Levels of conflict in reasoning modulate right lateral prefrontal cortex

Right lateral prefrontal cortex (rlPFC) has previously been implicated in logical reasoning under conditions of conflict. A functional magnetic resonance imaging (fMRI) study was conducted to explore its role in conflict more precisely. Specifically, we distinguished between belief–logic conflict and belief–content conflict, and examined the role of rlPFC under each condition. The results demonstrated that a specific region of rlPFC is consistently activated under both types of conflict. Moreover, the results of a parametric analysis demonstrated that the same region was modulated by the level of conflict contained in reasoning arguments. This supports the idea that this specific region is engaged to resolve conflict, including during deductive reasoning.This article is part of a Special Issue entitled “The Cognitive Neuroscience of Thought".

Research Highlights
► Right lateral PFC (rlPFC) was activated during multiple forms of conflict in deductive reasoning (transitive inference problems).
► Belief-logic conflict (4 types) was related to decreased logical reasoning performance and increased rlPFC activity.
► Belief-content conflict (presence of counterfactual statements) modulated performance and rlPFC activity independently of belief-logic conflict.
► Both belief-logic and belief-content conflict contribute to the belief-bias effect and associated rlPFC engagement.
► Various forms of conflict in deductive reasoning consistently activate a specific region within rlPFC.