Research ReportElectrophysiological evidence during episodic prospection implicates medial prefrontal and bilateral middle temporal gyrus

- Prospection was associated with decreased activity in medial frontal gyrus (MPFC).
- Prospection elicited increased activity in bilateral middle temporal gyrus (MTGs).
- MPFC and MTG effects were present for the comparison with resting and waiting.
- Prospection was related to higher phase coherence between MPFC-RMTG and LMTG-RMTG.
- MPFC-MTG interactions appear central to episodic prospection abilities.

fMRI studies have implicated the medial prefrontal cortex and medial temporal lobe, components of the default mode network (DMN), in episodic prospection. This study compared quantitative EEG localized to these DMN regions during prospection and during resting and while waiting for rewards. EEG was recorded in twenty-two adults while they were asked to (i) envision future monetary episodes; (ii) wait for rewards and (iii) rest. Activation sources were localized to core DMN regions. EEG power and phase coherence were compared across conditions. Prospection, compared to resting and waiting, was associated with reduced power in the medial prefrontal gyrus and increased power in the bilateral medial temporal gyrus across frequency bands as well as greater phase synchrony between these regions in the delta band. The current quantitative EEG analysis confirms prior fMRI research suggesting that medial prefrontal and medial temporal gyrus interactions are central to the capacity for episodic prospection.