Degree Type


Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Norman A. Scott


A story-telling task was developed to assess the ability of mild to moderate closed head injured (CHI) male medical center outpatients to spontaneously generate propositional thought. The Story-telling task (STT), an unstructured interview protocol and 12-item clinician scoring procedure, was designed as a new verbal measure of executive function, and its psychometric properties and clinical utility were explored in this study. The task consisted of clinician ratings of audio taped stories to three selected Thematic Apperception Test cards. The forty male subjects in the study (20 CYR patients and 20 control subjects, volunteers with an absence of head trauma or injury, neurological disease, or psychiatric disorder) were randomly assigned to one of two samples: an initial STT development sample, and a cross validation sample;Analysis of data from the initial sample (10 (CHI) subjects and 10 controls) revealed that the two medical center neuropsychologists who assisted in the development of the STT could use the rating system with a high degree of reliability. Control and CHI subjects significantly differed in STT scores and in employment status (CHI subjects had lower scores and all were unemployed, whereas all controls had higher STT scores and were employed). Data from the cross validation sample (10 CHI subjects and 10 controls) revealed that two additional psychologists with neuropsychological expertise, individuals at a second medical center and not involved in the development of the measure, were able to use the STT rating system with modest, but an acceptable degree of reliability after four hours of training. Moreover, the cross validation sample displayed a pattern of significant STT score differences and contrasts in employment status quite similar to that obtained in the initial sample;Data from both samples were combined to assess the utility of the STT in correctly classifying subjects as head injured or controls. The STT, when used as a single logistic regression predictor, performed comparably to two frequently used measures of executive functioning, the Tinkertoy Test and Design Fluency, and it was more effective that the widely used Controlled Oral Word Association Test.



Digital Repository @ Iowa State University,

Copyright Owner

Catharine M. Phillips-Bui



Proquest ID


File Format


File Size

113 pages