Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.


Psychological and Brain Sciences

Degree Program

Experimental Psychology, PhD

Committee Chair

DeCaro, Marci

Committee Co-Chair (if applicable)

Lyle, Keith

Committee Member

Lyle, Keith

Committee Member

Pani, John

Committee Member

Depue, Brendan

Committee Member

Roelfs, David

Author's Keywords

working memory; cognitive flexibility; attention; problem solving; mental set


Cognitive flexibility is a hallmark of individuals with higher working memory capacity (WMC). Yet, research demonstrates that higher WMC individuals are sometimes more likely to adopt rigid problem-solving approaches. The present research examines a novel account for these contradictory findings—that different WMC mechanisms interact in ways that both support and constrain cognitive flexibility. Across three studies, participants completed the water jug task—a problem-solving task requiring them to first establish and then break mental set using a complex strategy. Participants then completed measures targeting three WMC mechanisms: attention control, primary memory, and secondary memory. Study 1 demonstrated that primary memory and secondary memory predict breaking mental set in opposite directions. Study 2 replicated these findings while also demonstrating that attention control moderates these effects. Study 3 replicated these results using a less restrictive sampling procedure (i.e., participants were provided the complex strategy). The present research supports the proposed theory of functional opponency in WMC.