BOLD-Perfusion Coupling during Monocular and Binocular Stimulation
Author Information
Author(s): Gauthier Claudine, Hoge Richard D.
Primary Institution: Institut Universitairy of Gériatrie de Montréal, Montreal, QC, Canada
Hypothesis
Does spatial decoupling of flow and metabolic responses during stimulation of only a partial subset of the columnar regions in primary visual cortex lead to a significant shift in the ratio between BOLD and perfusion signals?
Conclusion
The study found that the BOLD and CBF responses to monocular visual stimulation were significantly reduced compared to binocular stimulation, but the ratio of BOLD to CBF did not differ significantly.
Supporting Evidence
- The average percent change in BOLD signal for monocular stimulation was significantly less than that for binocular stimulation.
- The percent flow increase during monocular stimulation was also significantly less than during binocular stimulation.
- The ratio of BOLD to CBF effect sizes did not differ significantly between monocular and binocular stimulation.
Takeaway
When one eye is covered, the brain's response is still strong, but not as strong as when both eyes are used, showing that the brain doesn't just focus on one part when it gets signals from both eyes.
Methodology
The study measured BOLD and perfusion signals in primary visual cortex during monocular and binocular stimulation using arterial spin-labeling and MRI.
Potential Biases
The BOLD activation maps may contain contributions from large draining veins, potentially diluting the observed effects.
Limitations
Data from two subjects was not analyzed due to poor quality of the perfusion data.
Participant Demographics
Eight healthy subjects (5 males, 3 females) aged 24 ± 2.6 years, with one left eye and hand dominant and seven right eye and hand dominant.
Statistical Information
P-Value
p<0.05
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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