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Published on: May 7, 2017
BOLD sensitivity to cortical activation induced by microstimulation: comparison to visual stimulation.
Fahad Sultan1, Mark Augath, Nikos Logothetis
1Department of Cognitive Neurology, HIH for Clinical Brain Research, University Tuebingen, 72076 Tuebingen, Germany. fahad.sultan@uni-tuebingen.de
Magnetic Resonance Imaging
|May 8, 2007
Summary
Electrical microstimulation spreads beyond expected brain regions, unlike visual stimulation. This finding is crucial for understanding brain mapping techniques and their limitations in neuroscience research.
Area of Science:
- Neuroscience
- Brain Stimulation
- Functional Neuroimaging
Background:
- Electrical microstimulation is a common technique to infer brain function.
- Understanding the spatial spread of brain activity is key for accurate functional mapping.
Purpose of the Study:
- To compare the spatial extent and amplitude of Blood-Oxygen-Level-Dependent (BOLD) responses from electrical microstimulation versus visual stimulation in the primary visual cortex.
- To investigate if electrical stimulation effects exceed predictions based on direct current spread.
Main Methods:
- Experiments were conducted on anesthetized rhesus monkeys.
- Intracortical electrodes were used for electrical microstimulation.
- BOLD responses were measured and compared between electrical and visual stimuli.
Main Results:
- Visual stimulation produced BOLD activities larger than predicted by the visual magnification factor.
- Electrical microstimulation resulted in a significantly greater spread of BOLD responses compared to visual stimulation.
- The observed spread confirmed that electrical stimulation's effects extend beyond the directly stimulated area.
Conclusions:
- Electrical microstimulation causes a wider spatial spread of BOLD responses than visual stimulation.
- The findings highlight the importance of considering the extensive effects of electrical stimulation in brain function studies.
- This research provides critical insights into the interpretation of functional neuroimaging data derived from electrical stimulation.
