Date of Award

Spring 2020

Document Type


Degree Name

Doctor of Philosophy (PhD)




Human Factors Psychology

Committee Director

Mark W. Scerbo

Committee Member

Yusuke Yamani

Committee Member

Mary Still

Committee Member

Kara Latorella


In the present study, undergraduate students viewed patient charts and entered numerical values from these charts into a medical record database. They were unexpectedly interrupted by secondary tasks that differed in relevance and complexity. The secondary tasks varied by whether they facilitated or inhibited (i.e., relevant or irrelevant) rehearsal of the suspended task and whether they placed a demand on working memory (i.e., high complexity or low complexity). The primary measures of interest were the duration of time needed to resume the primary task and perceived mental demand. The Memory for Goals model (Altmann & Trafton, 2002) predicts that task relevant interruptions would lead to faster task resumptions, when compared to task-irrelevant interruptions. The Time-Based Resource Sharing model (Barrouillet, 2007) predicts that high complexity interruptions would lead to slower task resumptions and higher perceived mental demand, when compared to moderate and low complexity interruptions. Alternatively, the Memory for Problem States model (Borst, 2015) predicts that high complexity and moderate complexity interruptions would not lead to significant differences in task resumption speed. Results revealed two important findings. First, participants resumed the primary task faster and reported lower perceived mental demand following relevant interruptions, when compared to irrelevant interruptions. Second, as the magnitude of interruption complexity increased, participants resumed the primary task slower and reported higher perceived mental demand. Thus, the findings offered support for the Memory for Goals and Time-Based Resource Sharing models, but not the Memory for Problem States model. In general, the current research illustrates the importance of minimizing the demand on attentional resources when interrupting individuals during the performance of visuospatial tasks, particularly when the interruption is irrelevant to the suspended primary task.


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