1. Cerebral cortical registration of subliminal visceral stimulation
Mark K. Kern, Reza Shaker 
Gastroenterology 
Volume 122, Issue 2, Pages (February 2002)
DOI: /gast
Copyright © 2002 American Gastroenterological Association Terms and Conditions

2. Fig. 1
Composite regions of cortical activity shown superimposed in color on a stereotaxic brain volume rendered in 3 dimensions. The right upper quadrant of the brain volume has been removed just above the midaxial plain (Talairach-Tournoux plane at z = 17mm) and to the right of the midsagittal plane. The activity shown represents the composite activity of all stage I volunteers in these planes in response to (A) subliminal, (B) liminal, and (C) supraliminal distentions. Also shown are the gross locations of the cortical regions defined by BA. The sensory/motor region (SM) was designated by BA 1, 2, 3, 4, 5, and 6; the anterior cingulate/prefrontal region (ACPF) by BA 8, 10, 24, and 32; the parietal/occipital region (PO) by BA 7, 18, 19, and 30. The insular cortex (I) was designated as the portion of the cerebral cortex deep within the lateral fissure consisting of several long gyri paralleling the lateral fissure and 5 short gyri located more rostrally.
Gastroenterology  , DOI: ( /gast )
Copyright © 2002 American Gastroenterological Association Terms and Conditions

3. Fig. 2
Comparison of total cortical activity volume in response to subliminal, liminal, and supraliminal rectal distention. The volume of cortical activity was directly related to the intensity of stimulation.
Gastroenterology  , DOI: ( /gast )
Copyright © 2002 American Gastroenterological Association Terms and Conditions

4. Fig. 3
Time course of the average percent of fMRI signal change in all activated regions and for all subjects during the 3 intensities of rectal distention. Gray, subliminal; black, liminal; red, supraliminal; gray rectangles signify the intervals of rectal distention.
Gastroenterology  , DOI: ( /gast )
Copyright © 2002 American Gastroenterological Association Terms and Conditions

5. Fig. 4
Comparison of maximum percent fMRI signal increase in response to subliminal, liminal, and supraliminal rectal distentions. There was a direct relationship between the intensity of the stimulus and magnitude of fMRI signal change (*P < 0.05).
Gastroenterology  , DOI: ( /gast )
Copyright © 2002 American Gastroenterological Association Terms and Conditions

6. Fig. 5
The colored areas on the anatomical and echo planar MRI images are regions of magnetic signal change during subliminal rectal distention from a representative male subject. The average magnetic signal time course for the 10 red voxels in the green box shown on the echo planar image is shown in the upper graph at right (mean ± SEM) where the gray regions on the graph represent intervals of sustained rectal distention. For the same 10 voxels, the average time course was calculated for the scanning sequence immediately following the subliminal distention scan wherein no rectal distention was performed.
Gastroenterology  , DOI: ( /gast )
Copyright © 2002 American Gastroenterological Association Terms and Conditions

7. Fig. 6
Average waveform for all correlated voxels in a representative subject. Intervals of perception-level rectal distention (tall gray regions on the graph) and subliminal distention (shorter gray regions) are separated by variable time intervals. Still, subliminal distentions at unexpected time intervals induce cortical activity.
Gastroenterology  , DOI: ( /gast )
Copyright © 2002 American Gastroenterological Association Terms and Conditions