Selective increase in the right hemisphere transcranial Doppler velocity during a spatial task

Area of Science:

• Neuroscience
• Cerebrovascular Physiology
• Medical Imaging

Background:

• Cerebral blood flow (CBF) regulation is crucial for brain function.
• Previous studies utilized positron emission tomography (PET) to identify tasks selectively increasing CBF.
• Transcranial Doppler ultrasonography (TCD) offers a non-invasive method to assess CBF velocity.

Purpose of the Study:

• To investigate if Transcranial Doppler ultrasonography (TCD) can detect changes in middle cerebral artery (MCA) blood flow velocity during tasks known to increase cerebral blood flow.
• To explore the hemispheric lateralization of cognitive tasks by measuring MCA blood flow velocity.

Main Methods:

• Transcranial Doppler ultrasonography was employed to measure mean blood flow velocity in the middle cerebral arteries.
• Participants performed two tasks: mah-jongg tile sorting and vibratory stimulation.
• Measurements were taken during right and left hand manipulations, with intervening resting periods.

Main Results:

• Significant increases in mean flow velocity were observed in the right MCA during both left (p < .0005) and right (p < .005) hand tile sorting.
• The left MCA showed a significant increase in mean flow velocity only during right hand sorting (p < .005), not left hand sorting (p = .13).
• Vibratory stimulation did not produce significant changes in MCA blood flow velocity.

Conclusions:

• The findings suggest a significant role of the right hemisphere in performing spatial tasks like mah-jongg tile sorting.
• Transcranial Doppler ultrasonography is a viable method for detecting task-related changes in cerebral blood flow velocity.
• The study highlights the utility of TCD in understanding hemispheric specialization during cognitive tasks.