Characterizing Brain Entropy During a Face-Name Paired Association Task

Abstract

Brain entropy analysis – a measure of the unpredictability of a physiological time series - has gained attention as a measure of the complexity of brain activity in functional neuroimaging research. Investigations of neuropsychiatric and neurodevelopmental conditions have consistently demonstrated significant alterations in brain entropy compared to healthy controls. Additional work in healthy participants has found a gradient of brain entropy differences across the functional connectome associated with the resting state, as well as brain entropy differences in task-based neuroimaging experiments. In this study, I examined whole brain entropy at rest and whole brain entropy during a face-name paired association task. Region of interest (ROI) analyses were employed to examine hippocampal activity during different phases of the face-name paired association task (e.g., encoding versus recognition). Results revealed no significant differences in whole brain entropy between the resting state and the task state. Further, no significant entropy differences were observed between separate phases of the task state, both at the whole brain level and within the hippocampal regions. Limitations such as sample size, task length, and study design may potentially account for null results; however, these results may also suggest that entropy may be a less robust measure when applied to a within-subjects design in healthy participants.