Top-down modulation of DLPFC in visual search: a study based on fMRI and TMS

Area of Science:

• Neuroscience
• Cognitive Psychology
• Visual Perception

Background:

• Inhibition of return (IOR) and attention orientation are crucial for effective visual search.
• The dorsolateral prefrontal cortex (dlPFC) is implicated in cognitive control during selective attention.
• Neural evidence for dlPFC's modulation of IOR in visual search remains limited.

Purpose of the Study:

• To investigate the neural mechanisms by which the dlPFC modulates the inhibition of return effect during visual search.
• To explore the causal relationship between dlPFC activity and IOR in different visual search tasks.

Main Methods:

• Employed event-related functional magnetic resonance imaging (fMRI) and dynamic causal modeling (DCM).
• Utilized region of interest (ROI) analyses to identify activated brain areas.
• Applied transcranial magnetic stimulation (TMS) with theta burst stimulation (TBS) to modulate dlPFC activity.

Main Results:

• The right dlPFC and temporoparietal junction (TPJ) showed selective activation during visual search.
• DCM revealed that the dlPFC → TPJ connection was modulated specifically in serial search.
• TMS-induced dlPFC modulation eliminated the IOR effect in serial search, correlating with behavioral reaction times.

Conclusions:

• The dlPFC exerts top-down control over the inhibition of return effect during serial visual search.
• This modulation may occur via working memory mechanisms retaining inhibitory tags.
• Provides causal evidence for dlPFC's role in visual search efficiency and cognitive control.