College of Liberal Arts & Social Sciences Theses and Dissertations

Graduation Date

6-2010

Document Type

Dissertation

College/Department Conferring Degree

Psychology

Keywords

cerebral hemisphere, reading goals, predictive inference, right hemisphere, time course

Abstract

During reading, individuals activate information that is not explicitly stated to make connections (i.e., inferences) about what is occurring in a text. Readers often make connections between events in a text and their background knowledge by generating expectations about what will occur next (i.e., generating a predictive inference). Although predictive inferences have been shown to improve text comprehension (Magliano et al.,1994), it is currently unclear whether readers routinely generate predictive inferences during reading. Multiple factors have been shown to influence predictive inference generation (e.g., Murray&Burke, 2003); Linderholm, 2002). For example, characteristics of the text (such as the level of textual constraint) and characteristics of the reader (such as an individual's goal during reading) influence how readers process predictive inferences. Specifically, readers generate more predictive inferences when a text is strongly constrained (Virtue, van den Groek, &Linderholm, 2002). In addition, the amount of time (i.e., the can influence how predictive inferences are processed (Till, Mross, & Kintsch, 1988). Specifically, some research does not find evidence of predictive inferences unless readers are given approximately 100 ms to generate an inference (Calvo &Castillo, 1996), whereas other research shows evidence of predictive inference generation after only 500 ms (Klin, Murray, Guzman, & Levine, 1999). Thus conflicting findings exist regarding the generations of predictive inferences. To further examine predictive inference generation, researcher can use a cognitive neuroscience approach to gain a better understanding of how predictive inferences are process in the cerebral hemispheres. Thus, the current study used a divided visual field paradigm to investigate how reading goals, textual constraint, and SOA influence predictive inference generation in the right and left hemisphere. Four experimental studies were conducted in which participants were presented texts that either strongly led to a specific outcome (i.e., were strongly constrained towards a specific predictive inference) or weakly led to a specific outcome (i.e.,were weakly constrained towards a specific predictive inference). Participants then made lexical decision to related target words that were presented to either the right visual field-left hemisphere or the left visual field of right hemisphere. In Experiment 1 and Experiment 2, participants were given an SOA of 500 ms to generate the predictive inference to examine an early time point during inference generation. In Experiment 3 and 4, participants were given an SOA of 1000 ms to generate the predictive inference to examine a later time point during inference generation. Additionally, participants in Experiment 2 and Experiment 4 were instructed to read as if they were preparing for an upcoming exam (i.e, there were given a study goal). Findings showed that reading goals influenced predictive inference generation in the right and left hemisphere at a long SOA, but not at a short SOA. Specifically, when readers were given a reading goal, strongly and weakly constrained predictive inferences were processed similarly in the left hemisphere at a long SOA, whereas strongly constrained predictive inferences showed greater facilitation than weakly constrained predictive inferences in the right hemisphere. In contrast, when readers were not given a specific reading goal, strongly constrained predictive inferences showed a processing advantage in the left hemisphere, whereas strongly and weakly constrained predictive inferences were processed similarly in in the right hemisphere at a long SOA. These findings suggest that reading goals differently influence how predictive inferences are processed in the hemispheres during reading. In addition, findings showed that overall, strongly constrained predictive inferences had a processing advantage over weakly constrained predictive inferences. These findings are consistent with existing theoretical frameworks.

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