Executive control over response priming and conflict: a transcranial magnetic stimulation study

Area of Science:

• Cognitive Neuroscience
• Neuroscience

Background:

• Stimulus-response correspondence (SRC) effects, where matching stimulus and response features facilitate performance, are well-established.
• Dual-route models propose parallel direct and indirect pathways for response preparation, explaining SRC effects.
• Recent findings indicate SRC effects are modulated by the preceding trial's correspondence.

Purpose of the Study:

• To investigate the neural underpinnings of the context-dependent modulation of SRC effects.
• To determine the causal roles of specific cortical regions in response preparation and conflict control.

Main Methods:

• Repetitive transcranial magnetic stimulation (rTMS) was used to transiently disrupt neural activity in targeted cortical areas.
• Participants performed a stimulus-response correspondence (SRC) task under different rTMS conditions.
• rTMS was applied to the left dorsolateral prefrontal cortex (DLPFC) and right posterior parietal cortex (PPC) at specific time windows relative to trial onset.

Main Results:

• Disruption of the left DLPFC 500-300 ms before trial onset hindered the context-dependent reduction of SRC effects.
• rTMS applied to the right PPC during visual stimulus presentation reduced overall SRC effects.
• These findings suggest distinct roles for the left DLPFC in conflict control and the right PPC in early visuomotor processing.

Conclusions:

• The left dorsolateral prefrontal cortex (DLPFC) is crucial for the context-dependent control of response conflicts.
• The right posterior parietal cortex (PPC) is involved in early visuomotor transformations and direct route priming.
• These results advance our understanding of the neural mechanisms underlying response selection and cognitive control.