Low frequency rTMS over posterior parietal cortex impairs smooth pursuit eye tracking

Area of Science:

• Neuroscience
• Oculomotor Control
• Cognitive Neuroscience

Background:

• The precise role of the posterior parietal cortex in smooth pursuit eye movements is not fully understood.
• Investigating the neural underpinnings of eye movement control is essential for understanding visual-motor integration.

Purpose of the Study:

• To explore the cognitive and neural systems controlling smooth pursuit eye movements.
• To determine the specific contribution of the posterior parietal cortex to oculomotor control using non-invasive brain stimulation.

Main Methods:

• Utilized low-frequency repetitive transcranial magnetic stimulation (rTMS) at 1 Hz.
• Administered 6-minute rTMS sessions at 90% of motor threshold over the posterior parietal cortex and motor cortex.
• Measured smooth pursuit eye tracking gain before and after rTMS in 18 participants across two sessions.

Main Results:

• Low-frequency rTMS over the posterior parietal cortex significantly reduced smooth pursuit velocity gain.
• rTMS applied to the motor cortex did not produce a significant effect on smooth pursuit gain.
• These findings highlight the involvement of the posterior parietal cortex in the gain control of smooth pursuit eye movements.

Conclusions:

• Low-frequency offline rTMS is an effective tool for investigating cortical involvement in oculomotor control.
• The posterior parietal cortex plays a critical role in modulating the velocity gain of smooth pursuit eye movements.
• Further research using rTMS can elucidate the neural circuitry underlying complex eye movements.