What if? Neural activity underlying semantic and episodic counterfactual thinking

Area of Science:

• Cognitive Neuroscience
• Neuroimaging

Background:

• Counterfactual thinking (CFT) involves simulating alternative realities.
• Episodic CFT (eCFT) activates the default network (DN), similar to episodic memory (eM).
• DN activity varies with counterfactual plausibility and self-focus.

Purpose of the Study:

• Investigate the source of differential DN activity in eCFT.
• Determine if DN sensitivity is to plausibility or episodic content.
• Compare neural responses to episodic vs. semantic counterfactuals.

Main Methods:

• Used fMRI to compare episodic and semantic counterfactuals (plausible/implausible).
• Included episodic and semantic memory reactivation tasks.
• Analyzed data using multivariate and univariate approaches.

Main Results:

• The DN was more engaged during episodic simulations (eM, eCFT) than semantic simulations.
• Semantic simulations activated inferior temporal and lateral occipital regions.
• The hippocampus showed higher engagement for implausible CFT, indicating binding of disparate information.

Conclusions:

• The default network is sensitive to the episodic nature of mental simulations.
• The hippocampus plays a role in integrating information for implausible counterfactuals.
• Findings inform the cognitive neuroscience of mental simulation and memory.