Continuous Theta Burst Stimulation Over the Right Orbitofrontal Cortex Impairs Conscious Olfactory Perception

Area of Science:

• Neuroscience
• Cognitive Science
• Sensory Perception

Background:

• The right orbitofrontal cortex (rOFC) is hypothesized to be crucial for conscious olfactory perception.
• Previous evidence relied on correlational neuroimaging and lesion studies, lacking temporal causality.

Purpose of the Study:

• To investigate the causal role of the rOFC in conscious olfactory perception.
• To evaluate the effect of disrupting rOFC activity on odorant detection using continuous theta burst stimulation (cTBS).

Main Methods:

• A crossover, double-blind, prospective, and longitudinal study design.
• 15 participants received both real and sham cTBS over the rOFC in separate sessions.
• Olfactory perception was assessed via a detection task at baseline and 5 minutes post-stimulation.

Main Results:

• Conscious olfactory perception, measured by task performance, significantly decreased after real cTBS over the rOFC (p = 0.017).
• Performance on the olfactory task improved after sham cTBS compared to baseline (p = 0.010).

Conclusions:

• The findings provide causal evidence supporting the right orbitofrontal cortex's involvement in conscious olfactory perception.
• The precise neural mechanisms underlying this effect require further investigation, potentially involving disruption of associated cognitive functions.