integrate information from different sentences as well as relevant
information (i.e., schemata) activated from long-term memory, or their prior
knowledge, into a coherent mental representation of the events, actions and
states presented in the written text. In cognitive psychology, these mental
representations are known as situation models (van Dijk&Kintsch, 1983: Kintsch, 1988) or mental
models (Johnson-laird, 1980- 1983). Successful
text comprehension has been equated with the construction of a coherent
situation model (Roloff, 1999). At the same
time, readers are engaged in two complementary processes: on the one hand, they
retrieve and update the propositional basis by means of bottom-up
processes based on their language knowledge, and on the other hand, they complement
this bottom-up analysis through top-down processes, i.e. associations
and predictions based on additional knowledge resources and on the information
already processed (Brawn & Yule,
1983). Thus, readers construct and update their mental model of textual meaning
by means of these interacting bottom-up and top-down processes throughout the
reading process. In this process, the existing model serves as a basis for the
interpretation of newly read information and is in turn continually tested and
updated by this new information. In fact, readers try to alleviate any probable
discontinuities in their mental model in order to maintain textual coherence.