Using neuroscience methods to examine how motivation affects elaboration during problem solving

Critical to problem solving is elaboration, a collection of working memory functions used during planning to formulate a solution. While elaboration is commonly measured through planning time, with the assumption that a longer planning time indicates more elaboration, recent studies have shown this is not always true. Thus, there is a need to develop a new method that provides a viable way to measure elaboration as it occurs during planning. Using Tower of London, the current research describes a series of experiments, which sought to determine the viability of potential behavioral and neuroscience methods to measure elaboration. In the first study, I focused on behavioral data applying a unique trial level analysis to rigorously test planning time as a suitable measure of elaboration, with results showing that the relationship does not exist. In the second study, I used fMRI to test whether functional connectivity between dorsolateral prefrontal cortex and frontoparietal regions might serve as a measure of elaboration, since many imaging studies have implicated these regions during planning. Results from this work showed that greater functional connectivity between dorsolateral prefrontal cortex and certain frontoparietal regions did predict performance indicating that this method may be effective for measuring elaboration. Finally, in the third study, I extended previous electroencephalographic studies showing an association between EEG theta band amplitudes and working memory, to test whether amplitude changes in this frequency range can serve as a reliable measure of elaboration. To do this I developed an analysis method to track transitory periods of intense theta synchronization during planning in an effort to measure elaboration. While tentative, results were encouraging as the analysis method was able to predict problem solving performance and was sensitive to motivational factors. From this series of studies I conclude that planning times as a method of measuring elaboration is ineffective, but establish the viability of both an EEG and fMRI method for measuring it. Having more effective measures of elaboration will provide new ways to investigate how factors like motivation and negative affect impact problem solving.