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Blood flow changes in human somatosensory cortex during anticipated stimulation
W C Drevets1, H Burton, T O Videen
1Division of Radiation Sciences, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St Louis, Missouri 63110.
Nature
|January 19, 1995
Summary
Anticipating touch or pain, brain blood flow decreased in areas outside the direct stimulation zone. This brain activity suggests spatial attention may suppress irrelevant background neural signals.
Area of Science:
- Neuroscience
- Cognitive Neuroscience
- Sensory Processing
Background:
- The somatosensory cortex processes touch, temperature, and pain.
- Spatial attention influences sensory processing and neural activity.
Purpose of the Study:
- To investigate brain blood flow changes in the somatosensory cortex during anticipation of stimuli.
- To explore the role of spatial attention in modulating sensory cortex activity.
Main Methods:
- Utilized Positron Emission Tomography (PET) to measure brain blood flow.
- Monitored changes in primary and secondary somatosensory cortices.
- Assessed responses to expected focal touch and painful stimuli.
Main Results:
- Anticipation of stimuli led to decreased blood flow in somatosensory areas outside the direct stimulation site.
- Attending to finger stimuli reduced blood flow in face representation zones.
- Attending to toe stimuli reduced blood flow in finger and face zones.
- Blood flow decreases were more pronounced ipsilaterally.
Conclusions:
- These findings support a model where spatial attention enhances signal detection by suppressing irrelevant neural activity.
- The somatosensory cortex exhibits anticipatory modulation based on spatial attention.
- Generalized suppression of background activity may underlie focused sensory perception.