Emotional and cognitive stimuli differentially engage the default network during inductive reasoning

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Brain Imaging

Background:

• The default network (DN) comprises interconnected cortical regions active during rest.
• Understanding the DN's role in distinct cognitive processes is crucial.

Purpose of the Study:

• To investigate the differential impact of emotional reasoning versus reasoning under certainty on the DN.
• To explore the neural instantiation of these reasoning types within the DN.

Main Methods:

• Event-related functional magnetic resonance imaging (fMRI) in healthy participants.
• A 2x2 factorial design presenting syllogistic arguments varying in emotional salience and certainty/uncertainty.

Main Results:

• Both emotionally salient reasoning and reasoning under certainty activated regions within the DN.
• Emotional reasoning preferentially activated the DN's dorsomedial (dMPFC) subsystem.
• Reasoning under certainty preferentially activated the DN's medial temporal (MTL) subsystem.

Conclusions:

• The DN is neurally involved in both emotional and certainty-based reasoning.
• The dMPFC subsystem supports self-relevant and introspective processing in emotional reasoning.
• The MTL subsystem supports mnemonic and semantic associations in certainty-based reasoning.