Cognitive limits in project management: An fMRI study on the relationship between information load, mental effort, and decision quality.

To understand how information load systematically affects mental effort and decision quality in a project management context, we conducted a functional magnetic resonance imaging study with 23 participants. We used a delayed-response task with a separate exposure period in which participants visually explored information about project performance in the form of graphs, a delay period in which participants could continue to mentally prepare their decision, and a response period in which they made decisions on the continuation of the project. While in a prestudy we found that an increasing information load affects the self-reported mental effort in a U-shaped form, that is, the medium load condition feels less cognitively demanding compared to the high and the low load conditions, in the main study, the blood oxygen level–dependent signal in regions of the brain associated with mental effort—namely, the left putamen—exhibited a more complex pattern. We found that when participants were presented with six compared to four graphs, the blood oxygen level–dependent signal reflected an increase during the exposure but not during the delay period. Instead, when increasing the amount of data points within the graphs (two, four, or eight), there was a signal increase during the delay but not in the exposure period. Further, we found a significant positive correlation between the activity in the left putamen (exposure and delay) and decision quality. Our results suggest that the left putamen plays a crucial role in the coordination of limited cognitive resources for acquiring information and decision making. We discuss the implications for project management.