Negative BOLD signal changes in ipsilateral primary somatosensory cortex are associated with perfusion decreases and behavioral evidence for functional inhibition
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Negative BOLD signal changes in ipsilateral primary somatosensory cortex are associated with perfusion decreases and behavioral evidence for functional inhibition. / Schäfer, Katharina; Blankenburg, Felix; Kupers, Ron; Grüner, Julie Marie; Law, Ian; Lauritzen, Martin; Larsson, Henrik B W.
In: NeuroImage, Vol. 59, No. 4, 2012, p. 3119-3127.Research output: Contribution to journal › Journal article › Research › peer-review
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T1 - Negative BOLD signal changes in ipsilateral primary somatosensory cortex are associated with perfusion decreases and behavioral evidence for functional inhibition
AU - Schäfer, Katharina
AU - Blankenburg, Felix
AU - Kupers, Ron
AU - Grüner, Julie Marie
AU - Law, Ian
AU - Lauritzen, Martin
AU - Larsson, Henrik B W
N1 - Copyright © 2011. Published by Elsevier Inc.
PY - 2012
Y1 - 2012
N2 - We used functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) to study the negative blood oxygenation level dependent (BOLD) signal and its underlying blood flow changes in healthy human subjects. This was combined with psychophysiological measurements to test that the negative BOLD signal is associated with functional inhibition. Electrical stimulation of the median nerve at 7Hz evoked robust negative BOLD signals in the primary somatosensory cortex (SI) ipsilateral to stimulation, and positive BOLD signals in contralateral SI. The negative BOLD signal in ipsilateral SI was accompanied by commensurate decreases in relative regional cerebral blood flow (rCBF). Conjunction analysis of the fMRI and PET data revealed a region in the ipsilateral postcentral gyrus showing overlap of negative BOLD signals and relative rCBF decreases. The current perception threshold (CPT) at the ipsilateral finger during concomitant stimulation of the contralateral median nerve increased significantly, suggesting augmented functional inhibition. Since the CPT in the ipsilateral hallux did not significantly change in response to median nerve stimulation, it is more likely that the CPT-increase for the finger is due to functional inhibition (Kastrup et al., 2008) than to changes in selective attention. In conclusion, our data provide evidence that stimulus-induced reductions in relative rCBF may underlie the negative BOLD signal, which in turn may reflect increments in functional inhibition.
AB - We used functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) to study the negative blood oxygenation level dependent (BOLD) signal and its underlying blood flow changes in healthy human subjects. This was combined with psychophysiological measurements to test that the negative BOLD signal is associated with functional inhibition. Electrical stimulation of the median nerve at 7Hz evoked robust negative BOLD signals in the primary somatosensory cortex (SI) ipsilateral to stimulation, and positive BOLD signals in contralateral SI. The negative BOLD signal in ipsilateral SI was accompanied by commensurate decreases in relative regional cerebral blood flow (rCBF). Conjunction analysis of the fMRI and PET data revealed a region in the ipsilateral postcentral gyrus showing overlap of negative BOLD signals and relative rCBF decreases. The current perception threshold (CPT) at the ipsilateral finger during concomitant stimulation of the contralateral median nerve increased significantly, suggesting augmented functional inhibition. Since the CPT in the ipsilateral hallux did not significantly change in response to median nerve stimulation, it is more likely that the CPT-increase for the finger is due to functional inhibition (Kastrup et al., 2008) than to changes in selective attention. In conclusion, our data provide evidence that stimulus-induced reductions in relative rCBF may underlie the negative BOLD signal, which in turn may reflect increments in functional inhibition.
U2 - 10.1016/j.neuroimage.2011.11.085
DO - 10.1016/j.neuroimage.2011.11.085
M3 - Journal article
C2 - 22155327
VL - 59
SP - 3119
EP - 3127
JO - NeuroImage
JF - NeuroImage
SN - 1053-8119
IS - 4
ER -
ID: 40174833