UC San Diego

In a series of 6 experiments, we investigated the impact of individual differences on mental model updating during reading of narrative texts. We presented short narratives that describe a protagonist as being spatially close (associated) or far away (dissociated) from a critical object, "George jogged home from work. He 'put on/took offʼ his faded "sweatshirt'." Every narrative concluded with a sentence that anaphorically referred to the critical object, "He was sorry 'it' was torn." Experiments 1 and 2 (n=44 in each) presented word (Experiment 1) and picture probe (Experiment 2) recognition tasks at the end of each narrative. Whereas word probes were equally likely to be accurately recognized across association conditions, picture probes were more accurately recognized when the critical object was in the foreground of the situation model. Results suggest that the representational format of the picture probes was more compatible with an analogue representation of the reader's situation model of the text. In Experiments 1 and 2, we found participants were faster to read the final sentence when the object was described as being spatially close to the protagonist. This difference in reaction times was positively correlated with verbal working memory capacity and mental rotation ability. Experiments 3 and 4 (n=44 in each) used a dual task paradigm to tax verbal (Experiment 3) and visuo-spatial (Experiment 4) working memory during comprehension of the texts. Experiment 3 revealed additive effects of association and verbal memory load on reading times for the final sentences, suggesting independent mechanisms. Experiment 4 revealed interactive effects of association and visuo-spatial load. Experiments 5 and 6 compared the difficulty of the concurrent load tasks on a letter search task and narrative text processing, respectively. Verbal and visuo-spatial tasks were equally disruptive in Experiment 5. In Experiment 6, visuo-spatial load led to more interference, especially in participants with fewer visuo-spatial resources. The demands of maintaining a heavy spatial load reduced the amount of visuo-spatial resources available for situation model updating, thus reducing the size of the association effect. Overall, results suggest readers recruit visuo- spatial working memory in the course of situation model updating